Congenital tuberculosis in a neonatal intensive care unit: case report, epidemiological investigation, and management of exposures

Disseminated tuberculosis was diagnosed at the autopsy of a 65-day-old premature infant who died in a 52-bed neonatal intensive care unit (NICU). Both parents and one sibling had previously had positive tuberculin skin tests (TSTs); none had active pulmonary tuberculosis, but a second sibling had hilar adenopathy. Congenital transmission was confirmed by isolation of Mycobacterium tuberculosis from the mother's endometrium and the infant's lung tissue. Both strains were identical by DNA restriction fragment analysis. TSTs were performed on 14 neonates, 27 NICU visitors, 11 contacts of the family, and 260 health care workers. TST conversion occurred in two nurses (0.8%); both had normal chest radiographs and received isoniazid therapy. Exposed neonates had negative chest radiographs, had negative gastric aspirates for acid-fast bacilli, and received isoniazid preventive therapy. Diagnosis of congenital tuberculosis requires a high index of suspicion. Transmission of tuberculosis in the NICU setting is unusual but can occur.

Limulus amebocyte lysate assay for detection of endotoxin in patients with sepsis syndrome. AMCC Sepsis Project Working Group

Clinical predictions alone are insufficiently accurate to identify patients with specific types of bloodstream infection; laboratory assays might improve such predictions. Therefore, we performed a prospective cohort study of 356 episodes of sepsis syndrome and did Limulus amebocyte lysate (LAL) assays for endotoxin. The main outcome measures were bacteremia and infection due to gram-negative organisms; other types of infection were secondary outcomes. Assays were defined as positive if the result was > or = 0.4 enzyme-linked immunosorbent assay units per milliliter. There were positive assays in 119 (33%) of 356 episodes. Assay positivity correlated with the presence of fungal bloodstream infection (P < .003) but correlated negatively with the presence of gram-negative organisms in the bloodstream (P = .04). A trend toward higher rates of mortality in the LAL assay-positive episodes was no longer present after adjusting for severity. Thus, results of LAL assay did not correlate with the presence of bacteremia due to gram-negative organisms or with mortality after adjusting for severity but did correlate with the presence of fungal bloodstream infection.

Predicting bacteremia in patients with sepsis syndrome. Academic Medical Center Consortium Sepsis Project Working Group

The goal of this study was to develop and validate clinical prediction rules for bacteremia and subtypes of bacteremia in patients with sepsis syndrome. Thus, a prospective cohort study, including a stratified random sample of 1342 episodes of sepsis syndrome, was done in eight academic tertiary care hospitals. The derivation set included 881 episodes, and the validation set included 461. Main outcome measures were bacteremia caused by any organism, gram-negative rods, gram-positive cocci, and fungal bloodstream infection. The spread in probability between low- and high-risk groups in the derivation sets was from 14.5% to 60.6% for bacteremia of any type, from 9.8% to 32.8% for gram-positive bacteremia, from 5.3% to 41.9% for gram-negative bacteremia, and from 0.6% to 26.1% for fungemia. Because the model for gram-positive bacteremia performed poorly, a model predicting Staphylococcus aureus bacteremia was developed; it performed better, with a low- to high-risk spread of from 2.6% to 21.0%. The prediction models allow stratification of patients according to risk of bloodstream infections; their clinical utility remains to be demonstrated.

Nosocomial legionellosis traced to a contaminated ice machine

OBJECTIVE

To investigate a case of nosocomial legionellosis, identify pathways of transmission, and effect control of the environmental source.

DESIGN

Case investigation and environmental culture surveillance.

SETTING

A 720-bed university teaching hospital. CASE PATIENT: A ventilator-dependent 66-year-old male developed nosocomial pneumonia due to Legionella pneumophila serogroup 6 after 3 months in an intensive-care unit (ICU). The patient had no intake of potable water except for ice chips from an ice machine in the ICU.

RESULTS

Cultures revealed L pneumophila serogroup 6 in the ice (4.3 colony-forming units/mL) and ice machine cold water (too numerous to count). Cultures from adjacent hot and cold taps, plus taps located near the patient, all were negative; ice machines and cold water on seven other patient units also were negative. Only sterile water had been used for tube feedings, mouth care, suctioning, and ventilator humidification. Hospital hot water previously had been colonized with L pneumophila serogroup 6, but all surveillance water cultures had been negative since chlorination of the hot-water system began the previous year; cold-water cultures had never before grown Legionella. The ice machine was disinfected with a 2-hour flush of 2.625% sodium hypochlorite. The supply line to the ice machine was replaced, and the cold-water pipe from the floor below was treated with 83 ppm sodium hypochlorite for 48 hours. All follow-up surveillance cultures of the ice machine remained negative through mid-1996. No additional cases of nosocomial legionellosis occurred.

