PREVALENCE OF BLOOD AND INTERNAL PARASITES IN

SHEEP TO BE SLAUGHTERED IN KHARTOUM STATE

Sudan

By

ABDELBASIT AHMED EDREES MOHEMED

(B. V. M. 2003, University of Khartoum)

Supervisor

DR. KHITMA HASSAN ELMALIK

(B. V. Sc., M. V. Sc., Ph. D.)

A Thesis Submitted to the University of Khartoum in Partial

Fulfillment of the Degree of Master of Tropical Animal Health,

(M. T. A. H.)

Department of Preventive Medicine and Veterinary Public Health,

Faculty of Veterinary Medicine, University of Khartoum

December 2006

I

To:

My parents and my sister

Soul of my grand mother

Soul of my grand father

My brothers... and my friends...

II

AKNOWLEDGEMENT

Thanks first and last to Allah, who gave me the health, strength and

makes this work possible. My appreciations and best thanks to:

• Dr. Khitma Hassan El Malik for her keen supervision and

valuable guidance.

• Dr. Atif Al Amin A. Gadir for data analysis and unlimited

help.

• The staff of the Department of Preventive Medicine and

Veterinary Public Health, especially Mr. Ahmed A. Wahid

for technical help and Mr. Babo Mahmoud for his efforts

during samples collection.

• My colleagues, especially Dr. Hatim A. Altahir for

providing transport during different stages of the study, also

my best thanks for Dr. Mohammed A.Elmoneim, Dr.

Mohammed Siddig Al Arabi, Dr. Mohammed El Wasik and

Dr. Ibrahim M. Elhassan for helping me in samples

collection.

• My brother Abd-El Elah Ahmed for the unlimited help and

continuous support.

VII

Abstract

This study was conducted on sheep brought from different states

of Sudan (Kordofan, White Nile, Darfour and Algadarif) to Khartoum

State to be slaughtered for local consumption and export. The study

conducted in three slaughter houses in the three towns of the state in the

period between April to June 2006, to investigate the prevalence of blood

and internal parasites and to assess the relationship between the

occurrence of these parasites and factors of, body temperature, origin,

breed, age and sex. A total of 150 samples were examined during this

study.

The results showed that, the prevalence of blood parasites was 15.3%,

Theileria spp. showed the highest prevalence rate (14.7%), only one

Babesias pp. parasite was detected with 0.6% prevalence rate. The results

showed high prevalence rate of internal parasites (27.3%), Eimeria spp,

Hemoncus, Strongyloides, Monezia and Fachiola spp. eggs were detected

in fecal examinations with prevalence rates 12%, 8%, 2.6%, 4% and 0.7%

respectively. Statistical analysis for results was done and showed no

correlation between prevalence of blood and internal parasites with

origin, breed, sex and ages of sheep. A strong relationship was detected

between prevalence of blood parasites and body temperature of sheep.

VIII

الخالصة

من مختلف واليات السودان اجريت هذه الدراسة على مجموعات الضان القادمة الى الخرطوم

رأس من الضان 150 طالت الدراسة عدد قدو, بغرض الذبح لالستهالك المحلى والتصدير

مسالخ ثالثة منالنيل االبيض والقضارف تجمعت فى, دارفور, القادمة من واليات آردفان

بطفيليات الدم الصابة ا هدفت هذه الدراسة الى تقصى معدل 0المختلفةمدنها فى الوالية

وعالقة بعض العوامل مثل درجة حرارة جسم الحيوان باإلصابة بالطفيليات، والطفيليات الداخلية

.آذلك تأثير ساللة وعمر وجنس الحيوان على القابلية لإلصابة بالطفيليات

بالنسبة % 14,7بمعدل % 15,3اظهرت النتائج ان معدل حدوث االصابة بطفيليات الدم قد آان

0بالنسبة لطفيل البابيزيا% 0,6لطفيل الثيليريا ومعدل

0

بواقع نسب بلغت % 27,3الدراسة اوضحت معدال عاليا لالصابة بالطفيليات الداخلية بلغت

, ليات االتية على التوالى الكوآسيديا لكل من الطفي% 0,7 و 4% -2,6% -8% -12%

0 والفاشيوالمونيزيا, سترونقلس, هيمونكس

0

اشارت نتائج التحليل االحصائى للمعلومات المدخلة الى عدم وجود عالقة بين الطفيليات

فيليات الدم ى عالقة قوية بين طلالكنها اشارت , عمر واصل الحيوان,جنس, المذآورة و ساللة

0سم الحيوانودرجة حرارة ج

IX

INTRODUCTION

Sudan is rich in its animal's resources. The country has an animal

population estimated at 40.468 million cattle, 49.797 million sheep,

42.526 million goats, 3.908 million camels, 37 million poultry and 110

thousands ton fishers (MARF 2005).In Sudan there are several breeds of

sheep, such as, Kabashi, Hamari, Shukri and Zagawi in north and western

Sudan, Watish in central Sudan and Nilotic sheep in southern Sudan.

Sudanese sheep comprise 31% of the total population of sheep in the

Arab region (AOAD, 1998) and they are raised in different parts of the

country for their meat, milk, and hides. Exports of live sheep and mutton

contribute significantly to the national income from foreign exchange

which was estimated to be US$ 109 million annually in 1998. Sheep also

have religion and social importance. They play an important role in

public health because they could be a source for several zoonotic diseases

transmuted to man, such as, Brucellosis and T.B.

Sheep production in Sudan faces many problems including infectious

diseases caused by bacterial, viral, and parasitic agents. Bacterial and

viral diseases have almost been brought under control either by drug

therapy or vaccination. Parasitic diseases, however, have largely been

neglected primarily because they do not often cause acute faetal disease.

Blood parasites are living organisms which inhabit on blood and feed on

its constituents or nutrients. The blood parasites are difficult to control

due to the resistance of some parasites to drugs, and there is no successful

vaccine against most of blood parasites due to several factors such as

antigenic variation and difficulties in propagation of these organisms in

artificial media.

The infection with blood parasites can be suspected from general

symptoms of diseases such as decrease in production, emaciation, loss of

X

appetite and jaundice. Animals also take time to reach the peak of

production after recovery.

Sheep may be affected by Trypanosoma. vicax, Trypanosoma.congolnse

and Trypanosoma.dimorphon thats cause Trypansomosis, or Theileria.

lestoquadri which cause malignant ovine Theileriosis, Babesia.motasi,

Babesia.ovis that cause ovine babesiosis. Prelarval stages for several

nematodes, the microfilaria, which appear in several diseases affect sheep

such as Elaeophoriasis (filarial dermatitis in sheep), Thelasiasis (eye

worm), Neurofilariasis, Cerebrospinal nematodiasis (lumber paralysis).

Helminthes parasites are known to prevail in this country (Gagoad and

Eisa (1968), Eisa and Ebrahim (1970), Elbadawi et al (1978) and Atta

Elmannan (1983). Helminthes of the gastrointestinal tract are major cause

of reduced productivity in ruminants throughout the world (Holmes

1987). In general the effect of parasitic diseases on livestock include

mortality losses, condemnation of meat, weight loss, depreciation of

animal's products and reduced resistance to other diseases as well as

expenditure on drugs. Also they cause anemia, Economic effects the

damaged of the skin due to ticks and flies bites, costs of treatment,

prevention and control of parasites and vectors.

Therefore the objectives of this study are:

1- To detect blood and internal parasites of sheep brought to Khartoum

state in ante-mortem examination as a reflection of the common parasitic

infections in the production areas.

2- To examine the effect of geographic origin of sheep in occurrence of

parasitic infections.

3- To detect the prevalence of parasitic infections in different age groups.

4- To suggest a feasible strategy for control of parasitic infestation in

sheep herds.

