Factors Associated with STI Screening Uptake Among Adolescent Girls and Young Women in Namibia

Abstract

Background: Sexually transmitted infections (STIs) remain a major public health concern among adolescent girls and young women (AGYW) in sub-Saharan Africa (SSA). Although routine STI screening is essential for early diagnosis and prevention, uptake among AGYW is often suboptimal and influenced by multiple individual and contextual factors. This study assessed factors associated with STI screening uptake among AGYW enrolled in HIV prevention programs in Namibia. Methods: A secondary analysis of anonymized programmatic data was conducted among AGYW aged 15–24 years who received services through the DREAMS project and REACH PHN activity between 2018 and 2024. Descriptive statistics, Chi-square tests, and multivariable logistic regression analyses were performed to identify factors associated with STI screening uptake. Results: A total of 26,689 AGYW were included in the analysis, of whom 97.2% were screened for STIs. STI screening uptake was significantly associated with district of residence, year of enrolment, inconsistent or no condom use, perceived risk of HIV infection, use of family planning, and having had sex under the influence of alcohol or drugs. AGYW who perceived themselves to be at risk of HIV and those using family planning methods had higher odds of STI screening, while those who reported sex under the influence of alcohol or drugs were less likely to be screened. Significant geographic disparities in screening uptake were also observed across districts. Conclusions: STI screening uptake among AGYW enrolled in HIV prevention programs in Namibia was high. While this may reflect the effectiveness of integrated, community-based service delivery models, the results should be interpreted with caution, as they are based on a convenience sample. However, behavioural and geographic disparities persist. Strengthening integrated sexual and reproductive health services, addressing substance-related barriers, and implementing targeted district-level interventions may further improve equitable access to STI screening among AGYW.

1. Introduction

Sexually transmitted infections (STIs) continue posing a significant global health concern, disproportionately affecting adolescents and young adults. The global burden of STIs is substantial and has a significant impact on sexual and reproductive health, which may lead to potentially serious complications. For instance, the World Health Organization reports that every day, globally, more than 1 million curable STIs (trichomoniasis, syphilis, chlamydia, and gonorrhoea) are acquired by people 15–49 years old, the majority of which are asymptomatic [1]. An estimated 374 million new infections occur annually in people aged 15–49 years [2,3]. STIs predominantly spread through unprotected sexual contact, such as vaginal, anal, and oral sex [4]. However, some STIs, such as syphilis, chlamydia, and gonorrhoea, can be transmitted through contact with infected blood or blood products, injecting drug use, during pregnancy, and childbirth. Among other population groups, adolescent girls and young women (AGYW) are particularly vulnerable [4] due to a combination of biological susceptibility, gender inequality [5], early sexual debut [6], alcohol and substance use [7,8], age-disparate relationships, inconsistent condom use [9], limited autonomy in sexual decision-making and barriers to accessing health services [10]. Untreated STIs can result in serious reproductive health complications, such as infertility [11], pelvic inflammatory disease [12,13], adverse pregnancy outcomes [14], and increased risk of HIV acquisition [11].

In sub-Saharan Africa (SSA), STI prevalence remains high [15], yet screening and early diagnosis among young populations are often inadequate [8,16], and access to resources remains limited [17,18]. Although many STIs are asymptomatic, routine screening is paramount for timely treatment and prevention of onward transmission. However, screening uptake among AGYW is influenced by multiple factors. Such factors include age [4,19], education, socio-economic status, sexual behaviour, stigma [6], health system accessibility, and awareness of STI services. In Namibia, significant progress has been made in strengthening sexual and reproductive health (SRH) services [20], particularly through integration with HIV prevention programs. Nevertheless, disparities in service utilization persist among adolescents and young women. Cultural norms, stigma [16,19], fear of discrimination [21], gender-based violence [22], sociocultural barriers [23], confidentiality concerns, and limited youth-friendly services continue to impede access to STI screening uptake. Moreover, evidence on the determinants of STI screening uptake among AGYW in Namibia remains limited. Therefore, this study seeks to address this gap by analysing individual-level factors associated with STI screening uptake among AGYW in Namibia to inform targeted public health interventions and improve sexual and reproductive health outcomes.

