Incidence rate and risk factors for giardiasis and strongyloidiasis in returning UK travellers

Background: Few studies have investigated incidence rate and risk factors for giardiasis and strongyloidiasis in returning UK travellers. The clinical presentations of these two diseases are often similar and difficult to distinguish. This study was conducted to investigate the incidence rate and the risk factors for symptomatic giardiasis and strongyloidiasis in returned tropical travellers. Methods: We retrospectively analysed 3306 consecutive attendances presenting to the emergency clinic at the Hospital for Tropical Diseases in London, the UK from September 2008 to May 2010. Odds ratios between the diagnoses and patient variables were analysed by logistic regression. Results: Giardiasis was diagnosed in 92/3306 cases (2.8%, proportionate morbidity), and the incidence rate per 1000 person-months was 12.5. Multivariate analysis with logistic regression revealed that Caucasian ethnicity (adjusted odds ratio (aOR): 2.37, 95% confidence interval (CI): 1.12–5.03, P value = 0.025), travel length ≥32 days (aOR: 2.63, 95%CI: 1.43–4.83, P = 0.002), travelling to South or South East Asia (aOR: 4.90, 95%CI: 2.03–11.8, P