CONCLUSIONS

Ice machines may be reservoirs of L pneumophila in hospitals. Both ice and water dispensed from these machines may be contaminated, and nosocomial transmission may occur. Successful long-term decontamination and control can be accomplished with shock chlorination.

Epidemiology of sepsis syndrome in 8 academic medical centers

CONTEXT

Sepsis syndrome is a leading cause of mortality in hospitalized patients. However, few studies have described the epidemiology of sepsis syndrome in a hospitalwide population.

OBJECTIVE

To describe the epidemiology of sepsis syndrome in the tertiary care hospital setting.

DESIGN

Prospective, multi-institutional, observational study including 5-month follow-up.

SETTING

Eight academic tertiary care centers.

METHODS

Each center monitored a weighted random sample of intensive care unit (ICU) patients, non-ICU patients who had blood cultures drawn, and all patients who received a novel therapeutic agent or who died in an emergency department or ICU. Sepsis syndrome was defined as the presence of either a positive blood culture or the combination of fever, tachypnea, tachycardia, clinically suspected infection, and any 1 of 7 confirmatory criteria. Estimates of total cases expected annually were extrapolated from the number of cases, the period of observation, and the sampling fraction.

RESULTS

From January 4, 1993, to April 2, 1994, 12759 patients were monitored and 1342 episodes of sepsis syndrome were documented. The extrapolated, weighted estimate of hospitalwide incidence (mean+/-95% confidence limit) of sepsis syndrome was 2.0+/-0.16 cases per 100 admissions, or 2.8+/-0.17 per 1000 patient-days. The unadjusted attack rate for sepsis syndrome between individual centers differed by as much as 3-fold, but after adjustment for institutional differences in organ transplant populations, variation from the expected number of cases was reduced to 2-fold and was not statistically significant overall. Patients in ICUs accounted for 59% of total extrapolated cases, non-ICU patients with positive blood cultures for 11%, and non-ICU patients with negative blood cultures for 30%. Septic shock was present at onset of sepsis syndrome in 25% of patients. Bloodstream infection was documented in 28%, with gram-positive organisms being the most frequent isolates. Mortality was 34% at 28 days and 45% at 5 months.

CONCLUSIONS

Sepsis syndrome is common in academic hospitals, although the overall rates vary considerably with the patient population. A substantial fraction of cases occur outside ICUs. An understanding of the hospitalwide epidemiology of sepsis syndrome is vital for rational planning and treatment of hospitalized patients with sepsis syndrome, especially as new and expensive therapeutic agents become available.

Neonatal Trichosporon beigelii infection: report of a cluster of cases in a neonatal intensive care unit

Trichosporon beigelii, a ubiquitous yeast found in soil, causes superficial dermatologic infections in normal hosts and rare cases of disseminated disease among immunocompromised patients. Neonatal cases are exceptionally rare. We report a cluster of cases of T. beigelii infections in a tertiary care hospital in Rochester, NY, during May to July, 1991. Three cases occurred in very low birth weight premature infants (23 to 25 weeks of gestation), two of whom died. The organism was isolated from urine alone in one case, skin and blood in one case and blood, tracheal aspirate and central venous catheter tip in one case. In a fourth, full term infant with respiratory distress syndrome T. beigelii was grown only from a femoral central venous catheter tip with no clinical evidence of infection. An epidemiologic investigation was performed and the mode of transmission in this outbreak was not identified, although cross-infection was suspected in the initial two cases. Our isolates were inhibited but not killed by usually achievable concentrations of amphotericin B. T. beigelii may cause outbreaks of serious infection in neonatal intensive care units, especially among premature infants.

Epidemiology and control of nosocomial viral infections

The impact of nosocomial viral disease, in terms of morbidity, mortality, and health care expenditures, should not be underestimated. Respiratory viruses, in particular, account for a substantial proportion of all nosocomial infections, especially among pediatric patients and the institutionalized elderly. The immunocompromised, very young, and chronically ill patients in hospitals are unusually vulnerable to serious viral illness. The emerging technology of rapid viral diagnosis will allow more timely and accurate recognition of viral infections, even in the smaller hospital with limited laboratory resources. Early recognition of viral diseases should, in turn, permit us to institute, and further evaluate, specific measures for their control. Appreciation of the epidemiology and transmission of these viruses will provide the framework for successful infection control strategies.

