SERO-PREVALENCE AND IDENTIFICATION OF CIRCULATING GENOTYPES OF HEPATITIS B VIRUS AMONGST PATIENTS ATTENDING SOME HOSPITALS IN NIGER STATE

Abstract

Hepatitis B virus (HBV) infection remains a major public health problem globally and accounts for about one million deaths worldwide in spite of the use of available vaccine and medications for mitigation of the disease. This study determined the seroprevalence, distribution of HBV infection, factors associated with the infection, and the genotypic patterns amongst patients attending selected hospitals in Niger State, Nigeria. A total of 500 blood samples were collected from five selected hospitals in Niger state. The samples were screened using Hepatitis B Surface Antigen (HBsAg) test kit for qualitative detection of Hepatitis B Surface Antigen in serum. DNAs were extracted from the 65 positive sera. HBV DNA genotyping and sequencing were performed on the HBsAg - positive samples, using Multiplex-PCR. For HBV genotyping, the second amplification products were analyzed using Agarose-Gel electrophoresis. Out of the 32 positive samples genotyped, five (5) were successfully sequenced and subjected to phylogenic analysis. Prevalence of Hepatitis B infection amongst the studied population was 13.0%. Female participants had a non-significantly higher prevalence (6.8%) of HBsAg infection than their male counterparts (6.2%, p>0.05). Participants within 41- 50 years age group recorded a significantly higher rate of infection (5.2%), compared to patients ≥ 50 years with 2.3% prevalence (p>0.05). The Civil Servants had a higher percentage prevalence of 6.4% followed by house wives (3.2%), while the least prevalence was observed among the students (1.6%). Patients without history of blood transfusion had significantly higher percentage prevalence (7.8%) compared to those with history of blood transfusion (5.2%, p>0.05). The results also revealed that participants with polygamous family type recorded higher prevalence of HBV infection (11.4%) compared to those belonging to the monogamous type (1.6%). Five (5) genotypes were identified amongst the 32 positive samples as follows: genotype A: 14 (34.1%); genotype C: 4 (9.8%); genotype D: 1 (2.4%); genotype E: 19 (46.3%); and genotype F: 3 (7.3%). Fifteen (15) samples accounting for 46.9% had co-infection of multiple genotypes; with A/E accounting for 31.25% (10/32), followed by C/ E, 9.375% (3/32) and the least was A/F, 3.125% (1/32). Most of the co‑infections were a combination of genotype E, the predominant genotype and others. Sequencing and phylogenic analysis of the five queried samples showed that genotype E had a percentage identity ranging from 98-100. The results obtained in this study shows that HBV is hyper-endemic in the study area and the circulation of the five HBV genotypes (A, C, D, E and F) amongst the study population of Niger state was confirmed; with HBV genotype E (HBV-E) predominating amongst the study population, probably due to the in ability of the innate immune response of the host to resist the strain. There is the need for more awareness and sensitization of people on the prevalence of HBV infection in Niger State. People need to be enlightened on the modes of transmission and spread of the virus through different information media outfits.