Prevalence of Hepatitis B and Associated Factors in the Garoua Central Prison, Cameroon: A Cross-Sectional Study ()
1. Introduction
Hepatitis B virus (HBV) infection is a major public health problem in Cameroon which is in a high endemicity region for HBV infection and where the estimated global prevalence of HBV infection is 11.2% [1] . But there is a wide variation in that prevalence according to age and site of study, as shown by Nsenga Djapa et al in Ebolowa where the prevalence in adults on one hand and in children and teenagers on the other hand were respectively 8.9% and 1.9% [2] [3] . Garoua City is the headquarters of the North Region of Cameroon, where the HBV prevalence is among the highest in the country [4] . HBV prevalence in prisons setting varies from one country or region to another from 5.9% in Switzerland to 23.9% in Taiwan region [5] [6] [7] [8] . Although there is a controversy on whether the transmission rate is higher in prison or outside, the Hepatitis B prevalence estimates are usually higher in prisoners compared to that of the general population, and this may be explained by a poor access to appropriate health care service, overcrowding, poor nutrition state and higher exposure to other risk factors like unprotected sex and tattooing before or during incarceration [9] [10] . Moreover, a US CDC work group determined that persons incarcerated or formerly incarcerated in a jail, prison, or other detention setting should be considered at increased risk and therefore tested for HBV infection [11] . In Sub-Saharan Africa, there is a scarcity of data regarding the HBV infection in prisons. The aim of this study was to determine the prevalence of HBsAg carriage and associated factors among persons incarcerated in the Garoua Central Prison.
2. Methods
2.1. Study Design and Setting
It was a cross-sectional study conducted among occupants of Garoua Central Prison from July 1 to July 31, 2023. Garoua City is the headquarters of the North Region, with an estimated population of 370,000 inhabitants in early 2023 [12] . There were approximately 1700 permanent detainees according to the prison administration office and there are 09 health professionals delivering healthcare service. The prison has 15 carceral rooms divided into 5 quarters for different groups of persons: male teenagers (below 18 years old), male adults (between 18 and 55 years old), male elders (above 55), females of all age groups, and the last quarter consisting of an area where males of all age groups are sent in case of illness. During admission, every prisoner is systematically screened for Human Immunodeficiency Virus (HIV) and put on treatment if needed according to the prison’s medical staff, but HBV screening is not done.
2.2. Sample Size and Sampling Technique
The minimal sample size for this study was calculated using OpenEpi [13] and was set at 402 individuals considering the confidence interval at 95% and the precision at 1%. The selection of participants was empirical. We consecutively included all prisoners willing to participate to the study and who gave their verbal consent. We did not include minor prisoners in our study.
2.3. Data Collection and Laboratory Method
We collected data using a pre-established data entry form organized in the following sections:
- Sociodemographic data: age, gender, marital status, education level;
- Incarceration history: number of incarcerations and duration of incarcerations;
- Risk factors of HBV infection: number of sexual partners, history of male to male sexual intercourse, history of blood transfusion, history of surgery, dental extraction, sharing of sharp materials in prison like needles or razor blades, injectable drug use (IDU), tattooing practice or ear-piercing, and history of sexually transmitted diseases;
- History of HBV immunization;
- Results of the HBV screening.
For hepatitis B infection screening, five milliliters of venous blood were collected with a plain tube from each study participant by trained laboratory personnel. The blood sample was allowed to clot at room temperature and centrifuged at 5000 rpm for 15 minutes, and then the serum separated. The serum specimen was tested for HBsAg using the CTK’s Onsite® rapid lateral chromatographic immunoassay test kits developed by CTK Biotech (Poway, CA, USA). This test kit with a relative sensitivity of 100% and relative specificity of 99.1% according to the manufacturer was used for qualitative detection of HBsAg in the serum. Inmates who tested positive on the rapid test had a confirmatory ELISA test.
HBV infection was diagnosed when HBsAg was detected in the sample by both the rapid-using test and the ELISA test. The outcome variable was the presence of HBV infection, while sociodemographic characteristics and risk factors of HBV transmission were the predictor variables.
We obtained an administrative authorization from the Garoua Central Prison’s administration and an ethical clearance (N˚ 0009/CERSH/NO/2023) from the North Regional Ethics Board on Medical Research. Prisoners confirmed positive for viral hepatitis were referred to the medical doctor in charge of the North prisons health service for proper management in collaboration with a gastroenterologist.
2.4. Statistical Analyses
Data were analyzed using the R® software for Windows version 4.2.1 [14] . The results were expressed in counts and percentages for qualitative variables. For quantitative variables, mean ± standard deviation (sd) for normally distributed variables, or median with interquartile range (IQR) were considered where appropriate. Comparison of categorical variables was done using Chi-square test or Fisher test whereas comparison of quantitative variables was done using t-test or Mann-Whitney test where appropriate. After the univariate analysis, we selected associated variables to HBV infection with p-value < 0.2 for a logistic regression model in order to look for independently associated factors to this HBV infection. The p-value was set at 5%.
