After a 10-year absence, Namibia has witnessed a sudden reappearance of polio, with 34 suspected cases and seven deaths recorded so far. The recent outbreak has been confirmed in five of the country’s 13 regions, but most cases have occurred in and around the capital, Windhoek.
Three of the 34 suspected cases of sudden paralysis are under investigation; three have been positively identified as polio. The majority of these cases involve people over 20 years of age, which is highly unusual. The polio virus is more likely to cause paralysis in adults than in children, and leads more often to death in older people.
Data gathered so far suggest that the adults affected by the Namibia outbreak had not been immunised, or were under-immunised, against polio. Since the disease mostly affects young children, vaccination campaigns typically target the population under the age of five rather than a country’s entire population.
The outbreak has been expanding at a worrying rate. ”The fear is that it is spreading so quickly,” said the United Nations Children’s Fund’s (Unicef) representative in Namibia, Khin-Sandi Lwin.
”Going from one case to 34 cases within a two-week period, it’s quite alarming,” she continued. ”Because it’s a population-wide issue, the whole population of the country needs to be immunised. It’s a small population in a very vast country, so we have to go out to every small community that’s spread out throughout the country.”
Unicef is working with Namibia’s national health authorities to plan an immediate response.
”Right now we’re raising the procurement for about five million polio vaccines, and that will be for two rounds of polio immunisation” said Lwin. ”We’re helping the government gear up for door-to-door vaccination along with outreach to the far, far corners of the country, as well as fixed-site vaccinations in the cities and towns.”
About 1 500 teams of vaccinators and 1 800 vehicles will be required to carry out this massive exercise.
Experience in outbreak response has shown that quick and repeated vaccination campaigns reaching the target population are highly effective. With such intervention, most outbreaks are stopped within six to 12 months.
The origin of the outbreak in Namibia has not yet been determined. But according to the World Health Organisation, the virus may have come from neighbouring Angola, which reported its most recent case of polio in November last year. As long as the virus circulates anywhere, all countries face a risk of importation.
Namibia has a functioning routine immunisation programme and meets international standards of surveillance for acute flaccid paralysis, a sign of polio.
The Global Polio Eradication Initiative has reduced the worldwide incidence of the disease by 99% since 1988; at present, however, the initiative faces a funding gap of $85-million for this year and a further $400-million for 2007 and 2008.
”Unicef has to support the government very quickly but our funding is very limited, so the first thing on the agenda is to raise the funds for the vaccines and for a major logistical operation,” explained Lwin.
The first round of polio immunisation in Namibia, vaccinating people of all ages, is planned for June 27 to 29. A second round, also covering all ages, will occur a month later from July 25 to 27, and a final round focusing on children under five will take place on from August 22 to 24.