Yellow Fever looks a lot like dengue haemorrhagic fever and is transmitted by Aedes Aegypti mosquitoes. It also affects monkeys and other vertebrates and is caused by a virus called Flavivirus Fibricus.
Yellow Fever [Illustration by Anup Singh]
But, if you have had it once, you are done with it. One attack will give you life long immunity. Infants born to mothers, who are immune to the disease, inherit antibodies that last up to six months of life.
Yellow fever is more prevalent in Africa, the tropical forests of America, Bolivia, Brazil, Colombia and Peru. The virus breeds at a temperature of about 24 degrees Celsius.
Symptoms:
The disease lasts for about three to six days and could range from being clinically indeterminate to severe. Some cases develop jaundice and have haemorrhagic manifestations such as black vomiting, black stool, bleeding from the nose, restlessness and decrease in urine output, and may slip into a coma. What is scary about the disease is that the fatality rate is as high as 80 per cent.
Control:
Fortunately, India is yellow fever-free, though it has all the conditions that is congenial for the virus to thrive. The Aedes Aegypti mosquito is found in abundance and the climatic conditions are just right for the virus to survive.
Besides, most people in India are not vaccinated and are succeptible to yellow fever. If the virus is transported here with an infected person, it would not take long before people here begin falling prey to the virus.
The only way to stay away from it is by keeping our houses and surroundings mosquito-free and by ensuring that all international travellers are checked and vaccinated.
A single dose of a vaccine can be administered to children after they are a year old. This imparts an immunity, which begins to activate after seven days of vaccination, and lasts for more than 35 years, and sometimes for life.
However, the World Health Organisation recommends revaccination every 10 years, especially if you do a lot of international travelling.
