Dr. Ghada M. El-Bassiony

Ass. Professor

Department of Entomology

Medical Entomology

Can be defined as the study of insects, insect-

borne disease and other associated problems that

affect human and public health

Veterinary Entomology

Can be defined as the study of insects, insect-

borne disease and other associated problems that

affect domestic animals.

Medical-veterinary arachnology

Medical-veterinary acarology

Insect-borne diseases of human influenced

human history (yellow fever, plague, louse-

borne typhus)

Also arthropods have greatly influenced

animal production and husbandry practices

The insect or arthropod, with any medical

importance, may be one of the three following

cases:

1- the causal agents themselves or the pathogens

(scabies & pediculosis)

2- the vector of pathogens (malaria)

3- developmental transfer hosts (for some

helminthes parasites)

Zoogeographical regions

It’s useful to be able to describe the distribution of

an insect or a disease by reference to these regions

rather than national boundaries and names.

The World Wide Fund for Nature (WWF): is an

international non-governmental organization founded on

April 29, 1961, and is working on issues regarding the

conservation, research and restoration of environment.

Modes of transmission

Vertical transmission:

parasites transmit by vectors within vector populations

1- transstadial transmission: sequential passage of

parasites acquired during one life stadium to the

next (mites &hard ticks) e.g. lime disease,

spirochetes

2- transgenerational transmission: occurs

transovarially - parasites infect the ovarian germinal

tissues

3- ventral transmission (La Cross virus by A.

triseriatus)

Horizontal transmission:

represents the role of the arthropod in the life cycle of the parasite 1- mechanical transmission

2- biological transmission

Propagation or multiplication

Cyclo-propagation

Cyclo-developmental without propagation

Differences between biological and mechanical

transmission

1- duration of the vector infectivity

2- character of the pathogen not the insect vectors

The pathogen the vertebrate host

insect

vector

ex: (malaria)

Many diseases have a forth component reservoir host

Several Biting Flies and Reduviid Bugs carry

infective stages of disease causing

pathogens. They are responsible for

spreading diseases like:

Malaria (Mosquitoes in genus Anopholes)

Plague (Rodent Fleas)

West Nile Virus (Mosquitoes)

Typhoid/Cholera/Dysentary (Muscid Flies)

Medical importance

of cockroaches

As vectors1- Blattela germanica

Acquire specific bacteria

and depositing it on food

2- they may be chronic

carriers.

3- experimentally they can

harbor pathogens.

As developmental hosts

of parasites

1- eye worm of poultry

2- the nematoda

Spirura gastrophiala of rats

3- the nematodaGongylonema neoplasticum

of rats

As allergy cause

Extracts give positive skin

test in allergic patients

and normal persons

Adult moths may feed on lachrymal secretions of wild or domestic mammels.

If the proboscis is contaminated with pathogenic bacteria, mechanical transmission may occur.

Larvae may produce allergens.

Mechanical vectors

Carry pathogens on

their bodies or their

digestive tract or moth

parts

May carry dysentery

germs or may

contaminate surgical

objects with bacteria

As developmental hosts of

parasites

Formica serve as a second

developmental host of

little liver fluke of sheep

(a trematode), the first

being a snail.

Making food inaccessible in case of pests

ants.

Isolation of sterile materials.

Using toxic baits.

JHA

Pesticides

Order Coleoptera

Adults feed on

decaying organic

matter or on plants

May be found on

vegetation during

the day

Attracted to bright,

white light at night

A- Some beetles secrete cantharidin

(e.g. blister beetles)

Hemolymph contains compounds

that cause a vesicating dermatitis

on contact with the skin

Resulting blisters are painful, but

do not require emergency

treatment

Contact with eyes may result in

severe debilitation

Large numbers of cases may

occur at the same time

Sometimes mistaken for chemical

agent injury

B- canthariasis and

scarabiasis

---------------------------

Invasion of body tissues

by beetles larvae or

adultsMost clinical cases involve enteric

canthariasis.

C. Annoyance by beetles

A- ingestion of toxic

beetles

-------------------------

Horses that ingest

quantities of these

beetles are

especially

susceptible to

cantharidin

poisoning.

B. mechanical vectors

of animal

pathogens.

C- intermediate hosts

of parasites like

cestodes,

trematodes and

nematodes.

Immediate wash skin surface

Proper wearing of the uniform in vegetation and

at night around lights

If one lands on you, blow it off, don't crush it

Pesticides out doors and are most beneficial

when applied to soil