Babesia duncani emerges in Eastern U.S. and poses treatment challenges
The tick-borne illness Babesia duncani (B. duncani) was initially identified in the western regions of the United States. The disease has always been presumed to be confined to the West Coast, while its counterpart – Babesia microti (B. microti) has been well established on the East Coast.
New research indicates, however, there may no longer be a division of babesial strains between the East Coast and the West Coast. In their article “Babesia microti – Borrelia burgdorferi Co-infection,” Parveen reports that B. duncani has now been identified in eastern USA and Canada.¹
“Since B. duncani is widespread in Canada, its southern spread into northeastern U.S., an area already endemic for Lyme disease, makes co-infections with B. duncani and B. burgdorferi [Lyme disease] a possibility that needs to be carefully investigated.”
“While this review focuses on co-infection with B. microti and B. burgdorferi, there is some evidence that co-infections with a diﬀerent Babesia species, B. duncani, and B. burgdorferi may be more common than previously suspected,” writes Parveen.Babesia duncani emerges as a threat on the East Coast and in Canada. Click To Tweet
The authors raise concerns regarding treatment given that, “Antibiotics used against B. microti are less eﬀective against B. duncani, making treatment of B. duncani potentially more challenging.”
“Clinical cases caused by Babesia duncani have been associated with high parasite burden, severe pathology, and death,” writes Abraham in The Journal of Biological Chemistry. ²
Animals fared worse. “In both mice and hamsters, the parasite causes uncontrolled fulminant infections, which ultimately lead to death,” writes Abraham.
Treatment for B. microti was not as effective for B. duncani in vitro culture, explains Abraham.
“Using this in vitro culture assay, we found that B. duncani has low susceptibility to the four drugs recommended for treatment of human babesiosis, atovaquone, azithromycin, clindamycin, and quinine.”
“These data suggest that current practices are of limited effect in treating the disease [B. duncani],” writes Abraham.
Editor’s note: I have diagnostic concerns. B. duncani is not routinely tested for in Canada and the Eastern USA. Individuals with B. duncani may go undiagnosed.
- Parveen N, Bhanot P. Babesia microti-Borrelia Burgdorferi Coinfection. Pathogens. 2019 Jul 31;8(3). pii: E117. doi: 10.3390/pathogens8030117. Review.
- Abraham A, Brasov I, Thekkiniath J, Kilian N, Lawres L, Gao R, DeBus K, He L, Yu X, Zhu G, Graham MM, Liu X, Molestina R, Ben Mamoun C. Establishment of a continuous in vitro culture of Babesia duncani in human erythrocytes reveals unusually high tolerance to recommended therapies. J Biol Chem. 2018 Dec 28;293(52):19974-19981.