In a Word document, please answer the questions below with short responses (3 to
ID: 86506 • Letter: I
Question
In a Word document, please answer the questions below with short responses (3 to 5 sentences will suffice for each question asked):Describe how vectors play a role in the transmission of disease.In what respects is leishmaniasis a vector-borne disease? Name some of the countries in the world where leishmaniasis is endemic and state why the disease is of particular concern to US military personnel.What are arboviral encephalitides? Describe the reservoirs and modes of transmission of this group of diseases to humans.
Explanation / Answer
1. The infectious diseases are transmitted through living organisms either humans or animals are called vectors. Those are mainly mosquitoes, insects, flies etc., Vectors can transmit infections through biological or mechanical
Biological: These can carry the pathogens that can multiply within their body and delivered to new host by biting
Eg: Anopheles - Malaria
Mechanical: In this the vector carries the infection agents on outside of their bodies.
2. Leishmania infantum is a protozoan parasite causes Leishmaniasis, the infection is transmitted to human beings through the bite of an infected female sandfly. There are several forms of leishmaniasis, most common are cutaneous leishmaniasis (skin sores) and visceral leishmaniasis affects several internal organs (usually spleen, liver, and bone marrow). Leishmaniasis is an example of biological vector transmitting disease. The life cycle of the transmission of the leishmania -
1. The sandflies inject the infective stage, metacyclic promastigotes, during blood meals
2. Metacyclic promastigotes that reach the puncture wound are phagocytized by macrophages
3. transform into amastigotes
4. Amastigotes multiply in infected cells and affect different tissues, depending in part on which Leishmania species is involved
5. These differing tissue specificities cause the differing clinical manifestations of the various forms of leishmaniasis.
6. In the sandfly's midgut, the parasites differentiate into promastigotes
7. Which multiply differentiates into metacyclic promastigotes and migrates to the proboscis.