|Year : 2016 | Volume
| Issue : 2 | Page : 60-67
Sexual behavior and risk factors for HIV infection among young people aged 15-24 years in North-Central Nigeria
Patricia Aladi Agaba1, Rahila Makai2, Clement T Bankat3, Phillipe R Chebu2, Temi Apena4, Ochanya Iyaji-Paul4, John A Idoko5
1 Department of Family Medicine; AIDS Prevention Initiative Nigeria, Jos University Teaching Hospital, Jos, Nigeria
2 AIDS Prevention Initiative Nigeria, Jos University Teaching Hospital, Jos, Nigeria
3 Hope Support Group, Jos University Teaching Hospital, Jos, Nigeria
4 Halt AIDS Group, Jos, Nigeria
5 Department of Medicine, University of Jos, Jos, Nigeria
|Date of Web Publication||13-Oct-2016|
Patricia Aladi Agaba
Department of Family Medicine, University of Jos, Jos
Source of Support: None, Conflict of Interest: None
Background: Young people continue to account for the majority of new HIV infections in Sub-Saharan Africa, yet a few studies focus on this group. We assessed sexual behavior, determined HIV prevalence infection, and explored risk factors for infection among young persons in Jos, Nigeria.
Methodology: This cross-sectional survey involved young people aged 15-24 years in Plateau State, Nigeria. Sociodemographic and sexual history was obtained. HIV counseling and testing was provided in accordance with national guidelines. Logistic regression was used to assess independent risk factors for HIV infection.
Results: Out of 4302 participants, 2032 (47.7%) were females, with a mean age of 19 ± 2 years, with males being older than females (P < 0.001). The mean age at sexual debut was 17 ± 2 years for females and 16 ± 3 years for males (P = 0.03). Three hundred and twelve (14%) males and 132 (6.5%) females had multiple sexual partners (P < 0.001). Majority (74.0%) had unprotected sex at their most recent sexual encounter. Seventy-eight (1.8%) participants were HIV-positive, out of which 75 were females (96.1%). Risk factors for HIV infection were female sex (adjusted odds ratio [aOR]: 53.47, confidence interval [CI]: 12.94-220.88), older age group (aOR: 5.37, CI: 2.68-10.77), residence in an urban area (aOR: 2.40, CI: 1.31-4.41), multiple sexual partners (aOR: 2.38, CI: 1.24-4.54), and being in a polygamous marriage (aOR: 3.31, CI: 1.17-9.32).
Conclusion: HIV prevention efforts in Nigeria need to focus on girls in the late adolescence who reside in urban areas and have multiple sexual partners, either by choice or in marriage setting, and equip them with skills to negotiate safe sex with their partners.
Keywords: Adolescents, HIV infection, risk factors, sexual behavior
|How to cite this article:|
Agaba PA, Makai R, Bankat CT, Chebu PR, Apena T, Iyaji-Paul O, Idoko JA. Sexual behavior and risk factors for HIV infection among young people aged 15-24 years in North-Central Nigeria. J Med Trop 2016;18:60-7
|How to cite this URL:|
Agaba PA, Makai R, Bankat CT, Chebu PR, Apena T, Iyaji-Paul O, Idoko JA. Sexual behavior and risk factors for HIV infection among young people aged 15-24 years in North-Central Nigeria. J Med Trop [serial online] 2016 [cited 2017 May 26];18:60-7. Available from: http://www.jmedtropics.org/text.asp?2016/18/2/60/192212
| Introduction|| |
Globally, 36.7 million people were living with HIV infection at the end of 2015, and 2.1 million of these infections were newly acquired in that year.  Sub-Saharan Africa bears an inordinate share of the HIV burden, with HIV epidemics being perpetuated primarily through sexual transmission of infection to successive generations of young people. HIV accounted for the second largest number of deaths among adolescents in 2013. , In the WHO Africa region, fewer than 1 in 5 girls and an even smaller proportion of boys aged 15-24 years know their HIV status.  Young people account for nearly half of new HIV infections in most regions. Given the practical difficulty of conducting HIV incidence studies, serial HIV prevalence over time in young women attending antenatal care clinics serves as a proxy measure for incidence, providing important indicators for epidemiological trends. It is believed that cases of HIV infection diagnosed among 15-24 year olds are indicative of overall trends in HIV incidence because this age group has likely initiated high-risk sexual behavior and HIV infection is likely to be recently acquired.
