Communicable Diseases

Question 1

Agent causing yellow fever

Answer 1

Flavivirus fibricus

Question 2

Reservoirs of yellow fever

Answer 2

Forest:Monkey’s and forest mosquitoes
Urban: Man and Mosquitos

Question 3

Host Factors that can influence uptake of yellow fever

Answer 3

Age
Sex
Occupation:wood cutters
Immunity: 1 attack gives life long immunity

Question 4

Environmental factors that influence the development of yellow fever

Answer 4

•Climate: Temp of 25 degrees or more, humidity 60% favours disease uptake
•social factors: urbanisation, long travels, living close to jungles

Question 5

Period of communicability of yellow fever

Answer 5

Man:3-4 days
Mosquitoes:Life

Question 6

Mode of transmission:
1. Jungle cycle
2.Urban cycle

Answer 6

1.Reservoir: Monkeys
Vector: Aedes aegypti
2.Reservoir: Man
Vector: Aedes aegypti

Question 7

Incubation period of yellow fever

Answer 7

3-6 days

Question 8

Control of yellow fever
A. Jungle
B. Urban

Answer 8

A. Vaccination with 17 D vaccine
B.
1.vaccination: 17 D vaccine 0.5 ml S/C
2.Control of vector (mosquitoes)
3. Surveillance

Question 9

Why are international measures required for yellow fever

Answer 9

1.Pakistan is yellow fever receptive area where yellow fever is not present but conditions that favour its development are present
2.unvaccinated population
3.vector and reservoir present in abundance
4.Environmental factors that favour its development
5.only disease agent absent

Question 10

Control measures for yellow fever

Answer 10

Travellers from endemic areas should carry certificates showing they are vaccinated at least 10 days before coming here
.if they can’t produce certificate quarantine for 6 days
Aircrafts/ships from endemic areas should be sprayed with insecticides
Airports kept free from breeding sites
Vaccination of travellers to endemic areas