HIV infection and sexual partnerships and behaviour among adolescent girls in Nairobi, Kenya.

Abstract

Early sexual partnerships place young women in sub-Saharan Africa at high risk for HIV. Few studies have examined both individual- and partnership-level characteristics of sexual relationships among adolescent girls. A cross-sectional survey of sexual history and partnerships was conducted among 761 adolescent girls aged 15-19 years in Nairobi, Kenya. Rapid HIV testing was conducted and correlates of HIV infection were determined using multivariate logistic regression. The HIV prevalence was 7% and seropositive adolescents had a younger age at sexual debut (P < 0.01), more sexual partners in 12 months (P = 0.03), and were more likely to report transactional or non-consensual sex (P < 0.01). Girls who reported not knowing their partner's HIV status were 14 times as likely to be HIV-seropositive than girls who knew their partner's status (adjusted odds ratio: 14.2 [1.8, 109.3]). Public health messages to promote HIV testing and disclosure within partnerships could reduce sexual risk behaviours and HIV transmission among adolescents.

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ORIGINAL RESEARCH ARTICLE
HIV infection and sexual partnerships and behaviour among
adolescent girls in Nairobi, Kenya
A F Rositch PhD MSPH*, P Cherutich MBChB MPH†, P Brentlinger MD‡, J N Kiarie MBChB MMed§,
R Nduati MBChB MMed** and C Farquhar MD MPH††
*Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA;†National AIDS/STD Control Programme,
Ministry of Health-Kenya, Nairobi, Kenya;‡Department of Global Health, University of Washington, Seattle, WA, USA;§Department of Obstetrics
and Gynaecology; **Department of Paediatrics, University of Nairobi, Nairobi, Kenya;††Departments of Medicine, Epidemiology, and Global
Health, University of Washington, Seattle, WA, USA
Summary: Early sexual partnerships place young women in sub-Saharan Africa at high risk for HIV. Few studies have examined
both individual- and partnership-level characteristics of sexual relationships among adolescent girls. A cross-sectional survey of
sexual history and partnerships was conducted among 761 adolescent girls aged 15–19 years in Nairobi, Kenya. Rapid HIV testing
was conducted and correlates of HIV infection were determined using multivariate logistic regression. The HIV prevalence was 7%
and seropositive adolescents had a younger age at sexual debut (P , 0.01), more sexual partners in 12 months (P ¼ 0.03), and were
more likely to report transactional or non-consensual sex (P , 0.01). Girls who reported not knowing their partner’s HIV status were 14
times as likely to be HIV-seropositive than girls who knew their partner’s status (adjusted odds ratio: 14.2 [1.8, 109.3]). Public health
messages to promote HIV testing and disclosure within partnerships could reduce sexual risk behaviours and HIV transmission
among adolescents.
Keywords: HIV, adolescents, risk factors, sexual behaviour, partnerships, sub-Saharan Africa, young women
BACKGROUND
Young people in sub-Saharan Africa continue to be one of the
populations at greatest risk for HIV infection, and the risk is
particularly high among young women.1,2In Kenya, the 2008
Demographic and Health Survey (DHS) reported the median
age of sexual debut among Kenyan women was approximately
18 years.2The prevalence of HIV among girls 15–19 years old
was 3%, which was four times the HIV prevalence among
boys of the same age.2In Africa, individual sexual risk beha-
viours such as young age at sexual debut, multiple partners
and commercial sex work have been associated with increased
risk of HIV acquisition among young adults.3–10However,
partnership-level characteristics among young people and
their association with HIV infection are less clearly understood
in sub-Saharan Africa.11,12The few studies on adult and adoles-
cent sexual partnerships have found characteristics, such as
concurrency13–17
andage
ners,3,10,18–21to be important factors for HIV risk and trans-
mission. Because early sexual partnerships may influence
adolescent risk of HIV acquisition, a more comprehensive
understanding of partnerships and sexual risk behaviours is
needed.
