Flies

There are many types of flies that are important in causing human disease. We will discuss some here but note that this is not inclusive of all flies that can be clinically important. Some are ectoparasites. Others are important vectors of parasites, bacterial pathogens, and viral pathogens.

Musca domestica (common house fly)

Musca domestica (adult) and larvae removed from the lung of a patient with pulmonary myiasis (see video below)

One of a number of live maggots retrieved from lung fluid aspirated from a patient in a long term care facility that had developed respiratory difficulty – video by W. Vientos

The common house fly is perhaps the most familiar of the flies. It is a mechanical vector of bacterial, viral, and parasitic diseases. The common house fly is also known to cause myiasis, a parasitic infestation by the larvae of the fly. Generally the eggs are laid in exposed or compromised body tissue. The eggs hatch releasing numerous larval stage flies or maggots. These maggots will feed on damaged tissue and eventually develop into mature flies. Maggots can be introduced into unusual host sites such as the lungs of patients that have been incapacitated for an extended length of time (elderly patients that are bed ridden are at risk).

Tsetse Fly (Glossina Species)

Tsetse Fly illustration by W. Vientos

The Tsetse Fly is an important vector of African Sleeping Sickness. The genus name is Glossina and there are multiple species present in the genus that will transmit the parasite.

The Sandfly (genus Lutzomyia and Phlebotomus)

Sandfly illustration by W. Vientos

The name Sandflies include a large variety of flies and is generally used to describe any number of species or genus of biting blood sucking flies found mostly in sandy areas. In the world of parasitology the most important of the Sandflies transmitting parasites are those of the genus Lutzomyia and Phlebotomus.

Botfly

Botfly illustration by W. Vientos

Life Cycle of the Botfly