Q.47 Yellow fever is caused due to the human-to-human transmission by-
1. Aedes aegypti
2. Culex
3. Dermacentor andersoni
4. Mycobacterium tuberculosis
Yellow fever spreads human-to-human via Aedes aegypti mosquitoes, the primary urban vector for this flavivirus.
Yellow Fever Transmission Overview
Yellow fever virus (flavivirus) cycles between mosquitoes and primates (monkeys/humans); urban human-to-human transmission occurs when infected Aedes aegypti bites viremic humans and feeds on others.
Sylvatic cycles use forest Haemagogus; Aedes drives outbreaks in tropics.
No direct human spread; mosquitoes bridge infections.
Correct Answer: 1. Aedes aegypti
Aedes aegypti is the key domestic vector, thriving in urban water containers, transmitting YFV during blood meals from infected to susceptible humans.
Efficient urban amplifier; vaccine and control target it.
Option Breakdown
| Option | Vector Type | Explanation | Correct? |
|---|---|---|---|
| 1. Aedes aegypti | Mosquito | Primary urban vector for human-to-human YFV spread via bites. | Yes |
| 2. Culex | Mosquito | Transmits West Nile/filariasis; poor YFV vector, lacks competence. | No |
| 3. Dermacentor andersoni | Tick | Rocky Mountain tick; no role in YFV (mosquito-only). | No |
| 4. Mycobacterium tuberculosis | Bacterium | Causes TB via respiratory droplets; not vector-borne or YFV agent. | No |
Cycle Details
Urban cycle: Aedes aegypti perpetuates human outbreaks; sylvatic uses Haemagogus on monkeys.
Prevention: vaccines, repellents, eliminate breeding sites.
