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 etal 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.

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 (Table1). 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 (Table2). Table3 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.

Table 1. Socio-demographic characteristics of prisoners and prevalence.

HBsAg: Hepatitis B surface antigen; sd: Standard deviation; IQR: Interquartile range.

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.

Table 3. Multivariate analysis of HBV infection associated factors.

aOR: Adjusted Odds Ratio; CI: Confidence interval.

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 etal [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 taboo between males 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.

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.

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