Parasitic Organisms in Blood Vessel and Lymph Nodes

1. Blood Trematodes2. Filarial Nematodes

Learning Objectives

• After completing this IT, student should be able to;– Understand morphology, life cycle, pathology,

laboratory findings and treatment of Schistosomes infection

– Understand morphology, life cycle, clinical symptoms and treatment of Blood Nematodes infection

BLOOD TREMATODES:Family Schistosomisidae

Muhaimin RamdjaDepartment of Parasitology

School of MedicineUNSRI

Members of this family:

• Parasites in blood vessels of birds and mammals

• The adult schistosomes have separate sexes

• Male having larger body provided with a ventral gynaecophoric canal embracing the darker slender female

Members of this family:

• Pharynx absent • Intestine reunited in the posterior half of

the body• The infective stage is a pharyngeal forked

tail cercaria• Cercaria developed from sporocyst in the

snail first intermediate host• Egg is unoperculated, fully embryonated

when laid, thin shell with spine or knob

HUMAN SPECIES

• Five species of schistosomes had been found developing to adult in humans, causing typical disease known as schistosomiasis or bilharziosis

• Several other species which adults were reported in animals, their cercaria can penetrate human skin causing dermatitis or swimmer’s itch

1. Schistosoma haematobium

• They are known as the vesical blood fluke causing the disease called schistosomiosis haematobia, schistosomal hematuria, vesical schistosomiosis, vesical bilharziosis

• They have been reported from Africa and Southwest Asia

Schistosoma haematobium• Adult worm inhibit vesical and pelvic

venous plexuses• Egg with terminal spine• Snail intermediate host belong to Bulinus,

Planorbis, Physopsis, Lymnea spp.• Baboon, monkeys and chimpanzees are

the reservoir host

2. Schistosoma mansoni• The Manson’s blood fluke causing

schistosomiosis mansoni, intestinal bilharziosis, or bilharziosis

• Their distribution cover most of Africa, part of Southwest Asia, some countries and islands in South America and West Indies

• Adult worms inhibit inferior mesentric vein • Egg characterized by having lateral spine

Schistosoma mansoni

• Biomphalaria, Australorbis, Tropicorbis spp are the snail intermediate host

• Baboons, monkeys and rodent are the animal reservoir hosts

3. Schistosoma japonicum• The Oriental blood fluke were reported

from China, Philippines, Japan, Indonesia and Taiwan

• They are in the superior mesentric vein• Causing schistosomiosis japonica,

Oriental schistosomiosis, Far Eastern schistosomiosis, Katayama Fever, Yantze Fever

Schistosoma japonicum

• Eggs have a rudimentary spine• Oncomelania spp are the intermediate

host• Dog, cat, cattle, buffaloes, sheep, goat,

horse, pigs and rodent are the reservoir hosts

4. Schistosoma intercalatum

• This intestinal schistosome is limited to several countries in Central and West Africa

• Causing schistosomiosis intercalata or intestinal schistosomiosis

• The adults are recovered in mesentric and portal vein

• Egg with a terminal spine

Schistosoma intercalatum

• Bulinus snails are the intermediate host• Monkey, sheep, goat, rodent were

reported as animal reservoir host

5. Schistosoma mekongi• The Mekongi schistosome were recovered

from Islands in Mekong river in Laos and Cambodia

• Causing schistosomiosis mekongi or Mekong schistosomiosis

• The adults reside in the superior mesentric and portal veins

• Egg with a lateral knob

Schistosoma mekongi

• The intermediate host is Neotricular aperta• Dog is the intermediate host

LIFE CYCLE

• The adult worms live in the blood vessel• Females migrate to small venules to lay

eggs close to the lumen of the intestine or bladder

• The vessels dilate to accommodate the worm during oviposition, so that the eggs wedged firmly into the venules