2. Methods

2.1. Study Design and Ethical Considerations

This secondary analysis examined programmatic data from AGYW aged 15–24 who received services through the Determined, Resilient, Empowered, AIDS-free, Mentored, and Safe (DREAMS) project and Reducing HIV Vulnerability: Integrated Child and Youth Health (REACH) Project Hope Namibia (PHN) activity, implemented by the PHN-led consortium from 4 June 2018 to 31 July 2023 and from 31 June 2023 to 31 August 2024, respectively. The study used a convenience sample of AGYW, as they were already enrolled in the DREAMS program. The study focused on STI screening among AGYW in the programs. The ethical considerations for the DREAMS program are explained in another publication [5]. No ethical clearance application was required for this study, as it involved secondary analysis of anonymized data.

2.2. Program Intervention and Population

Community engagement was conducted before the program was implemented. The program delivered a comprehensive package of SRH and HIV services through outreach teams linked to high-volume healthcare facilities. These teams, comprising nurses, peer educators, and social workers, extended services from health facilities into surrounding communities. Key interventions included HIV testing, rapid initiation of ART, provision of PrEP, distribution of short-acting contraceptive methods and condoms, post-violence care, and syndromic management of sexually transmitted infections (STIs).

To ensure that AGYW received services tailored to their specific needs, outreach teams conducted regular visits to group-based community platforms. Private and confidential consultations were provided in a variety of settings, including schools, church premises, temporary tents, and program vehicles. Awareness of service availability, schedules, and healthcare options was promoted through multiple communication channels, including flyers, posters, local radio broadcasts, social media platforms, and direct engagement by program personnel.

Medical supplies and commodities were procured through hub health facilities using established supply chain management systems. All services were delivered in accordance with national guidelines and documented using MOHSS-approved registers. Clinical oversight and quality assurance were maintained through supervision by nurse mentors and a program physician. Screening and management of sexually transmitted infections constituted a core component of the DREAMS intervention package and were integrated as essential elements of the program’s service delivery model. The other core components of the DREAMS intervention are discussed in other publications [5,20]. DREAMS supported STI prevention and control by training staff on STI management, increasing AGYW and sexual partner literacy about STIs, implementing routine STI screening at all entry points and using the syndromic management approach to diagnose and treat STIs.

2.3. Data Source

Anonymised data from the DREAMS program databases, including the DREAMS project and the REACH PHN activity, were used in this study. PrEP client records and clinical registers were the source documents for the data.

2.4. Outcome Variable (STI Screening: Screened vs. Non-Screened)

The outcome variable for this study was ‘STI screening.’ The responses to this statement were ‘Not screened,’ ‘Screened, needs treatment,’ ‘Screened, already on treatment,’ ‘Screened, no treatment needed,’ and ‘Refused.’ Participants who stated they were not screened were excluded from the analysis, as the reasons for non-screening were related to healthcare providers. Participants who declined screening were reclassified as ‘Not screened’, while the rest were reclassified as ‘Screened.’ Participants who were screened were assigned a code of ‘2,’ while those not screened were assigned a code of ‘1.’

2.5. Explanatory Variables

There were 15 explanatory variables in this study. The variables included the participants’ age, the number of biological children they had, their district, their participation in safe space HIV prevention sessions, their year of enrolment, their use of family planning, and knowledge of their partner’s HIV status. Additionally, the other explanatory variables were the consistency of condom use, experience of sexual violence, status of recurrent use of PEP, status of having sex under the influence of alcohol and drugs, the number of sexual partners, consideration of risk of HIV, and pregnancy or breastfeeding status.

