STI Screening for Women With Disabilities in Zambia

BACKGROUND AND SIGNIFICANCE

An estimated 1 million new curable STIs are acquired daily among people aged 15-49, totaling approximately 376 million new cases of chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), and syphilis annually. Left untreated, these infections cause acute illness, infertility, long-term disability, adverse pregnancy outcomes, and death, while facilitating HIV transmission. This burden falls disproportionately on populations already marginalized by structural exclusion. Women with disabilities, estimated at 300 million worldwide, represent one such population whose sexual and reproductive health needs remain persistently under-researched and under-prioritized.

Globally, an estimated 1.3 billion people (16% of the population) live with some form of disability. Disability prevalence is higher among women (19% of the global disabled population) than men (12%), and in low- and middle-income countries women constitute nearly three-quarters of persons with disabilities. In sub-Saharan Africa, STI prevalence among women in the general population ranges from 8.5% to 32.7%, with evidence suggesting even higher rates among women with disabilities, though disaggregated data remain scarce. Women with disabilities face compounding risk factors: healthcare provider biases assuming asexuality or incompetence; approximately 50% less sexual health education and services than non-disabled peers; higher documented rates of risky sexual behavior linked to limited relationship negotiating power; pervasive disability-related stigma; and a 3-4 fold higher likelihood of experiencing sexual violence. These factors interact with structural features of the health system to produce a cumulative disadvantage that disability-blind STI surveillance is not designed to detect.

In Zambia specifically, disability prevalence is estimated at 29.9%. Women with moderate or mild disabilities attending antenatal care have a 2.21-fold higher likelihood of HIV infection than the general antenatal population, pointing to a broader, largely uncharacterized STI burden beyond HIV alone. WHO provides general technical guidance on STI surveillance (case reporting, prevalence monitoring, antimicrobial resistance assessment, syndromic management validation), but this guidance does not specifically address persons with disabilities. Zambia's National HIV/AIDS/STI/TB Policy prioritizes triple elimination of HIV, syphilis, and hepatitis B through antenatal sentinel surveillance; because this architecture is built around routine antenatal attendance, it is structurally likely to under-capture women with disabilities, who face additional barriers to accessing antenatal services in the first place. Most health facilities lack basic disability-inclusive infrastructure, including ramps, sign language interpretation, and Braille materials, discouraging service access and leaving the true burden of undiagnosed infection in this population unknown.

The WHO Global Report on Health Equity for Persons with Disabilities identifies structural inequalities, including poverty and stigma, as key drivers intensifying sexual health risk for women with intellectual and psychosocial disabilities, who often face additional communication barriers and systemic neglect. Increased susceptibility to sexual abuse and violence, compounded by institutional dependency and restricted autonomy, further heightens STI exposure. Barriers to care span physical inaccessibility, negative provider attitudes, and a near-universal lack of disability-inclusive service design, culminating in low screening rates and high rates of untreated infection, with downstream consequences including infertility, cervical cancer, and accelerated HIV progression disproportionately observed in this population. Current STI programs seldom address these specific needs. A disability-inclusive prevalence study is therefore an overdue step toward identifying gaps in sexual health education and service delivery and guiding health system adaptations that reduce disparities.

This neglect is not incidental but reflects a broader historical pattern in which disability has been treated as peripheral to mainstream sexual and reproductive health research, policy, and programming, despite disability rights frameworks, including the UN Convention on the Rights of Persons with Disabilities, affirming the right of persons with disabilities to the same range, quality, and standard of free or affordable health care as provided to other persons, including in the area of sexual and reproductive health. Where disability is addressed within health systems at all, attention has historically concentrated on impairment-specific rehabilitation or assistive services, rather than on the sexual and reproductive health needs that persons with disabilities share with the general population but experience under markedly different structural conditions. Existing STI surveillance systems, including those operating in Zambia, were not designed with disability inclusion as a foundational consideration, meaning that even where a woman with a disability does engage with the health system, her disability status, and the distinct barriers associated with it, are unlikely to be systematically recorded or analyzed. This measurement gap perpetuates a form of statistical invisibility that in turn constrains the ability of policymakers to identify, prioritize, and resource disability-inclusive interventions, even where the political will to do so exists. Addressing this gap requires not only new prevalence data but also a demonstration of feasible, replicable methods for reaching and meaningfully engaging women with disabilities within routine and research-based health service delivery, a demonstration this pilot study is explicitly designed to provide.