LIFE CYCLE

• The egg works their way to the lumen of intestine or bladder

• The egg hatches when reach fresh water, produces mirasidium

• Mirasidium swims freely search of the appropriate snail host

• Mirasidium penetrates snail and develop to sporocyst

LIFE CYCLE

• Sporocyst produces cercaria 6 weeks after mirasidium penetrated snail hoster

• Cercaria is characterized by having long tail bifurcated at the posterior end, and with pharynx

• When fully developed, cercaria emerged from the snail, swim freely in the water

LIFE CYCLE

• Upon contacting the human skin, the cercaria penetrates the skin by secreting enzyme from its penetration glands

• The cercaria discard its tail outside the host, only its body migrates into blood vessels and find the way to its preferably niche

Pathology

• The organs and tissues most seriously involved are the intestinal tract and the liver

• The severity of the diseases is in general depend on the worm burden

• Eggs are the main agent of pathology • The heavier the infection, the greater the

pathology and morbidity

Pathology

• Light infections cause little pathology, while heavy infection can cause death

• The severity also depends on the species of the causative agents

• Schistosoma japonicum cause the most damage to the host due to the number of eggs released by female during her life time is larger than other spesies

Laboratory Findings

• Specific diagnosis is to recover characteristic eggs

• However, positive immunodiagnostic test together with history of the patient has stayed in an endemic area suggest the disease during incubation period or late chronic cases

Laboratory Findings

1. Microscopic finding characteristic eggs in host excreta; S. haematobium in urine, the other spesies in feces

2. Microscopic finding characteristic eggs in scraping and biopsy materials of host

3. Intradermal test 4. Immunologic test. The test of choice are

immunoblot and ELISA

Treatment

• Praziquantrel 40 mg/kg bwt, single dose is very effective

Prevention and Control

• Effective control and measure of schistosomiasis comprises at least three-fold program:

1. Treatment of infected individuals together with health education

2. Sanitary improvement of the environment and provision of safe water supplies

3. Eradication of the snail intermediate host

Filarial Nematodes

1. Wuchereria bancrofti2. Brugia malayi3. Brugia timori

Wuchereria bancrofti

Producing Bancroft’s filariasis

Morpholgy, Biology:

Adult worms: creamy-white, minute, thread-like nematodes with smooth cuticula.

Male: 40 mm x 0,1 mm. Caudal extremity is curved sharply ventrad.

Female measure: 80 to 100mm x 0,24-0,3 mm. Vivipar.

The adult worms live in the lymphatic system and the microfilariae in blood stream

Microfilaria:Measure: 244-296 x 7.5-10 µ, sheathed with periodicity nocturnal.

Appearance of the body: graceful or sweeping curves.

The nuclei of body are fine with oval shaped and circumscrift or dicrete.

The cephalic space ratio: length:breadth is as same as 1:1.

Lack of the tail nuclei.

Wuchereria bancrofti jantan

Wuchereria bancrofti betina

Mikrofilaria Wuchereria bancrofti

Lengkungan badan graceful

Intermediate hosts: Culex pipiens quinquefasciatus,

Anopheline mosquitoes, Mansonia and Aedes sp

Lengkungan badan indahsheath

sarung

Cephalic space panjang:lebar=1:1

Inti badan jelas dan discrete

Kepala Wuchereria bancrofti

Ekor Wuchereria bancrofti

Lack of the tail-nuclei

Life cycle: is as same as : Brugia malayi

Pathogenesis: dependent on several factors:

1.Tolerance of the individual to the parasite

2.Dosage of infective stage larvae inoculated by mosquito

3.Number of infective bites experienced at one time or on successive occasions

4.Anatomical location in the body where immature or mature filariae become temporary or permanent lodged.

5.Possibility of supervening infection with other bacterial infections (super-infection).

Pathophysiology and Symptomatology

1. Biological incubation: last one or more years

a. lymphangitis of extremity

b. Lympadenitis proximal to involved lymphatic

vessels.

c. Acute inflamation of the scrotum and its

contents

2. Symptomless: last for several years.

3. Acute stage: lymphangitis and lymphadenitis with filarial fever. The symptoms is as the same as with Brugia filariasis

4. Chronic stage with enlargement of the involved organ or member in the elephantoid type of the disease or development of lymphocele, frequently with rupture, in the less fibrosed type.Development of elephantiasis of leg or scrotum

The elephantiasis tissue usually consist strecthed, thickened skin.