The dataset’s discrete numerical age was recoded into 15–19 and 20–24 age categories. Pregnancy or breastfeeding status was categorized as ‘pregnant,’ ‘breastfeeding,’ or ‘neither.’ The number of biological children was categorized as ‘0 children,’ ‘1–2 children,’ or ‘≥three children.’ Responses to participation in safe space HIV prevention sessions, use of family planning, knowledge of partner’s HIV status, the consistency of condom use, experience of sexual violence, status of recurrent use of PEP, status of having sex under the influence of alcohol and drugs, the number of sexual partners, and consideration of risk of HIV were either ‘yes,’ or ‘no.’

2.6. Data Analysis

Data from DHIS2 were analysed with IBM SPSS version 29. Statistics such as percentages and frequencies were used to analyse nominal and ordinal data. Chi-square testing examined STI screening and participants’ characteristics. Statistically significant characteristics revealed in Chi-square tests were examined using binomial logistic regression to assess their associations with STI screening. Statistically significant characteristics revealed in binomial logistic regression were included in the multivariable logistic regression model. Multivariable logistic regression was used to calculate adjusted odds ratios for characteristics with statistically significant associations with STI screening at p-values < 0.05.

3. Results

3.1. Characteristics and Risk Factors of Participants

A total of 26,689 participants were included in this analysis. The majority of the participants were in the 20–24-years age group (n = 15,537; 58.2%), did not have children (n = 22,589; 84.6%), had not participated in safe space HIV prevention sessions (22,472; 84.2%), were not using any family planning method (19,455; 72.9%), knew their partner’s HIV status (n = 14,181; 53.1%), were not victims of sexual violence (n = 26,633; 99.8%), and were not recurrent PEP users (n = 26,658; 99.9%). Additionally, the majority of the participants did not have sex under the influence of alcohol or drugs (n = 26,521; 99.4%), did not have multiple or recurrent sexual partners (n = 26,241; 98.3%), considered themselves at risk of HIV (n = 17,381; 65.1%), and were neither pregnant nor breastfeeding (n = 25,794; 96.6%). Refer to

Table 1. Frequency distribution of characteristics and risk factors of participants.

Characteristics	Frequency n (%)
Age group (years)
15–19	11,152 (41.8)
20–24	15,537 (58.2)
Number of biological children
0	22,589 (84.6)
1–2	3908 (14.7)
≥3	192 (0.7)
Participated in safe space HIV prevention sessions
Yes	4217 (15.8)
No	22,472 (84.2)
District
Katima	4550 (17.0)
Omuthiya	3524 (13.2)
Onandjokwe	3914 (14.7)
Oshakati	977 (3.7)
Tsumeb	2431 (9.1)
Windhoek	11,293 (42.3)
Year of enrolment
2018	394 (1.5)
2019	2623 (9.8)
2020	7749 (29.0)
2021	6689 (25.1)
2022	4432 (16.6)
2023	1929 (7.2)
2024	2873 (10.8)
Using a family planning method
Yes	7234 (27.1)
No	19,455 (72.9)
Partner’s HIV status is unknown
Yes	14,181 (53.1)
No	12,508 (46.9)
Inconsistent or no condom use
Yes	17,222 (64.5)
No	9467 (35.5)
A victim of sexual violence
Yes	56 (0.2)
No	26,633 (99.8)
Recurrent HIV post-exposure prophylaxis (PEP) use
Yes	31 (0.1)
No	26,658 (99.9)
Having had sex under the influence of alcohol or drugs
Yes	168 (0.6)
No	26,521 (99.4)
Has multiple or recurrent sexual partners
Yes	448 (1.7)
No	26,241 (98.3)
Considers self at risk of HIV
Yes	17,381 (65.1)
No	9308 (34.9)
Pregnancy or breastfeeding status
Pregnant	831 (3.2)
Breastfeeding	64 (0.2)
Neither	25,794 (96.6)

for more details.

3.2. STI Screening Status

Among the 26,689 AGYW included in the analysis, 25,948 (97.2%) were screened for STIs. The results also reveal that more than 95% of participants in each age group and the biological children group were screened for STIs. More than 95% of participants who used or did not use condoms, were recurrent PEP users or not, used family planning or not, and had multiple or concurrent sexual partners or not, were screened for STIs. More details are in Figure 1.

