Empowering autonomy: high usability of dual HIV/syphilis and syphilis-only self- tests among key populations in Brazil
1
Fundação Oswaldo Cruz, Instituto Gonçalo Moniz, Salvador, Brazil
2
Universidade do Estado da Bahia, Departamento de Ciências da Vida, Salvador, Brazil
3
Universidade Federal da Bahia, Instituto de Saúde Coletiva, Salvador, Brazil
4
Universidade de São Paulo, Departamento de Medicina Preventiva, São Paulo, Brazil
5
Universidade Federal do Rio Grande do Sul, Instituto de Filosofia e Ciências Humanas. Departamento de Sociologia, Porto Alegre, Brazil
6
Universidade do Estado do Amazonas, Escola Superior de Ciências da Saúde, Manaus, Brazil
7
Université Lumière Lyon 2, ., Lyon, France
8
RESHAPE, INSERM U1290, ., Lyon, France
9
Ministério da Saúde, Departamento de HIV/Aids, Tuberculose, Hepatites Virais e Infecções Sexualmente Transmissíveis, Brasília, Brazil
10
Fundação Oswaldo Cruz, Instituto de Tecnologia em Imunobiológicos (Biomanguinhos), Rio de Janeiro, Brazil
Popul. Med. 2026;8(Supplement Supplement 1):A3150
ABSTRACT
BACKGROUND:
Self-testing can expand access to diagnostics. We assessed the usability of dual HIV/syphilis and syphilis-only self-testing among key populations in Brazil.
METHODS:
We conducted a cross-sectional study in São Paulo and Salvador, Brazil (2025), among individuals aged >15 years attending sexual and reproductive health clinics (#EuMeTesto/#ITestMyself Study). Participants included transgender and non-binary people, and cisgender individuals: men who have sex with men, pregnant women, male sexual partners of pregnant women, and cis women sex workers. Both self-tests were based on lateral flow immunochromatography. Participants were randomized (1:1) to perform either the dual or the syphilis-only self-test under direct observation by trained researchers. Completion of procedural steps and interpretation of standardized test results were recorded using a 10-item observational checklist. Usability was classified as poor (0-3 items correctly completed) or moderate (4-6) vs. good (7-10). Multivariable logistic regression estimated adjusted odds ratios (aOR) and 95% confidence intervals (95%CI) for factors associated with good usability (vs poor/moderate).
RESULTS:
A total of 228 participants were recruited (123 syphilis-only; 105 dual), mostly from Salvador, cisgender women, aged 18-30 years, and reporting a monthly income of US$ 250–500. Good usability was observed in nearly two-thirds of participants (63.4%: syphilis-only; 63.8%: dual), while poor usability was uncommon (10.6% and 9.5%, respectively) (Table 1). Younger age was associated with higher odds of good usability across both tests. For syphilis-only, higher income was associated with better usability, whereas never using condoms and reporting often/always transactional sex were associated with worse usability. For dual, reporting often or always transactional sex was associated with worse usability, while higher education and low HIV risk perception were associated with better usability (Table 2).
CONCLUSIONS:
Syphilis-only and dual demonstrated high usability among key populations in Brazil, supporting the feasibility of implementing syphilis self-testing and integrating dual self-testing into HIV/STI prevention strategies.
Self-testing can expand access to diagnostics. We assessed the usability of dual HIV/syphilis and syphilis-only self-testing among key populations in Brazil.
METHODS:
We conducted a cross-sectional study in São Paulo and Salvador, Brazil (2025), among individuals aged >15 years attending sexual and reproductive health clinics (#EuMeTesto/#ITestMyself Study). Participants included transgender and non-binary people, and cisgender individuals: men who have sex with men, pregnant women, male sexual partners of pregnant women, and cis women sex workers. Both self-tests were based on lateral flow immunochromatography. Participants were randomized (1:1) to perform either the dual or the syphilis-only self-test under direct observation by trained researchers. Completion of procedural steps and interpretation of standardized test results were recorded using a 10-item observational checklist. Usability was classified as poor (0-3 items correctly completed) or moderate (4-6) vs. good (7-10). Multivariable logistic regression estimated adjusted odds ratios (aOR) and 95% confidence intervals (95%CI) for factors associated with good usability (vs poor/moderate).
RESULTS:
A total of 228 participants were recruited (123 syphilis-only; 105 dual), mostly from Salvador, cisgender women, aged 18-30 years, and reporting a monthly income of US$ 250–500. Good usability was observed in nearly two-thirds of participants (63.4%: syphilis-only; 63.8%: dual), while poor usability was uncommon (10.6% and 9.5%, respectively) (Table 1). Younger age was associated with higher odds of good usability across both tests. For syphilis-only, higher income was associated with better usability, whereas never using condoms and reporting often/always transactional sex were associated with worse usability. For dual, reporting often or always transactional sex was associated with worse usability, while higher education and low HIV risk perception were associated with better usability (Table 2).
CONCLUSIONS:
Syphilis-only and dual demonstrated high usability among key populations in Brazil, supporting the feasibility of implementing syphilis self-testing and integrating dual self-testing into HIV/STI prevention strategies.
| eISSN: | 2654-1459 |
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