CURRENT EPIDEMIOLOGY OF POLIO IN PAKISTAN
As of 8th May 2014, 59 type-1 wild poliovirus (WPV) cases have been reported from nine districts/ towns/ tribal agencies/ FR areas (compared to eight in 2013 from seven districts/ towns/ tribal agencies/ FR areas). Moreover, WPV-1 has also been isolated from 29 environmental samples in 2014 (out of 102 samples for which results are available) from Gaddap, Baldia and Gulshan-e-Iqbal towns in Karachi Sindh, Peshawar in Khyber Pakhtunkhwa, Lahore and Rawalpindi in Punjab and Quetta in Balochistan. Eleven sabin-2 like poliovirus cases have been reported from FATA, (six from North Waziristan agency and five from FR Bannu).
Following are the key epidemiological characteristics of polio cases reported in 2014 so far:
• 52 (88%) polio cases are younger than two years (median age: 14 months).
• Based on recall of parents, 49 (83%) cases did not receive any OPV dose (through routine vaccinations and/or campaigns)
It is worth mentioning that, 82% (76/93) polio cases in 2013 and all except four in 2014 have been reported together from Khyber Pakhtunkhwa and FATA, indicating that these regions remain the key polio reservoirs in the country. Situa- tion in Karachi has also turned very concerning, considering the fact that all the three high risk towns (Gadap, Gulshan-e -Iqbal and Baldia) have the continuous presence of wild poliovirus during the last six months (positive environmental samples and polio cases). This situation in Karachi corre- lates with deteriorating quality of supplementary immuniza- tion activities (SIAs) in 2013 and early 2014.
In Punjab, environmental samples collected from Lahore (12th April) and Rawalpindi (28th Jan) has detected wild po- liovirus in 2014; however, in Rawalpindi the last two consec- utive environmental samples collected from the existing site (Safdar Abad) and the first sample from the new site (Dhok Dalal) are negative for the presence of wild poliovirus. The first environmental sample collected from the capital territory of Islamabad on 21st March was also turned negative for wild poliovirus.
Balochistan province did not report any polio case during 2013, However, isolation of wild poliovirus from environ- mental sample collected on 28th December and the latest two positive samples collected on 20 and 31 March 2014 from two different sites in Quetta is of great concern. The genetic analysis of the isolated virus indicates missed viral circulation for more than a year; which in turn indicates missed populations by the Supplementary Immunization Activities (SIAs) and AFP surveillance. The ongoing sub- optimal quality of SIAs in Quetta Block complements the findings of the genetic analysis. An impending polio out- break cannot be ruled out in the region.
It is important to highlight that environmental samples from Faisalabad and Sukkur have been negative for over a year and in Hyderabad for the last six months.
In conclusion, poliovirus circulation in the country can be seen over a wider geographically area (compared to first half of 2013). Keeping in view that the country is currently entering the high transmission season; the following is to re- emphasize as key to stopping wild poliovirus circulation dur- ing upcoming SIAs:
• Immediately gaining consistent access to all the chil- dren in North and South Waziristan agencies, FR Ban- nu, Bara and other unreached areas of FATA by taking on-board all the stakeholders and strengthening Civil Military Coordination.
• The population on the move from North & South Waziri- stan and Khyber agencies is to be tracked and vac- cinated on the transit points and at their destination in the adjacent districts of Khyber Pakhtunkhwa.
• Consistent access to all the children in reservoirs of central Khyber Pakhtunkhwa and Karachi ensuring se- curity arrangements for vaccinators to restore and maintain the confidence and sense of security among the frontline workers.
• Highest quality SIAs in Punjab, interior Sindh and Balo- chistan (specially Quetta block) to avert the risk of intro- duction and establishment of wild poliovirus • Ensuring strong oversight and accountability mecha- nisms for polio eradication activities at all levels.