JOURNAL REVIEW

Nielsen H, Rosthoj S, Machuca R, et al. Nosocomial child-to-child transmission of HIV. Lancet 1998; 352:1,520.

The authors use nucleotide sequencing to document nosocomial transmission of HIV to a child in a pediatric oncology unit at a hospital in Denmark. It is suspected that the nosocomially infected patient suffered an unobserved injury from a needle that was used on an HIV-positive child in the same ward and then disposed in a sharps box that was improperly located "within reach of children," the authors conclude.

"The present case is an exception that illustrates the rule," they report. "Large population-based studies in households of HIV-infected patients have not found transmission with normal social contact. But the case stresses the fact that blood and bloody body fluids of HIV-infected persons are infectious, and that even in health care settings with attention to precautions to prevent transmissions, the unexpected may occur."

At the age of two, the patient was diagnosed as having acute lymphoblastic leukemia. A Hickman-type central venous catheter was implanted, but no other invasive procedures were performed. During the next 24 months, the patient received cytotoxic chemotherapy and complete remission was obtained. The patient had been treated in a pediatric oncology unit also caring for children with HIV infection. The unit has seven single-bed rooms, and precautions to isolate children with transmissible infections are taken.

All minor procedures such as giving medication, intravenous infections, and blood collection are done with the child inside his or her own single-bed room under strict control measures to prevent transmission of bloodborne infections, the authors noted.

Hospital records showed that the patient and the presumed source of infection had been in the ward at the same time for 15 days. From stored serum samples, it could be shown that seroconversion occurred within a period of 12 months. Hospital records and nurses’ files contained no record of any incidents such as fights, bites, or accidents between the two children. An investigation showed no break in standard precautions for transmissions of infections except for the presence of a colored box for disposal of syringes in each single-bed room within the reach of children. It was not possible to document if the child had been in contact with such a box in a single-bed room other than the child’s own room.

"The health authorities concluded that based on viral genotyping, nosocomial transmission had occurred from another child with HIV infection, and that an unnoticed needlestick during an unobserved visit to the room of the source child was the most plausible explanation of transmission," the authors report.

•

Watanakunakorn C, Wang C, Hazy J. An observational study of hand washing and infection control practices by health care workers. Infect Control Hosp Epidemiol 1998; 19:858-860.

Hand washing compliance by health care workers appears to be influenced by the acuity of care being delivered, the authors found.

"The prevalence of hand washing in the surgical and cardiovascular ICU in our study was highest; as the intensity of care decreased, the prevalence of hand washing also decreased, being lowest on the general floor," they report.

During a six-week period, a medical student conducted an observational study of hand washing and infection control practices in a community teaching hospital. There was no difference in the prevalence of hand washing practices among the three work shifts. The prevalence of hand washing was higher in surgical (56.4%) and medical intensive-care units (39.2%) than in intermediate (30.0%) or general units (22.8%). The overall prevalence of hand washing was 30.2% (207 of 686 patient encounters).

Hand washing compliance varied significantly by job category, activity, and location. Residents washed hands more often (59.2%) than attending physicians (37.4%), nurses (32.6%), or other health care workers (4.2%). Hand washing was more frequent after certain activities such as examining patients, bathing, and emptying urine bags.

"There is a general perception that physicians are less inclined to follow infection control practices," the authors note. "Therefore, it was a pleasant surprise in our study to find that the prevalence of hand washing was highest in the physician groups, especially resident physicians."

Less encouraging was a finding that workers who wore gloves often did not wash their hands afterward. Gloves may give workers a false sense of security, leading them to neglect hand washing.

"Such lapses are dangerous, because hands can be contaminated through leaks in gloves or when gloves are removed," the authors note.

•

Veenstra DL, Saint S, Somnath S, et al. Efficacy of antiseptic-impregnated central venous catheters in preventing catheter-related bloodstream infection. A meta-analysis. JAMA 1999; 281:261-267.

Central venous catheters impregnated with a combination of chlorhexidine and silver sulfadiazine seem to be effective in reducing the incidence of both catheter colonization and catheter-related bloodstream infection in patients at high risk for catheter-related infections, the authors report.

Their study suggests that impregnated catheters reduce the risk of bloodstream infection associated with central venous catheters by about 40%. There are important clinical and economic implications of a 40% reduction, particularly for intensive care units. In ICUs, 3% to 7% of central venous catheters lead to catheter-related bloodstream infections (CR-BSIs), with an attributable patient mortality of 10% to 35% and associated costs of up to $30,000 per episode, they note.

Prevention of catheter-related infections traditionally has focused on the essential measures of aseptic insertion technique and proper catheter care. Despite these precautions, central venous catheters remain a significant source of nosocomial infections, the authors conclude. The findings of their meta-analysis indicate that central venous catheters impregnated with chlorhexidine-silver sulfadiazine are effective, but the decision to use them should be made based on considerations of the baseline risk of CR-BSIs in specific patient populations, potential reductions in morbidity and mortality, economic costs, and the risk of adverse events, they emphasize.

Data sources included studies identified from a computerized search of the Medline database from January 1966 to January 1998, reference lists of identified articles, and queries of principal investigators and the catheter manufacturer. Twelve studies met the inclusion criteria for catheter colonization and included a total of 2,611 catheters. Eleven studies with a total of 2,603 catheters met the inclusion criteria for catheter-related bloodstream infection. Most patients in these studies were from groups considered to be at high risk for catheter-related infections.