Synopsis of progress in reinfected countries
• In 2008, 5 cases have been reported, 1 type 1 and 4 type 3. This is the first importation of type 3 poliovirus into Angola. Genetic sequencing indicates that the first type 3 case detected (with onset of paralysis on 19 March) is related to virus from Uttar Pradesh, India.
• All cases have been in the Luanda area, where the second mop-up of the year was carried out on 18-20 April with mOPV1; a mix of mOPV1 and mOPV3 will be used during NIDs scheduled for 16-18 May due to the presence of type 3 poliovirus.
Central African Republic (CAR)
• CAR has reported its first case – a type 1 – since November 2004. Genetic sequencing is awaited to determine the origin of the virus.
• Detection of polio after a gap of over 3 years emphasizes the continued importance of sensitive surveillance, especially in the vicinity of endemic countries. NIDs were held on 4 April.
• With 2 cases reported this year, both type 3, Chad remains a high risk country for polio transmission due to weak operations during its 2 SIAs this year, conducted in the midst of insecurity. Following a meeting between government and partners in early April, SIAs have been scheduled in staggered phases across the country due to security constraints: the first of these took place in the last week of April; the next are due to take place end-May and end-June. It is critical to boost population immunity before the onset of the rains in June.
Democratic Republic of Congo
• Two cases have been reported this year, both type 1. The most recent is from the previously uninfected province of North Kivu; genetic sequencing is awaited to determine whether this represents a new importation.
• Following a mop-up targeting 400 000 children on 10-12 April, using mOPV1, large-scale SIAs are planned for 8-10 May and again in June (also with mOPV1).
Nepal and Niger
• Both countries continue to be exposed to repeated importations, due to their proximity to endemic areas of India and northern Nigeria respectively. Both also continue outbreak response activities; in Nepal, 4 SIAs have been held between December 2007 and April 2008, and no cases have been reported since 16 February. Niger's most recent campaigns were on 5 April, using mOPV1 along its border with Nigeria.
Horn of Africa
• Two polio cases were reported in the Ethiopia/south Sudan cross-border area, the first polio reported this year to the east of Chad.
• Confirmation of these cases, which are genetically related to previously circulating virus, underscores the need to sustain campaigns in this difficult-to-access area, and to urgently fill subnational surveillance gaps across central Africa. Although current population immunity levels across the Horn of Africa are higher than in 2004-2005, there is a risk of further polio spread, facilitated by frequent population movements.
• A combined cross-border outbreak response is currently being planned. Two large-scale SIAs covering the whole of southern Sudan (targeting 2.5 million children) and 52 districts of south-western Ethiopia bordering southern Sudan (targeting 400 000 children) will be held in early May and again in early June, using mOPV1. Longer-term plans, also to strengthen sub-national surveillance gaps across several countries in central Africa, are being formulated.