Diagnosis:

1.The history of lymphangitis in endemic area

2.To find the microfilariae in the peripheral blood at night (10 P.M to 2 A.M)

3. In chronic stage elephanthiasis and hydrocele

4.Radiology : calcification picture where the adult worms lodged and dead.

5.Antigen-antibody reaction

THERAPY

1.DEC: Massal treatment with DEC; 6 mgr/

body weight per oral, is taken every week 3

times at one dose, as long as 40 weeks.

2. Praziquantel.

Elephantiasis W. bancrofti

Lymphedema of breast, scrotum an lower right hand

Brugia malayi

SCIENTIFIC CLASSIFICATION• Kingdom : Animalia

Phylum : NematodaClass : SecernenteaOrder : SpiruridaFamily : FilariidaeGenus : BrugiaSpecies : Brugia malayi

• Binomial nameBrugia malayiBrug 1927

NAME OF DISEASENAME OF DISEASE

Lymphatic filariasisLymphatic filariasisSynonyms : Brugiasis malayi Synonyms : Brugiasis malayi Malayan filarial worm Malayan filarial worm

Geographic distribution:Geographic distribution: Philippines, Indonesia, Sri Lanka, Philippines, Indonesia, Sri Lanka, Vietnam, Thailand, China, MalaysiaVietnam, Thailand, China, Malaysia and in specific parts of Korea. and in specific parts of Korea.

Clinical definition: LYMPHATiC FILARIASISis an infection with one of several mosquito-borne filarial worms of the species Wuchereria bancrofti, Brugia malayi or Brugia timori, which live in the subcutaneous lymphatics or lymph nodes, with larvae circulating in the bloodstream.

CHARACTERISTICS morphology

• Adult worms (macrofilaria) are long and slender with a smooth cuticle and bluntly rounded ends. The head is slightly swollen and bears two circles of well-defined papillae. The mouth is small; a buccal cavity is lacking. The male is about 13,5-23,3 mm length and 70-80 µ breadth. Its tail is fingerlike. The female is 43,5 to 55 mm length and 130-170 µ wide. The vulva is near the level of the middle of the esophagus.

• microfilariae measure 177 to 220 by 8 µ, have a sheath and two elongated nuclei of tail with terminal constriction. Absence of nuclei in the cephalic space with ratio= length: width= 2:1.•They have nocturnal periodicity (Wet mount preparation).

–The microfilariae are sheathed and can be distinguished from W.bancrofti for size (275- 320x7,5-10), location of nuclei and tail nuclei. (Fresh examination, particular of the caudal space).

Picture:The tail is tapered and present a constriction. The last two nuclei are divided by the constriction. The sheath stains pink.

Two nuclei

(Caudal space of (Caudal space of B.malayiB.malayi, Giemsa stain)., Giemsa stain).

Picture:The cephalic space is longer than broad (in W.bancrofti is as long as broad). (Detail of the cephalic space of B.malayi microfilaria, Giemsa stain).

sheathCepahalic space

Ratio length: breadth= 2:1

bersarung

Badan kink-kink

Inti ekor 2

Gambar c:

Sarung jelas tercat

Cephalic space panjang:lebar= 2:1

Gambar d:

Inti ekor ada 2

Kepala dan ekor Brugia malayi

PICTURE: detail of the cephalic space. Microfilariae are usually nocturnally periodic but sub-periodic strains of B.malayi and W.bancrofti are observed. (wet mount, detail of the cephalic space of B.malayi microfilaria).

identification of microfilariae in stained smear is possible by observation of the stained sheath (W.bancrofti sheath does not stain). 

