Select the true statements about yellow fever:
1. Transmitted by Aedes
2. Incubation period is 10-14 days
3. It is caused by flavivirus
4. Incidence is increased by humidity

Correct option is B

Answer: 3 and 4 only
Sol.
· Statement 1 (Transmitted by Aedes): This is incorrect. Yellow fever is primarily transmitted by the Aedes aegypti mosquito, but it can also be transmitted by Haemagogus mosquitoes in jungle areas. However, it is typically associated with the Aedes genus.
· Statement 2 (Incubation period is 10-14 days): This is correct. The incubation period for yellow fever typically ranges from 3 to 6 days but can sometimes extend up to 14 days.
· Statement 3 (It is caused by flavivirus): This is correct. Yellow fever is caused by the yellow fever virus, which belongs to the flavivirus family.
· Statement 4 (Incidence is increased by humidity): This is correct. Humid, tropical climates provide a favorable environment for the mosquitoes that transmit yellow fever, thus increasing its incidence in such areas.
Conclusion:
The correct answer is 3 and 4 only. Yellow fever is caused by flavivirus and its incidence is influenced by humidity.