1

CHAPTER ONE LITERTURE REVIEW

1.1 Sheep Breeds and Their Distribution in Sudan:

The estimated Sudanese national sheep flock is 49.797 million

head (MARF, 2005). Sudan sheep are conventionally classified on the

basis of morphology and distribution into four main groups: Sudan

Desert, Sudan Nilotic, Sudan Arid Upland and Sudan Equatorial Upland

(Mcleory, 1961; Wilson and Clarke, 1975). Fused ecotypes from non-

systematic crossbreeding at the boundaries of the ecozones have also

been recognized.

More than 65% of the sheep in Sudan are of the Sudan Desert type (Ovis

aries) (Sulieman et al., 1990), which is believed to be a descendant of

sheep of Egyptian origin (Ovis longipes). They are distributed north of

latitude 18N, extending eastward into Eritrea and westward into Chad

(Wilson, 1991) and are raised under pastoral system in the eastern and

western regions of the country. Sudan Desert sheep are further classified

into tribal subtypes, e.g. Hamari, Kabashi, Shenbali in North and West

Kordofan States (Mukhtar, 1985), Shugor, Dubasi and Watish in the

Central States (Sulieman et al., 1990) and Bourug in the Butana area of

eastern Sudan.

In recent years, the use of Sudan Desert sheep as an export commodity

has increased. In 1991/92, it contributed about $60 million to the national

foreign exchange earnings at an annual off take rate of 600,000 head

(LMC, 1992).

2

1.2 Sheep Meat Production

Sheep in Sudan play important role in production of meat for local

consumption and export to numerous countries, a total of 76.728.000

head of sheep were slaughtered in period (2000 to 2004), statistical

information on Tables (1-1), (1-2) and (1-3) (MARF, 2005).

3

Table (1-1) Slaughter sheep and meat production for local

consumption

2000-2004

year No of slaughter sheep

(000) head

Local consumption

(000) ton

2000 12545 138

2001 12909 142

2002 14041 154

2003 18495 222

2004 18738 225

Total 76728 881

Table (1-2) Estimation of sheep meat production for local

consumption and export (000) T 2000-2004

year for export Local cons. Total

2000 120 138 258

2001 120 142 262

2002 120 154 274

2003 60 222 282

2004 60 225 285

Total 480 881 1361

4

Table (1-3) Export of sheep meat (ton) 2000-2004

year meat production

2000 6157.8

2001 4855.2

2002 7113.8

2003 7837.11

2004 5570.9

Total 31534.81

5

1.3 Parasitic diseases of sheep

1.3.1 Sheep Blood Parasites

1.3.1.1 Trypanosomosis:

Until recently Trypanosomosis in sheep and goats was not ranked as an

important disease. Kramer (1966) reported that the disease in Nigeria was

of little importance in these hosts, Stephen (1970) and Finelle (1973)

stated that sheep and goats are seldom infected with Trypanosomosis

under natural conditions.

Later studies indicated that not only are these animals naturally infected

by this disease, but also high mortality can occur (Griffin and Allonby,

1979). Evidence was obtained from experimental infection that sheep and

goats act as reservoir and may be important in the transmission of

Trypanosomosis (Khasanov and Ivanitskaya, 1974 and Mahmoud and

Elmalik, 1978).

Thousands of sheep and goats were examined since 1942 in the upper

Nile province Sudan but only T. vivax was identified (Karib, 1961).

In Sudan, Boid et al. (1981) suggested the role of sheep and goats in

Kassala province as reservoir after he found antibodies against

Trypanosoma. evansi circling on there blood.

Osaer et al. (1999) stated that trypanosomosis seem to affect sheep and

goat health and production. Masiga et al. (2002) showed that mall

ruminants are susceptible to trypanosomosis and revealed anaemia and

reduction in body weight.

Infected animals usually look healthy and normal infections were often

chronic or sub clinical and were rarely detected because of low

parasitaemia and trypanosoma concentration, on the other hand Kalu et

al. (1986) observed that.

6

1.3.1.2 Blood parasites transmitted by ticks:

Ticks are regarded as an important external parasites in animals'

especially in tropical and sub tropical zones where they transmit most of

the serious diseases, among which the majority are blood parasites and

Reckittsea.

1.3.1.2.1 Sheep Theileriosis:

Theileriosis are tick borne protozoan diseases caused by Theileria spp in

cattle, sheep, and goats as well as in wild and captive ungulates (Radostits

et al., 2000). The diseases are characterized by fever and

lymphoproliferative disorders, which may be associated with leucopenia

and\or anemia (Radostits et al., 2000).

The important pathogen of sheep and goats is Theileria hirci (synonym

Theileria lestoquardi), the cause of malignant ovine theilerioosis

(Radostits et al., 2000). The disease is enzootic from North Africa

through the Middle East to India (Radostits et al., 2000). Theileria hirci

cause disease in sheep similar to Theileria annulata in cattle (Radostits et

al., 2000). In a recent Sudan outbreak involving eight flocks, 22% of the

sheep affected and all affected sheep were died within 3-6 days (Radostits

et al., 2000). Anemia, jaundice, and enlargement of lymph nodes are

characteristic, and both piroplasms and schizonts can be demonstrated in

smears of blood and tissues respectively. An indirect fluorescent antibody

test is available (Radostits et al., 2000). Parvaquone and buparvaquone

may be used to treat early cases (Radostits et al., 2000). Benign ovine

theileriosis is caused either by T. ovis or T. separate in Africa (Radostits

et al. 2000).

7

1.3.1.2.2 Sheep Babesiosis:

Babesosis are a group of tick born diseases caused by several species of

protozoa of the genus Babesia. These organisms are capable of infecting

all species of domestic animals, and also found in some wild animals,

which serve as reservoir of infection (Losos, 1986a). During infection

with babesia, the release of pharmacologically active substance and

destruction of erythrocytes play a major role in the pathogenesis of the

disease. However, the proportionate role of each varies with the

individual species of babesia (Soulsby, 1982). Anaemia is associated with

the emergence of the parasites from red cells. Often, however,

erythrocytes loss is attributed to the mechanical rupture of red cells by the

parasites although there have been no detailed studies of this in domestic

animals (Mohoney, 1977).

Babesia ovis in sheep and goats is distributed throughout tropical and

subtropical areas. Also in southern Europe and the former Soviet Union

(Soulsby, 1982). Its effect is less severe than other babesia species.

Although an acute phase characterized by fever, jaundice,

haemoglobinuria and anaemia may be seen, and in the chronic form of

the disease about 1% of the erythrocytes is infected (Soulsby, 1982).

Comprehensive reviews of the literature on Babesia and its infection had

been published by many authors, among them, Riek (1968), Mahoney

(1977) and Levine (1988).

Piroplasmosis in the Sudan was early reported in the beginning of the past

century, Babesiosis was reported in 1905 but little research was done by

(Hoogstral, 1956), FAO (1983), Abdoun (1984), Hashim (1984),

Mohammed and Yagoub (1990).

8

1.3.1.2.3 Anaplasmosis

Anaplasmosis is an acute or sub acute febrile disease of wild and

domestic ungulates. It caused by the Rickettsia. Anaplasma marginale,

Anaplasma Centrale and Anaplasma ovis, the former being more

pathogenic. It is characterized by progressive anaemia and occasionally

icterus (Losos, 1986b). Twenty species of tick have been shown to

transmit Anaplasma. Trnsovarial transmission occurs and insects (blood

sucking flies e.g. deer flies, stable flies) play a significant role in

mechanical transmission (Soulsby, 1982). Anaplasmosis causes

subclinical forms of the disease in sheep and goats but could be serious to

exotic cattle. In more chronic cases there is a sever anaemia and recovery

is slow. Control by vaccination has been attempted by several means for

many years. (Soulsby, 1982).

