Detection of Babesia odocoilei in Humans with Babesiosis Symptoms

*Author to whom correspondence should be addressed.
Academic Editors: Raphael B. Stricker and Raul Colodner
Diagnostics 2021, 11(6), 947;
Received: 21 March 2021 / Revised: 13 May 2021 / Accepted: 24 May 2021 / Published: 25 May 2021
(This article belongs to the Special Issue Lyme Disease: Companion Diagnostics and Precision Medicine)
Human babesiosis is a life-threatening infectious disease that causes societal and economic impact worldwide. Several species of Babesia cause babesiosis in terrestrial vertebrates, including humans. A one-day clinic was held in Ontario, Canada, to see if a red blood cell parasite, which is present in blacklegged ticks, Ixodes scapularis, is present in humans. Based on PCR testing and DNA sequencing of the 18S rRNA gene, we unveiled B. odocoilei in two of 19 participants. DNA amplicons from these two patients are almost identical matches with the type strains of B. odocoilei in GenBank. In addition, the same two human subjects had the hallmark symptoms of human babesiosis, including night sweats, chills, fevers, and profound fatigue. Based on symptoms and molecular identification, we provide substantive evidence that B. odocoilei is pathogenic to humans. Dataset reveals that B. odocoilei serologically cross-reacts with Babesia duncani.
Clinicians must realize that there are more than two Babesia spp. in North America that cause human babesiosis. This discovery signifies the first report of B. odocoilei causing human babesiosis.
Perfect example of how Lyme/MSIDS doesn’t fit into any box but perhaps Pandora’s.  
Strain diversity is a large reason why people aren’t being diagnosed.  You can only find what you specifically test for.  This study shows there are undoubtedly people struggling with Babesia symptoms that remain undiagnosed and therefore untreated due to the fact B. odocoilei isn’t believed to be pathogenic to humans and isn’t being tested for.  
Now we know for sure.
Earlier this year Scott et al. found 71% of black legged ticks were infected with Babesia odocoilei.  In 2019, Scott et al. also provided the first report of black legged ticks co-infected with BBsl and B.odocoilei in Canada, as well as transstadial passage (remains with the tick throughout its life-cycle) of this species of Babesia in ticks found in birds. They also found 3 members of the Bbsl complex (Borrelia lanai-like spirochete, Bbss, and a distinct strain that may represent a separate Bbsl genospecies).
Their latest study now has proven Babesia odocoilei infects humans.  

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