3. Results
We included 1389 detainees out of 1700, representing 81.7% of prisoners. The median age (IQR) was 28 years (23 - 35). The mean age was 30.3 ± 9.2 years. Male gender represented 97.6% (n = 1355) of our sample, giving a sex ratio (M/F) of 39.9/1. Thirty-seven percent of detainees received no formal education and the most represented marital status was that of “single” group which counted 726 (52.3%) detainees (Table 1). The mean (±sd) number of incarcerations was 1.24 (±0.6), with the median (IQR) duration of incarceration of 12 (6 - 26) months. Hepatitis B virus global prevalence was estimated at 14.8% (95% CI: 13.0 - 16.7). The prevalence was estimated at 14.9% (95% CI: 13.1 - 16.9) in males and 8.8% (95% CI: 3.0 - 22.9) in females. However, this difference was not statistically significant (p = 0.3232). Upon univariate analysis, Age (OR: 1; 95% CI [1 - 1.0], p = 0.109), Injection drug use (OR: 1.3; 95% CI [1 - 1.8], p = 0.06), past history of HBV screening (OR: 1.5; 95% CI [0.8 - 2.4], p = 0.186) and a past history of surgery (OR: 0.3; 95% CI [0.1 - 1], p = 0,12) were selected for multivariate analysis. Other socio-demographic parameters like gender (OR: 0.6; 95% CI [0.2 - 1.4], p = 0.345), level of education (OR: 1.03; 95% CI [0.8 - 1.4], p = 0.857 – OR: 1; 95% CI [0.7 - 1.3], p = 0.786 and OR: 1; 95% CI [0.3 - 2.3], p = 0.950 respectively for Primary, Secondary and University level) and marital status (OR: 1.1; 95% CI [0.9 - 1.4], p = 0.4191 and OR: 0.3; 95% CI [0.1 - 0.9], p = 0.0848 and OR: 0.5; 95% CI [0.03 - 2.1], p = 0.5129 respectively for married, divorced and widow status) were not statistically associated with hepatitis B infection. Incarceration history also did not interfere with the hepatitis b infection status (Table 2). Table 3 summarized the multivariate analysis and showed that none of the included risk factors were associated with hepatitis B infection, although past history of surgery had an adjusted OR of 0.3 (95% CI: 0.05 - 1) but this was not statistically significant since p = 0.0881.
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Table 1. Socio-demographic characteristics of prisoners and prevalence.
HBsAg: Hepatitis B surface antigen; sd: Standard deviation; IQR: Interquartile range.
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Table 2. Univariate analysis of HBV infection associated factors.
HBV: Hepatitis B virus; OR: Odds ratio; CI: confidence interval; MSM: men having sex with men; STD: sexually transmitted diseases; HCV: hepatitis C virus; HIV: human immunodeficiency virus.
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Table 3. Multivariate analysis of HBV infection associated factors.
aOR: Adjusted Odds Ratio; CI: Confidence interval.
4. Discussion
The aim of this study was to determine the prevalence of Hepatitis B infection in the Garoua Central Prison and associated factors. In this prison, detainees were mostly of male gender, with the median age (IQR) of 28 years (23 - 35). As for the prevalence, it was estimated at 14.8% (95% CI: 13.0 - 16.7). As far as the associated factors were concerned, no risk factor was significantly associated with HBsAg positivity in our study. Because of overcrowding and injection drug use in prisons, detainees are at higher risk of infectious diseases among which hepatitis B is a major problem [15] . Furthermore, data on HBV infection in a given group of population is important for planning of care and preventive measures implementation, including immunization campaigns targeting this group. This prevalence of 14.8% in our study, which is considered as high, is in line with the HBsAg prevalence of 12.9% in blood donors at the Garoua Regional Hospital, the prevalence of 12.9% in the Douala New Bell Prison, Cameroon and the global prevalence of 11.2% in the country [1] [6] [16] . It is also in line with the hepatitis B infection prevalence in studies conducted in prisons in Ghana, Nigeria, Togo and Senegal which were estimated at 17.4%, 13.7%, 10.9%, and 14.1% respectively [17] [18] [19] . But it is in contrast with the prevalence of less than 7% of HBV infection in prisoners in Ethiopia, India and Switzerland [5] [20] [21] . This tends to confirm the fact that the prevalence of HBsAg in prisoners in west and central Africa is the highest across the WHO regions [15] . In contrast with Kowo et al [6] in Douala New Bell Prison where male-to-male sex, sharp objects exchange and illicit drug use among others were important associated factors, no risk factor was significantly associated with hepatitis B upon multivariate analysis in our study. Though we hypothesize that injection drug use and male-to-male sex were underreported because both are illegal in Cameroon, detainees did not want the circuit of drug and the injection material to be discovered and the male homosexuality taboo in our context, our results may just be the confirmation of the fact that the risk factors we studied must be considered as additional risk factors, since the main routes of transmission of hepatitis B in high endemicity regions (Sub-Saharan Africa and Eastern Asia) are the mother-to-child transmission and the early horizontal transmission [22] .
Though its monocentric nature is a limitation, our study targeted the main prison in the region with the highest prevalence of HBV in our country and included most of the detainees.
5. Conclusion
The present study found that the prevalence of Hepatitis B was high in the Garoua Central Prison. Although no additional risk factors for HBV infection were found among prisoners, there is a need to include the Garoua Central Prison and by the way other prisons in the country in the chronic viral hepatitis care program which should include HBV vaccination and comprehensive healthcare services.
Appendix: Questionnaire (Data Collection Form)
Form N˚___________
Name initials: Age: ____ Years ____ Sex: M F
Level of Education: None Primary Secondary University
Marital Status: Single Married Divorced Widow/Widower
Vaccination against Hepatitis B: Yes No
Number of incarcerations: ______ Duration of actual incarceration: __________
Number of sexual partners before incarceration: _____________
Male-to-male sexual contact (Question concerning males only): Yes No
Past History of surgery: Yes No
Past History of blood transfusion: Yes No
Past History of dental care: Yes No
Sharing of syringes or razor blades: Yes No
Use of injectable drugs: Yes No
Presence of tattoo: Yes No
Piercing of ears or other body parts: Yes No
Past History of Sexually transmissible Infection: Yes No
Hepatitis B screening done in the past: Yes No
Results of hepatitis B (HBsAg) rapid test: Positive Negative
Results of hepatitis B confirmation test (ELISA): Positive Negative