HIV is one of the most prevalent and debilitating sexually transmitted diseases with approximately 35.3 million people living with the virus globally [1] . The disease is generally regarded as a pandemic [2] . Sub-Saharan Africa has the highest regional prevalence with an estimated 23.5 million people living with HIV [3] . Cameroon had an HIV prevalence of 5.5% which was among the highest in West and Central Africa [4] . Although the prevalence has been observed to be declining over the past decade, the number of people living with the disease has been on the rise from 416,000 in 2000 to 560,000 in 2010, with a projected increase of up to 726,000 in 2020 [5] . Within the country, the disease is not evenly distributed with the highest prevalence reported in the North West Region (8.7%), East (8.6%), Yaoundé (8.3%) and the South West (8%) while the lowest prevalence has been reported in North (1.7%) and Extreme North regions (2%) [5] .

Sexual contact is the major mode of transmission of HIV [6] . Other modes include contaminated blood transfusions, hypodermic needles, and modes from mother to child during pregnancy, delivery, or breastfeeding [6] . Risk factors of transmission include those that have to do with sexual behavior such as unprotected sex [7] , anal sex [7] [8] , presence of other STDs [9] , commercial sex workers [10] [11] . Currently there is no cure or vaccine for HIV. Preventing new HIV infections is the most effective way to halt the epidemic. National HIV control programs are greatly hinged on the education of at-risk population through regular sensitization campaigns which focus on promoting responsible sexual behaviour, such as monogamy, a reduction in partners, and correct and consistent condom use; ensuring a safe blood supply, treating STIs, and the organization of regular screening campaigns to ensure people know their HIV status.

Despite all these efforts, the number of people living with the disease is still on the rise in the country, with an estimated 51,315 new infections per year [5] . The contributing factors to these staggering numbers remain to be investigated. We hypothesized that the problem may lie on people living with HIV (PLHIV), which is largely overlooked especially in the North West Region of Cameroon, where the highest prevalence of HIV has been reported [5] . By studying the sexual behaviour of PLHIV in the North West region of Cameroon, we hope to generate data that may be useful in designing HIV control programs in the area.

The Human Immunodeficiency Virus (HIV) causes HIV/AIDS, a disease associated with progressive weakening of the human immune system making the individual more likely to get infections that usually does not occur in immunocompetent individuals [14] . As mentioned above, Cameroon with a prevalence of 5.5% is among the

highest in West and Central Africa [4] . The impact of HIV/AIDS in Cameroon is heavily felt in the economic sector where the disease is taking a heavy toll on the youths, and also the society where an increasing number of children are being orphaned by HIV/AIDS [15] . The Cameroon government in 1986 created the National AIDS Control Committee (NACC) to coordinate AIDS programs nationally. Some of its main strategic plans were to prevent mother to child transmission; prevent HIV transmission through blood; enhancement of access to treatment and care and the involvement of all stakeholder in the fight against HIV/AIDs [16] . Through this program, considerable achievements have been made evidence by the decreasing prevalence of the disease [5] . Yet the number of new cases and PLHIV is still on the rise in the country [5] . The contributing factors behind these numbers are not clearly understood.

We studied the characteristics and sexual risky behaviour of PLHIV relative to controls and observed that PLHIV were generally less educated (P < 0.001). Most of them attained only primary education with just a few progressing to the secondary and tertiary levels. It was also observed that a majority of PLHIV were farmers or generally self-employed with no steady source of income contrary to the control who were more involved in the public service with a steady source of income. Looking at the mean ages of the participants who were mainly youths, this is a reflection of the economic impact of HIV [17] as not only PLHIV will not be able to work and raise enough money, but will also require significant care and medical attention. These findings have implications in the control of the HIV which should be designed to target mostly the poor, underprivileged, and the less educated members of the population.

In this study, it was observed that PLHIV were more into polygamy meanwhile the control were more into monogamy. Among participants that were once married, a majority of PLHIV were divorced or widows. These are some of the factors that push PLHIV to engage into risky sexual practices as they search for new partners. Among individuals that were single and never married, PLHIV were significantly (P = 0.001) more sexually active as a greater proportion reported being involved in multi-partner sex. A greater proportion of PLHIV also reported a history of STDs than the control (P < 0.001). These findings are in support of studies that report that multi-partner sex and STDs are risk factors for infection with HIV [9] [18] [19] .

In this study, 80% of PLHIV reported to have had sexual intercourse after being diagnosed of HIV, with only a few reporting that they used condoms (41.78%), and a good number of them reported that their partner was not aware of their HIV status (47.14%). Poor condom usage among PLHIV has also been reported in Douala, Cameroon [20] . Poor condom usage has been known as one of the risk factors for HIV infection [19] not only to those without infection but also for the acquisition of another HIV strain (superinfection) in PLHIV [21] . For those who reported that their partner was aware of their status, it is likely that they were a married couple and were both infected meanwhile for those that reported that their sexual partner was not aware of their HIV status, it is likely that they were not married and is characteristic of people with multiple sexual partners. These practices by PLHIV could be the driving force in the ever increasing number of new infections in the study area. Studies have shown that treating PLHIV with antiretrovirals reduces the risk of transmission 10 to 20 folds [22] and provides 96% protection of their partners [23] . This is good news to HIV control programs which to aim at increasing the coverage of antiretrovirals in addition to educating PLHIV on their sexual behaviour, all of which could play a significant role in reducing the number of new number of new infections.

In this study it was observed that PLHIV were significantly less educated, poor and underprivileged with no steady source of income. PLHIV were observed to indulge more into sexual risky behaviour such as polygamy, divorced, widows, practiced multi-partner sex and low usage of condoms that not only exposes them to acquisition of another HIV strain (superinfection) but leads to infection of their partners thereby driving the ever increasing numbers of new infections and PLHIV in the North West Region of Cameroon.

As recommendations, HIV control programs should be designed to target the poor and less educated members of the population as well as PLHIV. PLHIV should be educated on their moral standard and risky sexual behaviour that put themselves and others at risk of infection. Education of PLHIV will be more cost-effective if it is integrated within HIV treatment programs. Lastly coverage of antiretrovirals should be increased to include many more PLHIV in rural areas as it has been associated with reduced risk of transmitting the virus from PLHIV to their otherwise non-infected partner.

KET conceived the study, participated in data collection, performed the analyses and interpretation, conducted the literature search and review, and wrote the first draft. TBDK participated in data collection, conducted the literature search and review, and wrote the first draft. NDS participated in data analysis, conducted the literature search and review, and critically revised the manuscript. NAL participated in data analysis, conducted literature search and review, and critically revised the manuscript. All authors read and approved the final manuscript.