Q.100 Which one or more of the following parasites is/are typically transmitted by
mosquitoes as vector?
(A) Leishmania donovani
(B) Plasmodium vivax
(C) Wuchereria bancrofti
(D) Trichuris trichiura

Plasmodium vivax and Wuchereria bancrofti are typically transmitted by mosquitoes as vectors.​

Option Analysis

(A) Leishmania donovani causes visceral leishmaniasis (kala-azar) and transmits via phlebotomine sand flies, not mosquitoes. Sand flies bite at dusk and deposit promastigotes into the skin.​

(B) Plasmodium vivax causes benign tertian malaria and spreads through female Anopheles mosquitoes. Sporozoites from salivary glands enter the bloodstream during bites, targeting liver cells.​

(C) Wuchereria bancrofti causes bancroftian filariasis and uses mosquitoes like Culex, Anopheles, and Aedes. Microfilariae ingested during blood meals develop into infective larvae in the vector.​

(D) Trichuris trichiura (whipworm) transmits via fecal-oral route through embryonated eggs in contaminated soil or food, requiring no vector. Eggs hatch in the intestine after ingestion.​

Correct Answer

Options (B) and (C).​

Introduction to Parasites Transmitted by Mosquitoes

Mosquitoes serve as key vectors for parasites transmitted by mosquitoes as vector, spreading diseases like malaria and filariasis worldwide. In competitive exams like CSIR NET Life Sciences, identifying vectors for parasites such as Plasmodium vivax, Wuchereria bancrofti, Leishmania donovani, and Trichuris trichiura tests core parasitology knowledge. Understanding these transmission modes aids prevention strategies in endemic areas like India.​

Detailed Transmission Mechanisms

• Plasmodium vivax (Malaria): Anopheles mosquitoes inject sporozoites during bites; these invade hepatocytes, causing relapsing infections due to hypnozoites. Over 50% of malaria cases outside Africa involve P. vivax.​

• Wuchereria bancrofti (Filariasis): Culex and other mosquitoes uptake microfilariae from blood, maturing them into L3 larvae over 10-14 days for skin transmission. Affects 120 million globally, mainly in tropics.​

• Leishmania donovani (Kala-azar): Phlebotomus sand flies transmit amastigotes-to-promastigotes; no mosquito role despite co-endemicity. Visceral form targets spleen and liver.​

• Trichuris trichiura (Whipworm): Soil-transmitted helminth; eggs embryonate in moist soil (2-3 weeks) before fecal-oral uptake. Prevalent in poor sanitation areas, infects 500 million.​

Exam-Relevant Insights for CSIR NET

Questions on parasites transmitted by mosquitoes as vector often appear in Unit 5 (Developmental Biology & Vectors). Differentiate protozoans (Plasmodium: mosquito) from helminths (Trichuris: direct). Vector control via nets and insecticides targets mosquito-borne ones effectively.​