There is evidence that acknowledging the sexual activity of young people and meeting their sexual health needs with targeted education and prevention services can help reduce risky sexual behavior and its consequences. , Young people appear more likely to have sex with high-risk or multiple sexual partners and are less likely to use condoms.  Moreover, HIV programs generally struggle to reach and retain adolescents and tend to lack adolescent services. ,
Among Nigerian adolescents, HIV is predominantly heterosexually transmitted and has been ascribed to several sociocultural, economic, and individual factors.  Many young people in Nigeria have never been tested for HIV and therefore do not know their status despite engaging in sexual activity. The provision of HIV counseling and testing (HCT) services is therefore a good opportunity to not only get to know their HIV status but also encourage reduction in risky sexual behavior. Studies from developed countries have found low uptake of HCT among adolescents in spite of high-risk sexual behavior. , However, there is a dearth of studies linking sexual behavior and HIV infection among adolescents in Nigeria. In this study, we aimed to describe the sexual behavior, prevalence of HIV infection, and its risk factors among young persons aged 15-24 years in a North-Central Nigerian State.
| Methodology|| |
Study Site and Population
This study utilized data collected a part of a larger study and presented data from participants aged 15-24 years of age. The study took place in Plateau State, North-Central Nigeria, 2006-2009, except for its capital city, Jos, which the state is rural and agrarian. Its population of 3,206,531 million people includes 20 ethnic groups spread across 17 local government areas (LGAs). The Hope Support Group (HSG) is a registered group of persons living with HIV/AIDS and accessing care, treatment, and support services from the HIV treatment program at the Jos University Teaching Hospital (JUTH) in Jos. As part of its objectives to increase community awareness on HIV/AIDS and encourage community uptake of HCT services, HSG embarked on the provision of mobile community-based HCT with same-day testing and disclosure of results within Jos and environs. Six LGAs were covered using a convenient sampling technique, namely Jos North, Jos South, Jos East, Bassa, Mangu, and Riyom LGAs. For the purpose of this study, a community was defined as a group of individuals who live in proximity to one another and participate in common practice, depend on one another, make decisions together, identify themselves as part of something larger than the sum of their individual relationships, and commit themselves to the group's well-being. Based on referral data from stand-alone HCT centers and community-based organizations to the HIV clinic at JUTH, 22 communities were selected by simple random method. HSG embarked on the provision of mobile-free HCT with the aim of providing HIV/AIDS prevention education and HIV testing opportunities to members of the communities with a high volume of referrals of HIV-positive clients to the HIV clinic in JUTH. The Human Research Ethics Committee of the JUTH approved the study.
For each community identified, 2-3 advocacy visits were made to identify the key stakeholders and gatekeepers of the community. Meetings were held with various interest groups, and the intentions, aims, and objectives of the outreach were well outlined and questions and concerns addressed. Convenient date and venue for the proposed outreach were thereafter agreed upon.
Full-day outreaches were used to meet our objectives. Three days before each outreach, mobilization campaigns were carried out in the communities using the support group members and peer educators within the community. Market days and social meeting points were targeted to ensure maximum reach. The key stakeholders announced the dates and venues of the outreaches to their various constituencies. On the day of the outreach, a reception area, counseling rooms, testing area, and other convenient spaces were designated. HCT was offered to all community members with the opt-out option. Focus group discussions and group pretest counseling were employed because of the large turnout. The clients who indicated interest in having an HIV test were invited to register at the reception and were given an identification number.