LIFE CYCLE• Infective larvae are transmitted by infected biting

arthropods during a blood meal. The larvae migrate to the appropriate site of the host's body, where they develop into microfilariae-producing adults. The adults dwell in various human tissues where they can live for several years. The agents of lymphatic filariasis reside in lymphatic vessels and lymph nodes. B. malayi dwells particularly in the lymphatics, as with Wuchereria bancrofti. The female worms produce microfilariae which circulate in the blood.

•The microfilariae infect mosquitoes. Inside the mosquito, the microfilariae develop in 1 to 2 weeks into infective filariform (third-stage) larvae. During a subsequent blood meal by the insect, the larvae infect the vertebrate host. They migrate to the lymphatics, where they develop into adults, a slow process that can require up to 18 months.

• Recently B. malayi was found to contain an endosymbiotic bacterium, Wolbachia, in all life stages.[2] The genome sequence of this bacteria was determined at New England Biolabs. Experimental results indicate that the Wolbachia can be killed by treatment of the human host with doxycycline. Nematodes cured of the Wolbachia are sterile and have increased morbidity.

Arthropods are insects (mosquitoes)

Intermediate Hosts:

Mansonia annulata, M. annulifera, M

indiana, M. uniformis.

Aedes togoi.

Anopheles albotaeniatus. A. barbirostris,

A. sinensis and A. umbrosus

PICTURE OF Brugia malayi’s LIFE CYCLE

PATHOGENESIS• Multiplications1. However, no multiplication takes place in the

intermediate host. Adult male and female worms live in regional lymphatic vessels, where the female produces a large number of microfilariae, which circulate in the blood and may be ingested by a feeding vector mosquito.

2. The female worms show a circadian periodicity in microfilaria production.

3. The time of peak production varies among the species and geographic strains of worms and usually corresponds to the peak feeding period of the vector mosquitoes.

4. Microfilariae ingested by a vector mosquito migrate out of the midgut to the thoracic muscles, where they develop, molt several times, and finally migrate to the mouthparts of the mosquito as infective larvae. 5. Larvae quickly migrate to the lymphatics,

where they mature, mate, and produce microfilariae in the new host. The time from infection until microfilariae can be detected in the blood varies from 3 to many months.

•HABITATS AND HOST1. HABITATS

live in the lymphatic vessels and lymphnodes where they cause dilatation, inflammatory infiltrates and, at last, blockage of the lymphatic circulation.

2. HOSTHuman , through mosquitoes of the genus Mansonia, Anopheles and Aedes.as vector

•PATHOLOGY1. The larvae are injected intradermally with a mosquito bite

and find their way to the large lymphatics, where they mature and mate.

2. Swelling of lymph nodes containing adults is a common feature. However, when an adult worm dies severe lymphadenitis with chronic inflammatory to granulomatous reaction results, including eosinophils which ultimately leads to fibrosis. In some multiply infected individuals this may lead gradually to chronic lymphatic obstruction, which in a small percentage of cases progresses to the lymphedematous complication of elephantiasis, usually in an extremity.

3. internal organs, such as the spleen, and sometimes they migrate cyclically to the peripheral circulation, coincident with the biting/feeding habits of the prevalent transmitting mosquito. “Tropical eosinophilic with fever” with pulmonary infiltration is often attributed to this infection.

SYMPTOMS-PATHOGENECITY

Four stages of the disease are recognized. 1. The incubation period of 3 to 12 months in which there

are no symptoms. 2. The acute symptomatic stage in which some swelling of

the extremities may occur and this may be accompanied by pain, weakness of arms and legs, headache, insomnia. Fever is usually not present.

3. There is a period of recovery which is permanent if reinfection does not occur.

4. If there is continued reinfection the cycle repeats and elephantiasis may result.

•HOST DEFENCES

1. The reaction to developing and adult worms results in endothelial cell proliferation and thrombus formation within the lymphatic vessels.

2. Some aspects of the wide disease spectrum seen in lymphatic filariasis can be correlated with host immune responses.

3. Individuals living in endemic areas and frequently bitten by infective mosquito vectors vary in clinical manifestations.

