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We evaluated the BACTEC MGIT 960 system, which is a fully automated, noninvasive system for the growth and detection of mycobacteria with a capacity to incubate and continuously monitor 960 7-ml culture tubes. We studied 3,330 specimens, 2,210 respiratory and 1,120 nonrespiratory specimens, collected from 2,346 patients treated at six sites. Processed specimens were inoculated into the BACTEC MGIT 960 and BACTEC 460 TB systems, as well as onto Lowenstein-Jensen slants and Middlebrook 7H11/7H11 selective plates. From all culture systems, a total of 362 isolates of mycobacteria were recovered; these were recovered from 353 specimens collected from 247 patients. The greatest number of isolates of mycobacteria (289, or 80% of the 362 isolates) was recovered with the BACTEC MGIT 960, followed by the BACTEC 460 TB (271, or 75%) and solid media (250, or 69%). From all culture systems a total of 132 isolates of Mycobacterium tuberculosiscomplex were recovered. The greatest number of isolates of M. tuberculosis complex was recovered when liquid medium was combined with conventional solid media; the number recovered with BACTEC 460 TB plus solid media was 128 (97%), that recovered with BACTEC MGIT 960 plus solid media was 121 (92%), that recovered with BACTEC 460 TB was 119 (90%) and that recovered with all solid media combined was 105 (79%). The recovery with BACTEC MGIT 960 alone was 102 (77%). The mean times to detection (TTD) for M. tuberculosis complex were 14.4 days for BACTEC MGIT, 15.2 days for BACTEC 460 TB, and 24.1 days for solid media. The numbers of isolates of Mycobacterium avium complex (MAC) recovered were 172 (100%) for all systems, 147 (85%) for BACTEC MGIT 960, 123 (72%) for BACTEC 460 TB, and 106 (62%) for all solid media combined. The TTD for MAC in each system were 10.0 days for BACTEC MGIT 960, 10.4 days for BACTEC 460 TB, and 25.9 days for solid media. Breakthrough contamination rates (percentages of isolates) for each of the systems were 8.1% for BACTEC MGIT 960, 4.9% for BACTEC 460 TB, and 21.1% for all solid media combined.

Nosocomial fungal pulmonary infections (Zygomycetes, Aspergillus sp.) developed in two premature infants in a special care unit (SCU) adjacent to an area of renovation. Inspection showed that inadequate barriers permitted the passage of airborne particles between the two areas, and cultures confirmed a significantly higher (p≤0.05) density of mold spores in the SCU (0.88 cfu per hour per settling plate) compared to a construction-free comparison area (0.22 cfu per hour per settling plate). The major source of mold was the dust above the hospital's false ceiling. In another construction area, impervious barriers were shown to effectively restrict the dispersal of mold. Our experience adds Rhizopus to Aspergillus as a possible cause of construction-related nosocomial infection. Sporadic episodes will continue to occur until the hazards of renovation are appreciated and effective preventive measures are routinely instituted.

The transmission of perinatal hepatitis C virus (HCV) infection was studied retrospectively in 62 infants born to 54 HCV- and human immunodeficiency virus (HIV)-coinfected women enrolled in a prospective natural history study of HIV transmission. Infant HCV infection was assessed by nested RNA polymerase chain reaction. The overall rate of vertical HCV transmission was 16.4% (9/62). Most HCV-infected children did not develop antibodies to HCV. The rate of HCV infection was higher among HIV-infected infants (40%) than among HIV-uninfected infants (7.5%; odds ratio, 8.2; P = .009). This difference in transmission was not related to differences in maternal HCV load, as measured by branched DNA assay, or mode of delivery. Why HIV-infected infants of HCV- and HIV-coinfected women have significantly higher rates of perinatal HCV transmission remains to be elucidated. The rate of HCV transmission in HIV-uninfected infants of HCV- and HIV-coinfected women is similar to that reported for infants born to HIV-seronegative mothers.

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A Campylobacter species was isolated from blood from a febrile patient with precursor T-cell acute lymphoblastic leukemia, and after antibiotic treatment, a similar bacterium was isolated from blood 37 days later. Although phenotypic testing did not definitively identify the organisms, molecular analysis indicated that they were the same strain of Campylobacter fetus subsp. fetus and were of reptile origin. CASE REPORTA 20-year-old man presented to the hospital with a productive cough for 2 weeks and fever of 40.6°C for 1 day. Seven months earlier, a computerized tomographic scan of the chest showed a 7-cm-diameter mediastinal mass compressing the trachea. Peripheral blood flow cytometry at that time was diagnostic of precursor T-cell acute lymphoblastic leukemia. Because of pneumocystis pneumonia, which was treated, the patient then received trimethoprim-sulfamethoxazole prophylaxis three times a week on a continuing basis. Numerous courses of chemotherapy led to neutropenia, complicated by Candida tropicalis fungemia and then Streptococcus mitis bacteremia, which both resolved with treatment. Two weeks prior to admission, the patient received chemotherapy with methotrexate and 6-mercaptopurine.On the day the patient was admitted to the hospital, he reported worsening cough, fever, and epigastric pain. On examination, he appeared to be moderately ill with a temperature of 39.4°C, pulse of 110 beats/min, blood pressure of 110/48 mm of Hg, and respiratory rate of 14 breaths/min; his physical examination was otherwise normal. The leukocyte count was 3,900/mm 3 , with an absolute neutrophil count of 2,650/mm 3 and a platelet count of 52,000/mm 3 . He had 6.6 g of hemoglobin per dl. The chest X-ray was normal. After cultures were obtained, he was given cefepime intravenously. Two days after admission, one of four blood culture bottles was reported as growing Campylobacter species. Cefepime was changed to imipenem-cilastatin. He also was noted to have erythema and tenderness of the right arm in an area near a prior phlebotomy site. Vancomycin was added for presumed cellulitis and was continued for 1 week, with complete resolution of erythema. Multiple stool cultures (obtained after antibiotics were begun) were negative for Campylobacter species. Twelve days after admission to the hospital, the bloodstream Campylobacter isolate was noted to be resistant to trimethoprim-sulfamethoxazole but susceptible to levofloxacin, and the patient was discharged on oral levofloxacin (500 mg per day for 2 weeks).The patient recovered and was readmitted 3 weeks later for elective chemotherapy with cytarabine and etoposide. Four days after admission to the hospital, he developed abdominal pain and a temperature of 38.9°C. The chest X-ray was normal. After blood cultures were obtained, the patient was empirically treated with cefepime and metronidazole, which was changed 4 days later to intravenous levofloxacin and metronidazole. The absolute neutrophil count at that time was 11,300/mm 3 , which subsequently decreased to a nadir of Ͻ50...

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