Angola August 25, 2005 23:54 GMT
Increasing numbers of polio cases reported
As of August 23, seven cases of polio have been reported in Angola, a nation that has been free of the disease since 2001.
The first patient, from Luanda, fell ill in April 2005. The latest case, who lives in Benguela, developed symtpoms in early July. Cases have been reported from the provinces of Luanda, Lunda Sul, Moxico, Bengo, and Benguela. Cases are genetically linked to a strain of polio identified in northern India in 2004, and are thought to have been imported from there.
Angola completed a nationwide polio vaccination campaign in late July, a second is scheduled for late August, and a third round will take place in September. A synchronised campaign in DRC is being considered. Health authorities are considering using a combination of monovalent oral polio vaccine (mOPV) in the Luanda area and trivalent oral polio vaccine in the rest of the country to maximize results from the campaign. Surveillance efforts have been increased and neighboring nations have been notified about the case.
International health agencies had hoped to declare the world polio-free by December 2004. However, due to the re-infection of several African countries, the goal has been pushed back to December 2005. Polio remains endemic, or consistently present, in six countries in the world: Nigeria, India, Pakistan, Niger, Afghanistan and Egypt. The virus has re-established transmission in an additional five countries: Burkina Faso, Central African Republic, Chad, Cote D'Ivoire and Sudan. Cases were also recently reported in Ethiopia, Yemen and Indonesia.
Other countries that reported cases in 2004 were Saudi Arabia, Cameroon, Guinea, Mali, Benin and Botswana. These renewed outbreaks are linked to Nigeria, where vaccination was temporarily suspended from mid-2003 to mid-2004 due to local beliefs that the vaccine was harmful. Mass polio immunization drives are now being staged across Africa in an effort to eradicate the disease.
The Disease
In developing countries, the polio virus is often spread through food or water that has been contaminated with infected feces. In countries with higher sanitation levels, the disease is usually transmitted via respiratory droplets coughed by an infected person.
Initial symptoms include fever, headache, nausea and vomiting. The virus mainly affects children under five and will reach the central nervous system of approximately one out of every 100 patients, causing some form of paralysis.
International SOS Comment
SOS recommends that travelers visiting Angola be fully immunized against polio.
Primary vaccination
Primary vaccination against polio is usually given in childhood. Vaccination consists of four doses of oral (OPV) or injected (IPV) vaccine. In the United States, only IPV is used.
Travelers who have had a primary vaccination
Adults who have received a primary series with either IPV or OPV during childhood should have another dose of vaccine. This will give life-long immunity.
Travelers with uncertain or no immunity
Adults who are unvaccinated or uncertain of their vaccination status should be vaccinated before traveling.
Two doses of vaccine should be administered four to eight weeks apart. A third dose should be administered six to 12 months after the second dose.
Adult accelerated schedules
- If eight weeks or more remain before travel: give three doses, each separated by four weeks.
- If four to eight weeks remain before travel: give two doses, each separated by four weeks.
- If less than four weeks remain before travel, give one dose of vaccine.
In all cases, the remaining doses should be given later at the recommended intervals.