STUDY RATIONALE

Prioritizing screening of women with disabilities is essential given their heightened vulnerability and the near-total absence of disability-inclusive STI data in Zambia. This study will generate new, disability-specific prevalence data in Lusaka district, contextualized against existing general-population data to characterize disparity. It directly addresses a critical evidence gap constraining the development of evidence-based, disability-inclusive policy, and aligns with national and global health equity priorities. By quantifying STI burden and identifying health system shortcomings, the study will document health inequities experienced by this population, providing evidence policymakers can use to design interventions consistent with the WHO Global Strategy on Health Equity for Persons with Disabilities and supporting Zambia's progress toward Sustainable Development Goal 3.

RESEARCH QUESTIONS AND OBJECTIVES

The study is guided by three research questions: (1) What is the prevalence of cervical precancerous lesions, CT/NG, HIV, and syphilis among women with disabilities in Lusaka, Zambia? (2) What is the prevalence of anxiety, depression, and substance use among women with disabilities, and how are these associated with STI status? (3) How do intersectional factors, including disability type and severity, age, socioeconomic status, and education, influence access to STI-related healthcare and health-seeking behaviors?

Correspondingly, three objectives guide the study. Objective One: determine the prevalence of cervical precancerous lesions, CT/NG, HIV, and syphilis among women with disabilities, generating the first disability-disaggregated, multi-STI prevalence estimates for this population in Zambia. Objective Two: assess the prevalence of anxiety, depression, and substance use, and evaluate their association with STI status, contributing new evidence on co-occurring sexual and mental health vulnerability. Objective Three: analyze how intersectional factors affect healthcare access and health-seeking behaviors, using an integrated quantitative and qualitative approach grounded in an intersectionality framework.

STUDY DESIGN

This is a cross-sectional observational study assessing the prevalence of selected STIs, mental health conditions, and substance use, while exploring lived experiences and barriers related to STI screening, diagnosis, and treatment. The cross-sectional design efficiently generates prevalence estimates across multiple health domains within a single population contact, while integrating structured quantitative instruments with participants' own accounts to move beyond numerical disease burden toward understanding the structural and social conditions producing it.

STUDY SITE, POPULATION, AND SAMPLE SIZE

Study activities will be implemented at Kanyama 1st Level Hospital, Lusaka district, selected for its relative accessibility for women with disabilities and existing testing infrastructure, reflecting the study's commitment to reducing, rather than replicating, the barriers this population routinely encounters.

The target population comprises women aged 18-49 with physical and psychosocial disabilities residing in Lusaka district, recruited through purposive sampling in partnership with disability-focused organizations. Inclusion criteria: aged 18+ with confirmed disability (classified via WHO Disability Assessment Schedule, WHODAS); willing and able to provide informed consent; sexually active within the past 12 months. Exclusion criteria: women without disabilities; women with cognitive disabilities precluding independent consent; women otherwise unable to consent; severely ill or hospitalized women. These criteria reflect a deliberate ethical balance between inclusivity and ensuring all participants exercise full, independent autonomy.

A minimum sample size of 150 was calculated using a 95% confidence interval and 5% margin of error, based on existing STI prevalence estimates and the power required to detect meaningful differences in STI, comorbid mental health, and access outcomes. This was adjusted upward by 10% for anticipated non-response, yielding a target enrollment of approximately 165 participants - adequate precision for a pilot study designed to generate foundational evidence for larger subsequent research and intervention efforts.

PARTNERSHIPS AND RECRUITMENT

The study will collaborate with the Zambia Agency for Persons with Disabilities (ZAPD), which plan, promote, and implement measures to achieve equal opportunities for persons with disabilities. The partner will support participant identification, reflecting a "nothing about us without us" approach that positions disability-led organizations as active recruitment partners rather than treating the target population as passive research subjects.

Research Assistants and community health workers will undergo training on disability sensitivity to avoid stigma and ensure confidentiality. Community health workers, alongside sign language interpreters, will conduct health education at the ZAPD office and Kanyama 1st Level hospital discussing study procedures, risks, and benefits with potential participants. Women who consent will be transported to the health facility for sample collection; women who decline to sign a consent form will not be recruited under any circumstances.

