Hussain Imtiaz, Mach Ondrej, Habib Atif, Bhatti Zaid, Suhag Zamir, Oberste M Steven, Weldon William C, Sutter Roland W, Soofi Sajid B, Bhutta Zulfiqar A
From the *Department of Peadiatrics and Child Health, Aga Khan University, Karachi, Pakistan; †Polio Eradication Department, World Health Organization, Geneva, Switzerland; and ‡Polio and Picornavirus Laboratory Branch, Centers for Disease Control and Prevention, Atlanta, Georgia.
Pediatr Infect Dis J. 2017 Sep;36(9):e230-e236. doi: 10.1097/INF.0000000000001622.
Pakistan is one of the 3 remaining wild poliovirus endemic countries. We collected sera from children to assess the prevalence of poliovirus antibodies in selected high-risk areas for poliovirus transmission.
Children in 2 age groups (6-11 and 36-48 months) were randomly selected between November 2015 and March 2016 in 6 areas of Pakistan (Sindh Province: Karachi and Kashmore; Khyber Pakhtunkhwa Province: Peshawar, Bannu and Nowshera; Punjab Province: Faisalabad). After obtaining informed consent, basic demographic and vaccination history data were collected, 1 peripheral venipuncture was obtained, and assays to detect poliovirus (PV)-neutralizing antibodies were performed.
A total of 1301 children were enrolled and had peripheral blood drawn that analyzed. Study subjects were evenly distributed among survey sites and age groups. Anti-polio seroprevalence differed significantly among geographic areas (P < 0.001); in the 6-11 months group, it ranged between 89% and 98%, 58% and 95%, and 74% and 96% for PV serotypes 1, 2 and 3, respectively; in 36-48 months group, it ranged between 99% and 100%, 95% and 100%, and 92% and 100% for PV 1, 2, and 3, respectively. Having received inactivate poliovirus vaccine, malnourishment (stunting) and educational level of parents were found to be associated with presence of anti-polio antibodies.
The polio eradication program achieved overall high serologic protection; however, immunity gaps in young children in the high polio risk areas remain. These gaps enable sustained circulation of wild poliovirus type 1, and pose risk for emergence of vaccine-derived polioviruses. Focusing on the lowest socioeconomic strata of society, where malnutrition is most prevalent, could accelerate poliovirus eradication.
巴基斯坦是仅存的3个野生脊髓灰质炎病毒流行国家之一。我们收集儿童血清，以评估脊髓灰质炎病毒传播选定高风险地区的脊髓灰质炎病毒抗体流行情况。
2015年11月至2016年3月期间，在巴基斯坦的6个地区（信德省：卡拉奇和卡什莫尔；开伯尔-普赫图赫瓦省：白沙瓦、班努和瑙谢拉；旁遮普省：费萨拉巴德）随机选取了2个年龄组（6 - 11个月和36 - 48个月）的儿童。在获得知情同意后，收集基本人口统计学和疫苗接种史数据，采集1次外周静脉血，并进行检测脊髓灰质炎病毒（PV）中和抗体的检测。
共纳入1301名儿童并采集外周血进行分析。研究对象在调查地点和年龄组中分布均匀。不同地理区域的脊髓灰质炎血清阳性率差异显著（P < 0.001）；在6 - 11个月组中，PV 1、2和3型的血清阳性率分别在89%至98%、58%至95%和74%至96%之间；在36 - 48个月组中，PV 1、2和3型的血清阳性率分别在99%至100%、95%至100%和92%至100%之间。接受过灭活脊髓灰质炎疫苗接种、营养不良（发育迟缓）以及父母的教育水平被发现与脊髓灰质炎抗体的存在有关。
脊髓灰质炎根除计划总体上实现了较高的血清学保护；然而，脊髓灰质炎高风险地区幼儿的免疫差距仍然存在。这些差距使得野生1型脊髓灰质炎病毒得以持续传播，并构成了疫苗衍生脊髓灰质炎病毒出现的风险。关注社会经济地位最低且营养不良最为普遍的阶层，可能会加速脊髓灰质炎的根除。