HIV testing was conducted in accordance with existing national guidelines and testing algorithms.  A rapid test was reported negative if a participant had two parallel negative tests and positive if a participant had two parallel positive tests. Participants with one positive and one negative rapid test were considered indeterminate and a third rapid test assay was used as a tiebreaker. Therefore, if the tiebreaker test was negative, a negative test result was given and the converse was given as a positive test result. Determine HIV 1/2™ (Abbott Laboratories, Abbott Park, IL, USA) and HIV 1/2 STAT-PAK® (Chembio Diagnostics Inc., Medford, NY, USA) rapid test kits were used in parallel. Discordant results were resolved using Genie II (Bio-Rad Laboratories, France) as the tiebreaker.
Same-day testing with disclosure of results was employed. Group pretest counseling was provided in batches as the participants turned up for the outreach in groups of 8-12 participants. Individual posttest counseling was provided to all clients who had an HIV test. Clients who tested positive were linked to treatment and support services at JUTH.
Data were collected using an interviewer-administered questionnaire during the posttest counseling session. The instrument was a modified version of that used for the national sentinel survey.  The outcome measure had a positive HIV test result. We explored the association between those having a positive HIV test and the following independent variables: age (which was dichotomized into 15-19 and 20-24 years), marital status, level of education, religion, place of domicile (urban versus rural), condom use at last sex, number of sexual partners in the past 12 months, sex with a casual partner, multiple sexual partners, and early sex (age of sexual debut ≤15 years).
Epi Info version 3.5.3 (CDC, Atlanta, Georgia, USA) was used for data analysis. Means with standard deviation and median (interquartile range [IQR]) were calculated and analyzed using Student's t-test. Proportions for categorical variables were assessed for significance using Chi-square test. Bivariable cross-tabulations measured the association of our outcome variables (HIV-positive status) with each risk factor. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated for each association. In multivariate analysis, a logistic regression model including significantly associated risk factors was used to determine predictors of HIV-positive status. Risk factors were included in the model if they had P ≤ 0.25 in bivariate analysis. Two-tailed P < 0.05 was considered statistically significant.
Consent for testing was in-line with national HCT guidelines. The Human Research Ethics Committee at JUTH approved the protocol for the outreaches and data use.
| Results|| |
Of 4505 young persons aged 15-24 years who attended the outreaches, 241 were excluded from the analysis because they did not have HIV test even though they received HIV prevention education and pretest counseling.
The mean age of the 4302 participants included in this analysis was 19 ± 2 years, and 2032 (47.7%) were females. Male participants were older than the females (20 ± 2 vs. 19 ± 2, P < 0.001) and 2268 (53.1%) were aged between 15 and 19 years. Two thousand and thirty (64.0%) were students while 191 (4.5%) had not received formal education. The majority of participants (82.3%) were single. However, of those reporting single marital status, 37 (0.8%) were cohabiting with a regular sexual partner and 33 (0.7%) had regular sexual partners but were living apart. Three thousand eight hundred and sixty-four (91.6%) were of the Christian faith. One hundred and thirty-one female participants (5.2%) were pregnant at the time of the study. Details of other characteristics are shown in [Table 1].
|Table 1: Sociodemographic characteristics by HIV serostatus among young persons aged 15-24 years in Jos, Nigeria (n=4302)|
Click here to view
HIV-related Sexual Risk Behavior
The detail of sexual behavior as it relates to risk for HIV acquisition is shown in [Table 2]. The mean age at sexual debut was 17 ± 3 years for females and 16 ± 3 years for males (P = 0.03). The number of those with early sexual activity (sex before the age of 15) was 26 (1.3%) for females and 36 (1.6%) for males (P = 0.24). The median number of lifetime sexual partners was 1 (IQR: 1-11) for females while it was 1 (IQR: 1-21) for the males (P < 0.001). Three hundred and twelve (14%) males and 132 (6.5%) females admitted to having multiple sexual partners in the 12 months preceding the survey (<0.001). Condom use in the 12 months preceding the study was higher among males compared to the females (P < 0.001). More males reported having casual sex as compared to females (P < 0.001). Lower number of the female participants had used a condom at their most recent sexual act compared to the males (P < 0.001).