SPECIFIC CLINICAL SYMPTOMS

• The microfilariae are released into the blood. Infections involving small numbers of worms are often asymptomatic.

• Consist of intermittent fever and enlarged, tender lymph nodes may burst

• Swollen lymphatics and drain into the genitourinary system

• In a small number of chronic cases, permanent lymphatic dysfunction caused by repeated exposure to infection over a number of years results in the massive lymphedema and accumulation of excess tissue known as elephantiasis

DIAGNOSIS• Identification of microfilariae by microscopic

examination is the most practical diagnostic procedure

• It is important to time the blood collection with the known periodicity of the microfilariae. The blood sample can be a thick smear, stained with Giemsa or hematoxylin and eosin. For increased sensitivity, concentration techniques can be used.

• These include centrifugation of the blood sample lyzed in 2% formalin (Knott's technique), or filtration through a Nucleopore membrane.

•detection using an immunoassay for circulating filarial antigens constitutes a useful diagnostic approach, because microfilaremia can be low and variable.

* Molecular diagnosis using polymerase chain reaction is also possible.

*Identification of adult worms is possible from tissue samples collected during nodulectomies (onchocerciasis), or during subcutaneous biopsies or worm removal from the eye (loiasis).

Clinical Symptoms, Phase and Diagnosis• Lymphangitis, unfeelingness of skin portions; later:

chylurie, elephantiasis, i.e. giant swelling of organs • Incubation period : 3–16 months• Prepatent period: 7–24 months• Patent period: 8–10 years (adults live until 18–20 years)• Diagnosis: Microscopic analysis of smear preparations

or of membrane filtered material; microfilariae are found at 10 p.m. in the peripheral blood, serology

• Prophylaxis: Avoid bites of vector mosquitoes in endemic regions

TERAPHY AND TREATMENT

• Antibiotics to prevent secondary infections.

• Pressure bandages to reduce swelling. • Surgical removal of infected tissues to

improve lymph flow. • Chemotherapy to kill circulating

microfilaria. Diethylcarbamazine (Hetrazan), Metronidazole, Ivermectin

• Vector (intermediate host) control.

The therapical used in Communical Endemic filariasis:

Ivermectin: one dose oral: 100-400 meg/body weight

Diethylcarbamazine (DEC)

First day: 50 mgr/ peroral

second day: 50 mgr per oral tid

Third day : 100 mgr po tid

4th to 12 th: 6/mgr/BW in 3 dosis

Every one year : 6mgr/BW/ single dose

PLANNING OF CONTROL

• The approaches to the control of lymphatic filariasis were formerly based on the elimination of infection by treatment (diethylcarbamazine = DEC) and vector control for the prevention of infection.

• Both approaches were only marginally effective due to the poor macrofilaricidal activity of DEC and constraints of controlling Culex spp. in urban areas and Anopheles spp in the rural environment.

• Attempts to reduce the prevalence of lymphatic filariae include vector control and mass treatment campaigns using diethylcarbamazine citrate.

• This drug significantly reduces the level of microfilariae in the blood. However, it must be given over a prolonged period, and frequent side effects, such as fever, vertigo, headaches, nausea, and lymphatic inflammation, discourage patient cooperation. Ivermectin, a drug that has recently been shown to be effective in the treatment of onchocerciasis, is being evaluated for use in lymphatic filariasis.

• Combinations of diethylcarbamazine and ivermectin are being tested. In some areas single doses of these drugs in combination or singly are also being evaluated. Fewer side effects are experienced with the shorter treatments

•The control of lymphatic filariasis has been revolutionized by the finding that a single dose of ivermectin or DEC or both will eliminate microfilaraemia for several months due to an action against microfilariae and embryonic stages.

• With repeated dosing, once a year, microfilaraemia will not reach the level at which it could cause lymphoedema or elephantiasis.

