Strengthening human immunodeficiency virus surveillance through systematic data cleaning: a national retrospective validation of the human immunodeficiency virus treatment and care registry in Guyana, 2025.

BACKGROUND

Accurate human immunodeficiency virus (HIV) surveillance is essential for achieving the Joint United Nations Programme on HIV/acquired immunodeficiency syndrome (AIDS) (UNAIDS) 95-95-95 targets. Historically, Guyana's HIV datasets contained duplicate entries, silent mortality, and unverified migration, resulting in inflated denominators and under-reported viral suppression. In 2025, the National AIDS Programme Secretariat conducted the first national HIV data-cleaning and verification exercise to establish a validated treatment cohort.

OBJECTIVES

1. To verify and clean historical HIV treatment records.2. To quantify duplicate, deceased, migrated, and defaulter cases.3. To distinguish long- vs short-term defaulters.4. To assess the impact on UNAIDS cascade indicators.5. To model viral suppression gains through re-engagement.

METHODS

A national retrospective review of 12,824 records included deduplication, outcome verification, and cohort classification. Analytical outputs included Wilson 95% confidence intervals, chi-square distribution testing, and standardized residuals. Re-engagement modeling simulated suppression gains across 15-60% scenarios.

RESULTS

We identified 401 duplicates (3.1%), 1308 deaths (10.2%), and 454 migrations (3.5%), producing a validated eligible cohort of 10,661 people living with HIV, correcting 13.7% denominator inflation. Of eligible clients, 7268 (68.2%) were active, 2071 (19.4%) long-term defaulters, and 1322 (12.4%) short-term defaulters. Re-engagement modeling showed improvements of +2.6 percentage points at 25% return and +6.3 percentage points at 60%, indicating strong potential for accelerating the third 95.

CONCLUSION

National data validation substantially improved surveillance precision and clarified programmatic gaps. Re-engagement of short-term defaulters is a high-impact strategy for increasing viral suppression. Guyana's 2025 exercise provides a replicable model for improving regional HIV monitoring and advancing progress toward epidemic control.