Following consent, a trained research assistant will administer a structured WHODAS-based questionnaire, collecting sociodemographic and disability-related data to measure health and disability at the population and clinical level, identifying factors medical diagnosis alone may fail to predict. Participation involves one to two visits: the first for eligibility assessment, enrollment, sample collection, mental health screening, and same-day treatment of precancerous lesions where indicated; a second, where required, for STI (Chlamydia and/or Gonorrhoea) treatment referral.

DATA COLLECTION: SEXUALLY TRANSMITTED INFECTION SCREENING

Biological samples will be collected at a location convenient for participants - the health facility or a central location designated by the partner disability organization - with cervical cancer screening conducted at the study site to enable same-day treatment if lesions are identified.

For CT/NG, participants will self-collect vaginal swabs for Nucleic Acid Amplification Testing (NAAT), a less invasive, autonomy-preserving approach, processed on the GeneXpert (Cepheid, Sunnyvale, CA) platform over approximately 90 minutes. Participants may wait on-site for results or be informed within five working days if delayed. Participants testing positive will be asked to return with their partner, or refer the partner, for testing on the same platform and treatment to prevent reinfection. Testing and standard-of-care treatment are free for participants and partners, prescribed per investigator judgment. All positive participants receive counselling addressing the social, psychological, and physical risks of disclosure to a sexual partner.

Cervical precancerous lesions will be screened using Visual Inspection with Acetic Acid (VIA), enabling same-day treatment and reducing loss-to-follow-up risk for a population facing significant transportation barriers. A trained nurse applies 3-5% acetic acid to the cervix during speculum examination; results are scored positive when a well-defined, dense acetowhite area appears in the transformation zone after one minute under bright light, or negative if no change is observed. Suspected lesions may prompt same-day treatment with LEEP or cryotherapy, depending on clinical eligibility.

HIV and syphilis will be assessed using a one-step rapid point-of-care combination test (Bioquick HIV/Syphilis Duo), enabling same-day treatment initiation within 10-20 minutes. A trained provider collects 100-150 microliters of venous blood following standard phlebotomy procedure; the sample is tested immediately. Results are interpreted by control (C) and test (T) line development: both lines present indicates a positive/reactive result (anti-Treponema pallidum antibodies present); only the C line present indicates negative/non-reactive; no C line renders the assay invalid regardless of T line appearance, requiring repeat testing with a new device.

DATA COLLECTION: MENTAL HEALTH AND SUBSTANCE USE SCREENING

Although not originally designed for persons with disabilities, this study adapts validated mental health instruments while remaining attentive to accessibility needs during administration.

The EQ-5D-5L captures health status across five dimensions - mobility, self-care, usual activities, pain/discomfort, and anxiety/depression - with participants self-reporting one of five severity levels per dimension. Participants reporting severe or extreme anxiety/depression (level 4 or 5) are referred immediately to mental health support services.

Depression is assessed via the PHQ-9, a nine-question, patient-administered tool validated across LMIC settings including Zambia, with severity classified as: none (0-4), mild (5-9), moderate (10-14), moderately severe (15-19), and severe (20-27). This graduated scale allows characterization of symptom severity distribution alongside overall prevalence, informing both interpretation and individual referral decisions.

Substance use is assessed via the Alcohol, Smoking and Substance Involvement Screening Test (ASSIST), developed for WHO to support early identification of substance use-related risk in primary care settings. Its eight questions cover tobacco, alcohol, cannabis, cocaine, amphetamine-type stimulants, inhalants, sedatives, hallucinogens, opioids, and other drugs, generating a risk score per substance (low/moderate/high risk). Administration takes 5-10 minutes via electronic (e-ASSIST) or paper format. All research assistants are trained by a master trainer to ensure standardized administration. Participants with significant depression are referred to the Psychiatry Department for further management.

INTERSECTIONALITY FRAMEWORK AND ACCESS BARRIERS

Sociodemographic and socioeconomic data (age, education, income, employment) and clinical data on disability type, severity, and healthcare access will be collected using validated classification tools. Quantitative data will be integrated with qualitative insights using an intersectionality framework designed to understand how overlapping social identities and disability characteristics cumulatively affect access to STI services - a deliberate methodological choice, since a prevalence estimate alone cannot explain why disparities exist or how they are experienced.

