Prevalence of Hepatitis B Surface Antigen and Antibodies to Hepatitis C in the General Population of Benue State, Central Nigeria
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Am. J. Trop. Med. Hyg., 102(5), 2020, pp. 995–1000 doi:10.4269/ajtmh.19-0649 Copyright © 2020 by The American Society of Tropical Medicine and Hygiene Prevalence of Hepatitis B Surface Antigen and Antibodies to Hepatitis C in the General Population of Benue State, Central Nigeria Abraham O. Malu,1* Godwin I. Achinge,2 Priscilla M. Utoo,2 Jonathan T. Kur,3 and Solomon A. Obekpa2 1Jos University Teaching Hospital, Jos, Nigeria; 2Benue State University Teaching Hospital, Makurdi, Nigeria; 3Benue State Ministry of Health, Makurdi, Nigeria Abstract. There have been various estimates of the prevalence of hepatitis B and C infections in Nigeria. Recent studies have shown the prevalence to be lower than previously reported. The different populations studied might be responsible for this. It is important to have a real population data that would inform the policies to be adopted for eradication. We set out to determine the prevalence, risk factors, and pattern of hepatitis B and C in Benue State, Central Nigeria. Four thousand and five (4,005) subjects, aged 1 year and older, were selected through a multistage random sampling to represent all parts of the state. Trained health workers administered a validated questionnaire. Rapid test kits were standardized and used in determining the prevalence of the respective viruses. Hepatitis B surface antigen (HBsAg) and antibodies to hepatitis C virus (anti-HCV) were found to be positive in 5% and 1%, respectively, of subjects screened. The prevalence varied from one local government area to another, with HBsAg being 8% in the highest to 2% in the lowest LGC, and anti-HCV being 3% in the highest and 0% in the lowest. Age, previous close contact with a patient, and multiple sex partners were the most important risk factors for hepatitis B virus (HBV) infection, whereas age and previous blood transfusion were the most important risk factors for hepatitis C virus (HCV) infection. HBV immunization may be having an impact in reducing the prevalence of the virus. Nigeria appears to be moving from high endemicity to the intermediate one. INTRODUCTION the adult general population carried out by Lagos State gov- ernment gave a completely different picture, where HBV Hepatitis B and C are responsible for most cases of chronic prevalence was less than 2.1% and HCV much lower at liver disease (chronic hepatitis, cirrhosis, and hepatocellular 0.1%.14 A study from Cross River state among young children carcinoma) worldwide. They account for an even higher pro- aged 11–19 years also gave a much lower figure of HBsAg of portion of chronic liver diseases in sub-Saharan Africa and 15 1–3 1.2%. WHO modeling for Africa puts the current prevalence South East Asia. Studies in Nigeria have shown different of HBV at 4.6–8.5%.16 prevalence over the years, depending on the population With all these discordant results being reported in different studied and the diagnostic method used. Most studies have parts of the country and WHO modeling being very different given results that put Nigeria in the category of high preva- 4–10 from the currently used prevalence of 12.2% for HBV, it be- lence (greater than 8%). came desirable for us to carry out a systematic population- With immunization for HBV available and being used widely in 11,12 based study of the prevalence of HBsAg and antibodies to children since 2004, it is expected that the prevalence of hepatitis C (anti-HCV). The findings from the study will help HBV will gradually fall. Also, with the availability of curative both Nigeria and WHO determine whether or not Nigeria has treatment using highly effective oral treatment for HCV, it is moved from the hyperendemic to moderate or even low- hoped that HCV will gradually be eliminated through treatment 13 endemicity status as a result of infant immunization and other of those infected, thus reducing the pool of infective sources. control measures. Most studies in Nigeria did not use general population to Treatment for HCV is now highly effective. Although the determine the actual population prevalence. They relied on initial cost of treatment was prohibitive, it has come down blood donors, antenatal clinic population, those who patron- substantially. Elimination of HCV is, therefore, a worldwide ized health facilities for one reason or another, or those who target now.17 The Federal Government of Nigeria has outlined responded to advertisement for mass screening at worship a policy on tackling the problem of hepatitis, and treatment of centers, schools, or market places. All of these introduced 18 5–12 HCV is an important aspect of this. Some states have al- biases in the population actually screened. A recent study ready keyed into the initiative and are subsidizing