|Table 2: Sexual behavior stratified by sex among participants aged 15-24 years in Jos, Nigeria|
Click here to view
HIV Prevalence, HIV Status, and Risk Factors for Infection
Overall, 78 (1.8%, 95% CI: 1.4-2.3%) of 4302 participants were HIV positive. The majority of the HIV-positive participants were females (90.1%), giving a gender-based prevalence of 3.7% (95% CI: 3.0-4.7%) for females and 0.1% (95% CI: 0.0-0.4%) for males. [Table 1] shows the sociodemographic characteristics by gender and HIV prevalence of participants. The majority of HIV infections were found in the 20-24-year-old age group for both sexes, 64 of the 75 HIV infections (85.5%) in women and two of the two HIV infections (100%) in men. There were no HIV-positive males in the 15-19 years age group. There was no difference in HIV prevalence across the levels of education. There was, however, a significant difference in HIV prevalence across the listed occupations. Participants who resided in urban areas had higher prevalence of HIV infection compared to those residing in rural areas. Three of 134 (4.1%) pregnant female participants were HIV positive.
As shown in [Table 3], independent predictors of HIV infection following logistic regression analysis were female gender (adjusted odds ratio [aOR]: 53.47, 95% CI: 12.94-220.88), older age group (aOR: 5.37, 95% CI: 2.68-10.77), urban residence (aOR: 2.40, 95% CI: 1.31-4.41), multiple sexual partners (aOR: 2.38, 95% CI: 1.24-4.54), and being in a polygamous marriage (aOR: 3.31, 95% CI: 1.17-9.32).
|Table 3: Independent predictors of HIV infection among 4264 young persons aged 15-24 years in Jos, Nigeria|
Click here to view
| Discussion|| |
Our study found that among young persons aged 15-24 years in Jos, Nigeria, HIV prevalence was 1.8% (95% CI: 1.4-2.3), which is lower than the national average. Females compared to males were found to have higher prevalence of HIV infection despite high rates of risky sexual behavior among both sexes. The independent predictors of HIV infection among our participants were female gender, older age group (20-24 years), residence in an urban area, polygamous marriage, and history of multiple sexual partners.
Women account for half of all people living with HIV worldwide and nearly 60% of HIV infections in Sub-Saharan Africa. , In a demographic survey conducted in rural Kenya,  HIV prevalence among persons aged 13-34 years was reported to 20.5% among women while it was 10.2% among men of the same age group. A 2007 national HIV/AIDS and reproductive health survey in Nigeria also reported a higher prevalence of HIV infection among women (4.0%) as compared to men (3.2%). The HIV prevalence for women in that survey was not only higher than that for men but also higher than the national average of 3.6%.  A similar trend was also reported in a nationally representative survey of HIV and sexual behavior among young South Africans. 15.5% of women tested positive for HIV compared to 4.8% of the men.  In other developing countries outside of Sub-Saharan Africa, young women are also reported to be more affected by the HIV epidemic than their male counterparts.  A Haitian study recently reported HIV prevalence of 6.3% among women and 5.5% among men in the capital city of Port-au-Prince.  A convergence of biological and social factors interacts to make women more vulnerable to HIV infection in many settings. Inherent physiological risk factors are compounded by power differential that limits women's sexual decision-making. Gender power imbalances in sexual relationships, cross-generational as well as transactional sex, and women's economic dependence on men in most developing countries are all factors that contribute to fuel the largely female HIV epidemics in these settings. ,
Adolescence is marked by an increased likelihood of risk taking and sensation seeking, and social/community factors such as an increase in the prominence of peer relationships and a reduction in parental involvement can put young people at risk for HIV and other sexually transmitted infections. Structural factors (laws/policies related to condom accessibility, access to sexual health services, poverty, and stigma) can also place adolescents at risk. , Being aged 20-24 years (compared to 15-19 years) was a risk factor for HIV infection among our participants. This trend is in keeping with reports from other Sub-Saharan African countries. ,,, In South Africa, youth aged 20-24 years had documented HIV prevalence of 16.5%, compared to 4.8% among 15-19 year olds in a national survey.  