This study describes the evaluation of 108 patients who had indwelling urethral catheters for acute medical and surgical indications. Patients were evaluated daily, and cultures from bladders and drainage bags were obtained. Appropriateness for continuing catheterization was assessed using preset criteria. Twenty-five patients developed urinary tract infections. Exposure to antibiotics and a shorter duration of catheterization were the only factors that correlated significantly with a delayed onset or decreased prevalence of infection. Factors found to have insignificant effects included age, sex, maintenance of the closed system, underlying host disease status, catheter type, and reason for catheterization. No collection systems with one way valves were used, but significant colony counts in drainage bag urine preceded urinary tract infection in only two patients. Thirty-six percent of the total 562 catheter days were judged unnecessary. A major emphasis must be placed on prompt catheter removal if the prevalence of nosocomial urinary tract infections is to be reduced substantially in a cost-effective manner [Infect Control 1981; 2(5):380-386.]

Catheter-associated urinary tract infections remain the most common hospital-acquired infection. Regular bacteriologie monitoring of urine from catheterized patients has been advocated as a measure for reducing the morbidity associated with this infection. To assess the effectiveness of this measure we reviewed the records of 100 catheterized patients hospitalized before implementation of a monitoring program and 200 such patients admitted after a daily monitoring program was operational. We found that culturing urine from catheterized patients was infrequent prior to monitoring but, when done, patients usually were febrile, cultures usually were positive, and patients were treated. Monitoring identified more cases of bacteriuria, but less than half of the patients so identified were treated. Being febrile was associated with receiving antibiotics. Infection rates increased with duration of catheterization; long periods of catheterization typically occurred on the neurosurgical, orthopedic, and medical services. Daily bacteriologie monitoring of all catheterized patients is relatively inefficient and does not predictably lead to therapeutic intervention in infected patients. The cost:benefit ratio of this measure might be decreased by applying it to selected patients chosen on the basis of risk factors, including hospital service assignment (Infect Control 1981; 2(3):227-232.)

This communication is the third in a four-part series on nosocomial viral infections from the Strong Memorial Hospital. This third article discusses guidelines for prevention and control of exanthematous viruses, gastroenteritis viruses, adenoviruses and the picornaviruses other than rhinoviruses. Several uncommonly seen viruses, such as the virus of Creutzfeldt-Jakob disease and Marburg, Ebola, and Lassa fever viruses, also are reviewed briefly.

During a five-week period, Pseudomonas paucimobilis was isolated from maxillary sinus irrigation washes of four patients who attended an ear, nose and throat clinic. The saline irrigation solution was found to be contaminated with the same organism. Further investigation demonstrated the organism in a majority of hospital sinks surveyed. Although P. paucimobilis was isolated from clinical specimens, the presence of the organism did not appear to have clinical significance [Infect Control 1981; 2(3): 233-235.]

In recent months several advisory groups have issued recommendations urging hospitals to undertake comprehensive rubella control programs. The primary impetus for these suggestions has been the recognition that, despite a declining rubella incidence in the general population, pregnant women still are being exposed to this infection in hospitals.

In 1979 the Vanderbilt University Hospital initiated a limited rubella control program, encompassing new and current employees working in “traditional” high-risk areas of the hospital: obstetrics (wards and clinics), labor and delivery, nursery, pediatrics (wards and clinics), and the emergency department. Medical and nursing students also were included. All persons were tested serologically and immunization was offered to susceptibles, but was not required (except for students and house officers). The Infection Control Committee and hospital administration readily approved this program.

In a six-month period in 1978 61 patients at a university hospital became colonized or infected with methicillin-resistant Staphylococcus aureus (MRSA). Ninety-three percent of patients with MRSA were on surgical services. Patients with burns acquired MRSA more frequently than did other acutely ill surgical patients (p < .001), and often remained colonized for 30 days or more. The interval between admission and acquisition of S. aureus, number of antibiotics received, duration of antibiotic therapy before becoming colonized, and cost of hospitalization, were significantly greater in patients with MRSA infection than in matched controls with nosocomial methicillin-sensitive S. aureus infections. Acquisition of MRSA was epidemiologically associated with exposure to certain hospital personnel. Fourteen (6%) of 220 personnel exposed to MRSA patients harbored MRSA intranasally. Three of 14 colonized personnel carried MRSA intermittently for three or more months. Appropriate control measures failed to terminate the outbreak.