treatment. by the Federal Ministry of Health tried to circumvent these 4 To help states plan and budget properly, the true prevalence of problems by doing an actual population study. However, the HCV is important. The results from this study of anti-HCV in study population of less than 1,000 subjects for a country of Benue State will provide information that will be useful in more than 180 million people by then was not likely to give a helping the state, Nigeria, and other partners implement the true picture. It is unfortunately the current point of reference for policy on providing treatment for patients with HCV infection. the prevalence of HBV and HCV in Nigeria, and it gives HBV An accurate figure on both viruses is important because it is prevalence of 12.2% and HCV prevalence of 2.3%. This such figures that may help the state government work with maintains Nigeria in the hyper-endemicity zone. One expects other agencies to develop policy on control and treatment of that the universal policy on immunization of all new-born and those already infected with the viruses. infants since 2004 would have the effect of reducing the prevalence of hepatitis B surface antigen (HBsAg). A study of SUBJECTS AND METHODS This was a cross-sectional population-based study using * Address correspondence to Abraham O. Malu, Department of Medicine, University of Jos, Jos 930001, Nigeria. E-mail: aomalu@ the multistage random sampling to obtain the study subjects gmail.com as shown in Table 1. We selected two local government areas 995 996 MALU AND OTHERS TABLE 1 Communities in Benue State of Nigeria screened for hepatitis B and C Senatorial district (with 2016 projected population) Local government area (with 2016 projected population) Enumeration area 1 Zone A (2,020,634) Konshisha (303,284) Ikyurav Mbavaa Kwande (334,228) Mbayoor Mbakyor 2 Zone B (1,904,249) Makurdi (399,678) Lobi Agwanjukun Buruku (273,784) Binev Mbakyaan 3 Zone C (1,745,428) Oju (228,783) Aenu Okpokpo Ogbadibo (172,971) Ahaje 1 Aeona 1 (LGAs) from each of the three senatorial districts. The names was added. Strips were then observed for 15 minutes for HBV of the local governments in each district were written on and 10 minutes for HCV. When two colored bands appeared, it pieces of paper of equal size. They were then folded and put in was regarded as positive for HBsAg or anti-HCV, respectively. a basket, which was then shaken and one of us dipped a hand When only one band appeared in the control portion of the in the container without looking. The two local governments in strip, it was regarded as negative. When the control band did each district were chosen through this method. The same not appear but there was a band visible at the test portion, the process was used in selecting the two enumeration areas test was repeated, using a different strip. The same repeat (political wards) from each chosen local government. At the testing was performed when there was no band at both the ward level, compounds to be studied were selected by the control and test locations. investigator based on convenience. The compound of the Blood samples were collected from every 20th person, and community leader in the locality was usually first selected to every person positive for HCV antibodies, and brought back to promote acceptance by the community, followed by the the town, where it was centrifuged and serum kept at −20°C. compounds closet to that house in an expanding manner. In The plan was to use the serum of every 20th person for anal- each compound or house entered, all consenting subjects ysis for other markers of HBV and to use the serum of those aged 1year and older were recruited. positive for HCV by rapid testing for HCV confirmation through A pre-validated interviewer-administered questionnaire polymerase chain reaction (PCR). However, no funds were was used. The enumerators were community extension work- available for the HCV PCR, so it was not performed. The test ers or officers from the local area or doctors who spoke both results for HBV markers are a subject for another report. English and the local language fluently. They were recruited and Ethical approval for the study was obtained from the Benue trained in the administration of the questionnaire in English and State University Teaching Hospital Research and Ethics interpreting it in the local language where appropriate. Labo- Committee BSUTH/MKD/HREC/204B/2017/0014. ratory technicians already familiar with using rapid diagnostic Each LGC chairman and the local chiefs at each level were test kits were further trained to standardize their methods. The visited to obtain their consent for the study to be carried out in same technicians were used throughout the study. their domains. Each individual gave informed verbal consent Rapid diagnostic test kits (Nantong Egens Diagnosis Bio- following explanation of what the study entailed, except that technology Co.