In 2005–2006 we conducted a large cross-sectional survey of
adolescent girls seeking reproductive health services and found
discrepanciesbetweenpart-
that only 21% of sexually active female adolescents had ever
used a condom.22In the current study, we used data from
this survey to examine additional details of sexual behaviours
and male partners that expose adolescent girls to HIV. This
was done to better understand factors associated with the
high risk of HIV among adolescent girls and guide HIV preven-
tion interventions.
METHODS
Study sites and population
A detailed description of the recruitment procedures and study
sites were previously described.22Briefly, the study was carried
out in three health facilities in Nairobi, Kenya. The Kariobangi
and Lunga Lunga Health Centers are two of 10 municipal
clinics that offer voluntary HIV counselling and testing
(VCT), screening for sexually transmitted infections (STI) and
maternal and child health-care services. Over 30% of all
women presenting at these health centres were adolescents
seeking reproductive health care. The third site was the adoles-
cent health clinic at Kenyatta National Hospital (KNH), the
only public referral hospital in Nairobi. The KNH adolescent
clinic offers VCT, post-abortion care and antenatal care.
All adolescent girls presenting to the study sites between
August 2005 and May 2006 seeking reproductive health care,
defined as ante- or postnatal care, family planning and treat-
ment for STIs, were screened for participation in this
Correspondence to: A F Rositch
Email: arositch@jhsph.edu
International Journal of STD & AIDS 2012; 23: 468–474. DOI: 10.1258/ijsa.2012.011361

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cross-sectional study. To be eligible for inclusion, a woman had
to be 15–19 years of age, sexually active, able to communicate
in Swahili or English and able and willing to provide informed
consent. Written informed consent was obtained from all study
participants. According to national guidelines on reproductive
health and HIV testing and counselling mature minors, such
as those in this population who were married, pregnant or
seeking STI or reproductive health services, are not required
to get consent from their guardians or give assent.
This study received ethical approval from the institutional
review boards of the University of Washington and the
University of Nairobi. The focus of the main study was to
examine dual contraception among adolescents, thus adoles-
cents were excluded if they had not initiated sexual activity,
or if they had a previous hysterectomy or tubal ligation.22
After administration of the five-part questionnaire, consenting
girls were offered group or individual HIV counselling and
testing using the opt-out approach as per Kenyan Ministry of
Health Guidelines.
Measures and analysis
The study questionnaire was based on standardized questions
developed and validated by Monitoring and Evaluation to
Assess and Use Results-DHS and the Kenya Central Bureau
of Statistics. The questionnaire was administered by study
nurses to obtain individual-level information such as sociode-
mographic status, pregnancy and gravidity, perception of risk
for HIV infection and sexual behaviour. Partnership-level infor-
mation included the duration and type of relationship with the
partner, age difference, perceived faithfulness, knowledge of
partner’s HIV status and whether sexual relationships were
concurrent or serial. Partner- and partnership-related variables
were based on the girls’ reports without partner verification.
Most variables pertained to the ‘current’ partner (the main
partner with whom the girl was having a sexual relationship
with at the time of the questionnaire), however a subset per-
tained to the ‘other’ sexual partner (previous or other current
sexual partner in the last 12 months, if any). The primary
outcome measure was the HIV status of the female adolescents,
as indicated by the results of their HIV testing at the time of the
study. HIV testing was performed after the administration of
the questionnaire so as not to bias HIV risk perception. HIV-1
testing was conducted on site using the Determine HIV-1/
HIV-2 (Abbott Laboratories, Abbott Park, IL, USA) or the
Bioline HIV-1/2 (Standard Diagnostics, Yongin-si, Korea)
rapid tests. Positive tests were confirmed using the Uni-Gold
Recombigen rapid HIV test (Trinity Biotech Plc, Bray, Co
Wicklow, Ireland). Girls were classified as HIV-1 seropositive
if either Determine or Bioline were positive and confirmed
with a positive Unigold test, and as HIV-1 seronegative if the
Determine or Bioline was negative. Girls were classified as
HIV-1 seropositive if either Determine or Bioline were positive
and confirmed with a positive Unigold test, and as HIV-1 ser-
onegative if the Determine or Bioline was negative. If either
the Determine or Bioline test was positive and the confirmatory
Unigold test was negative, this was considered to be an indeter-
minate result and the participant was not included in this
analysis (n ¼ 1).