EPIDEMIOLOGY• Geographic Distribution:

Among the agents of lymphatic filariasis, Brugia malayi is limited to Asia;

• The endemic range of Brugia malayi is confined to South and South-East Asia from India in the west to Korea in the east.Its distribution is dependent on its mosquito vectors. The nocturnally periodic form is found in areas with rice fields and the nocturnally subperiodic form is found in rural villages and plantations along the lower reaches of major rivers in swamp forests . Partono has proposed the subdivision of B. malayi into zoophilic and anthropophilic strains. The former is transmissible to cats, monkeys, and laboratory gerbils

• B malayi is found mainly in Southeast Asia. In contrast to W bancrofti, which is transmitted by mosquitoes of the three major genera, the principal mosquito vectors of B malayi belong to the genus Mansonia. B malayi is less host-specific than W bancrofti; it has been recovered from naturally infected monkeys, cats, and dogs, and has been maintained in several laboratory animals

Lymphoedema particularly of the legs and scrotum,

hydrocoeles and chyluria

WORLDWIDE EPIDEMIOLOGY

Recent Updates

Elephantiasis of legs due to Brugia malayi. The patient from a remote island in southwestern sea of Korea had suffered from recurrent painful swelling of both legs for more than 30 years, which resulted in elephantiasis finally.

SWOLLEN LEGS DUE TO Brugia malayi

SWOLLEN LEGS DUE TO Brugia malayi

SWOLLEN LEGS DUE TO Brugia malayi

Microfilaria of Brugia malayi. Perpheral blood thick smear and Giemsa srain, X

450.

Microfilaria of Brugia malayi Laboratory Identification of Parasities of Public Health

Concern

sheath

Brugia malayi

Collecting mosquito larvae from rock pools along the coast of the Heugsan Island, Korea. Aedes

togoi transmits filaria, Brugia malayi at the area.

Brugia timori

Pendahuluan

Geografis ditribusi di Indonesia: (dr. Taniawati Supali, Dep Par. FK. UI) Lymphatic filariasis

Sumatera dan kalimantan: jenis Brugia malayi.

Jawa, Papua dan Irjabar: jenis W. bancrofti

Maluku Utara, dan Sulawesi: campuran

B. malayi dan W. bancrofti.

Nusa Tenggara Timur diketemukan jenis :

Brugia timori dan W. bancrofti.

Penemuan

Mikrofilaria Brugia timori diketemukan pertama kali oleh David dan Edeson th 1964 thn 1965 baru di deskripsikan di ketemukan di Portugis Timor

Crus Ferreira: 1965Pinhao: 1969

Sri Oemijati dan Partono 1971Kanda et al: 1975

Kurihara dan Sri Oemijati : 1976

Cacing dewasa oleh Partono, Davit T Dennis dan Felix Partono: 1977

Hospes Perantara: Anopheles barbirostris

Di Flores: A. barbirostris (Soeroto)

Periodisitas: nokturnal

MorfologiSecara umum mikrofilaria Brugia

timori lebih mirip dengan mikrofilaria malayi ukuran: 310 µ dan badan lebih lebar

Cephalic space: a length-to-width of about 3:1

Nukleus atau inti pada ekor sebaris dan lebih banyak jumlahnya dibandingkan dengan B. malayi. Ada 2 inti ekor jelas

Di daerah Sulawesi Selatan banyak terdapat di daerah Desa Mangkuna, Kabupaten Luwu Timur.

Microfilaria Brugia timori

Cephalic-space

sarung

Microfikaria Brugia timori

Cephalic space=3;1

Ekor inti dua (2)

Gambar h:

Inti badan batas kabur dan overlapping

Rongga kepala panjang:lebar= 3:1

Rongga kepala

3:1

Inti badan

Gambar i: Inti ekor

Inti terminal

Inti subterminal ada 2

Kepala dan ekor Brugia timori

Pathofisiology: sama dengan Brugia

malayi.

Gejala klinis: Terjadi pembengkakan terutama di daerah lipat paha.

Diagnosis dan pengobatan: sama dengan Brugia malayi