This intersectional analysis proceeds from the premise that disability does not operate as an isolated risk factor but interacts with other axes of social position, including age, socioeconomic status, educational attainment, and disability type and severity, to produce distinct configurations of vulnerability and access. A younger woman with a physical disability and higher educational attainment may, for instance, encounter a markedly different set of barriers than an older woman with a psychosocial disability and limited formal education, even though both fall within the same broad "women with disabilities" category typically used in health system planning. By systematically collecting the sociodemographic, socioeconomic, and disability-specific variables required to characterize these distinct configurations, and by triangulating this quantitative characterization with participants' own accounts of their experiences accessing STI-related care, the study aims to move beyond a single, undifferentiated estimate of disparity toward a more actionable understanding of which subgroups of women with disabilities face the most acute barriers, and why. This level of analytic granularity is intended to directly support the design of future interventions capable of addressing the specific, rather than generic, needs of different subgroups within this broader population.

DATA MANAGEMENT AND STORAGE

The CIDRZ data management system will serve as the primary data repository. Direct database server access is restricted to personnel responsible for monitoring and backup; all other access is governed by logical security controls across a secure, password-protected network. Weekly, research assistants submit completed forms to the Study Coordinator at CIDRZ headquarters for entry into a custom-built REDCap database, which includes automated range, consistency, verification, and identification checks. Forms with missing variables are flagged and returned to clinic staff for review before entry. The Data Coordinator ensures entered data is timely, complete, accurate, and consistent with source documents. The study team conducts fortnightly data reviews and prepares monthly monitoring reports.

DATA ANALYSIS PLAN

All participants with results for CT/NG, HIV, syphilis, or cervical cancer will be included in the prevalence analysis. Descriptive statistics (means, standard deviations, medians, interquartile ranges for continuous variables; frequencies and proportions for categorical variables) will be generated. STI prevalence will be reported with 95% exact confidence intervals using the Clopper-Pearson method, preferred for its statistical robustness at low observed prevalence, reported overall and stratified by age and STI type. Unadjusted prevalence ratios with 95% confidence intervals will estimate associations between STI outcomes and participant characteristics. A multivariable logistic regression model will be constructed using backward selection, with significance for retention set at 0.05; the Wald F test will select the best-fitting model among candidates. Further detail, including missing data handling and any subgroup analyses, will be documented in a separate statistical analysis plan.

EXPECTED OUTCOMES AND SIGNIFICANCE

The study expects to generate three categories of findings: robust, disability-disaggregated STI prevalence estimates for cervical precancerous lesions, CT/NG, HIV, and syphilis, the first such dataset for this population in Zambia; quantified prevalence of anxiety, depression, and substance use with their association to STI status; and characterization of key access barriers, including stigma and physical inaccessibility, generating actionable evidence for future disability-inclusive service design. Collectively, these findings are intended to advance health equity for women with disabilities in Zambia, closing a consequential evidence gap and fulfilling human rights obligations related to equitable sexual and reproductive health access. The evidence is expected to directly inform the Ministry of Health, ZAPD, and the broader regional and global community working to advance disability-inclusive health systems.

Beyond these immediate empirical contributions, this pilot study is designed to generate methodological learning of value well beyond its own sample size. As one of the first studies in Zambia to systematically integrate disability-inclusive recruitment, accessible consent procedures, multi-STI biological screening, and structured mental health assessment within a single research encounter for women with disabilities, the study will document practical lessons regarding feasibility, participant burden, retention across the one-to-two visit structure, and the operational requirements of partnering with disability-led organizations for recruitment. These lessons are expected to directly inform the design of larger, adequately powered follow-on studies, as well as the design of routine health service delivery models seeking to become more disability-inclusive. In this sense, the study's significance extends beyond the specific prevalence estimates it will generate to encompass a demonstrated, replicable model for how disability-inclusive sexual and reproductive health research can be conducted ethically, feasibly, and in genuine partnership with the population it seeks to serve, within a resource-constrained health system such as Zambia's. Given the scarcity of comparable studies elsewhere in the sub-Saharan African region, findings and methodological lessons from this study are also expected to hold relevance for researchers, program implementers, and policymakers working on disability-inclusive health beyond Zambia's borders.

