Severe Babesia microti Infection in an Immunocompetent Host in Pennsylvania

Abstract

Babesiosis, due to infection by a tick-borne protozoan (predominantly Babesia microti in North America), is an emerging health risk that is expanding into new areas and may be unfamiliar to clinicians in locations not previously considered endemic. Manifestations of infection can range from asymptomatic to life threatening, with severe disease more likely in those who have had a splenectomy, are immunocompromised, have chronic medical conditions, or are over 50 years of age. In this article, we describe an elderly but otherwise healthy man from an area not generally considered endemic for babesiosis who presented with severe hemolysis, acute renal failure, and high-level Babesia microti parasitemia; serological results suggestive of possible coinfection by Borrelia burgdorferi (the agent of Lyme disease, which is carried by the same tick as is Babesia microti) also was found. This report highlights that severe babesiosis can occur in an apparently normal host and underscores the continued geographic expansion of this pathogen and the need for early recognition and therapy.

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

“…While the incidence per population is higher in Connecticut and Rhode Island, a significant portion of TTB cases have occurred in New York—105 definite, probable, or possible cases to date—more than twice as many as in any other state . In this series, all implicated donors resided in one of nine states now considered endemic or in Pennsylvania, which is recognized as having emerging B. microti . More than half (55%) resided in one of four known highly endemic counties in New York.…”

“…17 In this series, all implicated donors resided in one of nine states now considered endemic or in Pennsylvania, which is recognized as having emerging B. microti. 7 More than half (55%) resided in one of four known highly endemic counties in New York. Babesia seroprevalence in blood donors has been found to be as high in 4.3% in hyperendemic foci in New York 29 and 3.0% in coastal Connecticut.…”

“…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.…”

“…In addition, we consider Maine and New Hampshire endemic based on recent published literature and Pennsylvania has seen increasing incidence and some endemic foci. [6][7][8][9][10] Distribution is variable; endemic states have hyperendemic foci and areas at much lower risk. Babesiosis can also be caused by other Babesia species, such as B. duncani on the West Coast of the United States.…”

Babesia microti: from Mice to Ticks to an Increasing Number of Highly Susceptible Humans

“…In New York State, the incidence of B. microti infection increased approximately 3-fold, from 1.7 cases per 100,000 persons in 2006 to 4.5 cases per 100,000 persons in 2015 (https://www.health.ny.gov/statistics/ diseases/communicable), and similar patterns have been observed in other states in which the pathogen is endemic (http://www.ct.gov/dph/cwp/view.asp?aϭ3136&qϭ 388390&dphNav_GIDϭ1601&dphPNavCtrϭ|#47477). In Pennsylvania, a state not traditionally considered to be at high risk for B. microti transmission, the incidence of disease increased 10-fold between 2005 and 2015 (17). The geographic expansion of B. microti outside the traditional states in which the pathogen is endemic includes Delaware, Maine, Maryland, New Hampshire, and Virginia (18,19).…”