Epidemiological Update - Polio Eradication Pakistan

This PowerPoint presentation was prepared for a September 2007 United Nations Children's Fund (UNICEF)-hosted meeting dedicated to examining polio communication efforts in Pakistan. In support of the final global push towards polio eradication, state-specific presentations were given by in-country communication and health practitioners working in Pakistan's polio-endemic states (Sindh, Balochistan, and the Northwest Frontier Province). These were assessed by an external panel of experts in the fields of development communication, mass media, epidemiology, and anthropology, who provided communication programme recommendations based on data presented by the country teams, as well as data gathered on field visits to the endemic states. Communication strategies presented at this meeting were primarily focused on:

1. Analysing the results of programmes implemented through September 2007
2. Detailing activities on national and sub-national levels, specific to social mobilisation, community engagement, underserved areas, media, and political advocacy strategies
3. Suggesting communication strategy and programme refinements for the next 6- to 12-month period, designed to support Pakistan’s polio eradication efforts

This presentation gives an overview of the epidemiological status of wild poliovirus (WPV) in Pakistan. It describes Pakistan's role in the global polio eradication initiative (PEI), polio trends in the area, and significant milestones achieved in the country from 1994-2007. An analysis of WPV zones of transmission is given, with focuses on cross-border sharing of virus strains between Pakistan and Afghanistan, mobile population movement, and security high-risk areas. Synchronisation of cross-border immunisation activities is also highlighted. The significant epidemiological characteristics of WPV cases that have emerged over the previous year are discussed in detail, as are strategies for supporting Pakistan's PEI through the country's expanded programme of immunisation (EPI) infrastructure. A projected scenario for WPV cases in Pakistan in 2008 is given, followed by a concluding analysis of the way forward.


Since the launch of polio eradication efforts in Pakistan in 1994, the country has managed to reduce the number of WPV cases per year from over 20,000 to 40 in 2006 and 13 to date in 2007. Supplementary immunisation activities (SIAs) are of a consistently high quality (>95% coverage) in the country, and the acute flaccid paralysis (AFP) surveillance and laboratory systems are reaching international standards.


Recent years have seen increasing geographic restriction of polioviruses in Pakistan, with a decrease in the number of main zones of transmission from 9 in 1997 to only 2 in 2007. Most notably, no cases have emerged in the largest province Punjab for over a year, indicating significant progress.


Pakistan and Afghanistan are considered to be one epidemiological block for WPV transmission, as frequent movement of populations across the long border results in sharing of polioviruses between the two countries. Many cases in both countries are reported from areas of compromised access due to security issues. Collaboration between Ministries of Health in both countries to synchronise immunisation efforts has resulted in over 200,000 children under 5 years of age vaccinated from mobile populations in August 2007.


Over the last year, a significant shift has been seen in the age group of the emergent cases in Pakistan, evidenced by an increase in the number of cases in those >35 months from 10% in 2006 to 46% in 2007. Pakistan also saw its first ever reported adult case of polio in 2007, in a 22 year old male. Generally, cases are seen most often in children from economically poor, illiterate families living in rural or urban slum areas. Suboptimal immunisation coverage is seen consistently in areas bordering with Afghanistan, as well as South Wazirstan and Tank.


The use of the polio infrastructure to support measles immunisation activities has resulted in greater acceptance of oral polio vaccine (OPV) in high-risk areas. Pakistan sees 21,000 deaths and 21 million cases related to measles annually. Specialised campaigns for routine immunisation have been initiated in refusal areas. The combined PEI and EPI infrastructure has become involved in supporting national public health emergencies (such as earthquakes, floods, and Avian Influenza outbreaks) and in facilitating research activities (for example, surveillance for bacterial meningitis).


The presenters suggested that the way forward for Pakistan's PEI programme should focus on:

1. Continued focus on high risk areas
2. Maintenance of high population coverage and quality immunisation activities
3. Sustaining communication activities
4. Improving routine immunisation and leveraging the PEI infrastructure more fully

To conclude, they observed that the epidemiological and virological data shows that Pakistan is close to WPV transmission interruption. Efforts are being made to ensure consistent high quality SIAs, with the use of the PEI approaches to strengthen EPI. Major challenges remaining include both accessing populations in security-compromised areas and reaching highly mobile populations.


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