A local doctor has warned people planning to travel to the Caribbean, or certain South American or African countries, that they must be vaccinated against yellow fever.
A local doctor has warned people planning to travel to the Caribbean, or certain South American or African countries, that they must be vaccinated against yellow fever.
This follows the announcement by the Department of Health that they will clamp down on people arriving from countries in the so-called Yellow Fever Belt – areas where the disease is prevalent – without a valid yellow fever vaccination certificate.
Those travellers will either be refused entry, kept under observation for six days, or vaccinated against yellow fever – all at their own cost. According to the World Health Organisation, nearly all major urban centres in the American tropics have been reinfested with the types of mosquito that spread the disease, and most urban dwellers are vulnerable because of low immunity to it.
Yellow fever, mentioned in historical texts dating as far back as 400 years, is a viral disease transmitted by the infected females of several species of mosquito, including the aedes Aegypti and haemagogus species.
According to a local doctor, Barbara Bull, the disease has an incubation period of three to six days and the symptoms come in two phases. The acute phase, with fever, back pain, headache, anorexia and vomiting, is followed by a toxic phase, with abdominal pain and vomiting, continued fever and jaundice – hence the name yellow fever.
Patients can bleed from the mouth, nose, eyes and stomach. Of those who suffer the toxic phase, half will die within 10 to 14 days and the rest will recover without persisting organ damage. The yellow fever virus is transmitted in two consecutive cycles involving monkey and human hosts, and mosquitoes, according to the website of the North Dakota Department of Health (http://www.ndhealth.gov).
In the first cycle, the virus is transmitted by the mosquito Aedes africanus and other Aedes mosquitoes (in Africa) or by Haemogogus mosquitoes (in the Americas); monkeys serve as its reservoir, and the primary humans infected are those who enter deep forests and jungles.
In the second cycle, the domestic mosquito Aedes aegypti, which lives in close relationship with humans, may transmit the virus, with humans being the sole hosts in the cycle. According to the website, an epidemic is established when an individual infected in the first cycle passes the virus to Aedes aegypti, which spreads the infectious agent to any urban dweller in the second cycle.
These mosquitoes have adapted to living among humans in cities, towns and villages. They breed in discarded tyres, flower pots, oil drums and water storage containers, close to human dwellings.
The World Health Organisation has estimated that there are approximately 200 000 cases of yellow fever a year worldwide, with 30 000 deaths. It is endemic in 11 countries in South America and more than 30 countries in sub-Saharan Africa.
Treatment for yellow fever is symptomatic and there is no specific remedy. Settlers Hospital manager Bongiwe Moyake said there had been no reported cases of yellow fever at the hospital. At the time of going to print, Doctor Bull was the only doctor in Grahamstown offering this vaccine. It costs R400 and she said the vaccine had to be administered 10 days before travelling to high-risk areas.
The yellow fever certificates were valid for 10 years, she said, beginning 10 days after the date of vaccination.
For more information, call the vaccine helpline, 0860 160 160, or visit your nearest travel clinic. Dr Bull can be contacted at 046 636 2063.
Additional source: http://www.ndhealth.gov (website of the North Dakota Department of Health).
Countries in the Yellow Fever Belt: Angola, Kenya, Burundi, Liberia, Benin, Mali, Burkina Faso, Mauritiana, Cameroon, Niger, Central African Republic, Nigeria, Chad, Congo, Equitorial Guinea, Sierra Leone, Ethiopia, Somalia, Gambia, Sudan, Gabon, Rwanda, Guinea, Tanzania, Guinea-Bissau, Togo, Ghana Uganda, Ivory Coast, Zaire, Argentina, Bolivia, Guyana, Brazil, Panama, Colombia, Peru, Ecuador, Surinam, French Guyana, Venezuela