Clinical, bacteriologie, epidemiologic and hospital infection-control observations related to an inter-hospital outbreak of methicillin-resistant Staphylococcus aureus are described. The outbreak involved 66 patients at the University of Oregon Health Sciences Center (UOHSC) and its closely affiliated VA hospital, the Portland VA Medical Center (PVAMC). No environmental source of infection was identified; person-to-person transmission was most likely responsible for its spread. Surveillance cultures demonstrated nasal colonization in house staff and nursing personnel at both hospitals. Inter-hospital transfer of infection was, in all likelihood, achieved via nasal carriage by a single physician. Case-control analysis indicated a significantly increased risk (p < 0.05) of acquisition of infection related to age, number of days hospitalized, severity of underlying disease and number of invasive procedures. Prior antibiotic receipt was a significant risk factor when analyzed by univariate analysis (p < 0.01), but, in contrast to previous studies, this was not a significant risk factor (p > 0.05) when related variables were controlled by multivariate analysis. Prevention of spread of infection by routine infection control measures was less effective at PVAMC than at UOHSC. Patients at PVAMC were significantly older and had longer durations of hospitalization (p < 0.05). Antimicrobial therapy of colonized patients and personnel appeared to assist in the control of the outbreak at PVAMC. Antimicrobial therapy with topical bacitracin and oral rifampin, alone or in combination with oral trimethoprim-sulfamethoxazole, was effective in eliminating colonization with methicillin-resistant S. aureus. [Infect Control 1981; 2(6):453-459.]

Blood isolates from 13 patients in one hospital were positive for Klebsiella pneumoniae over a two-week period. Vials of potassium chloride used in intravenous fluid admixture initially were suspected of being contaminated and thus causing the problem. However, a comparison of patients who had blood cultures positive for K. pneumoniae with control patients who had blood cultures negative for this organism during the same period identified no common features that would explain the increase in K. pneumoniae blood isolates. Careful evaluation of laboratory data suggested that six of the 13 culture-positive patients had probable pseudobacteremia, an explanation that would account for the increase in isolates above the endemic level of true K. pneumoniae bacteremia in the hospital. Epidemiologic data suggested that cross-contamination of adjacent and non-adjacent blood culture vials on the radiometric blood culture analyzer was the cause of pseudobacteremia; K. pneumoniae serotyping data supported this hypothesis. A mocktrial using the analyzer demonstrated that cross-contamination of non-adjacent vials by the sampling needles could occur. Changing the sampling needles of the analyzer daily, in accordance with the manufacturer's recommendations, prevented further episodes of pseudobacteremia from the analyzer. [Infect Control 1981; 2(6):460-465.]

Virus transmission within the hospital is related to trans-missibility of the virus and susceptibility of the population at risk. General guidelines for the use of cohort isolation, for the control of virus transmission in the hospital, and for the use of the communicable disease survey for pediatric patients and visitors to the hospital are outlined. We also present a brief review of how to collect and transport specimens for virus isolation to assist the infection control practitioner and the clinician, and conclude with recommendations for future investigations in the areas of virology and infection control [Infect Control 1981; 2(3):236-245.]

The control of Chagas' disease depends on breaking contact between Man and vector organisms living in the house fabric; the primary method utilized is residual insecticide spraying of houses. Ministries of health in afflicted countries have elaborated standard procedures for such combat programs. The first two phases of such a program in Mambai', Goias', Brazil are described. In the third phase of vigilance, community participation is necessary to detect residual organism populations in houses. A house improvement scheme applied to houses with persistent infection, is recommended as being most practical at this time. [Infect Control 2(6):466-470, 1981.]

The clinical usefulness of sputum cultures depends on the quality of specimens submitted to the laboratory. In a community hospital, during two separate surveillance periods, we evaluated ordering practices and circumstances under which sputum specimens were obtained and techniques to improve the quality of the specimens. Physicians themselves rarely participated in obtaining specimens of sputum, and members of the nursing staff directly instructed patients or supervised specimen collection in only one third of cases. The mean elapsed time from collection at the bedside to processing in the laboratory was two hours, with a range from several minutes to 13 hours. One fifth of all the specimens in this study were obtained from patients with no discernible evidence of lower respiratory tract infection. Microscopic screening revealed that one half of the specimens were of poor or uncertain quality. After the first survey, inservice education of nursing personnel in the proper techniques of sputum collection, along with regular use of the screening procedure in the clinical laboratory, failed to effect any long-term change in ordering patterns or collection practices. However, the screening procedure did improve the quality of the sputum cultured, through rejection of unsatisfactory specimens [Infect Control 1981; 2(4):307-11.]