1.3.1.3 Filarial worms

These worms inhabit connective tissues and blood vessels, on the serosae

and in many other regions (Dunn, 1978).

The adult worms of genus Setaria are commonly found in the peritoneal

cavity of the final host, (Dunn, 1978). The microfilaria produced by

female circulate in the blood are unsheathed and measure 190 um 256

um. Setaria may incriminate in the etiology of cerebrospinal filariosis in

aberrant infections (Jones et al., 1997 and Mahmoud et al., 2004). Its

intermediate hosts in the tropical areas are mosquitoes of many genera

(Anopheles, Ades, Culex, etc.) (Soulsby, 1982).

1.3.2 The internal parasites that affect sheep

In most sheep-raising areas, internal parasites (i.e. worms) are usually the

primary disease affecting sheep and lambs (Susan 2006). Sheep are more

susceptible to internal parasites than most other types of farm livestock.

9

Their small fecal pellets disintegrate very easily thus releasing the worm

larvae onto pastures (Susan 2006). They graze close to the soil surface

and to their feces. They are slow to acquire immunity. It takes 10 to 12

months for most lambs to develop immunity to parasites. Sheep also

suffer a loss of immunity at the time of lambing, which does not restore

itself until approximately four weeks after lambing (Susan 2006). Heavy

stocking rates and insufficient pasture rest periods further contribute to

the incidence of parasitic disease in sheep and lambs. Internal parasites

tend to be much less of a problem under range-type conditions where

sheep do not graze the same pasture twice in the same grazing season.

They are also less of a problem in arid regions, because parasites require

moisture for their development (Susan 2006). In the past, sheep producers

relied heavily on anti-parasitic drugs, called "anthelmintics" to control

internal parasites in their flocks. But the long-time use and in some cases

misuse of these drugs has resulted in parasites that have become

increasingly resistant to anthelmintics. Drug resistance has been

documented in all three drug families and is most commonly reported

with ivermectin and the benzimidazoles. In the U.S., few anthelmintics

are FDA-approved for use in sheep and lambs, and no new drugs are

likely to be developed. As a result, producers must develop more

integrated programs for controlling parasites, which do not rely

exclusively on drug therapy (Susan, 2006).

10

Table 1.4 Internal Parasites that affect sheep and goats (Soulsby, 1982) Clinical signs Ideal Conditions for

Development Life cycle Site Common name Genus and species

Blood loss (Anemia), Edema ("Bottle Jaw"), Weakness Wool breaks, Sudden death

warm, moist summer rainfall

18 to 21 days

Direct Abomasum Barberpole worm Wire worm

Haemonchus contortis

Production loss, Lack of appetite Diarrhea, Weight loss, Decreased wool production.

cool, moist 20 days Direct Abomasum Medium or brown stomach worm

Ostertagia circumcincta

Black scours, Reduced appetite Production loss, Ocassional death

warm, moist < 21 days Direct Abomasum Small intestine

Bankrupt worm Hair worm

Trichostrongylus

Weight loss, Diarrhea, Inflammation between toes

warm, moist 7-9 days Direct Small intestine

Common threadworm

Strongyloides papillosus

Loss of appetite Diarrhea Weight loss Decreased wool growth

cool, wet winter rainfall

20 days Direct Small intestine

small intestinal worm

Coopera spp.

Usually sub-clincial Diarrhea, loss of appetite, weight loss

cool, wet 20 days Direct Small intestine

threadneck worm

Nematodirus spp.

Usually no signs of infection. Coughing, fluid in lungs if disease is severe. Pneumonia

cool, wet 5 weeks Direct Indirect (snails, slugs)

Trachea and bronchi

lungworm hair lungworm

Dictyocaulus filaria Muellerius capillaris

Heavy infestations may result in unthriftiness and GI disturbances

Wet 6 weeks

Indirect(pasture mites)

Small intestine

tapeworm Moniezia spp.

11

Liquid diarrhea Off feed, depression Death

cool, wet Overcrowding

< 21 days Direct Small intestine.

coccidia Eimeria spp.

Diarrhea Dry 6-12 weeks

Direct Caecum whipworm Trichuris ovis

Unthriftiness, Diarrhea Blood loss, Anemia Sore feet

warm, most 1-2 months

Direct Small intestine

hookworm Bunostomum phlebotomum

Damage lining of small intestines cool, wet winter rainfall

5 weeks Direct Large

intestine nodule worm Oesophagostomum

Hindquarter weakness Ataxia, Paralysis Blindness

cool, wet 82-91 days

Indirect (snails, slugs)

central nervous system

meningeal worm deer worm brain worm

Paralaphostrongylus tenius

production losses Death Organ condemnation

Wet 8-12 weeks

Indirect (snails, slugs)

Liver liver fluke

Fasciola hepatica

12

1.3.2.1 Prevalence of Gastrointestinal Helminthes of Sheep in Africa

In Egypt Shawakt et al (1994) examined 250 abomasums of sheep

slaughtered in Cairo abattoir; the examination revealed that 43.7% of

these were harboring single or mixed nematode infections.

Trichostrongylus spp, Haemonchus contortus and Oestertagia spp, were

identified in the study with prevalence rate of 28.9, 22.2, and 17.18%

respectively. Abd-Rabo et al (1993) examined gastrointestinal tracts of

sheep from Kafr-Elshih governorate, Egypt; He encountered 9 species of

nematodes (Trichostrongylus axei, Strongyloides papilosus, Haemoncus

contortus, Ostertagia trifurcta, Parabonema skrjabini, Nematodirus

spathiger, Trichuris ovis, Chabertia ovina and Oesophagostomum

columbianum). The frequency of nematode infection in the abomasums,

small and large intestine were 21.67, 21.67 and 36.67 respectively.

El Azazy (1990) examined 96 abomasums from sheep and goats at

Zagazig abattoir, Sharkia province, in 1986 and 1987 he observed that

adult Trichostrongylus axei was the most numerous followed by adult

Haemoncus contortus.

In Nigeria; Fakae and Chiejina (1993) conducted a survey on

traditionally reared west African Dwarf sheep and goats in the eastern

Nigeria for over 12 months period during 1987 to 1988. They reported

that the most prevalent nematodes were Haemoncus contortus and

Trichostrongylus colubriformis and which usually occurred together in all

nematode infected animals. Their combined prevalence rates ranged from

90% to 100%. On the other hand, Cooperia curticei and

Oesophagostomum columbianum were present in relatively small

numbers.

Earlier Fakae (1990) studied the epidemiology of helminthes infections in

west African Dwarf sheep and goats in the savanna area of eastern

Nigeria for 12 months, the infections observed involved Haemoncus

13

contortus, Trichostrongylus spp., Taenia hydatigena metacestodes, O.

columbianum, Strongyloides spp., Cooperia spp. And Gaigeria

pachyscelis with a prevalence rates of 87.1, 63.8, 30.2, 22.4, 18.8, 17.2,

and 6% repectivaly. Anene et al. (1994) carried out a survey of

gastrointestinal parasites of 948 small ruminants in south eastern Nigeria

in the dry and rainy seasons; they reported that Strongylys (mainly

Haemonchus) was the most prevalent gastrointestinal parasites in sheep.

The prevalence rate reported in the dry season was 39.8% while that of

the wet season was 63.7%. Onyali et al., (1989) studied patent infections

of Strongyloides papillosus in lambs under one week of age and it was

suggested that either the short generation interval or prenatal infection

was the cause. Worm egg counts taken at monthly intervals indicated

ranges from 100-1000 eggs per gram (e.p.g) of feces.

