Disease Vectors

Definition

Living organisms, usually insects, that carry and transmit disease-causing pathogens from one host to another without themselves causing the disease.

Key points

• The female Anopheles mosquito transmits malaria (a protozoan parasite, Plasmodium), while the Aedes (aegypti) mosquito transmits dengue, chikungunya, and Zika.
• The Culex mosquito transmits filariasis and Japanese encephalitis; mosquitoes are the most important disease vectors in India.
• Houseflies spread cholera, typhoid, and dysentery by contaminating food; the sandfly transmits kala-azar (visceral leishmaniasis); tsetse flies (in Africa) transmit sleeping sickness.
• Ticks, fleas, and lice are also vectors: fleas carried plague (from rats to humans) and lice transmit typhus.
• Vector control measures include eliminating stagnant water (mosquito breeding sites), insecticide spraying, bed nets, and improved sanitation; many vector-borne diseases peak in the monsoon.

Why it matters for CAPF

Matching vectors to diseases (Anopheles to malaria, Aedes to dengue, sandfly to kala-azar, fleas to plague) is a high-frequency public-health question, and vector control matters for troops deployed in endemic field areas.

Common confusion

The female Anopheles spreads malaria, but Aedes (not Anopheles) spreads dengue and chikungunya; mixing up the two mosquitoes is the most common error. The vector carries the pathogen but is not the cause; malaria is caused by the Plasmodium parasite, not by the mosquito itself.

Related concepts

concept vaccines and immunity, concept types of immunity, concept antibiotics vs antivirals

Parent note

diseases and public health