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Dr. Ghada M. El-Bassiony Ass. Professor Department of Entomology Medical Entomology Can be defined as the study of insects, insectborne disease and other associated problems that affect human and public health Veterinary Entomology Can be defined as the study of insects, insectborne 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, louseborne 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 transmission 2- biological transmission Propagation or multiplication Cyclo-propagation Cyclo-developmental without propagation 1- mechanical 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 vectors 1- 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 nematoda Gongylonema 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 adults Most 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