Protocol for a Cross-Sectional Comparative Analysis of Condom Use and STI Prevalence Among PrEP Users and Non-Users at a Specialised STI Wellness Clinic in Eswatini

This prospective cross-sectional study conducted at a specialized clinic in Eswatini aims to compare condom use patterns and STI prevalence between PrEP users and non-users to inform future public health strategies and optimize sexual health interventions.

The Gist

The Big Picture: A "Safety Gear" Check-Up

Imagine you are at a busy gym. Some people are wearing high-tech, bulletproof vests (PrEP) to protect themselves from a specific danger (HIV). Others are relying on other methods, like just being careful or wearing a standard helmet (condoms), but not the high-tech vest.

This research paper is a plan (a protocol) for a study happening in Eswatini. The researchers want to check the gym floor to answer a simple question: Does wearing the "bulletproof vest" make people take off their "standard helmets" (condoms)?

They are worried about a phenomenon called "Risk Compensation." Think of it like this: If you put on a seatbelt in a car, you might feel so safe that you start driving a little faster. The researchers want to see if PrEP users feel so safe from HIV that they stop using condoms, which could accidentally expose them to other infections (STIs) that the vest doesn't protect against.

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The Cast of Characters

• The Location: The study is happening at the LaMvelase STI Wellness Centre in Manzini, Eswatini. Think of this as a specialized "health check-up station" for sexual health, where people come to get tested and treated.
• The Players:
  • The "Vest Wearers" (PrEP Users): People who have been taking HIV prevention medication for at least a month.
  • The "Non-Wearers" (PrEP Non-Users): People who have never taken this specific medication.
  • The Rule: Everyone must be HIV-negative and at least 15 years old.
• The Goal: To compare these two groups and see:
  1. Who is wearing condoms more often?
  2. Who is catching more "bugs" (STIs like chlamydia, gonorrhea, or syphilis)?

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How the Study Works (The Game Plan)

The researchers aren't doing a long-term experiment; they are taking a snapshot (a cross-sectional study) between February and June 2026.

1. The Line-Up: They will invite people coming to the clinic. They plan to pick every k-th person who walks through the door (like picking every 10th person in a line) to make sure they get a fair mix of people.
2. The Interview: A researcher will sit down with them in a private room and ask questions. It's like a chat about their life:
   • "How often do you use a condom?"
   • "Do you feel safer because you are on PrEP?"
   • "What is your job, age, and background?"
3. The Lab Test: Just like a routine check-up, they will take blood, urine, or swabs to test for STIs. This is the "truth-teller" part of the study because it doesn't rely on what people say they did, but what the lab finds.
4. The Math: Once they have the answers, they will use computer software (like a giant calculator) to see if there is a real connection between wearing the "vest" and taking off the "helmet."

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Why Do This? (The "So What?")

The authors explain that while PrEP is amazing at stopping HIV, it doesn't stop other infections.

• The Problem: If PrEP users stop using condoms because they feel "invincible" against HIV, they might get other infections.
• The Need: Eswatini has high rates of these infections. The researchers need to know if the "bulletproof vest" is causing people to drop their other defenses.
• The Outcome: If they find that PrEP users are using fewer condoms, the health officials can create better messages. Instead of just saying "Take the pill," they can say, "Take the pill and keep wearing your helmet."

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The Rules of the Game (Ethics & Safety)

The researchers are very careful about how they treat the people in the study:

• Secrets: All names are hidden. The data is like a locked diary that only the main researchers can open.
• Voluntary: No one is forced to join. If someone wants to leave the study, they can, and it won't affect their medical care.
• No Freebies: Participants aren't getting cash. Their "reward" is the free health check-ups and counseling they would have gotten anyway.
• Safety Net: If someone gets upset talking about their sexual history, counselors are there to help, just like a safety net at a circus.

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What to Expect Next

This paper is just the blueprint. The study hasn't happened yet.

• Timeline: They will start gathering data in early 2026 and finish by mid-2026.
• The Result: By late 2026, they hope to have a report that tells the Ministry of Health and the clinic staff exactly how PrEP is changing behavior in Eswatini.

In short: This study is a detective story in the making. The researchers are gathering clues to see if a powerful new tool (PrEP) is accidentally making people less careful in other ways, so they can fix the strategy before more people get sick.

