To determine the frequency of isolation of methicillin-resistant Staphylococcus aureus (MRSA) at Veterans Administration Medical Centers, 163 hospitals were surveyed; 137 responded. Between 1975 and 1984, the number of Veterans Administration Medical Centers with known MRSA increased from 3 to 111. This increase was geographically widespread and occurred in hospitals of all sizes. In Veterans Administration Medical Centers, isolation policies for MRSA-infected patients were (% of hospitals using): strict (19%), contact (52%), site-related (28%), no isolation (1%). For patients colonized with MRSA policies were: strict (15%), contact (44%), site-related (35%), and no isolation (6%). Only 41% of Veterans Administration Medical Centers reported discharging known MRSA-colonized patients to nursing homes. Most attempts to eradicate MRSA carriage used trimethoprim-sulfamethoxazole plus rifampin with or without bacitracin ointment; success rates were low. MRSA incidence is increasing at Veterans Administration Medical Centers across the United States. Improved regimens to eliminate MRSA carriage are needed.

In a prospective 12-month study at a university-affiliated pediatric hospital, isolation usage was quantitated by ward/service, season, isolation category and type of infection (community-acquired vs nosocomial). Such information may be helpful in designing hospitals, recognizing time utilization of the pediatric infection control nurse, and defining educational and isolation needs. Hospitals with multiple bed rooms and inadequate numbers of single rooms may be unable to meet current federal isolation guidelines.

The mean number of isolation days was 153 per 1000 patient days or 15.3% of bed days used. This ranged from 18.5% on the infant/toddler/preschool medical ward to 2.8% on child/teenage orthopedic surgery. Isolation requirements vary seasonally and rose to 32% in winter on one ward. Proportional frequencies of isolation category included enteric—29%, protective—28%, strict—16%, barrier (contact)—10%, multiply resistant organism (MRO)—8%, wound—5%, pregnant women (careful handwashing)—3%, blood and body fluid precautions—1%. Isolation of patients with and contacts of nosocomial infections account for 32% of isolation usage. During one third of the 365-day year, the hospital is unable to provide adequate numbers of single rooms for one to 20 patients.

We evaluated levels of bacterial colonization in the humidifying cascade reservoirs of 466 mechanical ventilators; 326 reservoirs were cultured after 24 hours and 140 were cultured after 48 hours of continuous mechanical ventilation. Bacterial colonization was absent in 284 (87.1%) of the humidifier reservoirs sampled at 24 hours and 125 (89.3%) of the reservoirs cultured at 48 hours. Levels of bacterial colonization in the remaining humidifiers were low (<100 organisms/mL). The median temperature recorded in the reservoir fluid of 30 different ventilators was 50°C (range 40° to 60°C). In vitro seeding of reservoir fluid at 50°C with 106 organisms/mL of four different species of nosocomial gram-negative bacilli and Staphylococcus aureus demonstrated rapid killing of all five strains over a 6-hour incubation period, and no significant bacterial aerosols were detected. Rates and levels of bacteria in heated humidifier reservoirs are low and nosocomial pathogens survive poorly at the median reservoir temperature of 50°C. We conclude that the heated humidifier reservoir on a mechanical ventilator is an unlikely source of colonization or bacterial aerosols, and therefore it can be changed every 48 hours with the ventilator tubing.

The increasing cost of energy directed our attention to testing the feasibility of low temperature washing. Hospital laundries use formulated chemicals at high temperature wash waters of 66°C. Wash water effluents and fabric bacterial counts of heavily soiled linen were correlated with alkalinity and temperature measurements to investigate the bacterial killing action of hot and cold wash formulas. Terry towels were found to be contaminated with 107 to 109 organisms per 100 cm2 at the beginning of the washing process. The most common gram-negative rods found were Klebsiella, Enterobacter and Serratia species. Staphylococci were the predominant gram-positives. Both cold and hot water washing including the bleach cycle reduced bacterial counts in fabric by 3 log10. Similarly, wash water cfu/mL declined 3 to 4 log10. A further 0.5 to 1.0 log10 reduction was effected in the 93.3°C drying cycle. Low temperature wash formulas were comparable to high temperature laundry with respect to bacterial counts and species. Cold water formulas at 31.1°C offer an alternative method to reduce energy consumption and maintain bacteriological and esthetic linen quality.

Because of the similarities in the spread of hepatitis B virus and the human immunodeficiency virus (HIV), health officials have been concerned about the acquisition of HIV infection by health care workers. This concern has led to numerous cross-sectional and prospective cohort studies during the last 3 years to evaluate the risks involved. The risk of occupationally acquired HIV infection has been shown to be considerably less than that of hepatitis B virus infection, however needlestick transmission has occurred.

The recent approval of ribavirin aerosol for the treatment of severe respiratory syncytial virus (RSV) in infants and young children is a significant addition to the antiviral drugs available today. When administered as an aerosolized form by face mask or mist tent for 20 to 21 hours per day, ribavirin effectively decreases the symptoms of RSV infection and the shedding of RSV virus.

Studies of other viral infections such as viral hepatitis, influenza A and B, Lassa fever, genital herpes, and herpes zoster have demonstrated promising, but inconclusive results. Further studies are needed to justify ribavirin therapy for these indications.