To describe the differences and compare the self-reported
sexual history and characteristics of sexual partnerships
among adolescent girls who were HIV-seropositive compared
with HIV-seronegative, Pearson chi-squared and Fisher’s
exact tests were used for categorical variables and the
Mann-Whitney rank-sum test was used for continuous covari-
ates. Unadjusted and adjusted odds ratios (AOR) with robust
95% confidence intervals (CI) for the associations between
female adolescent HIV infection and sociodemographic charac-
teristics and sexual behaviours and partnerships were calcu-
lated. The multivariate logistic regression model included all
covariates found to be significant in bivariate analyses (P,
0.05), in addition to study clinic which was included a priori
as a potential confounder; no interactions between the covari-
ates were found (P, 0.10). All analyses were conducted in
SAS version 9.2 (SAS Institute, Cary, NC, USA).
RESULTS
Description of study population
The final study population included 761 of 866 eligible female
adolescents (88% participation rate) (Figure 1) of whom 55
(7%) were HIV-infected. The median age of adolescents in the
study population was 18 years (interquartile range [IQR]:17,18
The majority of girls were recruited from the Kariobangi
Health Center (56%), were seeking ante- or postnatal care
(81%), or were married or cohabiting (68%) (Table 1). Most ado-
lescents had a primary education or less (73%) and were no
longer attending school (94%). Only 14% reported earning a
monthly income, with a median of approximately $32 US
dollars per month (IQR: $20–53).
Adolescent sexual behaviours
The median age at sexual debut was 16 years (IQR: 15–17) and
most girls were pregnant at the time of the study (76%) and
reported no previous pregnancies (67%) (Table 1). In the
previous 12 months, 14% of girls reported two or more sexual
partners, 9% self-reported STI and 20% reported any condom
use. Over their lifetime, 3% of the adolescents reported exchan-
ging sex for favours or money and 12% reported having been
forced to have non-consensual sexual intercourse. The majority
of the girls had not had a previous HIV test (60%). In a series of
questions to understand their perception of HIV risk, 24% of
adolescent girls responded strongly that they were too young
to get HIV, 8% thought that they had had sex with someone
at risk for HIV and 13% strongly believed that they were at
risk for HIV, although it is unknown which girls knew they
were HIV-seropositive prior to the study (Table 1).
Adolescent sexual partnerships
In this population of sexually active adolescent girls, 66% of
current sexual partnerships were with spouses or cohabitating
partners, and most partnerships were at least one year in dur-
ation (63%) (Table 2). Nearly all current sexual partners were
older men (97%), with a median age difference of five years
older (IQR: 3–7). Most girls felt their current partner had
been unfaithful (66%) at some point in the partnership. Five
percent of adolescents reported the use of drugs or alcohol at
the last sexual experience with their current partner. Less than
one-quarter of adolescent girls reported knowing their current
partner’s HIV status (23%); most had partners who had not
been tested or did not share their HIV status. A minority of
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Rositch et al. Adolescent risk factors for HIV infection
469

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adolescents (10%) reported having other sexual partners in the
last 12 months: 27% of these overlapped in time with a primary
sexual partner (i.e. concurrent sexual partnerships). The
majority of other partners were also older, and girls were
more likely to use a condom with their other partner than
with their current partner (42% versus 27%; P ¼ 0.01).
