A community outbreak of measles prompted a serologic survey of personnel in a hospital serving that community. Two hundred sixty-six personnel, primarily physicians (129) and nurses (100), voluntarily participated. Serum specimens were initially tested by the immunofluorescent antibody and enzyme-linked immunosorbent assay (EIA) methods. Specimens with negative results by either test were further examined using the hemagglutination inhibition and plaque neutralization (PN) methods. If EIA and PN results were negative, an individual was considered susceptible. Only one of the 98 participants born during or after 1957 and none of the 168 participants born before 1957 were serosusceptible. The low rate of serosusceptibility, in contrast to previous studies of young adults, appears attributable to the sensitivity of the testing methods used. Based on our experience, institutions considering a measles serologic testing and immunization program should expect to identify very few serosusceptible personnel, even among those born during or after 1957.

Varicella-zoster virus (VZV), one of the most common highly communicable agents of disease, stimulates aggressive infection control measures. In a 1-year period, at one hospital, at least 93 inpatients (82 adult patients, 11 pediatric patients) and 2 hospital staff with active varicella-zoster infections served as potential sources of nosocomial infection. Six incidents of exposure to the virus that occurred without the protection of standard infection control precautions were investigated by the infection control surveillance team. One hundred fifty-six patients and 353 hospital staff were exposed. Fifty-one patients had no history of varicella-zoster infection, but only five were susceptible by serologic testing. One hundred one staff members had no history of varicella-zoster, but only 11 were susceptible by serologic testing. These exposures resulted in three secondary varicella-zoster infections, six courses of varicella-zoster immune globulin prophylaxis and furlough of 13 staff members. Epidemiologic investigation consumed approximately 356 hours of staff time, and management of exposed persons cost approximately $41,500. Prospective knowledge of the immune status of health care workers would vastly decrease the time and effort required to control hospital VZV exposures.

Patients colonized or infected with methicillin-resistant Staphylococcus aureus (MRSA) in a Surgical Intensive Care Unit and Surgical Intermediate Care Unit were placed either in Strict Isolation or cared for with modified isolation precautions. The assignment was determined by the unit in which they were hospitalized. Units were changed from one form of isolation to the other and served as their own controls.

Over a 4-month study period, the rate of MRSA transmission did not change when the type of isolation precautions were altered. The ratio of colonized to infected patients also remained constant. Infected patients were usually first detected by clinical specimens, while colonized patients were usually detected by surveillance cultures performed under the study protocol.

Following the study, all hospitalized patients with MRSA were placed in modified isolation precautions. Total new acquisitions of MRSA in the hospital have decreased over the subsequent 6-month period.

From 1975 through 1982, the South Florida Hospital Consortium for Infection Control provided consultative and educational services to personnel of 20 community hospitals. To evaluate program efficacy, outbreak frequencies were compared at 11 hospitals with 5 to 8 years of experience through 1982. Annual outbreak rates during the first 4 membership years were compared with those of subsequent years, by service. Each hospital served as its own control. Outbreaks were most frequent in critical care and orthopedic-general surgery patients, and among hospital personnel. Critical care outbreaks occurred more often in hospitals classified as oncology centers (P<.05); their frequency did not decrease significantly after 4 years of membership. However, surgical outbreak rates did decrease from .36 annually in the first years to .03 thereafter (P<.01). This was not attributable to a secular decrease and is taken to indicate program efficacy. No change in frequency of hospital personnel outbreaks was evident.

The responses to a comprehensive survey of infection control practices for respiratory therapy equipment, previously published in the Readers' Forum section of Infection Control, are summarized in Tables 1 through 3. Responses were obtained from 205 United States hospitals; 65% were community hospitals and 38% had <500 ventilator days/year. In some cases, the total number of responses exceeded 100% because of practices that required multiple responses.

Imipenem, a new carbapenem ß-lactam broad-spectrum antibiotic, is highly active in vitro against most aerobic and anaerobic gram-positive and gram-negative bacteria isolated from infectious diseases of human beings. Except for enterococci and methicillin-resistant staphylococci most gram-positive cocci are inhibited by <2 μg/ml. Although the MIC-90 of methicillin-resistant staphylococci may be <4 μg/ml, these bacteria are usually resistant to imipenem by modified testing methods. The enterococcus, S. faecalis, has an MIC-90 of <8 μg/ml but bactericidal concentration may be much higher. Most Enterobacteriaceae are highly susceptible to imipenem with MIC-90 of 0.5 to 2.0 μg/ml. Proteus species are less susceptible with MICs of 4 to 8 μg/ml. Isolates of P. aeruginosa have variable susceptibility with MICs ranging from 0.25 to 16 μg/ml. Pseudomonas maltophilia and P. cepacia are usually resistant to imipenem. Except for Clostridium species, most strict anaerobes are susceptible to <1.0 μg/ml of imipenem. When combined with cilastatin (1:1 ratio), the renal elimination of the active form is increased. The serum half-life in normal renal function is about 1 hour and increases to 3.4 hours in anuria. Major adverse effects are similar to those of cephalosporins except for seizures in some patients. Colonization with fungi and drug-resistant bacteria occurs in about 5% of imipenem-treated patients. Clinical studies have demonstrated efficacy in 79% to 96% of patients treated.

Viral hepatitis B is one of the major concerns of today's healthcare workers. Of the 100,000 Americans infected each year, 5% to 10% of them are employed in healthcare professions. For every 500 identified high-risk personnel, as many as 50 could become infected with hepatitis B virus. Every hospital should have procedures in writing for pre- and post-exposure prevention of hepatitis B.