Excessive daytime sleepiness, sleep need and insomnia 3 years after Giardia infection: a cohort study

ObjectiveTo investigate whether prior infection with Giardia lamblia is associated with excessive daytime sleepiness, insomnia, and level of sleep need.DesignA questionnaire was sent to all confirmed cases of giardiasis 3 years after the outbreak and a control group matched on age and gender. Associations were evaluated by use of multiple regression analysis.ResultsExcessive daytime sleepiness (score ≥ 11 on the Epworth Sleepiness Scale) was reported by 31.5% of the Giardia-exposed and 14.1% of the controls. In multivariate analysis, excessive daytime sleepiness was independently associated with Giardia exposure, with an adjusted odds ratio of 1.40 (95% confidence interval [CI], 1.06-1.86). Insomnia was reported by 15.4% of Giardia-exposed and 8.8% of controls, adjusted odds ratio was 0.93 (95% CI, 0.65-1.35). Mean (SD) self-reported sleep need was 8 (1.4) hours among Giardia-exposed and 7.5 (1.1) hours in the control group (P < .001). The adjusted regression coefficient was 0.12 (95% CI, 0.01–0.24).ConclusionBeing exposed to Giardia was independently associated with excessive daytime sleepiness and larger sleep need, but not with insomnia.