Haematologic complications from human babesiosis: a case report

The Discovery of Zoonotic Protozoans in Fleas Parasitizing on Pets as a Potential Infection Threat

PURPOSE

Fleas are insects with a high medical and veterinary importance. They may participate in spreading of many pathogenic agents, but still there is limited information about their possible reservoir or vector role for protozoans. The main aim of this study was an attempt of detection zoonotic pathogens, such as Babesia microti and Toxoplasma gondii in fleas Ctenocephalides felis felis and Ctenocephalides canis.

METHODS

In 2013-2017, 155 fleas were captured from domestic dogs and cats in veterinary clinics, animal shelters and pet grooming salons in Upper Silesia Region in Poland. Then, the DNA was extracted from each Ctenocephalides flea by using the ammonia method. Samples were screened for the presence of B. microti and T. gondii using PCR and nested PCR methods.

RESULTS

B. microti was reported in 6.6% of C. felis felis and 9.1% of C. canis, whereas the prevalence of coinfection with B. microti and T. gondii was 1.9% in cat fleas and 2.3% in dog fleas.

CONCLUSION

This study shows the first cases of B. microti occurrence and B. microti and T. gondii coinfection in Ctenocephalides fleas. The estimation of prevalence of examined protozoans may be useful considering the possibility of infection among companion animals, as well as during presentation of the potential risk of infection in humans. In order to clarify the role of C. felis felis and C. canis in transmission of B. microti and T. gondii, the another studies with in vitro cultures and laboratory animals are needed.

Transfusion-Transmitted Babesiosis

Babesiosis is most commonly caused by Babesia microti and is transmitted via the bite of an infected Ixodes spp tick. However, Babesia is also transmitted via blood transfusion. In the United States, the first case of transfusion-transmitted babesiosis was recognized in 1979, and in recent years, the incidence has rapidly increased. Because most of the infected blood donors do not experience any symptoms, they pose a significant risk to the blood supply. Donor deferral for a history of babesiosis is currently performed but is ineffective. In March 2018, the FDA licensed a DNA PCR and antibody assay that were used in tandem in pivotal trials for screening blood donors for B microti; with other assays still being evaluated under investigational new drug protocols. Blood donation screening is essential to reducing the risk of transfusion-transmitted babesiosis, which is why blood centers collecting in geographic regions of highest risk have been testing since approximately 2010. Investigational NAT assays of higher sensitivity are pending FDA review. Further, in July 2018, the FDA issued a draft guidance for reducing the risk of transfusion-transmitted babesiosis. Release of the final guidance may be postponed until sensitivities and specificities of all current and potential strategies have been properly evaluated.

Autoimmune hemolytic anemia associated with babesiosis

BACKGROUND

Babesiosis is endemic in selected areas in North America. Babesia infection is commonly associated with anemia, thrombocytopenia, hyponatremia and elevated liver enzymes. Autoimmune hemolytic anemia (AIHA) is known to be caused by parasitic and viral infections but has not been well characterized.

CASE PRESENTATION

We describe two cases diagnosed with babesiosis triggering severe AIHA. One case had history of splenectomy, and the other was an elderly patient. Older, immunocompromised and asplenic patients may be particularly at risk for post-babesiosis AIHA (PB-AIHA).

CONCLUSIONS

The pathogenesis for conventional AIHA and PB-AIHA appears to be different, since splenectomy is a treatment for conventional AIHA, whereas PB-AIHA is seen more often in asplenic patients. Further investigation into this intriguing mechanism of host immune response to babesiosis may help to elucidate the overall mechanism of infection- triggered AIHA.

Babesiosis-associated immune thrombocytopenia

Thrombocytopenia is a common feature of babesiosis. The mechanism for thrombocytopenia in babesiosis remains elusive. We report a case of babesiosis with severe new onset immune thrombocytopenia (ITP). In addition to antibiotics treatment for babesiosis, ITP therapy was administered. ITP in the present case was most likely triggered by the babesia infection. The severity of ITP in this case was not proportional to the severity of parasitemia. The neoantigen triggering the autoimmune response in babesiosis requires further characterization.