What is Vector Borne Disease?
Vector-borne diseases are human illnesses caused by parasites, viruses, and bacteria that are transmitted by mosquitoes, sandflies, triatomine bugs, black flies, ticks, tsetse flies, mites, snails, and lice. Every year there are more than 700 000 deaths from diseases such as malaria, dengue, schistosomiasis, human African trypanosomiasis, leishmaniasis, Chagas disease, yellow fever, Japanese encephalitis, and onchocerciasis, globally.
The major vector-borne diseases, together, account for around 17% of all infectious diseases.
List of prevalent Vector-Borne Diseases in India
A) Malaria – Malaria is a potential life-threatening parasitic disease caused by parasites from Plasmodium viviax (P.vivax), Plasmodium falciparum (P.falciparum), Plasmodium malariae (P.malariae) andPlasmodium ovale (P.ovale)
- It is transmitted by the infective bite of Anopheles mosquito
- Man develops the disease after 10 to 14 days of being bitten by an infective mosquito
- There are two types of parasites of human malaria, Plasmodium vivax, P. falciparum, which are commonly reported from India.
- Inside the human host, the parasite undergoes a series of changes as part of its complex life cycle. (Plasmodium is a protozoan parasite)
- The parasite completes life cycle in liver cells (pre-erythrocytic schizogony) and red blood cells (erythrocytic schizogony
- Infection with P.falciparum is the most deadly form of malaria.
B) Kala-Azar – Kala-azar is a slow progressing indigenous disease caused by a protozoan parasite of genus Leishmania.
The parasite primarily infects the reticuloendothelial system and may be found in abundance in bone marrow, spleen, and liver
C) Filaria- Filariasis is caused by several round, coiled and thread-like parasitic worms belonging to the family filaridea. These parasites after getting deposited on skin penetrate on their own or through the opening created by mosquito bites to reach the lymphatic system.
D) Japenese Encephalitis – Japanese Encephalitis is a viral disease caused by female mosquitoes mainly belonging to Culex.
JE virus infection may result in febrile illness of variable severity associated with neurological symptoms ranging from a headache to meningitis or encephalitis. Symptoms can include a headache, fever, meningeal signs, stupor, disorientation, coma, tremors, paralysis (generalized), hypertonia, loss of coordination, etc.
E) Dengue- Dengue is a viral disease
- It is transmitted by the infective bite of Aedes Aegypti mosquito
- Man develops the disease after 5-6 days of being bitten by an infective mosquito
- It occurs in two forms: Dengue Fever and Dengue Haemorrhagic Fever(DHF)
- Dengue Fever is a severe, flu-like illness
- Dengue Haemorrhagic Fever (DHF) is a more severe form of the disease, which may cause death
- A person suspected of having dengue fever or DHF must see a doctor at once