In Ethiopia Bekele et al., (1992) conducted post-mortem examination on

122 gastrointestinal tracts of sheep. In their study, they reported rates

ranging from 66.7% to 100% for Dictyocoulus filarial and 64% to 100%

for Trichostrongylus colubriformis, low prevalence rates for

Trichostrongylus axei, Haemoncus contortus, Oesophagostomum

columbianum, Bunostomum. Trigonocephalum and Trichuris. Srjabini

were reported. Njau et al., (1990) also investigated the prevalence rate of

gastrointestinal parasites of sheep in that country, the parasites found

were Coccidia, Haemoncus contortus, Trichostrongylus colubriformis,

Trichostrongylus axei, Ostertagia spp., Trichuris. Ovis, Chabertia Ovina

and Faschiola hepatica. Lemma (1998) found a seasonal pattern of

Trichuris ovis in sheep, and showed that the seasonal variations were due

to humidity (rain).

In Mauritania,Jacauiet et al., (1995) performed 647 faecal eggs counts

and 53 necropsies on sheep and goats originating from three sites of the

Sahelian region. The examination revealed that Haemoncus contortus,

14

Oesophagostomum columbianum and Stilesia globipunctata were the

most prevalence species.

In Kenya; Ndarathi et al., (1989) examined a total of 1412 animals from

three Masai groups for parasites, their study showed that between 60% to

70% of the sheep and goats were infected with gastrointestinal parasites,

and they stated that Strongylosis was the most prevalent gastrointestinal

infection allowed by coccidian, while prevalence of other parasites was

less than 6%. In another study Ndarathi (1992) reported that prevalence

of Haemoncus contortus, Trichostrongylus spp. And Oesophagostomum

spp. Were 91.1, 6.4, and 1.7% respectively.

Pandey (1990) examined 304 abomasums of sheep grazing on natural

pasture in Highveld, Zimbabwe; Haemoncus contortus was found in 70%

the organs examined. He observed that the worm burden increased during

the rainy season and was followed by a decline with low worm load

throughout the dry season.

In Zaire, Chartier et al.,(1990) examined carcasses of sheep, and reported

that the most frequent species were Haemoncus contortus,

Trichostrongylus colubriformis and Oesophagostomum columbianum

with prevalence rates of 70.1, 78.6, and 100% respectively.

1.3.2.2 Prevalence of Gastrointestinal Helminthes of Sheep in Sudan

In kordofan, Kassala, Darfur and Blue Nile provinces Gagoad and Eisa

(1968) examined 322 abomasums of sheep, their study showed that 80%

of the sheep harbored Haemobcus contortus. They reported that the

incidence rate in kordofan, Kassala, Darfur and Blue Nile was 83, 73.5,

and 75% respectively. Eisa and Ebrahim (1970) examined gastrointestinal

tracts of sheep obtained from Elobied, they reported the occurrence of

Haemoncus contortus, Trichostrongylus colubriformis, Strongyloides

papillosus, Oesophagostomum columbianum, Chabertia ovina, Cooperia.

15

pectinata, Trichuris ovis and Monezia expansa. Haemoncus contortus

was found to be the most prevalent species.

Elbadawi et al., (1976) conducted a study of helminthes parasites in 140

sheep carcasses in the southern region of the country. They reported the

dominance of Paramphistomum spp. Followed by Cysticercus.

tenuicollis, Faschiola gigantica and Schistosoma bovis. Elgezuli et

al.,(1978) carried out a survey of helminthes parasites of cattle, sheep,

goats and camels at Kassala province, they examined 341 large intestines

of goats and 66 of sheep. Their study showed that 11.7% of goats

harbored Skrjabinem ovis, while non of the sheep harbored this parasite.

Elbadawi et al., (1978) studied the incidence of helminthes parasites of

sheep slaughtered in the western provinces. A total of 1397 carcasses

were examined, they encountered eight genera of helminthes parasites

vise tow genera of trematodes (Paramphistomum spp. and shistosoma.

ovis), three genera of cestodes and larval cestodes (Avitellina spp.

Monezia expansa and Hydated cyst), and three genera of nematodes

(Trichuris ovis, Oesophagostomum colmbianum and Haemoncus

contortus )

The highest incidence was for Haemoncus contortus, Schistosoma bovis

and Oesophagostomum clombianum with a rate of 45.5, 44.5 and 39.5

respectively. The incidence of Trichuris ovis, hydated cyst, Monezia

expansa and Avitellina spp. was 20, 12, 9 and 3% respectively. They

showed that the maximum combination of genera found in one animal

was four in their checklist of helminthes in Sudan. Eisa et al., (1979)

reported helminthes in sheep in the Sudan during the period 1902-1975.

They reported 20 genera of helminthes parasites 5 genera of trematodes

namely (Faschiola gigantica, Schitosoma bovis, Paramphistomum spp.

Dicrocoelium spp. and Cotylophoron cotylophorum), 6 genera of

Cestodes (Avitellina spp., Monezia expansa, Monezia benedeni, Stilesia

16

hepatica, Cystecercus tenuiocollis, Hydated cyst , Coenurus cereberalis ,

Coenurus serialis), and 9 genera of nematodes (Bunostomum spp.,

Chabertia ovina, Cooperia pectinata, Gaigeria pachyscelis, Haemoncus

contrtus, Trichuris ovis, Oesophagostomum columbianum, Strongyloides

papillosus and Trichostrongylus axei ).

Atta Elmannan (1983) investigated the gastrointestinal parasites of sheep

and goats in Sennar district (central region) by means of microscopical

and post mortem examination. He found eggs of 4 genera of parasites

during faecal examination, this comprised Trichostrongylid spp., Monezia

expansa, Strongyloides papillosus, and Trichuris spp. the incidence of

parasites in sheep was 83.9%. where incidence of infection with one

species was the highest (43.9%) and with four species was the lowest

(3%), he revealed that Trichostrongylus axei was the dominant species

during examination of gastrointestinal tracts.

Atta Elmannan et al., (1983) studied the prevalence of Oesophagostomum

columbianum in sheep in Sennar district, they examined a total of 28

gastrointestinal tracts for adults worms. They showed that 21 were

infected with a prevalence of 75%.

Ahmed and Elmalik (1997) investigated the prevalence of Nematodes in

sheep brought to Khartoum from different localities of Sudan, four genera

of Nematodes were identified from faecal culture, these include, H.

contortus, Strongyloide papillosus, Oesophagostomum spp., and

Trichostrongylus spp., with a prevalence rates of 56.3, 36.6, 3.7 and 3.4%

respectively. The highest of infection was observed during the rainy

season 85% compared with a rate of 35.6% during the winter.

Ghada (2000) studied the prevalence of gastrointestinal helminthes of

sheep from central Kordofan and White Nile state. She examined 1005

faecal samples from sheep, she showed that presence of different

helminthes eggs, which include, Trichostrongylus, Strongyloide

17

papillosus, Trichuris spp., Monezia expansa, Monezia bendeni and

Paramphistomum spp., with a highest prevalence rates in rainy season.

1.4 Transmission

1.4.1. Transmission of blood parasites:

1.4.1.1 Cyclic transmission:

In this mode of transmission the parasites are capable to develop

cyclically in side the vector.

Trypanosome in Africa are mainly transmitted by Glossina species (tsetse

fly) in which trypanosome are capable to develop cyclically in the

digestive tract of the fly. Different trypanosome species develop in

different regions of the digestive tract of the fly, these are Trypanosoma

congolense, T. vivax, T. brucei, T.simiae, T. suis (Hoare, 1972).

The piroplasms-infected erythrocytes are ingested by a clean tick (Larva

and nymph) when it feeds and piroplasm released which differentiate into

sexual stages in the gut of the tick (Schein, 1975). The parasite multiplies

to schizont after inoculation of sporozoites with saliva of infected ticks

into the vertebrate host and invades different leukocytes (lrvin et al.,

1982).

1.4.1.2 Mechanical transmission:

In this mode of mechanical transmission, the parasites are taken up with

blood and survive for short time in the mouth part of insect (Hoare,

1970).