Risk factors for HIV among adolescent girls
Differences were noted in the type of care being sought, as
HIV-seropositive adolescents were more likely to seek STI
and VCT services compared with HIV-seronegative adolescent
girls (Table 1). There was no difference in the proportion of
HIV-seropositive compared with HIV-seronegative girls with
an older partner (P ¼ 0.60) nor in the age difference of older
partners (P ¼ 0.68) (Table 2). There was no difference in
reported use of condoms by HIV-seropositive compared with
HIV-seronegative adolescent girls (P ¼ 0.77). Other partnership
characteristics, including use of drugs or alcohol prior to sex
(P ¼ 0.78) and concurrent partnerships (0.08) did not differ
between HIV-seropositive and HIV-seronegative girls.
Using univariate logistic regression models (Table 3), we
determined that adolescent girls who were earning an income
had a two-fold increased risk of being HIV-seropositive as com-
pared with those without an income (odds ratio [OR] ¼ 2.0;
95% CI ¼ 1.0, 3.9). In addition, each year increase in the age
at sexual debut (OR ¼ 0.8; 95% CI ¼ 0.6, 0.9) was associated
with a 25% decrease in the odds of HIV infection (Table 3).
Each additional year since sexual debut (OR ¼ 1.5; 95% CI ¼
1.2, 1.7) and additional lifetime sexual partner (OR ¼ 1.4; 95%
CI ¼ 1.0, 2.0) increased the odds of HIV infection among ado-
lescent girls. The odds of HIV infection were also increased
among adolescents who reported having an STI in the previous
year (OR ¼ 4.6; 95% CI ¼ 2.4, 8.9), ever exchanging sex
for money (OR ¼ 5.6; 95% CI ¼ 2.2, 14.1) and ever having
non-consensual sex (OR ¼ 2.86; 95% CI ¼ 1.5, 5.5). Adolescent
girls who reported not knowing their partner’s HIV status or
having partners who had not been tested had higher odds of
HIV infection (OR ¼ 17.7; 95% CI ¼ 2.4, 128.5).
In multivariate logistic regression models, the strongest inde-
pendent correlate of HIV infection among adolescent girls was
not knowing their sexual partner’s HIV status (AOR ¼ 14.2;
95% CI ¼ 1.8, 109.3) (Table 3). In addition, girls with more
years since sexual debut (AOR ¼ 1.3; 95% CI ¼ 1.1, 1.6), who
reported an STI (AOR ¼ 2.8; 95% CI ¼ 1.2, 7.6) and who had
ever given birth (AOR ¼ 2.0; 95% CI ¼ 1.1, 4.1) were signifi-
cantly more likely to be HIV-seropositive.
DISCUSSION
The prevalence of HIV was over 7% among sexually active ado-
lescents in our study populations, which was more than twice
the 2008 DHS estimate for all girls aged 15–19 years in
Kenya. Several modifiable risk factors, including knowledge
of partner HIV status, were strongly associated with HIV infec-
tion. Despite high HIV prevalence and ongoing unprotected
sex, a quarter of adolescents believed they were too young to
become infected with HIV. These adolescents also reported
sexual situations that put them at high risk for HIV, such as
exchanging sex for money and being forced to have sex
against their will. The results of this large, cross-sectional
survey of sexually active adolescent girls in Nairobi, Kenya,
demonstrate the urgent need to reach out to this population
at high-risk for HIV. Scaling up of adolescent friendly couple-
based interventions that include HIV testing, disclosure
support, condom distribution and antiretroviral therapy may
reduce HIV risk among young women in Africa.
Our results are consistent with previous literature that have
identified risk factors for HIV infection among adolescent
girls to be increased number of sexual partners, young age at
Figure 1
from three Nairobi health clinics
Flowchart of study participants by HIV infection and marital status. Final study population included 761 adolescent girls
................................................................................................................................................
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sexual debut, increased years since sexual debut and history of
STIs. Several studies have found strong associations between
HIVinfection and sexual
men.10,19,20,23Unlike previous studies, we observed no differ-
ence in the proportion of adolescents who currently or within
the previous year had older partners and no difference in
the age difference between recent partners among HIV-
seropositive compared with HIV-seronegative girls. Similarly,
Amornkul et al.24reported no association between male
partnershipswitholder
partner’s age and female HIV infection, however, young
women in their population were less likely to have older part-
ners. There is a strong body of literature suggesting that
sexual concurrency is a key driver of the HIV epidemic.15,25,26
Although there was a high prevalence of concurrent sexual
relationships in our young population, we did not find a clear
association with HIV infection. Our cross-sectional assessment
of concurrency was limited to only one other sexual partner in
the previous 12 months.