The results also show that Katima Mulilo had the highest prevalence of STI screening (99.6%), while Omuthiya had the lowest (91.7%). More details are in Figure 2 below.

3.3. Participants’ Characteristics Associated with STI Screening

The Chi-square test results reveal that STI screening was associated with the participants’ age group, number of biological children, district, year of enrolment, participation in safe space HIV prevention sessions, knowledge of partner’s HIV status, consistency in condom use, recurrence of PEP use, having had sex under the influence of alcohol or drugs, consideration of HIV risk, and family planning use status (p < 0.05).

Participants aged 15–19 years were more likely than those in the 20–24-years age group to have been screened for STIs, with a crude odds ratio (COR) = 1.35, 95% CI (1.16–1.57). However, this association did not hold in the adjusted analysis. Participants from Omuthiya, Onandjokwe, Oshakati, and Tsumeb were less likely to be screened for STIs than those from Katima Mulilo, with an adjusted odds ratio (AOR) = 0.08, 95% CI (0.05–0.12); AOR = 0.10, 95% CI (0.06–0.17); AOR = 0.39, 95% CI (0.18–0.87); and AOR = 0.15, 95% CI (0.09–0.25), respectively. Participants who were enrolled in 2018 and 2019 were less likely to be screened for STIs than those enrolled in 2024, with an AOR = 0.16, 95% CI (0.10–0.25), and AOR = 0.59, 95% CI (0.40–0.87), respectively. However, participants who were enrolled in 2022 and 2023 were more likely to be screened for STIs than those enrolled in 2024, with an AOR = 2.87, 95% CI (1.73–4.74), and AOR = 4.04, 95% CI (1.86–8.80), respectively. Participants who inconsistently or did not use condoms were more likely to be screened for STIs than those who consistently used condoms, with an AOR = 1.59, 95% CI (1.31–1.92). Furthermore, participants who considered themselves at risk of HIV and those who were using family planning were more likely to be screened for STIs, with an AOR = 1.63, 95% CI (1.35–1.96), and AOR = 2.25, 95% CI (1.72–2.93), respectively. However, participants who had sex under the influence of alcohol or drugs were less likely to be screened for STIs, with an AOR = 0.38, 95% CI (0.20–0.72). Refer to

Table 2. Participants’ characteristics associated with STI screening.

Characteristics	Crude Odds Ratio	95% CI *	Adjusted ** Odds Ratio	95% CI *	Chi-Square Test p-Value
Age group (years)					<0.01
15–19	1.35	1.16–1.57	1.17	0.99–1.37
20–24	Reference	Reference	Reference	Reference
Number of biological children					<0.01
0	0.16	0.02–1.14	NI	NI
1–2	0.85	0.11–6.30	NI	NI
≥3	Reference	Reference	NI	NI
District					<0.01
Katima Mulilo	Reference	Reference	Reference	Reference
Omuthiya	0.05	0.03–0.07	0.08	0.05–0.12
Onandjokwe	0.07	0.04–0.11	0.10	0.06–0.17
Oshakati	0.34	0.16–0.70	0.39	0.18–0.87
Tsumeb	0.09	0.06–0.15	0.15	0.09–0.25
Windhoek	0.58	0.35–0.96	0.61	0.37–1.02
Year of enrolment					<0.01
2018	0.06	0.04–0.09	0.16	0.10–0.25
2019	0.25	0.18–0.36	0.59	0.40–0.87
2020	0.45	0.33–0.63	0.75	0.51–1.09
2021	0.60	0.43–0.84	0.77	0.53–1.13
2022	2.28	1.43–3.64	2.87	1.73–4.74
2023	3.74	1.75–7.95	4.04	1.86–8.80
2024	Reference	Reference	Reference	Reference
Pregnancy or breastfeeding status					0.059
Pregnant	1.69	0.99–2.89	NI	NI
Breastfeeding	Undefined	Undefined	NI	NI
Neither	Reference	Reference	NI	NI
Participated in safe space HIV prevention sessions					<0.01
Yes	0.67	0.56–0.80	0.83	0.69–1.01
No	Reference	Reference	Reference	Reference
Partner’s HIV status is unknown					<0.01
Yes	2.05	1.76–2.39	0.91	0.75–1.10
No	Reference	Reference	Reference	Reference
Inconsistent or no condom use					<0.01
Yes	3.06	2.63–3.56	1.59	1.31–1.92
No	Reference	Reference	Reference	Reference
Recurrent HIV post-exposure prophylaxis (PEP) use					<0.01
Yes	0.41	0.10–1.74	NI	NI
No	Reference	Reference	NI	NI
Having had sex under the influence of alcohol or drugs					<0.01
Yes	0.40	0.22–0.75	0.38	0.20–0.72
No	Reference	Reference	Reference	Reference
A victim of sexual violence					0.651
Yes	1.57	0.22–11.37	NI	NI
No	Reference	Reference	NI	NI
Has multiple or recurrent sexual partners					0.11
Yes	0.68	0.42–1.09	NI	NI
No	Reference	Reference	NI	NI
Considers self at risk of HIV					<0.01
Yes	3.70	3.17–4.32	1.63	1.35–1.96
No	Reference	Reference	Reference	Reference
Using a family planning method					<0.01
Yes	4.04	3.12–5.23	2.25	1.72–2.93
No	Reference	Reference	Reference	Reference

