Human Babesiosis Caused by Babesia duncani Has Widespread Distribution across Canada.

Scott JD, et al. Healthcare (Basel). 2018.


Human babesiosis caused by Babesia duncani is an emerging infectious disease in Canada. This malaria-like illness is brought about by a protozoan parasite infecting red blood cells. Currently, controversy surrounds which tick species are vectors of B. duncani. Since the availability of a serological or molecular test in Canada for B. duncani has been limited, we conducted a seven-year surveillance study (2011⁻2017) to ascertain the occurrence and geographic distribution of B. duncani infection country-wide. Surveillance case data for human B. duncani infections were collected by contacting physicians and naturopathic physicians in the United States and Canada who specialize in tick-borne diseases. During the seven-year period, 1119 cases were identified. The presence of B. duncani infections was widespread across Canada, with the highest occurrence in the Pacific coast region. Patients with human babesiosis may be asymptomatic, but as this parasitemia progresses, symptoms range from mild to fatal. Donors of blood, plasma, living tissues, and organs may unknowingly be infected with this piroplasm and are contributing to the spread of this zoonosis. Our data show that greater awareness of human babesiosis is needed in Canada, and the imminent threat to the security of the Canadian blood supply warrants further investigation. Based on our epidemiological findings, human babesiosis should be a nationally notifiable disease in Canada. Whenever a patient has a tick bite, health practitioners must watch for B. duncani infections, and include human babesiosis in their differential diagnosis.

Establishment of a continuous in vitro culture of Babesia duncani in human erythrocytes reveals unusually high tolerance to recommended therapies.

Abraham A, et al. J Biol Chem. 2018.


Human babesiosis is an emerging tick-borne disease caused by apicomplexan parasites of the genus Babesia. Clinical cases caused by Babesia duncani have been associated with high parasite burden, severe pathology and death. In both mice and hamsters, the parasite causes uncontrolled fulminant infections, which ultimately lead to death. Resolving these infections requires knowledge of B. duncani biology, virulence, and susceptibility to anti-infectives, but little is known and further research is hindered by a lack of relevant model systems. Here, we report the first continuous in vitro culture of B. duncani in human red blood cells. We show that during its asexual cycle within human erythrocytes, B. duncani develops and divides to form four daughter parasites with parasitemia doubling every ~22 h. 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, with IC50 values ranging between 500 nM and 20 μM. These data suggest that current practices are of limited effect in treating the disease. We anticipate this new disease model will set the stage for a better understanding of the biology of this parasite and will help guide better therapeutic strategies to treat B. duncani-associated babesiosis.


For more on Babesia:

My husband and I both had Babesia.  Thankfully, that is one we are symptom-free from, but we treated for an entire year.  Dr. Horowitz states it’s one of the most tenacious coinfections he treats.

We used:

  • Mepron (750mg/5ml two times a day)
  • Allergy Research Brand Artemisinin (500mg 2X/day)
  • An intracellular such as one of the following:

*azithromycin (Zithromax) 500mg twice a day
*clarithromycin (Biaxin) 500mg  twice a day
*doxycline 100mg 2 pills twice a day
*minocycline 100mg  twice a day

Wise treatment overlaps.  It works synergistically and it helps prevent tolerance.

Babesia treatment is typically 3 weeks on, 1 week off.  I believe we pulsed the Artemisinin MWF.  This is a particular potent form and will give you a metallic taste in your mouth.  To read about it:  (I am not affiliated with any products or services).  I was thankful for the pulsing as I had heart-attack type herxes and the breaks from those were welcome!

See Babesia Treatment link above for a symptom check-list you can print and fill out.