Technical Summary

Technical Summary of the Protocol for a Cross-Sectional Comparative Analysis of Condom Use and STI Prevalence Among PrEP Users and Non-Users

Problem Statement and Context
Sexually transmitted infections (STIs) remain a critical public health challenge globally, with Southern Africa experiencing disproportionately high rates. In Eswatini, where the national HIV prevalence among adults is approximately 24.8%, the burden of STIs is alarmingly high, with studies indicating infection rates ranging from 15.5% to 22% among specific demographics. While Pre-exposure Prophylaxis (PrEP) has been successfully scaled up in Eswatini as a key HIV prevention strategy, its impact on sexual risk behaviors remains underexplored. A central concern is "risk compensation," a phenomenon where individuals may reduce condom use due to a perceived decrease in HIV risk while on PrEP. Conversely, some evidence suggests PrEP use might maintain or increase condom use due to heightened health awareness. Currently, there is a lack of local data in Eswatini regarding the dynamics between PrEP use, condom consistency, and STI prevalence. This gap hinders the optimization of sexual health interventions and the refinement of national prevention strategies.

Methodology
This document outlines the protocol for a prospective cross-sectional quantitative study scheduled to take place from February to June 2026 at the LaMvelase STI Wellness Centre in Manzini, Eswatini.

• Study Design and Population: The study employs a prospective cross-sectional design targeting HIV-negative individuals aged 15 years and older attending the clinic for STI services. Participants will be recruited via systematic random sampling from the clinic's client load.
• Sampling Strategy: The target sample size is calculated at 264 participants (240 minimum + 10% for refusal), based on an estimated STI prevalence of 19.4% derived from previous literature (Ginidza et al., 2017). Participants will be stratified into two cohorts: PrEP users (current or past use for at least one month) and PrEP-naïve individuals (never used PrEP).
• Data Collection: Data will be gathered through two primary sources:
  1. Structured Interviews: An interviewer-administered survey (available in English and Siswati) will capture demographic data, sexual behavior, condom use frequency and consistency, risk perception, and PrEP adherence.
  2. Clinical Records and Laboratory Testing: Medical records from the Client Management Information System (CMIS) will be reviewed. Laboratory testing will include rapid HIV tests, syphilis screening (RPR/Treponemal), Hepatitis B antigen testing, and Nucleic Acid Amplification Tests (NAATs) or rapid tests for Gonorrhea, Chlamydia, and Trichomonas vaginalis.
• Data Analysis: Data will be cleaned and analyzed using Stata 17. Descriptive statistics will summarize the population. Comparative analyses (T-test, Mann-Whitney, Pearson χ2, Fisher's exact test) will assess differences between PrEP users and non-users. Bivariate logistic regression will be utilized to identify factors influencing condom use and STI rates, with a significance level set at p < 0.05.
• Ethical Considerations: The study has received approval from the Eswatini Health and Human Research Review Board (EHHRRB 206/2025). Participation is voluntary, with informed consent obtained from adults and assent forms for minors (with a potential waiver for consent due to topic sensitivity). Strict confidentiality measures, including data anonymization and secure storage, are mandated.

Key Contributions and Scope
As a study protocol, this paper does not present empirical results but rather establishes the framework for generating them. Its primary contributions include:

• Defining the Research Gap: It explicitly identifies the need for context-specific data in Eswatini regarding the intersection of PrEP adoption and STI prevention behaviors.
• Methodological Rigor: It details a robust approach combining self-reported behavioral data with objective laboratory-confirmed STI diagnoses, addressing potential biases inherent in self-reporting.
• Operational Framework: It provides a comprehensive plan for recruitment, data management, and ethical oversight tailored to a high-volume, specialized STI clinic setting.

Results
No results are reported in this document, as the study has not yet commenced. The protocol anticipates findings that will describe the prevalence of STIs and patterns of condom use among the two cohorts.

Significance and Claims
The authors position this research as a necessary step toward optimizing public health strategies in Eswatini. The significance of the study lies in its potential to:

• Inform Policy: Provide evidence to guide the Ministry of Health and partners in refining national PrEP programming and STI screening guidelines.
• Enhance Interventions: Help determine whether PrEP introduction correlates with risk compensation (reduced condom use) or increased protective behaviors, allowing for targeted counseling and educational programs.
• Improve Service Delivery: Contribute to better resource allocation and service delivery models within specialized STI clinics.

The paper modestly acknowledges limitations, including the cross-sectional nature which precludes causal inference, potential selection bias due to the facility-based setting, and the reliance on self-reported data. However, it argues that the use of a high-volume, specialized clinic in a densely populated region will enhance the generalizability of the findings for similar settings in Eswatini. Ultimately, the study aims to support national efforts to eliminate AIDS as a public health threat by 2030 through data-driven, optimized prevention strategies.