Cytomegalovirus reactivation in critically ill immunocompetent patients.

CONTEXT: Cytomegalovirus (CMV) infection is associated with adverse clinical outcomes in immunosuppressed persons, but the incidence and association of CMV reactivation with adverse outcomes in critically ill persons lacking evidence of immunosuppression have not been well defined. OBJECTIVE: To determine the association of CMV reactivation with intensive care unit (ICU) and hospital length of stay in critically ill immunocompetent persons. DESIGN, SETTING, AND PARTICIPANTS: We prospectively assessed CMV plasma DNAemia by thrice-weekly real-time polymerase chain reaction (PCR) and clinical outcomes in a cohort of 120 CMV-seropositive, immunocompetent adults admitted to 1 of 6 ICUs at 2 separate hospitals at a large US tertiary care academic medical center between 2004 and 2006. Clinical measurements were assessed by personnel blinded to CMV PCR results. Risk factors for CMV reactivation and association with hospital and ICU length of stay were assessed by multivariable logistic regression and proportional odds models. MAIN OUTCOME MEASURES: Association of CMV reactivation with prolonged hospital length of stay or death. RESULTS: The primary composite end point of continued hospitalization (n = 35) or death (n = 10) by 30 days occurred in 45 (35%) of the 120 patients. Cytomegalovirus viremia at any level occurred in 33% (39/120; 95% confidence interval [CI], 24%-41%) at a median of 12 days (range, 3-57 days) and CMV viremia greater than 1000 copies/mL occurred in 20% (24/120; 95% CI, 13%-28%) at a median of 26 days (range, 9-56 days). By logistic regression, CMV infection at any level (adjusted odds ratio [OR], 4.3; 95% CI, 1.6-11.9; P = .005) and at greater than 1000 copies/mL (adjusted OR, 13.9; 95% CI, 3.2-60; P < .001) and the average CMV area under the curve (AUC) in log(10) copies per milliliter (adjusted OR, 2.1; 95% CI, 1.3-3.2; P < .001) were independently associated with hospitalization or death by 30 days. In multivariable partial proportional odds models, both CMV 7-day moving average (OR, 5.1; 95% CI, 2.9-9.1; P < .001) and CMV AUC (OR, 3.2; 95% CI, 2.1-4.7; P < .001) were independently associated with a hospital length of stay of at least 14 days. CONCLUSIONS: These preliminary findings suggest that reactivation of CMV occurs frequently in critically ill immunocompetent patients and is associated with prolonged hospitalization or death. A controlled trial of CMV prophylaxis in this setting is warranted

Babesia divergens–like Infection, Washington State

Most reported U.S. zoonotic cases of babesiosis have occurred in the Northeast and been caused by Babesia microti. In Washington State, three cases of babesiosis have been reported previously, which were caused by WA1 (for “Washington 1”)-type parasites. We investigated a case of babesiosis in Washington in an 82–year-old man whose spleen had been removed and whose parasitemia level was 41.4%. The complete 18S ribosomal RNA gene of the parasite was amplified from specimens of his whole blood by polymerase chain reaction. Phylogenetic analysis showed the parasite is most closely related, but not identical, to B. divergens (similarity score, 99.5%), a bovine parasite in Europe. By indirect fluorescent-antibody testing, his serum reacted to B. divergens but not to B. microti or WA1 antigens. This case demonstrates that babesiosis can be caused by novel parasites detectable by manual examination of blood smears but not by serologic or molecular testing for B. microti or WA1-type parasites

Rapid Identification and Differentiation of Candida albicans and Candida dubliniensis by Capillary-Based Amplification and Fluorescent Probe Hybridization

We developed a rapid genotypic assay to differentiate the germ tube-positive yeasts Candida albicans and Candida dubliniensis. Fluorescently labeled nucleic acid probe binding and subsequent denaturation from the target site in the PCR amplicons produced characteristic peak melting temperatures (T(m)) that identified each species. Peak T(m)s of C. albicans (n = 69) and C. dubliniensis (n = 28) isolates produced in the presence of their respective probes were 61.04 ± 0.64°C and 60.52 ± 1.01°C (averages ± standard deviations). No signal was generated when the C. albicans or C. dubliniensis probes were tested against DNA from their counterparts. Both probes reacted with Candida tropicalis DNA, but the T(m) was 51.85 ± 0.05°C with the C. albicans probe and 51.92 ± 0.10°C with the C. dubliniensis probe, differentiating C. tropicalis DNA from C. albicans and C. dubliniensis. A novel hybrid probe was designed to identify both species in a single reaction based on a 4°C difference in peak T(m)s. Our assay is rapid (≤2 h) and allows reliable detection and differentiation of the two germ tube-positive Candida spp

Rapid Identification of Commonly Encountered Candida Species Directly from Blood Culture Bottles

We report a rapid-cycle, real-time PCR method for identifying six Candida spp. directly from BACTEC blood culture bottles. Target sequences in the noncoding internal transcribed spacer regions of the rRNA operon were simultaneously amplified and interrogated with fluorescent probes to identify Candida albicans, C. glabrata, C. parapsilosis, C. tropicalis, C. krusei, and C. lusitaniae; these account for 88% of the yeast species isolated from positive blood cultures in our laboratory. Any of the first four species can be identified in a single reaction using two fluorescent hybridization probe sets. The antifungal-resistant species C. krusei and C. lusitaniae are detected in a second reaction, also with two probe sets. The assay was validated with DNA extracted from BACTEC blood culture bottles positive for yeasts (n = 62) and was 100% concordant with culture identification based on biochemical and morphological features of C. albicans (n = 22), C. parapsilosis (n = 10), C. tropicalis (n = 1) C. glabrata (n = 22), C. krusei (n = 2), and C. lusitaniae (n = 1). No cross-reactivity was observed in blood culture samples growing yeasts other than the above-mentioned species (n = 4), in those growing bacteria (n = 12), or in the absence of microbial growth. Our assay allows rapid (≤2 h) and specific detection of the most common Candida spp. directly from positive blood cultures and may facilitate delivery of optimal antifungal therapy