Tabanidae and other biting flies were incriminated for this type of

transmission in area far from tsetse main belt and in the countries out side

Africa. Hoare (1957) put forward hypothesis that Trypanosoma vivax had

become established in Mauritius and the new world by adapting

completely to mechanical transmission. He further argued that

18

Trypanosoma evansi originated from Trypanosoma brucei by similar

adaptation to mechanical transmission. Domizio (1930) and Spena (1948)

reported the occurrence of Trypanosoma vivax in Eritrea and central

Ethiopia, which are tsetse free areas. They both considered tabanids and

Stomoxid flies to be the vectors. Also Buxton (1955) mentioned that

Tabanids and biting muscids are important vectors of trypanosomes in

some tsetse free parts of Africa. Several authors wrote and conducted

studies on the role of tabanids and other biting flies in epidemiology of

Nagana and Surra. Roeder et al. (1984) described an incidence of acute

Trypanosoma vivax infection in cattle in high lands of Ethiopia where the

weather is too cold for tsetse survival. Outbreaks of Trypanosoma evensi

in cattle and buffaloes in India were reported to increase with the

increasing numbers of Tabanus spp. and Stoomoxys spp. In Vietnam,

Phung and Pham (1995) dissected biting flies and identified considerable

rate of T. evesi infection in tabanids, Stomoxys calcitrans and Heamatebia

exigua. Hussein et al. (1991) reported Atylotus spp. as vectors of

Trypanosoma evensi in camels in Saudi Arabia. Desquesnes and Dia

(2003) demonstrated the ability of one of the most common tabanids

found in Africa, Atylotus agrestis, to transmit T. vivax mechanically to

cattle.

1.4.2 Internal parasites transmission

1.4.2.1 Direct transmission

Nematode can be transmited directly in case of pasture contamination by

ingestion of free L3 (infective stage) such as Trichostrongyloid and

Strongyloid, however infection sometimes can happen by larval

penetration of the skin or by ingestion of the eggs containing a larva

(Radostits et al., 2000).

19

1.4.2.2 Indirect transmission

In case of nematodes, the first two moults usually take place in an

intermediate host and infection of the final host is either by ingestion of

intermediate host or by inoculation of the L3, when the intermediate host

such as blood sucking insect feeds (Radostits et al., 2000).

Trematodes are transmited by the snails as intermediate host, the infective

stage (cercaria, metacercaria) emerge from snail and swim to contaminate

the pasture.

The typical life cycle of cestodes is indirect with one intermediate host.

1.5 Diagnosis

1.5.1 Diagnosis of sheep blood parasites:

1.5.1.1 Diagnosis of sheep Trypanosomosis:

Clinical diagnosis of individual animals is indicated (Uilenberg, 1998)

but not confirmative (OIE, 1996).

Trypanosomoses can be diagnosed by direct parasitological, serological

or molecular techniques.

1.5.1.1.1 Parasitological methods:

These methods include examination of fresh drop of blood under cover

slip as a wet smear, stained thin and thick film. Thos are specific

techniques but theire sensitivity is relatively low, as parasitaemia is

generally low and fluctuating. Therefore, negative results do not always

mean that the animal is not infected. Negative test should be repeated

before establishing final diagnosis (OIE, 1996). More sensitive

parasitological method depends on the concentration of trypanosomes in

the buffy coat by microhaematocrit centrifugation techniques (Woo,

1970). This technique is efficient and may detect as few as 5

trypanosomes\ml (Kalu et al., 1986).

20

The relative efficiency of these several methods of diagnosis may vary

between trypanosomes species, the chance may be improved by used dark

ground \phase contrast and concentration techniques (Murray et al.,

1977). Also in this method measuring packed cell volume is indication of

the degree of anaemia (Woo, 1970; Murray et al., 1977; Brown et al.,

1990; OIE, 1996).

1.5.1.1.2 Serological methods:

The antibodies detection by several techniques has been tried for

diagnosis of trypanosomes. At the present the in direct fluorescence

antibody test (IFAT) allows detection of species-specific antibodies (OIE,

1996), the method had been widely applied for diagnosis for bovine

trypanosomosis in Africa (Luckins, 1992).

The enzyme linked immunosorbent assay (ELISA) has been used to

detect infection in camels (Luckins, 1999), buffalo and cattle (Payne et

al., 1991). Desquesnes et al., (1996) reported that Ag ELISA is an

important tool for epidemiological surveys.

1.5.1.1.3 Molecular biology techniques:

The principle of the molecular tests is the demonstration of the

occurrence of sequences of nucleotides, which are specific for

trypanosome subgenus, species or even type or strain (Uilenberge, 1998).

Polymerase chain reaction (PCR) is based on the use of an enzyme, DNA

polymerase enzyme. The technique was used to be an efficient tool for

estimation of the prevalence of African trypanosomosis (Solano et al.,

1999).

21

1.5.1.2 Diagnosis of tick born diseases

1.5.1.2.1 Provisional diagnosis:

The simples' diagnostic method is case history, clinical signs, post-

mortem findings and knowledge of disease and vector distribution (OIE,

2000), despite the fact that clinical picture of the disease is not

pathognomic (Lossos, 1986a). The clinical signs include fever,

enlargement of peripheral lymph nodes, difficult breathing, frothy nasal

discharge (Boulter and Hall, 2000).

Diarrhoea, lacrimation, dullness, haemoglobinuria in case of babesiosis,

recumbency and death may occur within two to three weeks post

infection (Gill et al., 1977; Uilenberg, 1981). Post mortem findings

include subcutaneous and pulmonary oedema, petichial hemorrhages on

various organs.

1.5.1.2.2 Laboratory diagnosis:

By Geimsa stained blood or tissue smears in order to detect schizonts in

lymph nodes and impression smears, while piroplasms appear in blood

smears (Soulsby, 1982; Norval et al., 1992).

1.5.1.2.3 Serodiagnosis:

The most suitable and commonly used serum antibody assay has been the

indirect fluorescence antibody test (IFAT) (Burridge 1971; Burridge and

Kimber, 1972; Burridge et al., 1974; Goodeeris et al., 1982). The test has

been widely used in epidemiological studies in different African countries

including Sudan (FAO, 1983).

Recently the enzyme linked immunosorbant assay (ELISA) is widely

applied in detecting circulating parasites-specific antibodies, antigens and

immune complexes (Dolan, 1989). The test has many advantages

compared with (IFAT).

22

1.5.1.2.4 Molecular techniques

Usage of molecular tools based on DNA hypridisation to detect parasites

were discussed by many authors. D,Olivera et al. (1995) reported the

detection of T. annulata in cattle using (PCR).

Two integrated approaches were developed to detect several Thieleria or

Babesia spp, in one assay (Figueroa et al., 1993; Allsopp et al., 1993).

Using these approaches multiple species can be detected in one assay

without performing independent PCR for each parasite (Gubbels et al.,

1999). PCR combined with reverse line blot (RLB) hybridization

(Gubbels et al., 1999) is used to detect and differentiate all known

Theileria and Babesia spp. on bases of their differences in 185 subunit

rRNA gene sequences (Gubbels et al., 1999). A similar approach has

been followed for detection and differentiation of Anaplasma spp.

Targeting the 165 rRNA gene (Jongejan, 2003).

1.5.1.3 Diagnosis of microfilaria

Detection of microfilaria in blood can be done by concentration method

after centrifugation of blood in micro haematocrit tube or in wet smear

covered with a cover slip. The larva may be detected by the snake-lie

movement under low magnifications (Jain, 1986). The recommended

method for stained blood film consists of adding 1.0ml of fresh blood to

10ml of 2% formalin solusion and centrifuged at 1,000-1,500 rpm for few

minutes. The sediment is examined microscopically as a wet smear after

being mixed with an equal volume of 1:1000 methylene blue (Jain, 1986).

