Endemic babesiosis in another eastern state: New Jersey

Abstract

In the United States, most reported cases of babesiosis have been caused by Babesia microti and acquired in the northeast. Although three cases of babesiosis acquired in New Jersey were recently described by others, babesiosis has not been widely known to be endemic in New Jersey. We describe a case of babesiosis acquired in New Jersey in 1999 in an otherwise healthy 53-year-old woman who developed life-threatening disease. We also provide composite data on 40 cases of babesiosis acquired from 1993 through 2001 in New Jersey. The 40 cases include the one we describe, the three cases previously described, and 36 other cases reported to public health agencies. The 40 cases were acquired in eight (38.1%) of the 21 counties in the state. Babesiosis, a potentially serious zoonosis, is endemic in New Jersey and should be considered in the differential diagnosis of patients with fever and hemolytic anemia, particularly in the spring, summer, and early fall.

Figure 1

Map of New Jersey showing its 21 counties. The eight counties in which reported cases of babesiosis were acquired from 1993 through 2001 are shaded in gray (the darker the gray, the more cases). The number of cases reported per county is shown under the name of the county.

Figure 2

The number of reported cases of babesiosis acquired each year, 1993–2001.