Screening for Babesia microti in the U.S. Blood Supply.

BACKGROUND: Babesia microti, a tickborne intraerythrocytic parasite that can be transmitted by means of blood transfusion, is responsible for the majority of cases of transfusion-transmitted babesiosis in the United States. However, no licensed test exists for screening for B. microti in donated blood. We assessed data from a large-scale, investigational product-release screening and donor follow-up program. METHODS: From June 2012 through September 2014, we performed arrayed fluorescence immunoassays (AFIAs) for B. microti antibodies and real-time polymerase-chain-reaction (PCR) assays for B. microti DNA on blood-donation samples obtained in Connecticut, Massachusetts, Minnesota, and Wisconsin. We determined parasite loads with the use of quantitative PCR testing and assessed infectivity by means of the inoculation of hamsters and the subsequent examination for parasitemia. Donors with test-reactive samples were followed. Using data on cases of transfusion-transmitted babesiosis, we compared the proportions of screened versus unscreened donations that were infectious. RESULTS: Of 89,153 blood-donation samples tested, 335 (0.38%) were confirmed to be positive, of which 67 (20%) were PCR-positive; 9 samples were antibody-negative (i.e., 1 antibody-negative sample per 9906 screened samples), representing 13% of all PCR-positive samples. PCR-positive samples were identified all through the year; antibody-negative infections occurred from June through September. Approximately one third of the red-cell samples from PCR-positive or high-titer AFIA-positive donations infected hamsters. Follow-up showed DNA clearance in 86% of the donors but antibody seroreversion in 8% after 1 year. In Connecticut and Massachusetts, no reported cases of transfusion-transmitted babesiosis were associated with screened donations (i.e., 0 cases per 75,331 screened donations), as compared with 14 cases per 253,031 unscreened donations (i.e., 1 case per 18,074 unscreened donations) (odds ratio, 8.6; 95% confidence interval, 0.51 to 144; P=0.05). Overall, 29 cases of transfusion-transmitted babesiosis were linked to blood from infected donors, including blood obtained from 10 donors whose samples tested positive on the PCR assay 2 to 7 months after the implicated donation. CONCLUSIONS: Blood-donation screening for antibodies to and DNA from B. microti was associated with a decrease in the risk of transfusion-transmitted babesiosis. (Funded by the American Red Cross and Imugen; ClinicalTrials.gov number, NCT01528449 .).

Seroreactivity to the C6 Peptide in Borrelia miyamotoi Infections Occurring in the Northeastern United States.

Background: There are no US Food and Drug Administration (FDA)-approved diagnostic tests for Borrelia miyamotoi infection, an emerging tick-borne illness in the United States. The purpose of this study was to evaluate whether the FDA-approved C6 peptide enzyme-linked immunosorbent assay (ELISA) currently used to diagnose Lyme disease may potentially serve as a diagnostic test for B. miyamotoi infections. Methods: Serum specimens from 30 patients from the northeastern United States with B. miyamotoi infection established by a polymerase chain reaction assay of a blood specimen were tested using the C6 ELISA. To reduce confounding with Borrelia burgdorferi coinfection, 6 sera were excluded: 3 from patients with a positive Western immunoblot for antibodies to B. burgdorferi and 3 from patients for whom immunoblot testing had not been performed. Results: Twenty-two of 24 (91.7% [95% confidence interval, 73.0%-98.8%]) evaluable B. miyamotoi patients were C6 ELISA reactive, principally on a convalescent-phase serum specimen. C6 ELISA index values were often well above the positive cutoff value of 1.1, exceeding 4 in 11 of the 22 (50.0%) C6 ELISA-reactive patients. Conclusions: Although previously regarded as a highly specific test for Lyme disease, the C6 ELISA is also regularly reactive on convalescent-phase serum samples of patients from the northeastern United States with B. miyamotoi infection.

Borrelia miyamotoi Disease in the Northeastern United States: A Case Series.

BACKGROUND: The first recognized cases of Borrelia miyamotoi disease (BMD) in North America were reported in the northeastern United States in 2013. OBJECTIVE: To further describe the clinical spectrum and laboratory findings for BMD. DESIGN: Case series. SETTING: Patients presenting to primary care offices, emergency departments, or urgent care clinics in 2013 and 2014. PARTICIPANTS: Acutely febrile patients from the northeastern United States in whom the treating health care providers suspected and ordered testing for tick-transmitted infections. MEASUREMENTS: Whole-blood polymerase chain reaction (PCR) testing was performed for the presence of specific DNA sequences of common tickborne infections (including BMD). Serologic testing for B. miyamotoi was performed using a recombinant glycerophosphodiester phosphodiesterase (rGlpQ) protein. Clinical records were analyzed to identify the major features of acute disease. RESULTS: Among 11,515 patients tested, 97 BMD cases were identified by PCR. Most of the 51 case patients on whom clinical histories were reviewed presented with high fever, chills, marked headache, and myalgia or arthralgia. Twenty-four percent were hospitalized. Elevated liver enzyme levels, neutropenia, and thrombocytopenia were common. At presentation, 16% of patients with BMD were seropositive for IgG and/or IgM antibody to B. miyamotoi rGlpQ. Most (78%) had seropositive convalescent specimens. Symptoms resolved after treatment with doxycycline, and no chronic sequelae or symptoms were observed. LIMITATION: Findings were based on specimens submitted for testing to a reference laboratory, and medical records of only 51 of the 97 case patients with BMD were reviewed. CONCLUSION: Patients with BMD presented with nonspecific symptoms, including fever, headache, chills, myalgia, and arthralgia. Laboratory confirmation of BMD was possible by PCR on blood from acutely symptomatic patients who were seronegative at presentation. Borrelia miyamotoi disease may be an emerging tickborne infection in the northeastern United States. PRIMARY FUNDING SOURCE: IMUGEN.

A qualitative study of physicians' perceptions of three decision aids.

The study objective was to investigate physicians' perceptions of three patient decision aids (DA). Semi-structured telephone interviews were conducted with 20 family physicians and 12 gynecologists about a DA for women considering long-term hormone replacement therapy; with 16 respirologists about a DA for the use of intubation and mechanical ventilation for patients with severe chronic obstructive pulmonary disease; and with 19 physicians (geriatricians, gastroenterologists, internists) about a DA for long-term placement of feeding tubes in the elderly. Participants were identified by a snowball sampling technique. The interviews were analyzed using standard qualitative methods. Most participants (81%) indicated some willingness to use the DAs. The characteristics of the DA viewed positively included it being: balanced, well organized, a useful tool, evidence-based, improves decision making process and multimedia. Some of the negative characteristics were stated as: too complex, the cost, the availability, only appropriate for certain groups of patients, and time consuming. The DAs were acceptable to most participants. Perceived positive and negative factors were similar for all DAs. Uptake of decision aids may be facilitated if physicians have an opportunity to examine and try them, and if they can have unfettered access to them for distribution purposes.