A literature review of laboratory-acquired brucellosis.

Brucellosis is a bacterial zoonotic disease which has been associated with laboratory-acquired infections. No recent reviews have addressed the characteristics of laboratory-acquired brucellosis (LAB). English-language literature was reviewed to identify reports of laboratory exposures to Brucella spp. and LAB cases between 1982 and 2007. Evaluation of 28 case reports identified 167 potentially exposed laboratory workers, of whom 71 had LAB. Nine reports were identified that summarized an additional 186 cases of LAB. Only 18 (11%) exposures were due to laboratory accidents, 147 (88%) exposures were due to aerosolization of organisms during routine identification activities, and the circumstances of 2 (1%) exposures were unknown. Brucella melitensis was the causative agent in 80% (135/167) of the exposures. Workers with high-risk exposures were 9.3 times more likely to develop LAB than workers with low-risk exposures (95% confidence interval [CI], 3.0 to 38.6; P < 0.0001); they were also 0.009 times likelier to develop LAB if they took antimicrobial PEP than if they did not (95% CI, 0 to 0.042; P < 0.0001). The median incubation period in case and summary reports was 8 weeks (range 1 to 40 weeks). Antimicrobial PEP is effective in preventing LAB. The incubation period may be used to identify appropriate serological and symptom surveillance time frames for exposed laboratory workers.

Utility of antimicrobial susceptibility testing in Trichomonas vaginalis-infected women with clinical treatment failure.

BACKGROUND: Antimicrobial resistance is one of the causes of treatment failure in women after standard nitroimidazole therapy for Trichomonas vaginalis infections. The Centers for Disease Control and Prevention provides drug susceptibility testing and guidance for treatment failures but the efficacy of the alternate recommendations has not been assessed. METHODS: T. vaginalis isolates from women who had failed at least 2 courses of standard therapy for trichomoniasis were submitted to the Centers for Disease Control and Prevention for susceptibility testing. Alternative treatment recommendations were provided based on in vitro drug susceptibility results and clinical outcomes were collected. RESULTS: Drug susceptibility results were available for 175 women tested between January 2002 and January 2008. In vitro, 115 of the 175 isolates demonstrated metronidazole resistance. For all isolates resistant to metronidazole, in vitro resistance to tinidazole was similar or lower. Clinical treatment outcomes were available for 72 women. Of the women receiving an alternative recommended nitroimidazole regimen, 30 (83%) of 36 were cured compared with 8 (57%) of 14 women who received a lower dose than recommended. Clinical and microbiologic success was attained in 59 (82%) of 72 women whose follow-up information was available, with some women requiring multiple treatment courses. CONCLUSIONS: Clinical and microbiologic cure rates were higher for women who were treated in accordance with the recommendation provided after in vitro testing compared with those who received a lower dose or a different drug. Susceptibility testing leading to tailored treatment may have a beneficial role for management of women with persistent trichomoniasis.

Transfusion-associated babesiosis in the United States: a description of cases.

BACKGROUND: Babesiosis is a potentially life-threatening disease caused by intraerythrocytic parasites, which usually are tickborne but also are transmissible by transfusion. Tickborne transmission of Babesia microti mainly occurs in 7 states in the Northeast and the upper Midwest of the United States. No Babesia test for screening blood donors has been licensed. OBJECTIVE: To ascertain and summarize data on U.S. transfusion-associated Babesia cases identified since the first described case in 1979. DESIGN: Case series. SETTING: United States. PATIENTS: Case patients were transfused during 1979-2009 and had posttransfusion Babesia infection diagnosed by 2010, without reported evidence that another transmission route was more likely than transfusion. Implicated donors had laboratory evidence of infection. Potential cases were excluded if all pertinent donors tested negative. MEASUREMENTS: Distributions of ascertained cases according to Babesia species and period and state of transfusion. RESULTS: 159 transfusion-associated B. microti cases were included; donors were implicated for 136 (86%). The case patients' median age was 65 years (range, <1 to 94 years). Most cases were associated with red blood cell components; 4 were linked to whole blood-derived platelets. Cases occurred in all 4 seasons and in 22 (of 31) years, but 77% (122 cases) occurred during 2000-2009. Cases occurred in 19 states, but 87% (138 cases) were in the 7 main B. microti-endemic states. In addition, 3 B. duncani cases were documented in western states. LIMITATION: The extent to which cases were not diagnosed, investigated, reported, or ascertained is unknown. CONCLUSION: Donor-screening strategies that mitigate the risk for transfusion transmission are needed. Babesiosis should be included in the differential diagnosis of unexplained posttransfusion hemolytic anemia or fever, regardless of the season or U.S. region. PRIMARY FUNDING SOURCE: None.

Molecular typing of novel Rickettsia rickettsii isolates from Arizona.

Seven isolates of Rickettsia rickettsii were obtained from a skin biopsy, two whole-blood specimens, and from Rhipicephalus sanguineus ticks from eastern Arizona. Molecular typing of seven isolates of R. rickettsii and DNA samples from two other Rh. sanguineus ticks infected with R. rickettsii was conducted by PCR and DNA sequencing of rompA and 12 variable-number tandem repeat regions (VNTRs). All DNA specimens from Arizona were identical to each other and to reference human and Dermacentor andersoni isolates of R. rickettsii from Montana in their rOmpA gene sequences and 10 VNTRs. Two of the twelve VNTRs had differences in the number of repeat sequences in isolates from Arizona compared to those from Montana, thus conferring the novelty of the Rh. sanguineus-associated R. rickettsii.

Isolation and identification of Rickettsia massiliae from Rhipicephalus sanguineus ticks collected in Arizona.

Twenty Rhipicephalus sanguineus ticks collected in eastern Arizona were tested by PCR assay to establish their infection rate with spotted fever group rickettsiae. With a nested PCR assay which detects a fragment of the Rickettsia genus-specific 17-kDa antigen gene (htrA), five ticks (25%) were found to contain rickettsial DNA. One rickettsial isolate was obtained from these ticks by inoculating a suspension of a triturated tick into monolayers of Vero E6 monkey kidney cells and XTC-2 clawed toad cells, and its cell culture and genotypic characteristics were determined. Fragments of the 16S rRNA, GltA, rOmpA, rOmpB, and Sca4 genes had 100%, 100%, 99%, 99%, and 99%, respectively, nucleotide similarity to Rickettsia massiliae strain Bar29, previously isolated from R. sanguineus in Catalonia, Spain (L. Beati et al., J. Clin. Microbiol. 34:2688-2694, 1996). The new isolate, AZT80, does not elicit cytotoxic effects in Vero cells and causes a persistent infection in XTC-2 cells. The AZT80 strain is susceptible to doxycycline but resistant to rifampin and erythromycin. Whether R. massiliae AZT80 is pathogenic or infectious for dogs and humans or can cause seroconversion to spotted fever group antigens in the United States is unknown.