Nosocomial viral respiratory infections

Nosocomial infections with respiratory tract viruses, particularly influenza and respiratory syncytial viruses, account for the majority of serious nosocomial viral disease. Chronically ill, immunocompromised, elderly, and very young hosts are especially vulnerable to potentially life-threatening involvement of the lower respiratory tract. Effective preventive strategies are based upon early accurate viral diagnosis and an appreciation of the epidemiology and mechanisms of transmission for each viral agent. Influenza viruses spread via airborne dispersion of small particle aerosols, resulting in explosive outbreaks; control measures emphasize immunization and chemoprophylaxis of susceptible patients and personnel, and isolation of those already infected. Transmission of respiratory syncytial virus, in contrast, seems to require closer contact, with virus passed on hands, fomites, or in large droplets inoculated into the eyes and nose at close range. Strategies for control of nosocomial respiratory syncytial virus are designed to interrupt hand carriage and inoculation of virus onto mucous membranes.

Mollaret's meningitis associated with acute Epstein-Barr virus mononucleosis

A 19-year-old man developed recurrent aseptic meningitis (Mollaret's meningitis) during the course of acute Epstein-Barr virus infectious mononucleosis. Serum contained heterophil antibody and Epstein-Barr virus-specific antibodies characteristic of acute infection. Seven brief episodes of aseptic meningitis were documented over the following one-year period, in each case with a polymorphonuclear pleocytosis in the cerebrospinal fluid. Acute infection with Epstein-Barr virus, or subsequent reactivation of virus, may account for some cases of Mollaret's meningitis.

Evaluation of cerebrospinal fluid in asymptomatic late syphilis

To help determine the role of lumbar puncture in evaluation of patients with asymptomatic late syphilis, we reviewed results of cerebrospinal fluid (CSF) testing of 47 asymptomatic patients with syphilis. Syphilis was of unknown duration (n = 27) or known duration of greater than one year (n = 20), and all patients had reactive rapid plasma reagin (RPR) tests and reactive fluorescent treponemal antibody absorption tests. Thirty-two per cent of subjects had abnormal CSF findings; these included elevated protein in nine (19%) of 47 and pleocytosis in six (13%) of 47. In most cases, the etiology of these abnormalities was uncertain. Asymptomatic neurosyphilis, diagnosed on the basis of a reactive Venereal Disease Research Laboratory (VDRL; Atlanta, GA) test of CSF, was present in three (6%) of 47 patients. Of the eight patients with RPR titers of greater than or equal to 1:128, three (38%) had neurosyphilis. These results suggest that lumbar puncture is indicated for patients with asymptomatic late syphilis or syphilis of unknown duration.

Isolation of Chlamydia trachomatis from men with urethritis: relative value of one vs. two swabs and influence of concomitant gonococcal infection

Two successive urethral swabs were used to obtain specimens for culture of Neisseria gonorrhoeae and Chlamydia trachomatis from 136 heterosexual men with urethritis. The first swab was used to culture N. gonorrhoeae and then C. trachomatis; the second was used to culture C. trachomatis only. C. trachomatis cultures from the second swab were positive more often (30 of 31 pairs) than were cultures from the first swab (22 of 31 pairs) (P less than .05). In addition, cultures from swab 2 had greater numbers of inclusions per coverslip more frequently (23 of 31 pairs) than did cultures from the first swab (six of 31 pairs) (P = .003). Numbers of chlamydial inclusions per coverslip were lower in specimens positive for both C. trachomatis and N. gonorrhoeae than in specimens positive for C. trachomatis only (P less than .02). In addition, the presence of N. gonorrhoeae in a specimen adversely affected the quality of the McCoy cell monolayer. In 17 of 21 instances of monolayer toxicity, cultures for N. gonorrhoeae were positive (P less than .01). These results demonstrate that when specimens from men with urethritis are cultured for N. gonorrhoeae and C. trachomatis, use of a second swab will improve rates of recovery of C. trachomatis. Material present in specimens that contain N. gonorrhoeae may adversely affect rates of isolation of C. trachomatis.