Yellow FeverJuly 9th, 2008 - 11:12 am ICT by Amrit Rashmisrisethi
Yellow fever is a viral haemorrhagic infection. It is common in tropical Africa and Latin America. Yellow fever (YF) is caused by virus. Its importance lies in its virulence and also an increasing incidence among travelers to the endemic areas.
Yellow fever is spread by mosquitoes which feeds on wild animals infected with the YF virus and these mosquitoes transfer the infection to people who are in the jungle.
Just a bite from an infected mosquito, the virus multiplies at the site of the bite and spreads to adjacent lymph nodes, liver, spleen, bone marrow and heart muscle. The virus is found in the bloodstream during the incubation period of three to six days and the early stages of the illness.
The onset of illness is fever, chills, headaches, backache, muscle aches, nausea, vomiting, congestion of the face and eyes and a slow heart beat. The fever lasts three to four days.
The illness progresses in about 15%. There is fever, vomiting, upper abdominal pain, yellowness of the eyes.
About 30 to 50% of those with liver/kidney failure die a week or so after the onset of illness.
The World Health Organization (WHO) estimates that the risk of YF infection to a non vaccinated person entering an endemic area in Africa is one in 267 and the risk of death is one in 1,333. The risks in Latin America are 10 times lower.
There are estimated to be more than 10 million travelers to endemic areas, the incidence of imported cases of YF in non-endemic countries is low because of high YF vaccination rate among travelers.