1. Immunization
OPV III immunization in all provinces of Pakistan
A "fully immunized child" is one who has received at least 1 dose of Bacilli Calmette-Guérin (BCG) vaccine, 3 doses of oral polio vaccine (OPV), DPT3 and measles1 vaccine. EPI programs target is to immunize children of 0-11 months against seven EPI target diseases. According to EPI surveys 2001, Khyber Pakhtunkhwa was the best performing province with 89% immunization (OPV III) in fighting against polio. The lowest immunization results were in Baluchistan and Gilgit Baldistan with 52% and 34.6% immunization respectively. The EPI surveys are regularly conducted in Pakistan by the Ministry of the Health in collaboration with WHO and other organizations that are active in fight against polio. The main aim of the surveys is to get data about the immunization, to identify the regions that are at the risk so that the special consideration should be given to these areas in planning the programs, in future.
Figure 1 shows the percentage immunization of OPV III vaccination in different provinces of Pakistan during the last decade (2001-2010). The vaccination campaigns conducted from 2002-2004 shows approximately the same results as in previous exercise in 2001. Azad Jammu and Kashmir (AJK) and KPK were the best performing provinces with 88% and 74% immunization and Baluchistan and Gilgit Baldistan having the lowest immunization 54%, 58% respectively. The main reason for the lowest immunization in Baluchistan and Gilgit Baldistan are the poor infrastructure, low education rate, lack of political well and highly diverse and inaccessible population. In 2005, over all reported immunization was 65%, the immunization campaign highly affected due to severe earthquake in the northern area of the Pakistan, due to which a huge population migrated to the other areas of the country. The surveys conducted during 2006 to 2010 in all the province of Pakistan (Figure 1) shows that vaccine immunization has been greatly improved in door-to-door immunization campaigns.
AJK and Punjab remains the highest performing provinces. As compared to the other parts of the country lowest immunization was observed in FATA due to fight against terrorism and security concerns in that region. As appeared from the data most of the cases are clustered at its borders with Afghanistan. Pakistan shares common epidemiological block with Afghanistan. So both countries should synchronize their efforts for fight against polio.
Immunization survey of OPV I, II and III in Pakistan
Each year about 10-20% children fail to receive their third dose against poliomyelitis. In 2001, 86% of the target population of 0-11 months and above received their first dose against but only 76% received OPVIII (Figure 2). Similarly 13% children in 2002 and 2003, 10-12% in 2004 and 2005 and up to 7% children in 2010 could not receive their third dose against polio. This could possibly be the reason why polio has not being eradicated from Pakistan. The country has made significant improvement in EPI immunization as compared to its neighboring countries, but there is need to adopt a more aggressive implementation strategy to compete with other countries of the region.
2. Surveillance
Pakistan held 5 rounds of national immunization days (NID) and two sub NIDs in 2001, but still 119 cases of polio were reported (Figure 3). 20 cases were confirmed in Baluchistan (8 cases in Quetta), 18 in Punjab, 25 cases registered in Sindh, and 22 in KPK (4 cases in the Peshawar District). In 2002 the number of cases decreased from 119 to 90. Most cases were reported from northern Sindh, southwestern Punjab, the Peshawar district and the southern area of Khyber Pakhtunkhwa (KPK) [12]. In general more polio cases were reported in 2003 as compared to 2002, 103 cases were reported in this year. But, in the start of second half of 2003, the number of cases began to reduce, that is 55 cases were reported in second half of 2003 compared to 60 during the same period in 2002. In 2004, a total of 59 polio cases were confirmed, 38 caused due to WPV1 and 19 due to WPV3. During 2003 to 2004, the number of reported polio cases reduced about 50%, with 46 cases due to serotype 1 (WPV1) and seven due to WPV3 (Figure 4) [13]. Punjab, the well populated province of Pakistan, reported 3 polio cases during the first half of 2004 and 14 cases, mostly from southern Punjab, during the second half. The genetic sequencing shows that certain viruses detected in Punjab were directly imported from Sindh and KPK. But analysis of genetic sequencing also suggests that at least two WPV1 and one WPV3 lineage were identified in Punjab during 2004.
Twenty eight polio cases were reported in 2005. Out of these twenty seven cases were WPV1, and one was WPV3 (from Quetta district in the Baluchistan province). In 2006 the number of reported polio cases from 17 districts was increased from 28 to 40. Of the 40 cases, 20 were caused due to WPV1 and 20 due to WPV3. Most of the WPV1 cases were identified from Sindh Province or from security-compromised areas in KPK [14]. In 2007 the number of polio cases reduced from 40 (cases reported in 2006) to 32 cases (reported from 18 districts), 19 cases were caused due to WPV1 and 13 due to WPV3. While this number greatly increased during 2008. In this year 118 cases were reported, out of which 81 cases were caused due to WPV1 and 37 due to WPV3 [15]. This is because of the failure to conduct SIAs in the conflict affected border areas of Pakistan and Afghanistan; large areas of KPK and FATA were too dangerous to conduct SIAs. Also political and management issues in Sindh and Baluchistan badly affected the supervision and conduct of immunization programs. In 2009, Surveys reported 89 polio cases (60 WPV1, 28 WPV3, and one mixed WPV1/WPV3) [16]. 144 cases were reported (120 WPV1 and 24 WPV3) in 2010. 100 cases were reported from conflict-affected areas, including 23 cases from FATA and 73 cases from other parts of KPK [17]. Until now 87 new polio cases are reported this year. 35 cases are reported from Baluchistan, one from Gilgit-Baldistan one from Punjab, 17 from Sindh, 26 from Fata and seven from Khyber-Pakhtunkhwa. Of the 17 cases reported in Sindh; Hyderabad, Umerkot, Tando Allahyar and Jamshoro reported one case each, Badin, Tando Muhammad Khan and Sanghar reported two each, Thatta reported three and Karachi reported four [18]. Case report survey of 2009 shows that all the provinces were at the risk and the possible reason was the heavy flood, which badly affected more than 50% area of the country. The affects of the recent flood possess potential risk on a number of fronts including damaged health infrastructure, increased pressure on management and compromised quality of the drinking water, sanitation and increased displaced population. High risk population groups included migrants, internally displaced persons (IDP) due to war against terrorism and afghan refugees. If we focus our study on the case report of polio month wise, we found that the polio increases in some months (July to November) due to environment effects, use of poor quality drinking water and unhygienic conditions resulted in previous summer. The concerned authority should have to design a plan with the top political commitment to prevent Pakistan from becoming the last remaining reservoir of polio virus circulation on the globe.