Indirect Immunofluorescence Test for Human Babesia microti Infection: Antigenic Specificity

Chisholm, Emily S.; Sulzer, Alexander J.; Ruebush, Trenton K.

doi:10.4269/ajtmh.1986.35.921

Cited by 22 publications

(10 citation statements)

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“…The one malaria-infected donor who was positive for antibodies to both B. microti antigens had very high responses (Ͼ27,000). Although IFA cross-reactivity between sera from malaria-infected patients and antigens from B. microti has been previously reported (4), the magnitude of the responses to both recombinant antigens and the fact that some of the malaria samples were submitted from regions of the United States where babesiosis is endemic suggest the possibility that this individual may have been infected with both malaria and B. microti. We hypothesize that the use of a two-antigen MBA for screening of low-prevalence populations would minimize the number of false positives and, in the case of blood donor screening, would detect the majority of babesiosis-positive donors while all but eliminating unnecessary donor deferrals.…”

Section: Discussionmentioning

confidence: 87%

Multiplex Assay Detection of Immunoglobulin G Antibodies That Recognize Babesia microti Antigens

Priest

Moss

Won

et al. 2012

Clin Vaccine Immunol

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Human babesiosis, a blood-borne infection caused by several species of Babesia, including B. microti, is an emerging disease that is endemic in the Northeast, upper Midwest, and Pacific Northwest regions of the United States. Risk factors for babesiosis include exposure to the infected tick vector and blood transfusions from infected donors. In this work, we cloned and expressed two of the immunodominant antigens from B. microti and used them in a multiplex bead format assay (MBA) to detect parasitespecific IgG responses in human sera. The MBA using recombinant B. microti secreted antigen 1 (BmSA1) protein was more specific (100%) and slightly more sensitive (98.7%) than the assay using a truncated recombinant BMN1-17 construct (97.6% and 97.4%, respectively). Although some antibody reactivity was observed among sera from confirmed-malaria patients, only one Plasmodium falciparum sample was simultaneously positive for IgG antibodies to both antigens. Neither antigen reacted with sera from babesiosis patients who were infected with Babesia species other than B. microti. Both positive and negative MBA results were reproducible between assays and between instruments. Additional studies of these recombinant antigens and of the multiplex bead assay using blood samples from clinically defined babesiosis patients and from blood donors are needed to more clearly define their usefulness as a blood screening assay.

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Section: Discussionmentioning

confidence: 87%

Multiplex Assay Detection of Immunoglobulin G Antibodies That Recognize Babesia microti Antigens

Priest

Moss

Won

et al. 2012

Clin Vaccine Immunol

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“…The identity of a Babesia isolate can be verified by measuring seroreactivity with various sera obtained from Babesia-infected humans and animals. As described previously (7,22,29), the IFA test has a high degree of specificity for diagnosing chronic infection and identifying the species of the Babesia parasite. In general, the degree of cross-reactivity between known species of the Babesia parasite and the suspected agent of human babesiosis may eventually be used to identify the species responsible for human infection.…”

Section: Discussionmentioning

confidence: 97%

“…Because parasitemias in infected persons may be exceedingly sparse (34), laboratory diagnosis that depends solely on a demonstration of babesial organisms within erythrocytes by examining Giemsa-stained thin films may not be sufficient for detection of subclinical exposure. In addition, inoculation of the patient's blood into hamsters to amplify the undetectable parasitemia (2,4,9,11,17) and serologic testing for diagnosing chronic babesial infection and identifying the species of Babe-sia causing the infection (6,7,33) are required for a fully confirmed laboratory diagnosis.…”

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confidence: 99%

Human babesiosis in Taiwan: asymptomatic infection with a Babesia microti-like organism in a Taiwanese woman

et al. 1997

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An asymptomatic Babesia infection was confirmed by laboratory diagnoses. The intraerythrocytic protozoan (designed TW1) isolated from a 51-year-old Taiwanese woman appeared to be morphologically consistent with small-form piroplasm, and measurements indicated that it had a body size of 1.5 to 2.5 m in diameter. The typical features of ring, binary, and tetrad forms were observed in Giemsa-stained thin blood smears. A persistent and low-grade parasitemia was established after hamster inoculation. Indirect immunofluorescentantibody reactivities indicate that this strain (TW1) of Babesia was serologically related to, but not identical to, the Babesia species (B. microti) that infects rodents. Antibody titers in the patient's sera combined with the clinical symptoms suggested that the present case was a chronic and subclinical babesial infection. A neighborhood human serologic survey indicated that the infection may have been acquired accidentally from an infected rodent and localized within the same family. Indeed, rodents from areas around the neighborhood were trapped, and a high prevalence (83%) of babesial infection was observed. The possible vector responsible for the transmission remains to be identified.

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“…An IFA assay for IgG antibodies to B. microti was used as described earlier . Briefly, sera were diluted fourfold starting at 1:4 to 1:4096.…”

Section: Methodsmentioning

confidence: 99%

Experimental transfusion‐induced Babesia microti infection: dynamics of parasitemia and immune responses in a rhesus macaque model

et al. 2016

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BACKGROUND Babesiosis is an emerging tick-borne infection in humans. The increasing numbers of reported cases of transfusion-associated babesiosis (TAB), primarily caused by Babesia microti, represents a concern for the safety of the U.S. blood supply. STUDY DESIGN AND METHODS This study investigated kinetics of parasitemia, innate immune responses and dynamics of antibody responses during B. microti infection in rhesus macaques using blood smears, quantitative PCR (qPCR), flow cytometry, and indirect fluorescent antibody testing. A total of 6 monkeys were transfused with either hamster or monkey-passaged B. microti infected erythrocytes (2 and 4 monkeys, respectively) simulating TAB. RESULTS The prepatent period in monkeys inoculated with hamster-passaged B. microti was 35 days compared with 4 days in monkeys transfused with monkey-passaged B. microti; the latter monkeys also had markedly higher parasitemia levels. The duration of the window period from the first detected parasitemia by qPCR analysis to the first detected antibody response ranged from 10–17 days. Antibody responses fluctuated during the course of the infection. Innate responses assessed by the frequencies of monocytes and activated B cells correlated with the kinetics and magnitude of parasitemia. On day 14, additional activation peaks were noted for CD14+CD16+ and CD14−CD16+ monocytes and for CD11c+ myeloid dendritic cells, but only in animals transfused with monkey-passaged B. microti. Parasitemia persisted in these immunocompetent animals, similar to human infection. CONCLUSION The results suggest that transfusion-associated transmission of B. microti leads to rapid onset of parasitemia (day 4) in rhesus macaques, detectable antibody response 14 days later and persistent parasitemia.

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Indirect Immunofluorescence Test for Human Babesia microti Infection: Antigenic Specificity

Cited by 22 publications

References 0 publications

Multiplex Assay Detection of Immunoglobulin G Antibodies That Recognize Babesia microti Antigens

Multiplex Assay Detection of Immunoglobulin G Antibodies That Recognize Babesia microti Antigens

Human babesiosis in Taiwan: asymptomatic infection with a Babesia microti-like organism in a Taiwanese woman

Experimental transfusion‐induced Babesia microti infection: dynamics of parasitemia and immune responses in a rhesus macaque model

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