Table 1
Kenya
Sociodemographic and sexual characteristics of female adolescents attending reproductive health clinics in Nairobi,
HIV-seronegative (n 5 706)
N (%) or median (IQR)
HIV-seropositive (n 5 55)
N (%) or median (IQR)
Overall (N 5 761)
N (%) or median (IQR)Characteristics?
Sociodemographics
Age in years
Reason for attending clinic
Ante- and postnatal, family planning
STI evaluation, VCT, reproductive needs
Marital status
Not currently married†
Married
Partnered/cohabitating
Participant is an orphan
Yes
Current living situation
Lives with parent(s) or family member(s)
Lives with current partner
Lives with non-relative, other‡
Education level attained
Primary or less
Vocational, secondary and greater
Still attending school
Yes
Currently earn money
Yes
Monthly income
18 (17–18)18 (17–18)18 (17–18)
612 (87%)
94 (13%)
43 (78%)
12 (22%)
655 (86%)
106 (14%)
233 (33%)
282 (40%)
185 (26%)
15 (27%)
24 (44%)
16 (29%)
248 (33%)
306 (41%)
201 (27%)
99 (14%)11 (20%)110 (14%)
208 (29%)
312 (44%)
186 (26%)
14 (25%)
29 (53%)
12 (22%)
222 (29%)
341 (45%)
198 (26%)
496 (72%)
190 (28%)
45 (83%)
9 (17%)
541 (73%)
199 (27%)
39 (6%)2 (4%)41 (6%)
91 (13%)
$33 ($20–53)
13 (24%)
$20 ($13–33)
104 (14%)
$32 ($20–53)
Sexual behaviours
Age at first intercourse
Years since sexual debut§
Currently pregnant
Yes
Number of previous pregnancies
0
1
2þ
Number of sexual partners in last 12 months??
1
2þ
Treated for STI in last 12 months
Yes
Ever exchanged sex for money
Yes
Ever had non-consensual sex††
Yes
Previous HIV test
Yes
Individual beliefs of HIV risk‡‡
Too young to get HIV
Had sex with someone at risk of HIV
At risk for HIV
16 (15–17)
1 (1–3)
15 (14–16)
3 (2–4)
16 (15–17)
2 (1–3)
535 (77%)39 (71%)574 (76%)
467 (68%)
105 (15%)
115 (16%)
27 (50%)
9 (17%)
18 (33%)
494 (67%)
114 (15%)
133 (17%)
607 (87%)
91 (13%)
42 (76%)
13 (24%)
649 (86%)
104 (14%)
54 (8%) 15 (28%)69 (9%)
18 (3%) 7 (13%) 25 (3%)
75 (11%) 14 (25%)89 (12%)
274 (40%) 22 (40%)296 (40%)
170 (24%)
52 (7%)
91 (13%)
9 (17%)
9 (17%)
10 (19%)
179 (24%)
61 (8%)
101 (13%)
STI ¼ sexually transmitted infections; VCT ¼ voluntary HIV counselling and testing; IQR ¼ interquartile range
?Missing data: marital status (n ¼ 6); education level (n ¼ 21); still attending school (n ¼ 20); currently earning money (n ¼ 22); number sexual partners (n ¼ 8); treated for STI
(n ¼ 7); exchanged sex for money (n ¼ 11); non-consensual sex (n ¼ 5); currently pregnant (n ¼ 9); previous pregnancies (n ¼ 20); previous HIV test (n ¼ 13)
†Not currently married includes separated, divorced and widowed
‡Non-relative, alone, unknown or other
§Years since sexual debut is equal to current age minus age at sexual debut
??For pregnant adolescents, this refers to the 12 months before realizing they were pregnant
††Self-reported response to the question ‘have you ever been forced to have sex against your will?’