Data from a rural district in Kenya also demonstrated the same trend as well as data from Haiti where those aged 20-25 years were responsible for 75.2% of the HIV infections, compared to 22.3% among 16-19 year olds in an urban population of young Haitians. , Different risk behaviors are driving the epidemic depending in the area of the world under consideration. In Nigeria as in most of Sub-Saharan Africa, heterosexual transmission is a dominant mode of transmission, and similar patterns of acquisition are seen. In general, in these areas where heterosexual transmission of HIV is predominant, males are becoming infected at slightly older ages than females and lower rates. This is attributed to males having either younger or more similar aged female partners at coital debut. , However, a common theme throughout the differing epidemics in different parts of the world is the impact of individual-level risks as the core factors determining transmission and the many social networks, community, and public policy factors potentially impacting these individual-level risks.  Since one of the goals of the global fight against the HIV/AIDS epidemic, especially in the countries most affected, is reducing the prevalence of HIV infections among young people aged 15-24 years, effective prevention programs must target not only individual-level risk factors but also network, community, and public policy level issues in a manner that is culturally acceptable to those at risk.
The majority of the HIV-infected participants in our study resided in urban communities. Similarly, among South African youth, those living in urban informal areas had the highest HIV prevalence while those living in rural informal areas had the least prevalence.  Urban women in India have been reported to have higher risk of acquiring HIV, compared to women in rural areas.  Likewise, women in Kenya, who reported residence in an urban center at some point in their lives, had higher HIV prevalence compared to those who had lived all their lives in a rural setting.  Urbanization and migration increase opportunities for sexual encounters and provide new models of sexual behavior, with transgression of the more restrictive traditions that exist in rural areas. 
Marriage has been associated with risk for HIV infection in developing countries. , In our study, polygamous marriage was a risk for HIV infection. In India, having sex exclusively with one's husband was found to be the only risk factor for the majority of women with HIV. ,, Low frequency of condom use within marriage has been reported and may be responsible for the increased risk within the context of marriage in Africa as the men who are usually older tend to have multiple concurrent sexual partners often within the context of a polygamous marriage structure.  A previous study in our setting had linked sexual activity among young people to a polygamous family background.  HIV prevention efforts must, therefore, target married couples in our setting. We also demonstrated that having multiple sexual partners is a risk factor for HIV infection. The greater the numbers of sexual partner's young people have, the greater their potential exposure to HIV will be. Partner reduction is, therefore, one of the key factors of most HIV prevention programs.
The findings of our study have implications for HIV prevention efforts among young people in North-Central Nigeria. Equipping young girls with skills to negotiate safe sex with their older male sexual partners, in addition to income-generating activities to reduce women's economic dependence on men, will improve the skewed power structure. Since polygamous marriage has been demonstrated to be a risk for HIV, prevention programs targeting couples, especially in polygamous settings, will have to be incorporated into mainstream HIV programs. In addition, youth living in urban areas have increased vulnerability to HIV and should be specifically targeted by risk reduction programs.
Few studies in our setting have linked sexual behavior with HIV status among young people. Our study, therefore, provides useful data to inform policy on HIV prevention efforts among adolescents. Our large sample size also allows for generalization of our findings within North-Central Nigeria. However, the cross-sectional nature of our study means we could not determine causality. Another limitation of our study was the reliance on self-reported sexual behavior. Respondents often provide socially acceptable answers rather than the true picture, especially with regard to sensitive information such as sexual behavior. We attempted to minimize information bias by having trained counselors administer the questionnaire during the process of posttest counseling.
| Conclusion|| |
Our study showed low rates of condom use during sex among young persons in North-Central Nigeria. Young women aged between 20 and 24 years, residing in urban areas that reported a history of multiple sexual partners, and were married in a polygamous setting were particularly at increased risk of HIV infection. Efforts should emphasize safe sex practices as well successful sex negotiation skills for young girls. The role of marriage, especially within the context of polygamy and its effect on HIV transmission, should be explored and targeted by HIV education and prevention efforts in our setting.
