Validation of a new quantitative PCR (qPCR) approach: a screening tool for hepatitis B in pregnant women at high risk of transmitting hepatitis B virus to newborns in Mali.

Abstract

Introduction: Worldwide, hepatitis B virus (HBV) infection in people at risk is a major public health problem. Mother-to-child transmission (MTCT) is high in Africa, where 70% of hepatitis B cases, or 4.5 million infected children, are under the age of five, probably due to vertical transmission during pregnancy, childbirth or breastfeeding. Management of HBV infection is a major concern, particularly the availability of affordable viral load in a resource-constrained country like Mali. The aim of this study was to develop and validate a method for the detection and quantification of HBV DNA by qPCR in pregnant women, a population at risk of transmitting the virus to newborns. Methods: We enrolled 74 pregnant women with positive AgHBs in this study. Their viral loads were previously determined at the Reference Centre Lab. We designed specific probes and primers for the HBV PreC gene, for detection and quantification by qPCR. We adapted this new real-time PCR on different machines for HBV DNA quantification. Results: Nine out of nine (9/9) samples with a viral load (VL) between 10000-100000 International Units/milliliter (IU/mL) and 4/4 with a VL > 100,000 IU/mL were detected and quantified. Of the fifty-five (55) samples with a CV of 12-10000 IU/mL, 38/55 samples with a CV > 1000 IU/mL were detected and 17/55 samples between 12-1000 were not detected.  6/6 negative samples were not detected by our new qPCR. Conclusion: This new qPCR protocol has demonstrated effective detection and identification of high CV samples over 1000 IU/mL in pregnant women. It could be extended to other high-risk populations such as immunocompromised individuals.