Poliovirus in Cameroon – update


WHO has reported further cases of wild polio virus in Cameroon. Three additional wild poliovirus type 1 (WPV1) cases have been reported with onset of paralysis during the month of January from three new regions (North West, Adamaoua, and Centre). The identification of these cases indicates continued WPV transmission and geographic expansion of infected areas following detection of four cases in October 2013.

In total, seven WPV1 cases have now been reported from West, North West, Centre and Adamaoua Regions, with onset of paralysis ranging from 1 October 2013 to 31 January 2014. Genetic sequencing of WPV1 isolates suggests prolonged undetected circulation of poliovirus. Due to continued poliovirus circulation in Cameroon, gaps in surveillance, and influx of vulnerable refugee populations from Central African Republic, WHO is elevating the risk assessment of international spread of polio from Cameroon to very high.

Implemented control measures
Cameroon conducted three nationwide immunization campaigns with a fourth nationwide activity starting on 9 March 2014. Polio vaccine uptake varies across regions. The main reason for non-vaccination of children is that houses had not been visited (43% of non-vaccinated children). Analysis of overall population immunity suggests that more than 40% of children remain under-immunised. The continuation and expanding spread of transmission indicates serious gaps in quality of outbreak response.

Cameroon is planning additional emergency outbreak response activities, including converting a subnational immunisation campaign to a full nationwide activity in April 2014, and implementing nationwide campaigns in May and June 2014.

It is important that all countries, in particular those with frequent travel and contacts with polio-affected countries and areas, strengthen surveillance for acute flaccid paralysis cases in order to rapidly detect any new virus importations and to facilitate a rapid response. Countries, territories and areas should also maintain uniformly high routine immunisation coverage at the district level to minimize the consequences of any new virus introduction.

WHO’s International Travel and Health recommends that all travelers to and from polio-affected areas be fully vaccinated against polio.

For more information please click here http://www.who.int/csr/don/2013_03_17_polio/en/