Incidence of Rodentolepis nana infection within people seeking asylum and refugees attending health screening at an integrated refugee health service.

Background: Rodentolepis (Hymenolepis) nana (R. nana) is the most common cestode to infect humans, and whilst most infections are asymptomatic, those with a high burden of infection can present with abdominal pain, diarrhoea, or growth stunting. The Respond service, London, offers screening and treatment for common infections to people seeking asylum and refugees (PSAR), including testing for gastrointestinal parasites such as R. nana.

Methods: We present a retrospective observational analysis of all positive R. nana results in patients screened by the Respond service between April 2016 and July 2023. A positive result was defined by the presence of R. nana ova on stool microscopy for ova, cysts and parasites (OCP) or R. nana DNA detection using the Novodiag® Stool Parasite assay (NSP), a cartridge based multiplex molecular assay. We explore incidence of R. nana infection and efficacy of treatment in PSAR presenting to an integrated refugee health service.

Results: R. nana was identified in 54/1797 (3%) of patients who had a stool sample collected in the Respond service. Median age of patients was 15 years (interquartile range [IQR] 9-17), and 38/54 (70%) were male, reflecting the sex demographic of the cohort. Coinfection with other parasites occurred in 28/54 (52%) of the cohort. Of the 27 patients who tested positive for R. nana where their family members were also tested, 11 patients (41%) had family members who were also infected with R. nana. Treatment failure (defined as failure to clear R. nana detected by OCP/NSP after treatment with praziquantel) occurred in 43% of the patients for whom a clearance sample was returned.

Conclusions: We show a significant prevalence of R. nana in people seeking asylum screened within the Respond cohort. We show significant clustering within family units and a relatively high treatment failure rate. We propose prompt treatment of positive cases to prevent transmission within families, and consideration of treatment of family units simultaneously to prevent re-infection.