The following background data on babesiosis in the United States are abstracted from Gideon www.GideonOnline.com and the Gideon e-book series. [1,2] (primary references are available on request)
Time and Place:
Babesiosis was first diagnosed in the United States in 1968.
– Of 214 cases of babesiosis reported worldwide during 1975 to 1986, 200 occurred in the United States.
– Most cases are reported from Rhode Island , Massachusetts, New, Minnesota, New Jersey and Connecticut.
– Occasional cases are reported from Maryland, Virginia, New Jersey and Georgia.
– Highest incidence is reported during the warmer months.
– Babesia microti accounts for most cases, but B. equi may cause human disease in California, and B. divergens in Missouri (implicated in a single, fatal case).
– Infection due to Babesia duncani has been reported in Washington State (Babesia WA1) , California (Babesia CA1 and WA1) and Missouri (Babesia MO1)
– Most infections due to these new species have occurred among splenectomized individuals; whereas 95% of B. microti infections are reported in persons with intact spleens.
– Human infection by a Babesia divergens-like strain has also been reported in Washington State.
– There is evidence that Babesia WA1 infection is not limited to the west coast region.
Additional Geographic Notes:
Babesiosis was first documented in New York State in 1975.
– Six cases (0 fatal) were reported on Long Island during a two-month period (1982 publication)
– 139 patients were hospitalized for babesiosis in New York State during 1982 to 1993 – nine of these infections were fatal.
– 560 cases were reported in the state to 2001.
– 371 cases were reported in the Lower Hudson Valley during 2001 to 2008, including 119 in 2008.
– Infection has also been documented in humans and ticks (Ixodes scapularis) in upstate New York.
– Three cases were reported New York City in 2000 – possibly acquired in Westchester County (an area not previously known to be endemic).
160 cases were reported in Nantucket, Massachusetts during 1969 to 1998.
– 1.6% of residents of Nantucket Island, Martha’s Vineyard and Block Island are seropositive toward Babesia divergens, and 4.5% toward B. microti.
Babesiosis was first identified (2 cases) in Rhode Island in 1994.
– 189 cases were reported in Rhode Island during 1998 to 2004, including 48 in 2004.
– Rhode Island averaged ca. 2 cases per year during 1994 to 1999.
– 140 cases were reported from Block Island during 1991 to 2000. The rate of symptomatic infection on the island is estimated at 516 per 100,000 per year.
40 cases of babesiosis were reported in New Jersey during 1993 to 2001.
– 32 cases were reported in Wisconsin during 1996 to 2005.
– The first case of babesiosis in Tennessee was reported in 2010.
159 cases of transfusion-associated infection were reported during 1979 to 2009, involving 19 states : 21 during 1980 to 1997; 18 (5 fatal) during 2005 to 2007; 122 during 2000 to 2009.
– 16 cases of transfusion-related babesiosis were reported in New York City in 2002, 25 in 2003; 16 in 2004; 18 in 2005; 38 in 2006; 25 in 2007; 39 in 2008.
– 21 cases of transfusion-related babesiosis were reported in Rhode Island during 1999 to 2007.
– No cases of fatal babesiosis acquired through transfusion were reported in 1997; 1 in 1998; 0 during 1999 to 2004; 2 in 2005; 3 in 2006; 3 in 2007.
– Seroprevalence in blood donors on Shelter Island (Suffolk County, eastern Long Island) was 4.3 percent in May 1998.
– A case of transfusion-associated babesiosis was reported in California in 2007.
– A case of transfusion-associated Babesia duncani infection was reported in California in 2008.
– A case of fatal transfusion-associated babesiosis was reported in Delaware in 2009.
– 1.4% of blood donors from endemic areas in Connecticut (0.3% from non-endemic areas) were seropositive in 1999; 1.0% in 2000; 1.4% in 2001.
– A rare case of congenital babesiosis has been reported in New Jersey (2009 publication)
2003 (publication year) – A Czech national acquired babesiosis while traveling in the United States.
2003 (publication year) – A Swiss national acquired B. microti infection in the United States.
2005 – Hong Kong reported it’s first case of babesiosis – imported from the eastern United States.
2009 – A Dutch traveler acquired concurrent babesiosis and Lyme disease following a trip to the United States.
Reservoirs and Vectors:
The vector in the northeast is Ixodes scapularis (I. dammini), and the usual reservoir is the white-footed mouse (Peromyscus leucopus).
– Enzootic transmission of Babesia divergens has been demonstrated among cottontail rabbits (Sylvilagus floridanus) on Nantucket Island, Massachusetts.
Enzootic transmission of Babesia divergens among cottontail rabbits (Sylvilagus floridanus) by Ixodes dentatus has been documented on Nantucket Island, Massachusetts.
– Enzootic infection has been identified among rodents in Maine.
– 75%, 37% and 25% of white-footed mice (Peromyscus leucopus) have antibodies to B. burgdorferi, Anaplasma phagocytophilum and Babesia microti respectively. 13% have antibodies to all 3 pathogens. (Connecticut, 2001 to 2003)
A genetically-distinct strain of B. microti is enzootic to Microtus oeconomus and Clethrionomys rutulis in coastal Alaska.
– The transmission cycle of B. microti in Colorado consists of Ixodes spinipalpis and prairie voles (Microtus ochrogaster).
1982 (publication year) – An outbreak (6 cases) of babesiosis was reported on Long Island.
1988 to 1989 – An outbreak (6 cases) of babesiosis was reported in Connecticut.
1. Berger SA. Infectious Diseases of the United States, 2011. 1030 pp, 464 graphs, 8237 references. Gideon e-books, http://www.gideononline.com/ebooks/country/infectious-diseases-of-the-united-states/
2. Berger SA. Babesiosis: Global Status, 2011. 18 pp, 218 references. Gideon e-books. http://www.gideononline.com/ebooks/disease/babesiosis-global-status/
Note featured on ProMED