One hundred fifty-three critical care patients with documented cimetidine and antacid use were prospectively studied with serial gastric pH determinations and semiquantitative gastric fluid cultures. This study documents the abnormal gastric colonization of patients with therapeutically altered gastric acidity by hospital acquired gram negative rods (GNR). Three hundred twenty-four gastric fluid cultures from 153 patients revealed 152 (47%) positive cultures for GNR, 78 (24%) sterile specimens, and 94 (29%) positive for mixed oropharyngeal flora. One hundred forty (59%) of the 236 cultures at a pH of 4 or greater were positive for GNR. In contrast, only 12 (14%) of the 88 cultures at a pH of less than 4 were positive for GNR (p<.001). Forty-six (52%) of 88 cultures at a pH of less than 4 were sterile as compared to only 32 (14%) of 236 sterile cultures at a pH of 4 or greater (p<.001). At low pH, cultures are predominately sterile and at a pH of 4 or greater the flora dramatically changes to hospital acquired GNR. This artificially maintained reservoir of gram negative rods in the critically ill patient is a potential reservoir of organisms causing nosocomial bacteremia or pneumonia in this high risk population.

Standardized suspensions of 78 staphylococci and micrococci were stored in different diluents and tested periodically for 3 weeks to determine their ability to maintain viability. In 92% of the tests, diluent suspensions yielded viable organisms for at least 21 days. Organism survival was maintained in the following order, from best to worst: skim milk, tap water, 0.9% NaCl, deionized water, Dianeal (peritoneal dialysis) fluid, 0.2% bovine serum albumin and 5% glycerol. In 81% of the instances, oxacillin-susceptible staphylococci survived better than oxacillin-resistant staphylococci.

Any consideration of infection following clean surgery, particularly cardiothoracic must include both exogenous and endogenous sources. The MRC Study on Hip Surgery presents a particular challenge. Although uncontrolled antibiotic prophylaxis reduced the infection rate almost as well as a laminar flow operating theater, further analysis of the data correlated the incidence of infection with the theater air counts and more significantly considered the sources of Staphylococcus aureus infections. Data on swabs from patient and theater staff at the time of surgery were available for 14 of the 28 patients who subsequently developed deep infections with S. aureus. Overall 25% of patients and 33% of staff were carriers. Bacteriophage typing revealed that 2 patients, 2 surgeons and 7 theater staff carried the infecting type at the time of the surgery. In two instances there was no correlation and in the last a member of the surgical staff on leave at the time carried the relevant strain. This at least provides a clue that exogenous infection can be important, and justifies attempts to clean the environment as well as the patient.

Four cases of purulent complications in the heart following acute myocardial infarction are described. Fever occurred during the first week after coronary occlusion. In one case thrombophlebitis at an infusion site was followed by purulent pericarditis. One patient had an infected mural thrombus with peripheral septic embolic, and two suffered from streptococcal endocarditis. The association between these infections and recent acute myocardial infarction could be related to tissue necrosis and local thrombosis, but the increasing risk of bacteremia following invasive monitoring procedures in these patients is a risk factor that should not be ignored.

The present study provides the first systematic evaluation of strategies for increasing handwashing of hospital staff. Nursing staff on two intensive care units (ICUs) were observed over a 3-month period. After baseline observations, two interventions were implemented on the experimental unit: 1) changing to an emollient handwashing agent, and 2) providing feedback to staff about the frequency of handwashing. Feedback focused on the previous day's handwashing following completed patient contacts, interrupted patient contacts, and critical procedures. No increase in handwashing was observed following introduction of the emollient soap. However, when feedback was provided on the experimental ICU, handwashing following completed patient contacts (the major dependent measure) increased to 92%, and was significantly higher than handwashing on the control unit. Follow-up observations suggested that compliance on the experimental unit appeared to return to baseline levels.

