advanced search

<< Back To Home

- - - A STUDY EVALUATING POLIOVIRUS ANTIBODIES AND RISK FACTORS ASSOCIATED WITH POLIO SEROPOSITIVITY IN LOW SOCIOECONOMIC AREAS OF PAKISTAN

Saturday, 23rd of February 2013

 

•  A STUDY EVALUATING POLIOVIRUS ANTIBODIES AND RISK FACTORS ASSOCIATED WITH POLIO SEROPOSITIVITY IN LOW SOCIOECONOMIC AREAS OF PAKISTAN

M.A. Habiba, S. Soofia, N. Alia, R.W. Sutterb, M. Palanschc, H. Qureshid, T. Akhtare,

N.A. Molodeckyb, H. Okayasub, Zulfiqar A. Bhuttaa, ,

a Aga Khan University, Karachi, Pakistan

b WHO, Headquarters, 20 Avenue Appia, CH-1211, Geneva 27, Switzerland

c Centers for Disease Control and Prevention (CDC), Atlanta, GA, USA

d Pakistan Medical and Research Council (PMRC), Islamabad, Pakistan

e Khyber Medical University (KMU), Peshawar, Pakistan

Corresponding author at: Division of Women & Child Health, Aga Khan University, Karachi, Pakistan. Tel.: +92 213 4864782; fax: +92 21 34934294/34932095.

 

Abstract below; also at http://www.sciencedirect.com/science/article/pii/S0264410X13001564

Full text available to journal subscribers

Background

Seroprevalence studies provide important data on performance of immunization programs, susceptible groups and populations at-risk of future outbreaks. Identifying risk factors that affect seroconversion of the oral polio vaccine (OPV) will enable the polio eradication initiatives to increase seroprevalence. This paper describes the first population-based seroprevalence survey in Pakistan.

Methods

This study evaluated the seroprevalence of poliovirus (PV) types 1, 2, and 3 antibodies to OPV in an illustrative sample of 554 subjects 6–11 months of age in three geographic locations of Pakistan (Lahore, Karachi, and Peshawar) representing a low socioeconomic at-risk populations. Antibody titers were measured and sero protection rates and geometric median titers were compared among different geographic regions and populations, as were demographics and OPV vaccination history collected by questionnaire. Univariate and multivariate analyses were conducted on subject characteristics to assess for potential risk factors for failure to sero-convert.

Results

The average seroprevalence of PV1, PV2, and PV3 was 96.0%, 87.9% and 86.7%, respectively. The lowest sero protection rate for all three serotypes was for Karachi with 90.2%, 73.8%, and 78.8% for PV1, PV2, and PV3, respectively. Significant regional variation in PV3 seroprevalence was found (range: 74.2–100%). In the univariate analysis, age, total and campaign OPV doses were associated with higher seroprevalence, whereas stunting, respondent education and diarrhea in the past six months were significant risk factors for failure to sero-convert.

Conclusions

These findings demonstrate consistently high levels of antibody response to PV1 and more geographically varied response to PV2 and PV3. Additionally, important risk factors affecting seropositivity were identified.

Highlights

â–º The ongoing polio virus circulation in Pakistan is a global public health threat. â–º Study presents the first immunity profile of polio antibodies in Pakistan. â–º Association of polio seropositivity with various risk factors is established. â–º Innovative strategies are required to achieve polio eradication from Pakistan.