‡‡Risk belief categories are not mutually exclusive
................................................................................................................................................
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In sub-Saharan Africa, commercial sex work has been
strongly associated with HIV positivity. Few studies have
examined occasional transactional sex and HIV infection
among adolescent girls.27–29In our population of adolescents,
a small percentage of girls reported ever exchanging sex for
money or favours, and those who did were more than five
times as likely to be HIV-seropositive. However, there was a
diminished association between a girl reporting having ever
exchanged sex for money and HIV infection after controlling
for other risk factors. The difference between unadjusted and
adjusted estimates may be due to the fact that we were not
able to include data on frequency or duration of transactional
sex and due to the small numbers of adolescent girls reporting
transactional sex. Similarly, we observed a strong association
between self-reported non-consensual sex and HIV infection,
but this association was attenuated after controlling for con-
founding variables. It is likely that trauma associated with
non-consensual sex and lack of condom use in these high-risk
situations put these adolescents at an increased risk of HIV,
however, in this study we cannot distinguish between verbal
or physical persuasion, coercion by other means and rape.
Adolescent girls enrolled in the study were asked if they
knew their current or previous sexual partner’s HIV status.
Having a partner who was not tested, or not knowing the
result if the partner was tested, was the strongest independent
predictor of HIV infection. These girls were more than 14
times as likely to be HIV-seropositive compared with girls
who had partners who were tested and shared their HIV test
results. This finding is independent of the partner’s actual
HIV status, which we did not know. Although knowledge of
partner status was not collinear with other risk factors in the
model, it is possible that this variable is actually a proxy for
male partner’s actual HIV status or related to other unmeasured
confounders. For example, it is possible that partners who did
not share or did not know their status were more likely to be
HIV-seropositive as compared with tested partners who dis-
closed their HIV status. In addition, the observed association
could be due to differences in sexual risk behaviours among
those who know compared with those who do not know
their partner’s HIV status. The association between knowledge
of partner status and HIV seropositivity, however, is based on a
small sample size, which limited our ability to explore the
association between partner test outcome knowledge and risk
factors for HIV such as condom use.
The main strength of this study was the large number of
at-risk sexually active adolescent girls who provided extensive
Table 2
Characteristics of adolescent sexual partnerships in Nairobi, Kenya
HIV-seronegative (n 5 706)
N (%) or median (IQR)
HIV-seropositive (n 5 55)
N (%) or median (IQR)
Overall (N 5 761)
N (%) or median (IQR) Characteristics?
Relation to current sexual partner
Spouse/cohabitating partner
Boyfriend/fiance ´/other†
Current relationship duration ? 1 year
Yes
Current partner is older
Yes
Age difference with current partner‡
Any condom use with current partner in last 12 months
Yes
Belief that current partner has been unfaithful
Yes
Knowledge of partner’s HIV status
Yes, know status
No, do not know status§
Drug or alcohol use at last sex
Yes
Has had sex with other man in last 12 months??