ETHICAL CONSIDERATIONS

This research demands commitment to respect for persons, autonomy, dignity, protection from harm, and genuine inclusion throughout. By prioritizing accessible consent processes, safeguarding privacy, mitigating harm, and centering participant autonomy, the study upholds applicable ethical standards while advancing critical, previously unavailable knowledge. Ethical approval will be obtained from UNZABREC and the National Health Research Authority prior to any study activity.

Consent discussions will be conducted in private. Consent will be offered in accessible formats (Braille, plain language, visual aids, audio recordings) as appropriate to each participant. Two original consent forms will be completed, dated, and signed by the participant and a research assistant; the participant retains one, the second is kept at the study site.

Participants may withdraw consent at any time without justification. Following withdrawal, no further evaluations or data collection will occur, except safety data per participant consent. A withdrawn participant may authorize continued use of previously collected data, or request destruction of identifiable samples and data, which investigators will honor. Withdrawn participants continue to receive standard-of-care.

Risks are minimal and comparable to local standard-of-care cervical cancer screening: initial speculum coldness and pelvic pressure, possibly followed by mild cramping; short-term discomfort after colposcopy/biopsy, manageable with oral pain medication; possible vaginal bleeding or discharge for several days, during which participants are advised against vaginal insertion (including intercourse, tampons, douching) until healed. Participants experiencing heavy bleeding, severe pain, fever, or chills are advised to seek immediate care. Community awareness of participation or results could result in stigma; the study team will minimize this risk through rigorous privacy protection, and will work with affected participants and families as preferred should it occur.

Privacy risks inherent to data collection will be mitigated through anonymization, unique study identification numbers, and physical protection against unauthorized access. Records will be kept in a lockable cabinet at CIDRZ headquarters, with access restricted to authorized study personnel, the sponsor, health authorities, and ethics committee representatives, to the maximum extent permitted by law. Given the risk of disclosure of STI exposure to partners potentially resulting in abuse or abandonment, participants receive counselling on safe partner notification approaches. Sample collection occurs in a private room.

Participants are counselled on the benefits of testing and treatment for their overall health, and on the importance of partner testing to prevent reinfection.

An adverse event (AE) is any medical occurrence affecting a participant, regardless of causal relationship to study procedures. A serious adverse event (SAE) results in death, is life-threatening, requires or prolongs hospitalization, results in persistent disability, involves a congenital anomaly, or is otherwise an important medical event. Given the minimal-risk nature of study procedures, procedure-related AEs are expected to be no greater than minimal; all suspected AEs are reported to the Principal Investigator immediately, with re-training arranged if AEs occur more frequently than expected. All SAEs are categorized and reported to UNZABREC per its requirements; urgent safety measures trigger immediate ethics committee notification.

A protocol deviation is any nonconformity from the approved protocol, including consent or confidentiality deviations, regulatory non-compliance, or participant complaints, occurring at any point from first enrollment through data/specimen close-out. Examples include enrolling an ineligible participant or conducting procedures before consent completion. All deviations and violations are categorized and reported to UNZABREC per its requirements.

DISSEMINATION PLAN

Upon study completion, findings will be presented to the Ministry of Health, healthcare providers, and other stakeholders, including partner disability organizations. Manuscripts will be submitted to peer-reviewed journals, and findings presented at national and international conferences, including the NHRA conference and other dissemination meetings. Authorship will follow the uniform requirements for manuscripts submitted to biomedical journals.

STUDY TIMELINE

The study is expected to run over 12 months. The first three to six months are dedicated to protocol adaptation for ethics submission, receipt of approvals, and site preparation (staff hiring/training, community sensitization with ZAPD, testing kit procurement). Enrollment, sample collection, and linkage to care are estimated at three months, running alongside ongoing quality assurance review of case report forms and monthly monitoring. A further three months are allocated to data cleaning, analysis, and final report preparation, followed by stakeholder presentation and dissemination. The sponsor and investigators reserve the right to terminate the study for valid scientific or administrative reasons before reaching target enrollment, with due consideration for participant interests should this become necessary.

STUDY TEAM AND SPONSORSHIP

This study is sponsored by the Centre for Infectious Disease Research in Zambia (CIDRZ), an established research institution with substantial experience in HIV, infectious disease, and population health research in Zambia. The study is led by a multidisciplinary team combining clinical, public health, and social science expertise spanning biomedical STI screening and treatment, mental health assessment, and the qualitative and intersectional analysis of healthcare access barriers experienced by women with disabilities.