We are grateful to the members of the Hope Support Group, Jos University Teaching Hospital, the staff and management of the AIDS Prevention Initiative Nigeria Plus at the Jos University Teaching Hospital and Halt AIDS group, Jos. We are also grateful to the communities that participated in this study.
Financial Support and Sponsorship
The HCT outreaches were funded in part by the US Department of Health and Human Services, Health Resources, and Services Administration (U51HA02522-01-01).
Conflicts of Interest
There are no conflicts of interest.
| References|| |
Olasode OA. Sexual behaviour in adolescents and young people attending a sexually transmitted disease clinic, Ile Ife, Nigeria. Indian J Sex Transm Dis 2007;28:83-6.
Raffaelli M, Crockett LJ. Sexual risk taking in adolescence: The role of self-regulation and attraction to risk. Dev Psychol 2003;39:1036-46.
Rosenberg NE, Pettifor AE, De Bruyn G, Westreich D, Delany-Moretlwe S, Behets F, et al
. HIV testing and counseling leads to immediate consistent condom use among South African stable HIV-discordant couples. J Acquir Immune Defic Syndr 2013;62:226-33.
Federal Ministry of Health [Nigeria]. National HIV/AIDS and Reproductive Health Survey, 2007 (NARHS Plus). Abuja, Nigeria: Federal Ministry of Health; 2008.
Inungu J, Lewis A, Mustafa Y, Wood J, O′Brien S, Verdun D. HIV testing among adolescents and youth in the United States: Update from the 2009 behavioral risk factor surveillance system. Open AIDS J 2011;5:80-5.
McGarrigle CA, Mercer CH, Fenton KA, Copas AJ, Wellings K, Erens B, et al
. Investigating the relationship between HIV testing and risk behaviour in Britain: National survey of sexual attitudes and lifestyles 2000. AIDS 2005;19:77-84.
Federal Ministry of Health Nigeria. The 2005 National HIV Seroprevalence Sentinel Survey among Pregnant Women Attending Antenatal Clinics in Nigeria: Summary Position Paper, Abuja; 2006.
WHO, UNICEF and UNAIDS. A Guide on Indicators for the Monitoring and Reporting on the Health Sector Response to HIV/AIDS. Geneva: World Health Organization; 2011. Available from: http://www.who.int/hiv/data/tool2011/en
. [Last accessed on 2011 Oct 15].
Amornkul PN, Vandenhoudt H, Nasokho P, Odhiambo F, Mwaengo D, Hightower A, et al.
HIV prevalence and associated risk factors among individuals aged 13-34 years in rural Western Kenya. PLoS One 2009;4:e6470.
Pettifor AE, Rees HV, Steffenson A, Hlongwa-Madikizela L, MacPhail C, Vermaak K, et al
. HIV and Sexual Behaviour among Young South Africans: A National Survey of 15-24 Year Olds. Johannesburg: Reproductive Health Research Unit, University of the Witwatersrand; 2004.
Dorjgochoo T, Noel F, Deschamps MM, Theodore H, Dupont W, Wright PF, et al
. Risk factors for HIV infection among Haitian adolescents and young adults seeking counseling and testing in Port-au-Prince. J Acquir Immune Defic Syndr 2009;52:498-508.
Hallett TB, Gregson S, Lewis JJ, Lopman BA, Garnett GP. Behaviour change in generalised HIV epidemics: Impact of reducing cross-generational sex and delaying age at sexual debut. Sex Transm Infect 2007;83 Suppl 1:i50-4.