In late January and early February 1983, an outbreak of skin infections (7 of 145 infants) caused by a penicillin/erythromycin resistant strain of Staphylococcus aureus (SA), phage type 3A/3C, occurred in our newborn nursery. A week following the first cluster of infections, another nursery outbreak due to SA with the same antibiogram occurred in a nearby community hospital (11 of 114 infants). Subsequently, a second cluster of infections with the same SA was identified at our nursery. The epidemic strain was carried in the anterior nares of a single nurse who worked at both hospital nurseries on alternate weeks. Investigation revealed that the nurse had an upper respiratory tract infection during each of these outbreaks—simulating “a cloud baby.” No further infections have occurred since this nurse was treated and her SA nasal carrier state eliminated.

It is widely held that bubbling humidifiers do not produce microaerosols, although prior studies have resulted in conflicting evidence. We have studied this phenomenon in a clean room using an airborne particle counter and samplers for airborne bacteria. At gas flow rates between 10 and 80 L/min, a Cascade 1 humidifier produced between 460 and 999 water droplets/L humidified gas. Total water volume aerosolized was approximately 10-8 ml/L humidified gas. Seventy-three percent of the particles had diameters between 1 and 5 microns. With the reservoir containing 6.4 × 106P. aeruginosa/ml, it produced between 2 and 9 P. aeruginosa/Lhumidified gas. Most of the bacteria were in particles of a size likely to be deposited in the lung. This bacterial carryover was between 20 and 150 times the amount predicted by multiplication of the water volume aerosolized times the concentration of bacteria in the humidifier reservoir. An Air Life humidifier produced fewer particles which were also of a size likely to be deposited in the lung and, when the reservoir contained P. aeruginosa, it aerosolized bacteria. Wick-type humidifiers did not produce detectable aerosol or bacterial carry-over. Although the clinical significance of these findings has not been established, they provide a rationale for the CDC recommendations for procedures designed to keep bubbling humidifier reservoir water uncontaminated.

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.

A prospective multicenter study of 1,032 cesarean sections was performed to identify risk factors for postoperative wound infection. The overall rate of wound infection was 6.6% (3.8% in elective cases and 7.5% following nonelective operations), with considerable interhospital variation. Obesity was recognized as a patient-related risk factor, while risk factors inherent to the obstetric situation were duration of ruptured membranes prior to operation, fetal and labor monitoring by intrauterine devices, and omission of the use of plastic draping and redisinfection of the skin before closure. Logistic regression analysis was used to estimate the influence of these factors on the probability of wound infection. Certain risk factors associated with and overrepresented in nonelective operations would explain the increased infection rates in these, and the observed interhospital variations did not differ from the expected rates when the distribution of other risk factors was considered.

This retrospective cohort study reviews the incidence of bacteremia in 48 patients undergoing hemodialysis using subclavian vein dialysis catheters (SDC) as temporary vascular access. Twelve (25%) of these patients had catheter-related bacteremia, and the most frequently isolated organisms were coagulase-negative staphylococci. Three patients developed right-sided endocarditis and one of diem died due to pulmonary embolism. The presence of possible risk factors for SDC-related bacteremia, including duration of catheterization and number of hemodialysis procedures, were not statistically different when patients with and without bacteremia were compared, with the exception of a significantly lower incidence of bacteremia among those patients receiving antibiotic therapy at the time of catheter insertion. The use of resterilized catheters was not a risk factor. Specific guidelines for SDC insertion and care were established and followed, after which the infection frequency was reduced to 7.5% (1 episode per 45.5 patient-weeks of catheter use) in this high-risk population

A procedure-oriented isolation system, Category 1, 2, 3, and 4, was introduced at a 547-bed, acute and rehabilitative medical center. The system consisted of four categories of isolation which followed a numerical sequence that represented the necessary attire needed to complete the procedure. After 1 year of use, personnel compared the procedure-oriented system with the previously-used system (Strict, Respiratory, Wound and Skin, Enteric, and Limited Barrier). Personnel found the procedure-oriented system easier to understand (84%) and follow (83%). Seventy-six percent felt their isolation techniques had improved with the new system. A reduction in the cross-infection rate with methicillin-resistant Staphylococcus aureus did coincide with the use of the new isolation system, however, no causal relationship was established. The Category 1, 2, 3, and 4 isolation system was well received by personnel and was found to be an effective alternative to the previous, more complicated system used in this setting. Further evaluation of this system in other settings would seem warranted.

