We concluded a prospective epidemiologic study of ventriculostomy-related infections (ventriculitis or meningitis) in 172 consecutive neurosurgical patients over a two-year period to determine the incidence, risk factors, and clinical characteristics of the infections. Ventriculitis or meningitis developed in 19 of 172 patients (11 per cent) undergoing a total of 213 ventriculostomies. When data from all these cases plus five cases of nonventriculostomy-related infection were combined, cerebrospinal-fluid pleocytosis was more significantly associated with the diagnosis of ventriculitis or meningitis (P less than 0.0001) than were fever and leukocytosis (P = 0.07). Risk factors for ventriculostomy-related infections included intracerebral hemorrhage with intraventricular hemorrhage (P = 0.027), neurosurgical operations (P = 0.016), intracranial pressure of 20 mm Hg or more (P = 0.019), ventricular catheterization for more than five days (P = 0.017), and irrigation of the system (P = 0.021). Previous ventriculostomy did not increase the risk of infection with subsequent procedures. We conclude that ventriculostomy-related infections may be prevented by maintenance of a closed drainage system and by early removal of the ventricular catheter. If monitoring is required for more than five days, the catheter should be removed and inserted at a different site.

Sequential outbreaks of infection in a neonatal intensive care unit were due to multiple antibiotic-resistant strains of Klebsiella pneumoniae of different serotypes. In investigations of these outbreaks, the transfer of resistance to gentamicin, ampicillin, cephalothin, carbenicillin, and kanamycin from gentamicin-resistant organisms to standard laboratory recipients and between recipients was observed. Purified plasmid DNA, isolated from all multiple antibiotic-resistant strains, was analyzed by agarose gel electrophoresis, which revealed a common, large plasmid component with a molecular size of 71 megadaltons. Analysis of drug-resistant progeny suggested this plasmid encoded resistance to antibiotics and the information needed for its transmission. The identity of the plasmid from three different sources was established by the use of restriction-enzyme fingerprinting. The dissemination and persistence of this plasmid in environmental and fecal organisms, despite the disappearance of multiple antibiotic-resistant K. pneumoniae, provided a potential source for spread to other bacteria.

An outbreak of infections due to Enterobacter cloacae occurred in the burn center at the Medical College of Virginia (Richmond, Virginia) in 1976. Fifteen patients had bacteremia due to E. cloacae; 10 cases of bacteremia occurred during a six-week period in January and February. The development of bacteremia was significantly related to the extent of third-degree burn and to admission to the burn center in January and February but not to the presence of an intravenous cannula, underlying disease, or antimicrobial therapy. E. cloacae was spread by contaminated hands of personnel and by cross-contamination of hydrotherapy water. A shortage of staff appeared to be an important factor in the occurrence of the outbreak. Control measures included an increase in the number of personnel, instruction of personnel in proper aseptic technique, and adoption of a new hydrotherapy protocol.

An outbreak of bacteremia and meningitis in a neonatal intensive care unit is described. Seven cases occurred in premature infants with severe underlying diseases. An epidemiological investigation failed to document the reservoir of the epidemic strain but suggested that its transmission among the infants was via the hands of hospital personnel. All patients had nasogastric tubes and multiple intravascular devices, and the portal of entry may have been either the gastrointestinal tract or the sites of the intravascular devices. Conventional biotyping of isolates failed to differentiate between isolates from infected patients and isolates recovered from prevalence surveys and from the environment. However, rapid identification systems (API-20S [Analytab Products, Plainview, N.Y.] and the AutoMicrobic system [Vitek Systems, Inc., Hazelwood, Mo.]) were able to distinguish isolates recovered from infected patients and hands of hospital personnel from isolates recovered during prevalence and environmental surveys and 29 isolates from widespread geographical areas. This is the first known report of a nosocomial neonatal outbreak of bacteremia and meningitis due to Streptococcus faecium; it underscores the importance of identifying streptococci to species level.

A methicillin- and rifampin-resistant strain of Staphylococcus aureus was introduced into a university hospital by interstate transfer of an infected surgical patient. An outbreak occurred, and 17 patients became infected or colonized with the epidemic strain. Reservoirs appeared to be patients who were infected or colonized with the resistant S aureus and possibly two nurses who were nasal carriers. The outbreak isolate was likely spread by contact with contaminated hands of personnel. A retrospective case-control study identified tracheostomy, debridement, and irrigation of wounds by power spray and prolonged nasogastric intubation as risk factors for acquisition of the epidemic strain. Analysis of factors by groups indicated that surgical procedures, wound care procedures and instrumentation of the respiratory tract were significantly associated with cases. The nasal carrier state was eradicated in two nurses by topical application of 5% vancomycin. The epidemic strain was eradicated from the hospital 8 months after it was introduced.