Rositch AF, Cherutich P, Brentlinger P, Kiarie JN, Nduati R, Farquhar C. HIV infection and sexual partnerships and behaviour among adolescent girls in Nairobi, Kenya. Int J STD AIDS 2012;23:468-74.
Harper GW. Sex isn′t that simple: Culture and context in HIV prevention interventions for gay and bisexual male adolescents. Am Psychol 2007;62:803-19.
Borek N, Allison S, Cáceres CF. Involving vulnerable populations of youth in HIV prevention clinical research. J Acquir Immune Defic Syndr 2010;54 Suppl 1:S43-9.
Gregson S, Gonese E, Hallett TB, Taruberekera N, Hargrove JW, Lopman B, et al
. HIV decline in Zimbabwe due to reductions in risky sex? Evidence from a comprehensive epidemiological review. Int J Epidemiol 2010;39:1311-23.
Shisana O, Rehle T, Simbayi LC, Zuma K, Jooste S, Zungu N, et al
. South African National HIV Prevalence, Incidence and Behaviour Survey, 2012. Cape Town: HSRC Press; 2014.
Hallett TB, Stover J, Mishra V, Ghys PD, Gregson S, Boerma T. Estimates of HIV incidence from household-based prevalence surveys. AIDS 2010;24:147-52.
National AIDS Control Council, National AIDS/STI Control Programme. Sentinel Surveillance of HIV and AIDS in Kenya 2006. Nairobi; 2007.
Shisana O, Connolly C, Rehle TM, Mehtar S, Dana P. HIV risk exposure among South African children in public health facilities. AIDS Care 2008;20:755-63.
Wilson CM, Wright PF, Safrit JT, Rudy B. Epidemiology of HIV infection and risk in adolescents and youth. J Acquir Immune Defic Syndr 2010;54 Suppl 1:S5-6.
Ghosh P, Arah OA, Talukdar A, Sur D, Babu GR, Sengupta P, et al.
Factors associated with HIV infection among Indian women. Int J STD AIDS 2011;22:140-5.
Lydié N, Robinson NJ, Ferry B, Akam E, De Loenzien M, Abega S; Study Group on Heterogeneity of HIV Epidemics in African Cities. Mobility, sexual behavior, and HIV infection in an urban population in Cameroon. J Acquir Immune Defic Syndr 2004;35:67-74.
Central Bureau of Statistics (CBS) [Kenya], Ministry of Health (MOH) [Kenya], and ORC Macro. Kenya Demographic and Health Survey 2003. Calverton, Maryland: CBS, MOH, and ORC Macro; 2004.
Auvert B, Buvé A, Ferry B, Caraël M, Morison L, Lagarde E, et al
. Ecological and individual level analysis of risk factors for HIV infection in four urban populations in sub-Saharan Africa with different levels of HIV infection. AIDS 2001;15 Suppl 4:S15-30.
Newmann S, Sarin P, Kumarasamy N, Amalraj E, Rogers M, Madhivanan P, et al
. Marriage, monogamy and HIV: A profile of HIV-infected women in South India. Int J STD AIDS 2000;11:250-3.
Kenyon C, Boulle A, Badri M, Asselman V. "I don′t use a condom (with my regular partner) because I know that I′m faithful, but with everyone else I do": The cultural and socioeconomic determinants of sexual partner concurrency in young South Africans. SAHARA J 2010;7:35-43.
Slap GB, Lot L, Huang B, Daniyam CA, Zink TM, Succop PA. Sexual behaviour of adolescents in Nigeria: Cross sectional survey of secondary school students. BMJ 2003;326:15.
Glynn JR, Kayuni N, Banda E, Parrott F, Floyd S, Francis-Chizororo M, et al
. Assessing the validity of sexual behaviour reports in a whole population survey in rural Malawi. PLoS One 2011;6:e22840.
[Table 1], [Table 2], [Table 3]