From WHO, polio outbreaks detected in Angola and Congo, excerpt but please read the whole report :
" 8 September 2010 : Angola and the Democratic Republic of Congo (DR Congo) are experiencing outbreaks of wild poliovirus type 1 (WPV1).
In Angola, the outbreak which began in April 2007, has this year spread to re-infect previously polio-free areas in Angola (the provinces of Bie, Bengo, Huambo, Lunda Norte, Lunda Sul and Uige), as well as to neighbouring DR Congo, re-infecting Kasai Occidental province which borders Angola. This outbreak is classified as 're-established' transmission, as it has persisted for a period greater than 12 months.
In DR Congo, in addition to newly-imported virus from Angola this year, a case detected in Katanga province with onset of paralysis on 20 June 2010, in the east of the country, has been genetically-linked to virus previously imported from Angola, last detected in eastern DR Congo in 2008. In 2009, a case was detected in Burundi, which was linked to the same transmission chain. DR Congo was previously regarded by the Advisory Committee on Poliomyelitis Eradication (ACPE) has having 'suspected' re-established transmission, and this suspicion is now confirmed.
Given the recent progress achieved in Nigeria (99% reduction in cases this year compared to the same period in 2009), west Africa (no cases since 1 May 2010) and the Horn of Africa (no cases in more than 12 months), central Africa is now considered to be the greatest risk to Africa's polio eradication efforts. Angola's outbreak is currently the only geographically expanding outbreak in Africa. This situation increases the risk to achieving the next global milestone of the new Global Polio Eradication Initiative (GPEI) Strategic Plan 2010-2012, the cessation of all re-established WPV transmission by end-2010."