Poliomyelitis in Chad

Chad is experiencing outbreaks of both wild poliovirus type 1 (WPV1 – 65 cases in 2011) and wild poliovirus type 3 (WPV3 – three cases) reports the World Health Organization (WHO). The WPV3 outbreak has been ongoing since November 2007, and Chad is therefore considered to have re-established WPV3 transmission. A WPV1 outbreak began in September 2010 (as a result of a newly-imported virus from northern Nigeria), and has since been intensifying. Originally restricted to the greater N’Djamena area, WPV1 has spread in 2011 to other areas of the country, including areas bordering Central African Republic, Cameroon and Sudan). Historically, Chad has been associated with further international spread of poliovirus. Between 2004 and 2006, WPV1 spread from eastern Chad into Sudan, and subsequently to other areas of the Horn of Africa, Saudi Arabia, Yemen and Indonesia, resulting in 1,230 cases in these countries and over US$500 million in...