Bold numbers show statistically significant results; NI—Not included; * CI is the 95% confidence interval; ** Adjusted for Age, District, Year of Enrolment, Participation in safe space HIV prevention sessions, Knowledge of partner’s HIV status, Condom use, Having had sex under the influence of alcohol or drugs, Consideration of HIV self-risk, and Use of a family planning method.

for more details.

4. Discussion

Our study examined factors associated with STI screening uptake among AGYW enrolled in the DREAMS and REACH PHN programs in Namibia. Of the 26,689 participants included in this analysis, 25,948 (97.2%) were screened for STIs, while 741 (2.8%) refused STI screening. High STI screening uptake (97%) shows the effectiveness of community-based, facility-linked outreach models embedded within the DREAMS program. Such models reduce structural barriers to SRH services and offer youth-friendly, confidential care. Similar high STI test uptake has been reported in other community-based interventions in other SSA countries, including Zimbabwe [18], South Africa [24], and Zambia [2]. However, the findings should be interpreted with caution, as the study included a convenience sample of AGYW who were already enrolled in the DREAMS program.

Our findings reveal that STI screening was associated with the participants’ age group, consistency in condom use, year of enrolment, knowledge of their partner’s HIV status, number of biological children, participation in safe space HIV prevention sessions, district, consideration of HIV risk, recurrence of PEP use, having had sex under the influence of alcohol or drugs, and family planning use. This also corroborates the findings of Hensen et al. (2024) [2], who posit that age, marital status, educational attainment, and having ever given birth are associated with STI screening. Additionally, district-level variations in STI screening were observed. For instance, participants from Omuthiya, Onandjokwe, Oshakati, and Tsumeb were significantly less likely to be screened than those from Katima Mulilo. These geographic disparities may reflect differences in service availability [25], outreach intensity, inequalities in access to health facilities [26], health workforce distribution, and sociocultural factors [27]. Urban and peri-urban areas, such as Katima Mulilo, may benefit from stronger program implementation, improved health infrastructure, and greater exposure to health promotion activities. These findings highlight the need for geographically targeted strategies and tailored counselling to ensure equitable access to STI screening services and resources across districts.

Nevertheless, the year of enrolment was also significantly associated with STI screening uptake. Participants enrolled in earlier years of the program (2018–2019) were less likely to be screened than those enrolled in 2024. Notably, participants enrolled in 2022 and 2023 had higher odds of screening. This pattern likely reflects program maturation, improvements in service integration, and increased emphasis on routine STI screening over time. The DREAMS program has been evolving positively over time in addressing bottlenecks in accessing care among AGYW [28] through expanded SRH services for AGYW [29]; improved HIV education, training, and awareness [30]; strengthened monitoring systems; and greater community trust, which may have contributed to improved screening uptake.

