Disease Vectors and Pathogens

Tuberculosis is a disease caused by the bacterium Mycobacterium tuberculosis. Influenza is caused by Haemophilus influenzae.  The infected person coughs and sneezes. These diseases are transmitted through the air droplets while sneezing and coughing. The causative agent survives in the air droplets and through the air, the disease is transmitted to the other person. 

The organisms or agents which are responsible for the development of a disease or any infection is known as a pathogen. The ability of the organism to cause disease is pathogenicity. The microbes like the virsues, bacteria, and fungi are known as the pathogens which cause a certain type of infection. 

Rabies is a major public health problem in India. The disease occurs in all parts of the country except Lakshadweep islands because of lack of dogs (vector of rabies virus) in that particular region. About 7-10 thousand cases are reported every year. About 30,000 persons contract rabies and die; more than 2 million people are exposed to animals every year and about 1 million are administered anti-rabies vaccines.

The diseases, which spread from one person to another person or from animal to person are called as communicable diseases. It is also termed as infectious or contagious diseases. Housefly is a major factor in contributing communicable diseases. Housefly comes in contact with waste products and eatables. When it flies from wastes to eatables, it transports bacterial agents from wastes to eatables. Due to consumption of such eatables, the persons infected with microbes of various diseases, person gets sick. 

House flies are the vectors of several infectious agents. The pathogen may attach with flies when they sit on the waste materials. They cause typhoid, cholera, salmonellosis, dysentery, tuberculosis, anthrax, and parasitic worms carried to human food on the fly’s body parts or in its regurgitations or defecations.

Houseflies are considered mechanical vectors because they carry pathogens on their bodies and legs, transferring them directly to food or surfaces, rather than the pathogen undergoing a developmental cycle within the fly.

Tropical diseases encompass all diseases that occur solely, or principally, in the tropics. In practice, the term is often taken to refer to infectious diseases that thrive in hot, humid conditions, such as malaria, leishmaniasis, schistosomiasis, onchocerciasis, lymphatic filariasis, Chagas disease, African trypanosomiasis, and dengue.

Tsetse, sometimes spelled also known as tik-tik flies, are large biting flies that inhabit much of tropical Africa. The bite leads to transmission of sleeping sickness and nagana.

Rupture of RBC result in septicemia because of release of hematite granules in the blood resulting in characteristic chills and high fever.

Elephantiasis is caused by parasitic filarial worms (nematodes), whereas the other diseases listed are caused by protozoan protists.

Kala-azar known as Black Fever is caused by sandfly bites which exhibits the symptoms of fever, weight loss, enlargement of liver and spleen. If it is not treated at the early stage it proves to be the fatal which could take life of the infected person.

Diseases that are caused due to drinking of contaminated water are called waterborne disease. It is caused due to the presence of certain pathogens in water such as protozoan. Diarrhea is the most common waterborne disease that occurs in children. Dehydration, pale skin, loose motions, bloody stools, etc are the symptoms of diarrhea. Amoebiasis is a parasitic infection of intestines, the symptoms of which are diarrhea, fatigue, abdominal discomfort and flatulence, etc

Housefly feed on waste, excreta, and garbage which contains the infectious disease-causing germs. Houseflies became the carrier of these pathogens and they get entered in our body through the food we eat or water we drink since houseflies feed and sit on eatable items.