Reported Cases of Human Anaplasmosis in Minnesota by Year
In 2015, 613 confirmed or probable cases of anaplasmosis (10.8 cases per 100,000) were reported, up from the 448 cases reported in 2014. Despite small annual fluctuations in reported cases, the overall trend is an increase in yearly case totals over time. Three hundred eighty-five (63%) cases reported in 2015 were male. The median age of cases was 58 years (range, 10 to 94 years), 14 years older than the median age of Lyme disease cases. As is typical, most cases had illness onsets during the summer months, with 56% of cases reporting illness onsets in June and July. In 2015, 168 (27%) anaplasmosis cases were hospitalized at some point for their infection, with a median duration of 4 days (range, 1 to 38 days).
The number of anaplasmosis cases has been increasing since the first cases of HA were reported in Minnesota in the mid-1990s. A variety of factors, including increasing physician awareness, increasing infection rates in ticks, and expanding tick distribution, may have led to this trend.
- Reported Cases of Human Anaplasmosis in Minnesota
by Year, 1996-2013 (PDF: 104KB/1 page)
Graph showing the number of reported cases of human anaplasmosis in Minnesota by year.