Furthermore, AGYW who inconsistently or did not use condoms were more likely to be screened, suggesting that perceived vulnerability may motivate health-seeking behaviour. Similarly, participants who considered themselves at risk of HIV had significantly higher odds of STI screening. These findings align with evidence indicating that risk perception is a key driver of preventive health service utilization among young people [31,32,33]. Conversely, AGYW who reported having sex under the influence of alcohol or drugs were less likely to be screened, highlighting how substance use may impair judgment [34,35], reduce engagement with health services [36], and exacerbate vulnerability to untreated STIs. The strong association between family planning use and uptake of STI screening underscores the benefits of integrated SRH services. AGYW accessing contraceptive services are more likely to interact with healthcare providers and receive comprehensive advice on SRH counselling and STI screening. This finding supports the existing literature [37,38,39,40] that advocates for integrating STI services within family planning and HIV prevention platforms to improve coverage and continuity of care among AGYW. An alternative explanation is that AGYW who are more motivated to seek healthcare are more likely to use both services. There is also a need to improve peer support, expand SRH [41], enhance partner services to increase STI screening uptake, and enhance point-of-care diagnostics [2].

4.1. Implications of the Study in Policy and Practice

From a policy perspective, policymakers should prioritize the scale-up and sustained funding of integrated outreach programs that bring STI screening services closer to AGYW, particularly in rural districts. Secondly, the observed district-level disparities highlight the need for targeted resource allocation and differentiated service delivery approaches. Strengthening outreach intensity, workforce capacity, and service availability in lower-performing districts could reduce inequities in STI screening uptake. Routine program monitoring should incorporate geographic performance indicators to guide adaptive implementation. Thirdly, the statistical significance between STI screening, HIV risk perception, and family planning use shows the value of service integration. Policies should promote the routine integration of STI screening into family planning, HIV testing, PrEP, and antenatal care services for AGYW. Such integration can normalize STI screening, reduce stigma, and maximize opportunities for early detection and treatment. Finally, the reduced likelihood of screening among AGYW who engage in substance use highlights the need for targeted interventions addressing alcohol and drug use within SRH programs. Integrating anti-substance use campaigns and screening, counselling, and referral services into AGYW-focused programs may enhance engagement with STI screening and reduce sexual health risks.

4.2. Study Limitations

Despite the important insights derived from the analysis, this study has several limitations. First, the analysis relied on secondary programmatic data, which may be subject to reporting inaccuracies and missing information. Second, the cross-sectional nature of the data limits causal inference, as associations observed cannot establish temporal relationships. Additionally, the study population comprised a convenience sample of AGYW enrolled in the DREAMS program, which may limit generalisability to AGYW not engaged in similar interventions. Despite these limitations, the large sample size and real-world programmatic context strengthen the relevance of the findings for policy and practice.

5. Conclusions

Our study shows high uptake of STI screening among AGYW participating in the DREAMS and REACH PHN programs in Namibia. However, the findings should be interpreted with caution since the study included a convenience sample of AGYW already enrolled in the DREAMS program. STI screening was influenced by several factors, such as age group, number of biological children, district, year of enrolment, participation in safe space HIV prevention sessions, knowledge of partner’s HIV status, consistency in condom use, recurrence of PEP use, having had sex under the influence of alcohol or drugs, consideration of HIV risk, and family planning use. The findings show the importance of integrated, community-based SRH service delivery models. The study also revealed important gaps across districts and behavioural subgroups. Strengthening integrated services, addressing geographic inequities, and tailoring interventions for AGYW at higher behavioural risk becomes imperative. Such interventions can sustain and improve STI screening coverage, inform youth-responsive STI prevention strategies, and, in turn, contribute to improved SRH outcomes among AGYW in Namibia.