Human Babesiosis, Maine, USA, 1995–2011

Abstract

We observed an increase in the ratio of pathogenic Babesia microti to B. odocoilei in adult Ixodes scapularis ticks in Maine. Risk for babesiosis was associated with adult tick abundance, Borrelia burgdorferi infection prevalence, and Lyme disease incidence. Our findings may help track risk and increase the focus on blood supply screening.

Babesiosis Surveillance — United States, 2011–2015

“…For the period of 2011-2015, the first 5 years of national surveillance, the reported cases of babesiosis occurred most frequently in spring and summer and in the Northeast and upper Midwest. Changes in the annual number of reported cases over time (from a low of 909 cases for 2012 to a high of 2,074 cases for 2015) might reflect actual increases in disease incidence in certain areas (e.g., Maine [30] and New Hampshire) but also could reflect changes in case ascertainment (e.g., because of changes in health care-seeking behaviors or clinicians' awareness of babesiosis). Documenting where and how persons are exposed is needed for monitoring the geographic ranges and occurrence of tickborne and transfusion transmission of B. microti and other Babesia species.…”

Coinfection by Ixodes Tick-Borne Pathogens: Ecological, Epidemiological, and Clinical Consequences

“…By 2013, this number had reached nearly 1,800. The recent emergence of babesiosis is due to an increased incidence in areas known to be endemic for decades [50, 56] but also results from the geographic spread of B. microti into new territories situated on the edge of well-established endemic areas [57–59]. Of note, the geographic expansion of B. microti has been restricted to areas already endemic for Lyme disease (Figure 2).…”

Transfusion‐transmitted and community‐acquired babesiosis in New York, 2004 to 2015

“…Seven states have historically been considered endemic: Connecticut, Rhode Island, New York, Massachusetts, New Jersey, Minnesota, and Wisconsin. In addition, we consider Maine and New Hampshire endemic based on recent published literature and Pennsylvania has seen increasing incidence and some endemic foci . Distribution is variable; endemic states have hyperendemic foci and areas at much lower risk.…”