A drop of serum in slide covered with cover slip examined for viable

larvae (Jain, 1986).

23

1.5.1.4 Diagnosis of internal parasites

1.5.1.4.1 Gross examination

Feacal samples should be examined for any intact specimens such as

Moniezia spp. segment and Oesophogostomum species adults.

Examination of the smear only indicates the presence of infection

regardless of its quantification (Dunn, 1978).

1.5.1.4.2 McMaster Technique

Mc Master Technique depends on the examination of a precise volume of

suspension of faeces in floatation solution, to allow an estimation of the

number of eggs and larvae present in a sample. The natures of solution

vary according to the animal origin of the suspected material and mixing

performed in various ways. The essential equipment is a slide that

consists of two layers of glass separated by a known distance and having

on the upper layer a ruled squire of known area (King, 1976).

1.5.1.4.3 Concentration methods

Concentration depends on specific gravity of the eggs and is not reliable

in estimating the intensity of an infection, and can be achieved by

sedimentation or floatation (King, 1976).

1.5.1.4.3.1 Sedimentation

The parasite eggs do not float, but deposit in the solution either by slow

natural precipitation of faecal suspension or by the use of centrifugation.

This method is relevant to fascioliasis, schistosomiasis and

paramphistomiasis (King, 1976).

24

1.5.1.4.3.2 Flotation

In this method the specific gravity of the solution is higher than the

specific gravity of the eggs. Thus the solution used is at saturation or

semi-saturation such as sodium chloride and sugar (sucrose). The method

is used for nematodes.

1.6 Control

1.6.1 Control of sheep Trypanosomosis:.

1.6.1.1 Treatment of Trypanosomosis:

By using trypanpcidal drugs for the treatment and or prevention is the

most widely accepted method for controlling the disease (Tacher, 1982;

Losos, 1986).

Chemoprophylactic drugs are used in highly tsetse infested areas and the

only difference from curative drugs that in case of prophylaxis the drug

persist longer (Uilenberge, 1998).

The available and common trypanocidal drugs are Diminazen-acturate

(Berenil), Quinapyramine sulphate and chloride (Antrycide) and

Isometamidium (Samorin).

1.6.1.2 Vector control:

In vector control several methods were applied, these are including bush

clearance to minimize the density of flies by destroying the tsetse shelter

and resting sites (Ford, 1970; Finelle, 1974; Walker, 1986). This method

is seldom used now (Finelle, 1974). Elimination of game animals in order

to starve tsetse flies by reducing the source of food (Ford, 1970). Due to

the world concern to conservation wild life, the method no longer used.

25

1.6.1.3 Use of insecticides:

Application of insecticides like chlorinated hydrocarbons chiefly DDT

and dieldrin in the past (Finelle, 1974), organophosphrus and pyrethroids

are applied in ground or aerial spraying. This is most effective method

(Allsopp, 1984). Synthetic pyrethroid is also applied by dipping or used

as pour on, depending on the particular insecticide used, ticks and other

ectoparasites may also be reduced. The use of traps and insecticide-

impregnated targets with or without attractants is a method to suppress

tsetse populations (Challier and Laveissiere, 1973; Vale, 1974, 1993;

Brandl, 1988; Bauer et al., 1995).

1.6.1.4 Biological control:

Recently application of sterile insect technique has been achieved

successfully in Zanzibar by systematic releases of sterile male among the

target population (Feldmann and Hendrichs, 2001). This method is very

specific and not polluting (Uilenberg, 1998).

1.6.1.5 Tabanids control:

The most suitable method to control tabanids is the use of chemical

attractants to trap males, this help to reduce the disease out side the tsetse

belt (Mohammed et al., 2000).

1.6.2 Control of Ticks and tick-borne diseases

1.6.2.1 Treatment

1.6.2.1.1 Chemotherapy

Usage of ox tetracycline and chlortetracycline are affective in arresting

macro- and micro schizonts formation in the beginning of the infection of

Theileriosis and also used for treatment of anaplasmosis (Sousby, 1982).

26

Diminazene aceturate (Berenil) at a dose of 3.5 mg\kg B.W

intramuscularly in case of Babesiosis and combined with oxyteteracycline

15mg\kg B.W. for theileriosis treatment.

Halofuginone lactate at 1.2 mg\g B.W. given orally shown to be highly

effective for theileriosis (Schein and Voiget, 1979).

Parvaquone (Clexon) is effective at 10 mg\kg B.W. administered

intramuscularly in two injections with 48 hours interval (Gille et al.,

1984; MacHardy and Morgan, 1985; Musisi et al., 1985; Mehta et al.,

1987 and Unsuren et al., 1988).

Buparvaquone (Butalex) is twenty times more effective than parvaquone,

it is given at 2.5 mg\kg B.W. (McHardy et al., 1985).

Imidocarb (Imizol) is used as chemotherapy and also eliminate

anaplasmosis from carrier animals (Roby and Mazzola, 1972) cited by

Soulsby (1982).

1.6.2.1.2 Chemoprophylaxis

By subcutaneous inoculation of ground suspension of infected tics with a

subsequent intramuscular injection of oxytetracycline (Malik et al.,

1987).

1.6.2.2 Vaccination

Vaccination against tropical theileriosis is established in some parts of the

world namely Israel, Turkey, Iran and Iraq (Soulsby, 1982 and Losos,

1986) attenuated vaccines obtained by serial passage of schizont infected

lymphocyte, and this provided a significant protection (Srivastava and

Sharma, 1977; Broun, 1979). Development of vaccine against tropical

theileriosis in cattle and malignant ovine theileriosis in sheep in Sudan is

needed to be evaluated experimentally (Jongejan, 2003).

27

1.6.2.3 Control of ticks:

Using acricides in dips for large herds and hand spray or used as pour on

(Drumond, 1976; Losos, 1986a).

1.6.3Treatment of microfilaria

Many broad spectrum anthelmintics have a high efficiency against

Microfilaria (Drudge et al., 1969), one of those drugs, is Ivermectin, it is

a drug of choice to eliminate Microfilaria in horses (Pollitt and

Holdworth, 1986) at 0.2mg\kg B.W.

Other drugs include Diethyl carbamazine a microfilaricidal in both man

and animals at a dose of 5-8 mg\kg B.W. daily for 21 days. Also systemic

corticosteroids are recommended (Cello, 1971).

1.6.4 Control of internal parasites

Fischer and Say (1989) explained that the control of gastrointestinal

parasites depends mainly on drug prophylaxis for eliminating the

parasites by regular treatment. The animal should be given antihelmentics

at the end of the rainy season in order to improve the adaptation of the

animal to harsh dry season conditions. A second treatment by

antihelmentics should be given at the end of the dry season so that the

infection of pasture by parasites at the time of the first rains can be

reduced.

On the other hand, Thursfiled (1996) described that the level of infection

with some nematodes can be reduced by mixed, alternate and sequential

grazing.

28

CHAPTER TWO

MATERIALS AND METHODS

2.1 Study sites description

The study was conducted in Khartoum State which is situated in Northern

Sudan between latitude 16°N and 14°N. The total area extends over

approximately 21,000 square kilometers.

Khartoum state contained three basic Towns (Khartoum, Khartoum North

and Omdurman), each of them is divided administratively into a number

of localities. One slaughter house was selected randomly from each town

to be the site for the study, Al Sahafa abattoir represented Khartoum,

Ghanawa abattoir represented Omdurman and Kuku abattoir represented

Khartoum North. The selection was done on the basis of the number of

animals slaughtered, as these are the largest in the three towns also the

animals are brought from all over the country to these slaughter houses

2.2 Sampling

Sampling was done according to Thrusfield (1995), the slaughter houses

were selected from Khartoum state (Khartoum, Khartoum North and

Omdurman). All animals in each slaughter house were sampled at the

time of the visit, this samples collection method called Cluster sampling

or Two-stage sampling method.

