Risk factors associated with hepatitis B and C in rural population of Burera district, Rwanda

Introduction Several studies have shown that older people have a higher risk of exposure to viral hepatitis B and C than younger people. This study aimed to determine the seroprevalence of hepatitis B and C and their associated factors in people aged 45+ years old in Burera, a rural district of Rwanda. Methods A cross sectional study was conducted from July to December 2017 during a mass campaign of hepatitis B (HBV) and hepatitis C (HCV) screening and vaccination of eligible populations against HBV in Burera District. Blood samples were collected and hepatitis B surface antigen (HBsAg) and an antibody against hepatitis C (Anti-HCV) were detected using an Enzyme-Linked Immuno-Sorbent Assay (ELISA). The associated factors were identified using a structured questionnaire and the data was analyzed using SPSS software. Results Of the 374 people included in this study, 53.2% were females. The median age was 56 years old with an interquartile range (IQR) of 50 - 63 years old. The prevalence of HBV and HCV infection was 6.4% and 9.4%, respectively, with 0.3% co-infection rate. Age, social economic level, history of blood transfusion, history of never using a condom, as well as a history of injury with a used sharp material were significantly associated with HCV infection. Conclusion The study showed a high seroprevalence of both HBV and HCV in Burera’s elderly population aged 45+ years. Several factors associated with HBV and HCV in this study could be prevented through education and improved hygiene.


Introduction
Historically, hepatitis has been described as a common cause of jaundice in the young population, which can develop into a chronic condition [1]. The hepatitis B virus (HBV) and hepatitis C virus (HCV) were discovered in the late 20 th century as the major causes of hepatitis [2,3]. In their chronic state, apart from being associated with cirrhosis and Hepatocellular Carcinoma (HCC) due to the prolonged immune clearance phase, 3.5% of the world's population (more than 250 million people) are infected with HBV with about one in five people residing in sub-Saharan Africa (SSA) [4][5][6][7] suffering from this disease.
Three percent (more than 170 million people) of the world population are infected with HCV with the majority also living in developing countries [3][4][5][6][7]. The transmission of HBV and HCV occur when the virus has been exposed to percutaneous or mucosal membrane.
According to Wertheim et al. [8], HBV is more easily transmitted through sexual contact, breast-feeding and transfer of other body fluids (saliva, semen, vaginal secretions, menstrual blood, and tears) of infected individuals rather than HCV. Other risks for infection include blood transfusion, unsafe use of therapeutic injectable drugs, sharing razors, and tattooing [9]. Health care workers (HCW), intravenous drug users (IVDU), patients on hemodialysis, blood product users and people located in high prevalence regions

After obtaining ethical approval from Butaro Hospital Ethical
Committee and INES review board, a cross-sectional study was conducted in Burera district from July to December 2017. The study population was comprised of adults (45+ years old) who were selected among the Burera population that attended a mass campaign for screening for hepatitis B and C. Verbal consent was obtained from 374 participants. Participants were then asked to provide socio-demographic information and the information related to the exposure on the risk factors associated with HCV and HBV infections. We drew 4 ml of blood from each participant through venipuncture using a vacutainer and an ethylene-diamine-tetra-acetic acid (EDTA) anticoagulant tube. Blood was centrifuged (Universal 320 R) at 3000 rpm. The obtained plasma was kept at -20°C until the test day. Murex Both kits were 100% sensitive and the absorbance, which is equal or greater than the cut off value, was considered as positive. Data were organized and entered in SPSS software version 20. Demographic characteristics were presented using frequencies and percentages, Chi-square (χ 2 ) test was used to assess the factors associated with HBV and HCV infections. A P value of less than 0.05 was considered significant.

Results
Of the 374 participants, the median age was 56 years, with an Interquartile range (IQR) of 50 to 63 years, with 53.2% being females and 46.8% being males. Most of the participants were married, working as farmers, with little to no education. The participants in this study were distributed equally across all social economic categories (Table 1) Table 2, Table 3, people aged between 58 to 68 years were most likely to be HBV positive with 9 of 81 (11.1%) participants in this age group testing positive for HBV. In terms of HCV, high seropositivity was found in the age group of those 68+ years old, with 13 of 66 (18.4%) participants testing HCV positive. Data assessing risk exposure are presented in Table 4, Table 5. Eighty-nine point six percent (335 of 374) of study participants who had never used a condom were significantly found HCV positive (p-value of 0.037).
Sixty-one percent (228 of 374) of those who shared personal items, 60% (224 of 374) who had been injured with a used sharp piercing material had a higher likelihood of HCV positivity (p-value of 0.029).

Discussion
Hepatitis B and C viral infections are hepatocyte specific agents that lead to all 96% of all viral hepatitis-related deaths [2]. Various studies have been conducted to describe and understand the burden of disease and to recommend preventive measures to eradicate infections. In 2015, the HBV and HCV prevalence were between 4.6-8.5% and 0.7-2.4%, respectively in Africa [7]. We found a higher seroprevalence than other studies conducted in Rwanda which might be due to the increased exposure and decreased immunity of the population in the topic. Other studies found the prevalence ranging from 2.4 to 4.5% for HBV and 1. Developing countries have a historically high prevalence of HCV, which is echoed by the findings of this study. Moreover, in this study, HCV antibody was detected amongst those who engage in unprotected sex and those who had an accidental injury with a used sharp object which is contradictory to many studies [14,16,18]. HBV has been efficiently linked with unprotected sex [22]. However, evidence shows that the relation between HCV and unsafe sexual intercourse is a rare case which is highly reported in men who have sex with men [23]. Despite that perspective, the contradiction observed in the population of Burera suggests that cohort studies could more effectively assess the association between this behavior and infection rates.

Conclusion
We found a high seroprevalence of HBV and HCV infections in Burera citizens aged 45+ years. Despite the fact that HBV and HCV have similar transmission modes, a striking difference in the seroprevalence was observed and only HCV had statistically significant association, including age, social economic level, blood transfusion, lifetime of unsafe sex intercourse and injury with a used sharp/piercing material.
This study highlighted the absence of HBV vaccination among the targeted population. Through education and improved hygiene, the identified factors can be prevented. A cohort study is needed to determine the prevalence of HBV and HCV in the general population to better understand associated risk factors.

What is known about this topic
• The prevalence of HCV infection in Rwanda increases with age, however HBV infection varies within age, and both are high among older person; • There are no known risk factors associated with viral hepatitis B in Rwanda.

What this study adds
• The prevalence of HBV and HCV is very high in older citizens in Rwanda; • Blood transfusion, history of never using condom, injury with a used sharp material and social economic level are associated with HCV among older citizens in Rwanda.

Competing interests
The authors declare no competing interests.  Table 1: socio-demographic and socio-economic characteristics of participants