Persistence of Babesia microti Infection in Humans

Abstract

Persistent infection is a characteristic feature of babesiosis, a worldwide, emerging tick-borne disease caused by members of the genus Babesia. Persistence of Babesia infection in reservoir hosts increases the probability of survival and transmission of these pathogens. Laboratory tools to detect Babesia in red blood cells include microscopic detection using peripheral blood smears, nucleic acid detection (polymerase chain reaction and transcription mediated amplification), antigen detection, and antibody detection. Babesia microti, the major cause of human babesiosis, can asymptomatically infect immunocompetent individuals for up to two years. Chronically infected blood donors may transmit the pathogen to another person through blood transfusion. Transfusion-transmitted babesiosis causes severe complications and death in about a fifth of cases. Immunocompromised patients, including those with asplenia, HIV/AIDS, malignancy, or on immunosuppressive drugs, often experience severe disease that may relapse up to two years later despite anti-Babesia therapy. Persistent Babesia infection is promoted by Babesia immune evasive strategies and impaired host immune mechanisms. The health burden of persistent and recrudescent babesiosis can be minimized by development of novel therapeutic measures, such as new anti-parasitic drugs or drug combinations, improved anti-parasitic drug duration strategies, or immunoglobulin preparations; and novel preventive approaches, including early detection methods, tick-avoidance, and blood donor screening.

Babesia microti Confers Macrophage-Based Cross-Protective Immunity Against Murine Malaria

“…Chronic B. microti infection lasting for at least 56 days was confirmed by microscopy, and is in agreement with past studies showing chronic, low-parasitemic B. microti infection persisting for 6 months in BALB/c mice (Welc-Faleciak et al, 2007), as well as in wild rodents (Pawelczyk et al, 2004). In fact, persistent and sometimes recrudescent babesiosis has also been reported in humans, with an asymptomatic carrier state lasting up to 2 years in immunocompetent individuals, while more prolonged and severe infection is common in asplenic patients (reviewed by Bloch et al, 2019). The spleen, main site of immune response to babesiosis, undergoes disruption of its normal architecture; splenomegaly, coupled with enlargement of the white and red pulp regions, is typical of murine babesiosis (Coleman et al, 2005;Djokic et al, 2018a,b) as well as other intraerythrocytic infections, including malaria (Leisewitz et al, 2004;Buffet et al, 2011).…”

Protein Regulation Strategies of Mouse Spleen in Response to Babesia Microti Infection

“…The chromatographic conditions for DIA were the same as those for DDA spectral library construction. The DIA mass spectrometry parameters were as follows: (a) DIA mode; scanning range for a full scan, 350~1200 m/z; resolution of the precursor ion, 60,000; automatic gain control (AGC) target, 3×10 6 ; and maximum ion injection time (maximum IT), 50 ms; (b) HCD normalized collision energy, 27%; (c) DIA MS2 scanning, 34 consecutive windows, each of which was set to 26 m/z and a 1 m/z overlap between 2 adjacent windows; and (d) MS2 scan resolution, 30,000; AGC target, 1×10 6 ; and maximum IT, set to auto.…”

Transient Transfection of the Zoonotic Parasite Babesia microti

“…This parasite invades and multiplies within red blood cells (RBCs) and infections vary greatly in their presentation depending on the age and immune competency of the host [1]. Severe symptoms are observed in neonates, or in older adults, possibly due to depressed cellular immunity and in the immunocompromised of any age, particularly splenectomized individuals [2]. In patients who were hospitalized with severe B. microti infection, death occurred in 10% of the cases.…”