2.3 Study population

All sheep from different origins, in different age group and sex brought to

slaughter house at the time of visit were targeted as study population.

29

2.4 Samples collection

For blood and internal parasites detection, blood samples, faecal samples

were collected, tick infestation was observed, and body temperature was

taken, information on origin, breed, sex and age were recorded for each

animal.

2.4.1 Blood sample collection

A total of 150 blood samples were collected form the ear vein of sheep

for both thin blood smear and wet amount examinations. Samples were

placed in a cool box and transferred to the laboratory before processing

for parasitological examination.

2.4.2 Faecal samples collection

Fresh faecal samples were collected from the rectum of every individual

sheep in plastic vacutainer. The samples were labeled and immediately

transferred to the laboratory for faecal examinations.

2.4.3 Ticks observation Ticks were observed on individual selected animals according to the

presence or absence.

2.5 Parasitological examination

2.5.1 Wet blood mount:

One drop of fresh blood was placed on a slide, covered with a cover-slip

and examined microscopically for detection of motile parasites at 10×40

magnification.

2.5.2 Thin blood film:

Thin blood films were prepared on slides, dried and fixed with absolute

alcohol. Then these smears were stained with 5% diluted giemsa stain

30

solution for 45 minutes. Films were washed using distilled water, dried

and examined microscopically under oil immersion at 10×100

magnification for blood parasites detection.

2.5.3 Faecal examination

2.5.3.1 Flotation method

Two to three grams of the faeces were taken in a mortar, ground and

mixed thoroughly in a saturated sodium chloride solution. The suspension

was poured through a tea sieve into a beaker to remove the large particles.

The solution was poured into a small bottle until it was completely filled

to make a convex meniscus at the top. Then it was covered with a clean

grease-free cover slide. The cover slide was removed after 10 minutes

and placed on a clean slide to be examined under Low power 10 × 20

magnifications. The examination was done systemically to cover all the

cover slip.

2.5.3.2 Sedimentation

Two to three grams of the faeces were mixed with water and put in tubes.

the tubes were centrifuged three times for 5 minutes, each supernatant

fluid was removed and replaced each time. The deposits were taken and

placed on slides with covers slip and examined microscopically at high

power 10× 40 magnifications for detection of parasites ova.

2.6 Data analysis

Microsoft Excel (windows 2003) and state 6.0 for windows 98/95/NT

were used for data analysis. Chi-square (χ2) was used for assessing the

statistical associations of various factors for presence of blood and

internal parasites. Logistic regression model was employed to obtain the

31

odds ratio (OR) only for those factors which gave statistical significant by

using chi-square (χ 2).

If the odds Ratio was greater than one the factor could be a risk factor for

the presence of blood or internal parasites.

32

Table (2.1) Description of the study population

Origin

Breed

Sex

Age

Slaughter

House

No. of

animal

examined

White

Nile

Gadaref

Kordofan

Darfur

Kabbashi

Ham

ari

Baladi

Male

Female

< 1

1 - 2

> 2

Elsahafa

50

-

45

5

-

5

-

45

47

3

44

4

3

Ghanawa

50

-

-

26

24

35

14

-

14

9

11

28

9

Kuku

50

40

-

10

-

36

15

-

41

36

20

31

-

Total

150

40

45

41

24

76

29

45

102

48

75

63

12

33

Chapter Three

Results

The results showed that, the prevalence of blood parasites in

Khartoum state was 15.3% (n≡150) with 18% (n≡50), 16% (n≡50) and 12

% (n≡50) in Omdurman, Khartoum North and Khartoum respectively

(Table 3-1).

Also the prevalence of internal parasites was 32%, 28% and 22% in

Khartoum North, Omdurman and Khartoum respectively (Table 3-1).

Ticks presence observed was 16, 8% and 8% in Omdurman, Khartoum

and Khartoum North respectively (Table 3-1).

No motile parasites were detected (Table 3-1), high temperatures were

observed only in Omdurman with 6% prevalence rate (Table 3-1).

The highest prevalence rates was due to Theileria spp., 12%, 14% and

18% in Khartoum, Khartoum North and Omdurman respectively with

14.7% total prevalence (Table 3-2). Only one animal showing Babesia

spp was detected in Khartoum North (2% prevalence rate as 0.6% of total

rate) (Table 3-2). Tick infestation was observed at 8%, 16% and 8%

prevalence rates in Khartoum, Omdurman and Khartoum North

respectively, with 10.7% total prevalence rate.

On the other hand results of internal parasites indicated the presence of

protozoa, nematodes, cestodes and trematodes, (Eimeria, Hemoncus,

Strongyloide,, Monezia and Fachiola spp). Trophozoites or eggs were

detected in fecal examinations with prevalence rates 12%, 8%, 2.6%, 4%

and 0.7% respectively (Table 3-3).

Coccedia spp prevalence rate was the highest (10%, 16% and 10% in

Khartoum, Khartoum North and Omdurman respectively) (Table 3-3).

The prevalence of Heamonchus spp was 6%, 8% and 10% in Khartoum,

Khartoum North and Omdurman respectively (Table 3-3).

34

2%, 4% and 6% were the prevalence rates of Monezia spp in Khartoum,

Khartoum North and Omdurman respectively (Table 3-3). Strongyloides

prevalence was 4%, 2% and 2% prevalence rates in Khartoum, Khartoum

North and Omdurman respectively (Table 3-3). Fasciola was found in

only one sample from Khartoum North with 2% prevalence rate (Table 3-

3).

Statistical analysis showed no correlation between prevalence of blood

parasites and place of origin (χ2 = 3.7027, p=0.295), age (χ2 = 4.047, p =

0.132), sex (χ2 = 0.915, p = 0.339), breed (χ2 = 3.065, p = 0.216) and ticks

presence (χ2 = 0.640, p = 0.424) (Table 3-4).

Also there are no co relation between presence of internal parasites and

origin (χ2= 2.023, p = 0.568), age (χ2= 0.585, p = 746), sex (χ2=0.321, p =

0.571) and breed (χ2 = 0926, p = 0.629) (Table 3-5).

A strong association was found between presence of blood parasite and

temperature (t-test = -628.515, p = 0.000) (Table 3-6).

35

Table (3.1): Parasitic Burden of Animals Examined

Parameters

Khartoum

Location

Omdurman

Khartoum

North

Total

No of animal

examined

Body temp.

Normal

High temp.

Tick presence

Positive

Stained blood film

Blood parasites

Fecal exam

Sedimentation

method

Internal parasites

Floatation method

Internal parasites

50

100%

_

8%

12%

_

22%

50

94%

6%

16%

18%

_

28%

50

100%

_

8%

16%

2%

30%

150

98%

2%

10.7%

15.3%

0.6%

26.7%

36

Table (3.2) the prevalence of blood parasites in slaughter houses in

Khartoum state

Slaughter house

No. of

animal

examined

Prevalence %

Theileria spp Babesia spp

No. (%)

Elsahafa

Kuku

Ghanawa

Over all prevalence

50

50

50

150

6(12%) _

7(14%) 1 (2%)

9(18%) _

22(14.7%) 1 (0.6%)

37

Table (3.3): The prevalence of internal parasites in slaughter houses in Khartoum state

Slaughter

house

Eimeria spp

No. (%)

Heamonchus

spp No. (%)

Strongyloides

No. (%)

Monezia spp

No. (%)

Fasciola No.

(%)

Total

Elsahafa

Kuku

Ghanawa

5 (10%)

8 (16%)

5 (10%)

3 (6%)

4 (8%)

5 (10%)

2 (4%)

1 (2%)

1 (2%)

1 (2%)

2 (4%) 3 (6%)

_

1 (2%)

_

11 (22%)

16 (32%)

14 (28%)

Total 18 (12%) 12 (8%) 4 (2.6%) 6 (4%) 1 (0.7%) 41(27.3%)

38

Table (3.4): The relationship between presence of blood parasites and

origin, age, sex, breed and tick infestation.