Yes
Relation to other sexual partner
Spouse, boyfriend or fiance ´
Friend, acquaintance or relative††
Concurrent sexual relationship‡‡
Yes
Other partner is older
Yes
Age difference with other partner§§
Any condom use with other partner
Yes
462 (65%)
244 (35%)
40 (73%)
15 (27%)
502 (66%)
259 (34%)
438 (63%) 36 (67%)474 (63%)
683 (97%)
5 (3–7)
53 (98%)
5 (3–9)
736 (97%)
5 (3–7)
140 (20%) 10 (18%)150 (20%)
464 (67%) 29 (58%)493 (66%)
174 (25%)
532 (75%)
1 (2%)
54 (98%)
175 (23%)
586 (77%)
33 (5%) 3 (6%) 36 (5%)
68 (10%)8 (15%)76 (10%)
46 (68%)
22 (32%)
5 (63%)
3 (38%)
51 (67%)
25 (33%)
14 (23%)4 (57%) 18 (27%)
51 (91%)
3 (2–5)
7 (88%)
3 (2–4)
58 (91%)
3 (2–5)
19 (28%)2 (25%) 21 (27%)
IQR ¼ interquartile range
?Missing data: current partner age difference (n ¼ 14); unfaithful (n ¼ 18); sex with other man (n ¼ 8); concurrent relationship (n ¼ 9); other partner age difference (n ¼ 5);
condom with other partner (n ¼ 5)
†Other includes friends, other acquaintances and unknown (n ¼ 25)
‡This includes: overall 97% of women had older partners (n ¼ 736); 98% of HIV-seronegative (n ¼ 53) and 97% of HIV-seropositive women had older partners (n ¼ 683)
§‘No’ includes women who do not know their partner’s status (n ¼ 35) and women with partners who have not been tested (n ¼ 552)
??Other man refers to a different partner than the current sexual partner, in the last 12 months
††A relative/family member (n ¼ 1)
‡‡Self-reported response to the question: ‘In the last 12 months, would you say one sexual relationship ended before the other relationship started?’ Response options: yes,
one man a time (serial) or no, more than one man at a time (concurrent)
§§This includes: overall 91% of women had an older partner (n ¼ 58); 91% of HIV-seronegative (n ¼ 51) and 88% of HIV-seropositive (n ¼ 7) had older partners
................................................................................................................................................
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data on individual sexual characteristics and data on their
sexual partnership characteristics. However, we could not
distinguish between sexually transmitted HIV and vertically
transmitted HIV in this population. This study focused on
adolescents who were seeking care for gynaecological problems
such as STIs or family planning and pregnancy-related issues.
Whereas this population is likely representative of sexually
active adolescents in urban settings in sub-Saharan Africa,
these findings may not be generalizable to all groups of adoles-
cents, including young women in rural settings, those not
seeking gynaecological or ante- and postnatal care, or those
with less education or fewer resources related to health-seeking
behaviour. Also, the majority of adolescents in our study were
currently pregnant, making these findings less generalizable to
nulligravid young women. However, there were no statistically
significant differences in the sexual histories or prevalence of
HIV among our pregnant compared with non-pregnant partici-
pants. Most questions on sexual behaviour were based on the
previous 12 months or recent partnerships in order to minimize
recall bias yet remain representative of the girls’ histories of
sexual risk and partnerships. The use of face-to-face interviews
to obtain self-reported information may have resulted in adoles-
cent girls under-reporting their high-risk sexual behaviours and
partnerships.30Published studies have documented significant
differences in sensitive data obtained on face-to-face interviews
versus a more confidential method such as audio computer-
assisted self-interview.31
In summary, nearly one-quarter of sexually active adolescent
girls believed they were too young to become infected with
HIV. We found a low prevalence of condom use, despite
Table 3
partnership characteristics
Comparison between HIV-seronegative and HIV-seropositive adolescents’ sociodemographic, sexual behaviour and
Unadjusted odds ratio (95% CI)P value Adjusted odds ratio (95% CI)?
