High hepatitis B seroprevalence and risk factors for infection in pregnant women on the Thailand-Myanmar Border.

Tristan Banks,Aung Myat Min,Nay Win Tun,Mary Ellen G Tyrosvoutis,Rose Mcgready,Joy Kang,François Nosten,Borimas Hanboonkunupakarn,Sunaree Wanyatip,Lily Keereecharoen,Isabella Watts,Wiriya Simmawong

doi:10.3855/jidc.7422

Abstract

Infection from Hepatitis B primarily results from peri-partum vertical transmission and the risk increases in the presence of hepatitis B e antigen. We aimed to evaluate a new screening program for hepatitis B in pregnant women as a component of antenatal services in a marginalized population. Counseling and screening for hepatitis B screening was offered to all women at the first visit, at Shoklo Malaria Research Unit (SMRU) antenatal clinics on the Thai-Myanmar border. Point-of-care rapid diagnostic tests (RDT) were used throughout the period of evaluation. A certified Thai Public Health laboratory at Mae Sot Hospital verified RDT positive cases using enzyme-linked immunosorbent assay (ELISA) for HBsAb and HBeAg. Risk factors for hepatitis B were identified by data linkage to antenatal care records. There were 523 (8.5%) RDT positive for HBsAg among 6158 women tested (Aug-2012 to April-2014). Of these 373 (96.9%) of 385 sent for confirmation were positive by ELISA i.e. RDT false positive rate of 3.1% (95% CI 1.7- 5.4). The overall confirmed HbsAg prevalence was 8.3% (511/6158) (95% CI 7.6-9.0). HBeAg prevalence was 32.7% (114/350) (95% CI 27.9-37.7) of cases tested. Risk factors for HBsAg positivity included age >25 years (OR 1.24, CI 1.03-1.49, p 0.021) and Karen heritage (OR 1.73, CI 1.39-2.15, p < 0.01). High hepatitis B seroprevalence amongst migrants and refugees accessing SMRU antenatal services likely reflects that of Kayin State, Myanmar, and perinatal prevention programs are required. False positive cases with HBsAg RDT complicate what is theoretically a straightforward screening.

Highlights

Infection from Hepatitis B primarily results from peri-partum vertical transmission and the risk increases in the presence of hepatitis B e antigen
It is well documented that the earlier in life a person is exposed to the hepatitis B virus, the more chance there is of progression to chronic hepatitis B infection and long term consequences [3]
Infection rates are as high as 85-90% when hepatitis B e antigen (HBeAg) is present, compared to 5-31% when only hepatitis B surface antigen (HBsAg) is present [5]

Summary

Introduction

Infection from Hepatitis B primarily results from peri-partum vertical transmission and the risk increases in the presence of hepatitis B e antigen. Results: There were 523 (8.5%) RDT positive for HBsAg among 6158 women tested (Aug-2012 to April-2014). Of these 373 (96.9%) of 385 sent for confirmation were positive by ELISA i.e. RDT false positive rate of 3.1% (95% CI 1.7- 5.4). Prevalence varies considerably throughout the world and is highest in sub-Saharan Africa and Asia It is the 10th leading cause of death worldwide, with mortality attributable to long-term sequelae, namely liver cirrhosis and hepatocellular carcinoma [1]. The risk of transmission is greater in the presence of hepatitis B e antigen (HBeAg) or high viral loads. Infection rates are as high as 85-90% when HBeAg is present, compared to 5-31% when only hepatitis B surface antigen (HBsAg) is present [5]

Objectives

Methods

Results

Discussion

Conclusion