Primary care and community-based screening for Chagas disease in London, United Kingdom, August 2023 to January 2025.

BACKGROUNDChagas disease (CD), a tropical parasitic disease caused by Trypanosoma cruzi, is increasingly recognised as a public health concern among Latin American migrants living in non-endemic settings. In London, United Kingdom (UK), home to over 160,000 people from endemic countries, no formal population-level CD screening programmes exist.AIMTo investigate the seroepidemiology of CD infection in Latin American adults living in London, UK.METHODSA cross-sectional, observational study utilising questionnaires and serological (T. cruzi) screening was performed between August 2023 and January 2025. Adults born in South America, Central America or Mexico (or whose mothers were born there) were eligible to participate. Screening was offered in primary care sites and by point-of-care serological testing at community events. Outcomes were seroprevalence, screening yield, positive predictive value of screening tests and linkage to care.RESULTSIn primary care, of 2,739 eligible individuals offered screening, 276 (10.1%) accepted. At community events, 247 were screened. Of the 523 screened, 20 (3.8%) participants had positive screening tests, and CD was confirmed in 14 (2.7%), all born in Bolivia. Seroprevalence was lower in those screened in primary care (1.1%) than at community events (4.5%). The number needed to screen to detect one confirmed case (linked into care) was 37 overall, 92 in primary care and 22 at community events.CONCLUSIONSScreening for CD through primary care in the UK is highly challenging, with both low uptake and low yield amongst those tested. Targeted community-based outreach approaches result in higher screening yield and linkage to care.