Sociodemographics
Age in years
Marital status
Not currently married
Married
Partnered/cohabitating
Care type sought
Ante- or postnatal, family planning
STI, VCT, other
Health clinic
Lunga Lunga
Kariobangi
KNH
Participant is an orphan
Yes
Years of education
Currently earn money
Yes
1.2 (0.9, 1.5)0.33
REF
1.3 (0.7, 2.6)
1.3 (0.7, 2.8)
0.66
REF
1.8 (0.9, 3.6)
0.08
REF
3.5 (1.4, 8.3)
5.0 (1.9, 13.6)
0.003
3.0 (1.2, 7.6)
2.6 (0.7, 9.3)
1.5 (0.8, 3.1)
0.9 (0.8, 1.0)
0.22
0.002 1.0 (0.8, 1.1)
2.0 (1.0, 3.9) 0.030.5 (0.2, 1.2)
Sexual behaviour and partners
Age at first intercourse
Years since sexual debut
Number of partners in last 12 months
Treated for STI in last 12 months
Yes
Ever exchange sex for money
Yes
Ever non-consensual sex
Yes
Any condom use in last 12 months
Yes
Ever given birth
Yes
Currently pregnant
Yes
Previous HIV test
Yes
Current sex partner is older
Yes
Age difference with current partner
Knowledge of partner’s HIV status
No, do not know status
Drug or alcohol use at last sex
Yes
Other sexual relationships
Serial relations in last 12 months
Concurrent in last 12 months
0.8 (0.6, 0.9)
1.5 (1.2, 1.7)
1.4 (1.0, 2.0)
,0.001
,0.001
0.03
1.3 (1.1, 1.6)
1.2 (0.7, 2.2)
4.6 (2.4, 8.9)
,0.001 2.8 (1.1, 7.6)
5.6 (2.2, 14.1)
,0.001 1.8 (0.5, 7.2)
2.9 (1.5, 5.5)
,0.001 1.9 (0.8, 5.5)
0.9 (0.4, 1.8)0.77
2.2 (1.3, 3.8) 0.012.0 (1.1, 4.1)
0.7 (0.4, 1.4) 0.33
1.0 (0.6, 1.7)0.95
1.7 (0.2, 12.9)
1.0 (1.0, 1.1)
0.60
0.68
17.7 (2.4, 128.5)
,0.00114.2 (1.8, 109.3)
1.2 (0.4, 4.0) 0.78
REF
4.4 (0.9, 22.0)0.08
CI ¼ confidence interval; STI ¼ sexually transmitted infection; VCT ¼ voluntary HIV counselling and testing; KNH ¼ Kenyatta National Hospital; REF ¼ referent group
?Health clinic attended was included in adjusted model as an a priori confounder. Age at sexual debut was not included in the multivariable model due to collinearity with years
since sexual debut. All other variables with P , 0.05 in bivariate analysis were entered into the final adjusted model
................................................................................................................................................
Rositch et al. Adolescent risk factors for HIV infection
473

Page 7

multiple
reinforce messages of condom use would have the dual
benefit of HIV and pregnancy prevention, both important
public health issues for young women. Although most individ-
ual sexual characteristics were more strongly associated with
HIV infection than partnership characteristics, the exception
was knowledge of partner’s HIV status. Our data strongly
support ongoing ‘know your status’ campaigns. ‘Know your
partner’s status’ represents a tangible intervention to reduce
HIVtransmission withinyoung
Messages that emphasize disclosure within partnerships
regarding HIV testing outcomes should be incorporated into
HIV testing and prevention programmes. In light of the fact
that up to 50% of all couples that present to VCT services in
sub-Saharan Africa are HIV-discordant,32,33these intervention
messages are applicable to individuals of all ages in sexual
partnerships.
andconcurrentpartnerships.Programmesthat
heterosexual couples.
ACKNOWLEDGEMENTS
Competing interest and declarations: The authors have no
competing interests to disclose.
Author’s contribution: AFR conducted the data analysis and
was the primary author of this manuscript; PC designed the
study, acquired the data and was involved in the drafting and
review of this manuscript; PB was involved in the conception
and design of the study, and drafting and reviewing the manu-
script; JNK was involved in the conception and design of the
study, and drafting and reviewing the manuscript; RN was
involved in the design of the study, data collection and review-
ing the manuscript; CF was involved in the conception, design
and data collection of the study and drafting and reviewing the
manuscript. All authors have read and approved the final
manuscript.
Funding statement: AFR was supported in part by the NIH
FogartyInternational Center
Clinical Research Fellows Program at Vanderbilt University
(grant R24 TW007988). PC was a scholar in the AIDS
International Training and Research Program supported by
the NIH Fogarty International Center (grant D43 TW00007).
CF received support from the NIH grant K24 AI087399–01A1.
through theInternational
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(Accepted 13 February 2012)
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