Background/Objectives: Community-based data collection represents a methodological shift towards democratizing data gathering, ensuring those most affected become active agents in data creation and interpretation. The SafeSpace project in Guinea-Bissau implemented community-led point-of-care rapid testing for HIV, hepatitis B (HBV), hepatitis C (HCV) and syphilis through four community-based organisations (ADPP, RENAP, Enda Santé, AGUIBEF), with technical support from GAT and ISPUP. This abstract discusses the 18-month experience of implementing community-based epidemiological surveillance within this project.

Methods: Integrated community-based testing sessions are conducted by community health activists who administer a structured questionnaire capturing sociodemographic information, testing history, and current testing results performed according to availability and needs. People were identified using a unique alphanumeric identifier enabling tracking of successive visits. This instrument was co-developed with participating organisations. Health activists underwent one-week in-person training combining theoretical instruction and supervised fieldwork. Paper-based questionnaires are digitized monthly into an online platform for analysis. Monthly epidemiological indicators are generated and shared with organisations for joint monitoring and decision-making.

Results: From April 2024 to September 2025, 23,701 testing sessions were documented, including 4,869 HIV tests, 20,696 HBV tests, 4,425 HCV tests, and 15,445 syphilis tests. Participants included 50.6% cis women, 46.7% cis men, and 2.1% trans persons. Key populations represented 11.0% sex workers and 4.2% men who have sex with men. Priority groups included 61.8% youth and 45.2% women of reproductive age. HIV reactivity was 2.0% among cis women and 0.9% among cis men, HBV reactivity was 2.1% in women and 3.3% in men, and syphilis reactivity was 0.3%. Referral to care ranged from 81.5% (HIV) to 63.3% (HCV).

Conclusions/Recommendations: Community-based organisations engage in generating and interpreting surveillance data, which guides programme monitoring and activities. Preliminary results prove this model valuable in countries with fragile health systems, enabling epidemiological monitoring of infectious diseases among hard-to-reach populations. Data quality challenges persist and require continuous improvement. A revised questionnaire, informed by current experience, awaits ethics approval. Ongoing dialogue advances integration of community-based surveillance with the country's formal epidemiological surveillance system.

Funding: Expertise France. FCT UID/4750/2025 e LA/P/0064/2020.