Rising health care costs have prompted hospitals to turn to reprocessing and reuse of disposable devices as a cost-saving measure. The safety, efficacy, and cost benefit of such a practice are largely unknown. Classification schemata are presented as a means of categorizing the reasons for reprocessing and the types of adverse effects that may result from reprocessing and reuse. The very limited literature on reuse of disposable devices is reviewed. Examples of the categories of reprocessing and adverse effects are provided from a review of the experience with reprocessing and reuse at a university medical center. With the rising pressure for containment of health care costs, it is likely that this practice will expand further. The practice of reprocessing and reuse should be subjected to scientific study.

Although Bacillus cereus is a well-known cause of food-borne illness, hospital-related outbreaks of food-borne disease due to B. cereus have rarely been documented. We report a hospital employee cafeteria outbreak due to foods contaminated with B. cereus in which an outside caterer was employed to prepare the suspect meals. Data were collected from 249 of 291 employees who had eaten either of the two meals. With a mean incubation period of 12.5 hours, 64% (160 of 249) of employees manifested illness. Symptoms, which averaged 24.3 hours in duration, included diarrhea (96.3%), abdominal cramps (90%), nausea (50.6%), weakness (24.7%), and vomiting (13.8%). Eighty-seven employees sought medical attention, 84 of whom were seen in an emergency room. Although a significant difference was not demonstrated in food-specific attack rates, B. cereus was cultured from both rice and chicken items that were served at both meals. Sixty-three employees submitted stools for culture that grew no enteric pathogens, but none were examined for B. cereus. This food-borne outbreak demonstrates: (1) the need for hospital kitchen supervisors to ensure proper handling of food when outside caterers are employed; (2) that significant differences in food-specific attack rates may not be demonstrated in outbreaks, which may be related to several factors; and (3) the importance of notifying microbiology laboratory personnel when B. cereus is a suspect enteric pathogen, since many laboratories do not routinely attempt to identify this organism in stool specimens.

Sera from 275 employees of three hospitals were tested for the presence of antibodies to polio virus. Immunity was found to increase with age, and was higher in personnel directly involved in patient care than in the others. Previous exposure to poliomyelitis as well as a history of previous immunization did not correlate with the immunological status of the employee. When antibodies against one of the three polio types or more could not be demonstrated, the employee was vaccinated by an inactivated polio virus vaccine.

The Centers for Disease Control Advisory Committee on Immunization Practices has based recommendations for hepatitis B vaccine for hospital employees on studies done in large urban hospitals. Data on the prevalence of hepatitis B in employees of small hospitals have been lacking. We measured hepatitis B surface and core antibody in 422 employees of six small, rural hospitals who were exposed to blood. The overall prevalence among those “high-risk” employees was 5.5%. The highest prevalence was found in General Nursing, Intensive Care Nursing, Recovery Room, IV Therapy, Laboratory, and Respiratory Therapy, although differences were seen between hospitals. Results of such testing for individual hospitals may have a major impact on the cost-effectiveness of vaccination programs for their employees.

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 studies described here evaluate the efficacy of the chlorxylenol-containing surgical scrub formulations against the Chlorhexidine gluconate-containing formulations using the Glove Juice Test, as recommended by the FDA's panel to develop guidelines for the study of antiseptic agents. Similar reports from the literature evaluating the relative efficacies of the iodophor-containing and the hexachlorophene-containing formulations are cited. Results fail to detect any significant differences in the efficacy of these two preparations, each significantly reducing the bacterial flora on the hands as indicated by immediate post-wash colony counts, and each demonstrating the continuing ability to significantly reduce bacterial growth with continued regular use.

The frequency of handwashing in two intensive care units (ICUs) was observed. Handwashing after direct contact with patients or their support equipment was recorded. The ratio of beds to sinks was 1:1 in the medical ICU and 4:1 in the surgical ICU. Surveillance of physicians, nurses, and other personnel demonstrated a greater frequency of handwashing by nurses (63%) compared with physicians (19%) and other personnel (25%). The nurses in the unit with one sink per bed had a significantly greater number of handwashes (76%) than those in the unit with fewer sinks (51%).