We describe the 11th case of bioterrorism-related inhalational anthrax reported in the United States. The presenting clinical features of this 94-year-old woman were subtle and nondistinctive. The diagnosis was recognized because blood cultures were obtained prior to administration of antibiotics, emphasizing the importance of this diagnostic test in evaluating ill patients who have been exposed to Bacillus anthracis. The patient's clinical course was characterized by progression of respiratory insufficiency, pleural effusions and pulmonary edema, and, ultimately, death. Although her B anthracis bacteremia was rapidly sterilized after initiation of antibiotic therapy, viable B anthracis was present in postmortem mediastinal lymph node specimens. The source of exposure to B anthracis in this patient is not known. Exposure to mail that was cross-contaminated as it passed through postal facilities contaminated with B anthracis spores is one hypothesis under investigation.

The usual methods employed to reduce the risk of transfusion-associated cytomegalovirus (TA CMV) disease have been to transfuse blood or cellular blood components that are CMV antibody-negative or to administer deglycerolized frozen red cells. To determine if the reduction of white cells (WBCs) in blood by filtration will also eliminate TA CMV disease in a high-risk population, 48 surviving very low birth weight (less than 1250 g) neonatal infants born to CMV-seronegative mothers at three participating institutions in the Hartford, Connecticut area and receiving at least one CMV-seropositive blood transfusion were studied. The incidence of TA CMV disease in 26 neonatal patients who received blood prepared by a modified spin-cool-filter technique and in 22 neonatal patients who received blood filtered through a WBC-reduction filter was compared with the incidence of transfusion-associated disease in similar populations reported in other studies. The CMV antibody prevalence of the blood donor population was found to be 37 percent. At the time of discharge of the individual neonatal infants in the population studied, and/or 2 to 6 months later, 47 of the 48 who had undergone transfusion had CMV antibody-negative serologic tests and/or urine culture. The other infant transiently seroconverted because of passive transfer of the antibody. None of the 48 neonatal infants had clinical evidence of CMV infection. This study indicates that WBC reduction of donor blood can reduce and perhaps prevent TA CMV disease in high-risk neonatal patients.

The clinical significance of specimens with low sample-to-cutoff (S/Co) ratios in the Ortho VITROS chemiluminescence assay (CIA) for detection of antibodies to hepatitis C virus (HCV) was evaluated. In one study of 482 CIA-reactive samples, none of the 83 samples with S/Co ratios of <5 was HCV RNA positive. In a subsequent study, 332 samples with S/Co ratios of between 1 and 20 were tested with the recombinant immunoblot assay (RIBA). None of the 163 samples with S/Co ratios of <5 was RIBA positive, 83% were RIBA negative, and 28 samples (18%) were RIBA indeterminate. HCV RNA and/or clinical evidence of hepatitis was not found in the 27 indeterminate cases examined. These results show that over 99% of samples with very low S/Co ratios (<5) have no evidence of HCV infection. Therefore, we suggest that the HCV antibody testing algorithm for the VITROS assay might be modified to eliminate supplemental testing of samples with very low S/Co ratios.Assays for the detection of hepatitis C virus (HCV) antibodies have high false-positive rates, particularly in low-prevalence populations. Therefore, other tests such as recombinant immunoblot assay (RIBA) or HCV RNA PCR are used to confirm positive HCV antibody screening tests. To facilitate usage of the supplemental testing, the Centers for Disease Control and Prevention (CDC) published guidelines that incorporate anti-HCV assay signal-to-cutoff (S/Co) ratios into reflex testing algorithms for HCV antibody testing, in order to provide a more systematic approach for the laboratory diagnosis of HCV and minimize the number of specimens that require supplemental testing (2). Data obtained with three anti-HCV screening assays were used for these recommendations: two enzyme immunoassays (EIAs) (Abbott HCV EIA 2.0 and ORTHO HCV version 3.0 enzyme-linked immunosorbent assay) and one enhanced chemiluminescence immunoassay (CIA) (VITROS anti-HCV assay; Ortho-Clinical Diagnostics).The VITROS anti-HCV CIA has recently been shown to be at least as specific and sensitive as conventional EIAs (7, 9), and use of this CIA has been increasing. However, detailed studies of the CIA S/Co ratio value predictive of a positive supplemental HCV test have been limited (7, 9). The CDC guidelines have suggested reflex supplemental testing for samples with S/C ratios of Ͻ8.0 in the VITROS anti-HCV assay based on the evaluation of a total of 1,326 reactive samples, with only 142 of these specimens having S/Co ratios of Յ7.9 (2).We started using the VITROS anti-HCV assay shortly after its Food and Drug Administration approval in August 2001 and have prospectively applied reflex supplemental testing to all samples with S/Co ratios of between 1.00 and 20.0 in the setting of a population of U.S. veterans (8). The objectives of the present study were (i) to determine the S/Co ratio predictive of detectable HCV RNA; (ii) to evaluate, in samples with low S/Co ratios (between 1 and 20), the relationship between S/Co ratios and the number and types of bands detected by RIBA; (iii) to assess, for samples with i...

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