Giardiasis, 2018

During 2018, 508 cases of Giardia infection (9.1 per 100,000) were reported. This represents a 22% decrease from the median number of cases reported annually from 2008 through 2017 (median, 654 cases; range, 620 to 846). Recent immigrants and refugees accounted for 8% of cases. An additional 15% of cases reported international travel in the 3 weeks prior to illness onset. Excluding recent immigrants and refugees, the median age of cases was 35 years (range, 7 months to 98 years). Eighteen percent were <10 years of age, and 30% were >50 years of age. Fifty-seven percent of non-immigrant and refugee cases were male. Giardia infections had a summer/fall seasonality; 48% of non-immigrant and refugee cases occurred during July through October. Thirty-eight (7%) cases required hospitalization, for a median of 4 days (range, 2 to 27 days). Seven outbreaks were identified in Minnesota that accounted for 16 laboratory-confirmed cases. Five outbreaks were associated with person-to-person transmission in child care settings. One outbreak was associated with consumption of surface water along a Lake Superior hiking trail, and one outbreak was associated with swimming at a beach. Additionally, six Minnesota residents were involved in two outbreaks associated with backcountry camping trips in states outside Minnesota.

• For up to date information see>> Giardiasis (Giardia)
• Full issue>> Annual Summary of Communicable Diseases Reported to the Minnesota Department of Health, 2018