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

To investigate whether prior infection with Giardia lamblia is associated with excessive daytime sleepiness, insomnia, and level of sleep need.

A 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.

Excessive 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).

Being exposed to Giardia was independently associated with excessive daytime sleepiness and larger sleep need, but not with insomnia.