A 32-month-old girl living near Mogadishu was recently paralysed by wild poliovirus, the World Health Organization (WHO) announced on 11 May. It is Somalia’s first case caused by wild poliovirus since March 2007.
Polio immunization campaigns have not occurred in some central and southern parts of the strife-torn nation since 2009. Beginning 14 May, the country plans to vaccinate 350,000 children living in the Banaadir region, where the infection occurred. A nationwide immunization campaign is “under discussion”, according to the WHO.
Genetic testing to determine the virus’s origin is underway and should be complete this week, according to a WHO representative.
Only Pakistan, Afghanistan and Nigeria have never interrupted wild poliovirus transmission, and until now those three countries were the only ones that had recorded wild poliovirus cases in 2013 — 26 versus 53 this time last year. Chad and Niger recorded wild polio infections in 2012.
Meanwhile, Pakistan’s rugged North Waziristan region recorded its first polio case since local Taliban leaders halted vaccinations there last year. The ban was a response to US drone strikes in the mountainous region (see ‘Taliban halts polio vaccination over drone strikes’). The infection was caused by a vaccine-derived strain of poliovirus. The vaccine can cause polio when its strains mutate into pathogenic forms, but this occurs only in extremely rare cases in populations where immunity is low.
Update 15 May 2013
Genetic now testing suggests that the polio virus in Somalia is linked to viruses circulating in Northern Nigeria, according to a WHO representative. For more on polio in Nigeria, see our recent feature Polio’s moving target.
Update 22 May 2013
A four month old girl in eastern Kenya was paralyzed by wild polio virus, the WHO announced today. Two close contacts have also tested positive for the virus (most children infected with polio virus do not develop paralysis, but shed infectious virus in their faeces). Kenya last recorded a polio case in July 2011. In a release, WHO said there is a very high risk that polio outbreak would spread to other countries in the Horn of Africa, because of low vaccine immunity and extensive population movement in the region.