Factor

Chi-square(χ2)

P-value

Origin

Age

Sex

Breed

Ticks

3.7027

4.047

0.915

3.o65

.640

0.295

0.132

0.339

0.216

0.424

39

Table (3.5): The relationship between presence of internal parasites

and origin, age, sex and breed.

Factor

Chi-square (χ2)

P-value

Origin

Age

Sex

Breed

2.023

0.585

0.321

0.926

0.568

0.746

0.571

0.629

40

Table (3.6): The association between presence of blood parasites and

animal body temperature

Factor

No of

animals

examined

SE

t-test

p-value

Temperature

150

0.503

-628.515

0.000**

**: highly significant (P< 0.01)

NB. Normal body temperature ranged 39ºc- 40 ºc according to Radostits et al (2000).

41

Chapter Four

Discussion

The study showed no Trypanosomiasis infection in the

samples examined. That agrees with different workers (Stephen, 1970

and Findle, 1973) who stated that sheep and goats are seldom infected

with trypanosomes under natural conditions. Khasanove and Tranitskaya

(1973), Mahmoud and Elmalik, (1978) established experimental infection

of Trypanosoma and showed that sheep and goats may act as reservoir

and may be important in the transmission of trypanosomosis, Karib

(1961) stated that thousands of sheep and goats were examined in the

Upper Nile Province but only T.vivax was identified. Boid et al (1981)

suggested the role of sheep in Kassala Province as reservoir after he

found antibodies against T. evansi circulating in their blood. On the other

hand the study revealed a higher prevalence of Thieleriosis compared to

Babesiosis. Radositits et al (2000) cited that in an outbreak of Thieleria

infection involving 8 flocks, 22% of sheep were affected and all of them

died within 3-6 days. Losos (1986) reported that Theileria hirci in Africa,

Asia and Europe causes enzootic diseases; The young lambs contract a

relatively mild form of the disease which renders mature animal immune;

The mortality rate in sheep is relatively low about (16%) in infected

cases; The distribution of T.ovis is comparable to the distribution of

T.hirci. In general piroplasmosis in Sudan was early reported in the

begining of past century and Babesiosis was reported in 1905, yet limited

research was done such as the work by Hoogstrsal (1956), FAO (1983),

Abdoun (1984) Hashim (1984) Mohamed and Yagoub (1984).

The results of the present study showed high prevalence rate of internal

parasites infection (Coccediosis, Monezia infection, Strongyloid

infection, Haemonchosis and Fsciolosis), the protozoa were the most

common and they belonged to the genera Eimeria spp. (Coccedia.)

42

Similarly, Osman, et al (1990), reported outbreaks of coccediosis among

sheep and goats in fattening centers around Khartoum state. Other

workers recorded the presence of internal parasites of sheep in Sudan, in

kordofan, Kassala, Darfur and Blue Nile provinces. Gagoad and Eisa

(1968) examined 322 abomasums of sheep, their study showed that 80%

of sheep harbored Haemonchus contortus. They reported that the

incidence rate in kordofan, Kassala, Darfur and Blue Nile was 83%,

73.5%, and 75% respectively. Eisa and Ibrahim (1970) examined

gastrointestinal tracts of sheep obtained from Elobied, they reported the

occurrence of H. contortus, T. colubriformis, S. papillosus, O.

columbianum, Chabertia ovina, Cooperia pectinata, Trichuris ovis and

M. expansa. H. contortus was found to be the most prevalent species.

This study revealed that there was no effect of sheep place of origin on

the prevalence of blood and internal parasites that might be due to

similarities of management conditions in various areas of origin, (White

Nile, Gadaref, Kordofan and Darfour). Also sheep in various locations

may meet in different occasions during seasonal migrations of herds.

Negative relationship was obtained between ticks infestation and blood

parasites infection. This could be attributed to the fact. That ticks dropped

during the period of travels.

Also the study revealed that there was no effect of breed on the

prevalence of blood and internal parasites (χ2= 0.005, p> 0.05). That

could be attributed to the fact that the animals examined were genetically

more than 65% of the sheep in Sudan are of the Sudan Desert type (Ovis

aries) (Sulieman et al., 1990), which is believed to be a descendant of

sheep of Egyptian origin (Ovis longipes). Therefore the so called breeds

may be types rather than distinct breeds. Sudan Desert sheep are further

classified into tribal subtypes, e.g. Hamari, Kabashi, Shenbali in North

and West Kordofan States (Mukhtar, 1985), Shugor, Dubasi and Watish

43

in the Central States (Sulieman et al., 1990) and Bourug in the Butana

area of eastern Sudan.

No correlation (χ2= 0.483, p> 0.05) was found in this study between sex

and presence of blood and internal parasites. Similar results were reported

by Flach et al. (1993), who stated that there was no relationship was

established between infection of engorged nymphs of ticks and sex of

host animal. Thus sex is not a determining factor in susceptibility to tick-

borne parasites. Both sexes graze in same under similar field conditions

which may explain the negative correlation between sex and internal

parasites.

This study was conducted in the hot season (April, May, June), when the

ova and egg and worm counts decreased, while both high faecal egg

output and high worm counts were observed during the rainy season. This

could be attributed to the suitability of environmental conditions of

moderate temperature and moisture prevailing during the rainy season

(Temp 28-31ºC; RH 37.5-70%) providing optimum requirements for

development of infective nematode larvae (Pandey, 1990; Onyali et al.,

1990; Agyei, 1991; Rahman, 1992). Both egg and worm counts decreased

at the end of the rainy season and this might be due to a self-cure

phenomenon as these animals have been sensitized for several months

during the rainy season and subsequently lost their worm burdens (Altaif

et al., 1980; Altaif and Issa, 1983; Chaudhry et al., 1988). This decrease

continued throughout winter and summer and was probably induced by

dryness. This fact is in conformity with observation of several authors in

some African countries such as Nigeria. Okon and Enyenihi (1977),

Ogunsusi (1979), and Chiejina and Fakae (1984) studied pasture

infectivity with trichostrongylid larvae in that country and showed that

the dry season was unfavourable for pre-parasitic development and

survival of nematode larvae. In Tanzania, Connor et al. (1990) reported

44

that egg output declined and remained low during the dry season due to

lack of moisture. In addition Chiejina et al. (1989) reported that the dry

season is responsible for the rapid drying out of faecal pellets leading to

death of parasite eggs and larvae. On the other hand sheep brought to

Khartoum state came for local and export marketing, which means

owners select healthy, youngest and fit animals. Also this study was

conducted on relatively small number of sheep (150) compared with total

number brought to the state annually for export and local consumption.

According to MARF (2005) in the last five years from 2000 to 2004,

more than 76 millions head of sheep were slaughtered for local

consumption and 480 thousands ton were exported. With the above

mentioned in this study the results showed that high prevalence of blood

parasites (15.3%) and (27.3%) with regards to for internal parasites,

which are very harmful for man and sheep, with regards to helth and

economy, there is direct loss from expected condemnations of affected

parts and decrease in animal proteins available for human consumption so

it is vital to:

1- Pay more attention to sheep blood and internal parasites,

epidemiology and control nation wide.

2- Conduct similar surveys for blood and internal parasites, to cover

all animals brought from various states of Sudan to Khartoum for

local and international consumption.

3- Apply practical methods of prevention and control such as use of

chemotherapeutic control, vector control and continuous veterinary

monitoring in the slaughter houses especially in ante- mortum

inspection.

4- Draw attention to the exported sheep and try to minimize losses in

production due to the parasites.

45

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