Our study showed that males were more associated with HBV infection as compared to females. This has been established in previous studies [12, 14, 15] and could be attributed to hormonal and some protein expression differences. Oestrogen has been shown to play a protective role in females at reproductive age [16–18]. Some particular unusual apolipoprotein (A-I) found only on the hepatocytes of males have been shown to predispose them to the infection and its associated complications .
People with no income or with a monthly income of < 100,000XAF were more associated with the infection as compared to people with ≥ 100,000XAF monthly income as seen in another study . We could attribute this to the fact that people who earn more money can easily have access to the best and safest health practices (afford vaccines for instance) and life style that would limit their contact or the possibilities of them sharing objects/materials that may have been contaminated. Low income level have been shown to be a major characteristic of people living in rural areas both in Cameroon  and other parts of the world [22–25]. Our study also showed that people who live in rural areas were significantly more associated with HBV infection as compared to those in urban areas as seen in other studies [10, 26–28]. Poverty, high level of illiteracy, limited knowledge on preventive care, poor access to health care and dearth of sensitization may all account for the poor health outcomes in rural areas [25, 29].
Participants with ≤ secondary level of education were independently and significantly associated with HBV infection. Some other studies [30–32] have recorded similar findings. People with higher educational attainment tend to live a healthier live as compared to those with little or no educational background . Routine comprehensive health talks on HBV infection in primary and secondary schools could help to curb the transmission of HBV in our community as this would guarantee youth awareness of the infection and its preventive measures during the early stages of their academic lives.
Individuals with a history/presence of other sexually transmitted infections (STI) were significantly associated with HBV infection in our study population. This was also noticed in other studies [34, 35]. Despite all the identified sexual risk behaviours, our study instead showed that people who always use condoms were more associated with HBV infection. Some of the participants who “claimed” to be loyal users of condom also admitted having contracted at least one STI (chlamydia infection, gonorrhoea, syphilis etc) before in their lives and this gives us every reason to doubt their response or doubt their knowledge on proper use of condoms. Unfortunately, our study did not get into the details of assessing knowledge and practise of proper use of condoms. Assessment of sexual risk behaviours is usually very challenging because some people tend to be very reserved and shy when it comes to presenting the truth about their sexual life even for research purpose where there is a guarantee of confidentiality and no disclosure of identity [36, 37]. Interestingly, we realised that participants who knew their sexual partners were positive for HBV infection were independently and significantly not associated with the infection as compared to those who knew their partners were negative and those who did not know the status of their sexual partners. This tells us that people who knew their partners were HBsAg positive probably took adequate precautions like getting vaccinated, practising safe sex etc to ensure that they do not contract the infection themselves over time. People who did not know their partner’s status or knew that their partners were HBsAg negative probably paid less attention to safety precautions and/or vaccination against the infection over time.
History of blood transfusion was not associated with HBV infection in this study. This was observed in other studies as well [14, 38–40] but one study conducted in the North West Region of Cameroon  found an association. As a result of better diagnostic and screening methods of Transfusion Transmitted Infections (TTI) prior to blood transfusion, HBV transmission via this route seems to be decreasing over time . The careful and meticulous screening of donor’s blood usually disqualifies many donors due to HBsAg positivity. Our study further throws more light on this as blood donation was recorded as the second most common reason why our participants got tested for the first time and this exercise alone detected HBV infection in 48 (22.5%) of the 212 HBV infected participants.
The third most common reason for HBV screening in this study was subjection to some obligatory administrative requirements (14.9%). This includes requirements for a job acquisition, immigration, academic admissions etc. If these obligatory testing requirements where not applicable, some of the people in this particular group could have still been ignorant of their status even up till date. The idea of subjecting people to an obligatory testing as an administrative requirement can help improve uptake of HBV testing. However, because most of such institutions are not healthcare institutions, we cannot guarantee if they consider linking people to care (for those who test HBsAg positive) or vaccine acquisition (for those who test HBsAg negative) after testing as per the recommendations of WHO .
Thirty-seven (only 8.7%) of our participants got tested for the first time because they wanted to receive the HBV vaccine. HBV pre-vaccination testing (HBsAg or anti-HBc) is usually recommended for people in high risk groups (healthcare workers, sexual and household contacts of HBV infected persons etc) and for foreigners born in HBV endemic areas as per CDC. It could be quite important for this recommendation to as well include natives of HBV endemic regions like Cameroon as this would help improve uptake of HBV testing as well as identify those who do not need the vaccine because of a current infection or presence of an already developed natural immunity to the infection. Identifying such people prior to vaccination can be cost effective on their part as they would not have to pay for a vaccine they don’t need. The cost of taking the complete vaccine is way more expensive than the cost of doing the test in Cameroon.
Only 7 (1.7%) participants got tested for the first time as a result of sickness or clinical manifestations which could make the doctor to suspect HBV infection. The long-term asymptomatic nature of the disease greatly influences the number of people who end up getting tested as doctors seldom request for the test. As such, many infected cases go undetected and their ignorance could promote disease progression and further transmission to other uninfected susceptible people. In order to improve on the uptake of HBV tests in hospitals even in the absence of corroborative signs and symptoms of HBV infection, medical doctors could as well propose the test as some form of opportunistic screening  to every patient they attend to. This is a strategy that is currently being implemented to scale up HIV testing in Cameroon as approved by the public health sector. Considering the fact that HBV is more prevalent than HIV in our population and also the fact that HBV and HIV infection are both major public health problems, it could be helpful to as well adopt and encourage the hospital opportunistic screening strategy for HBV in Cameroon.
Voluntarily taking part in a free screening exercise was the most common reason for doing HBV test for the first time in this study. As a matter of fact, 93 (54.4%) participants did HBsAg test for their first time during our free screening exercise. The widest age range (16–65 years) at first HBsAg test was also found in this group of people. The significant proportion from our free screening was quite evident because the exercise lasted for long (about 4 years) and as such, could cover more people over time. However, the “free screening exercise” pretext as a reason for HBV testing may have been overrated in this study because our screening period just might have presented itself at a time when some participants realised the importance of doing the test for various reasons (pre-marital, pre-vaccine etc) but chose not to disclose these reasons to us. Another issue worth addressing here is the cost of doing HBsAg test. Although HBV infection happens to be more prevalent as compared to HIV in our community, HBsAg test is more expensive than HIV test. “Free screening exercises” are usually free of charge and this aspect alone is a huge motivation for people to voluntarily subject themselves to it. Considering the fact that Cameroon is classified as a lower middle-income country according to world bank and also the fact that our study revealed an association between low income and HBV infection, a practical approach to detect more HBV infected people in our community could be to significantly lower the cost of the test or to offer the test free of charge.
In conclusion, male sex, low income level, rural settlement, ≤secondary level of education, history of STI and ignorance of sex partners HBsAg status were all significantly associated with HBV infection. Free screening, blood donation and administrative requirements were the most common reasons for HBV testing in our study population. Sensitization even at the level of primary and secondary schools could help educate the population early enough to prevent transmission. Uptake of HBV testing and early detection can be improved if more (prolonged) free/opportunistic screenings are carried out and if the health sector subsidizes the cost of the test significantly as a means to encourage people to get tested.