Inge Gurevich

Yield of stool cultures, ova and parasite tests, and Clostridium difficiledeterminations in nosocomial diarrheas

Stool cultures for bacterial pathogens, ova and parasites, and Clostridium difficile are usually ordered for patients with nosocomial diarrhea. In the interest of cost containment we undertook an 18-month retrospective study to assess the cost/benefit of performing each of these three tests. During the study period nosocomial diarrhea developed in 118 patients. Of 452 bacterial stool cultures ordered, only one was positive for Campylobacter jejuni and none for ova and parasites. However, of 126 cultures examined for C. difficile, 47 showed positive results. We conclude that bacterial stool culture and ova and parasite identification are not indicated for patients with nosocomial diarrhea. Elimination of these unnecessary stool tests (bacterial/ova and parasite) would have saved the hospital approximately +7530 in the 18-month study period.

Colonization and bacteremia related to duration of triple-lumen intravascular catheter placement

The increased use of triple-lumen catheters has brought with it an increase in sepsis. We undertook a study to determine whether this increase was related to the length of time a catheter was in place. Culture of the fluid in each of the three lumens of all triple-lumen catheters in the medical intensive care units was done daily for a 6-month period. In 14 of 31 catheters, 28 of 93 lumens showed bacterial or fungal growth. A temporal relationship between the time a catheter was placed and the onset of catheter colonization and patient sepsis was established (p less than 0.01). Catheter colonization preceded sepsis in three of four patients who became bacteremic with the same organisms that were cultured from the lumens and the catheter tips. As a result of this study, centrally placed intravascular lines are now changed every 7 days in our institution with a noticeable decrease in line-related sepsis.

Comparison of blood cultures obtained simultaneously by venepuncture and from vascular lines

This study was designed to compare blood cultures drawn simultaneously from a pulmonary artery line or arterial line (line) and a peripheral site by venepuncture (VP). Two or three cultures were obtained by VP and from a line during each febrile episode in 79 patients. Line blood cultures were falsely negative in 1.3% of cultures and VP blood cultures were falsely negative in 2.0%. Three point eight per cent of blood cultures drawn from lines were falsely positive (contaminated), and 1.7% of VP cultures were falsely positive. No significant correlation was found between falsely positive line cultures and a positive three-way tap culture, line in use for 4 days or more, insertion of line during an emergency. We recommend that in the critically ill patient an arterial or pulmonary artery line may be used for obtaining reliable cultures.

Disinfection of respirator tubing: a comparison of chemical versus hot water machine-assisted processing

A comparison of machine-assisted chemical disinfection, using a glutaraldehyde solution, and machine-assisted hot water disinfection was made by placing a large inoculum (approximately 10(7) colonies of Pseudomonas aeruginosa or Acinetobacter calcoaceticus var. anitratus) in sets of tubing before processing. Machine-assisted chemical processing proved to be the most efficient method with a disinfection failure rate of 6 per cent (two positive tubes out of 35). Machine-assisted hot water processing had a disinfection failure rate of 83 per cent (44 of 53 tubes were not successfully disinfected). Some of the tubes that were disinfection failures were dried in a hot air cabinet after the initial sampling, which further reduced the colony counts in the tubing but did not totally eliminate growth except in one tube. The colony counts after drying, showed that A. anitratus was 15 per cent more sensitive to hot air drying than Ps. aeruginosa, but this was not a statistically significant reduction.

Non-parenteral transmission of cytomegalovirus in a neonatal intensive care unit.

Abstract Cytomegalovirus (CMV) was transmitted non-parenterally from an infant with congenital CMV who lived only 8 h to four other infants who were in the neonatal intensive care unit at the same time. Two infants with cytomegalovirus died. The dizygotic twin of one of the dead infants presented with a cytomegalovirus-specific IgG titre of 1:640 at 4 months of age, while the mother of the twins had a negative titre. Direct or indirect contact was thought to be the mode of spread in this outbreak of CMV.

Presumed autoclave failure due to false-positive spore strip tests

The sterilizing processes in autoclaves and ethylene oxide sterilizers are challenged on a regular basis with a controlled inoculum of spores from two Bacillus species. Within a two-day period in March 1980, the seven autoclaves at this 550-bed hospital appeared to have failed in their function of killing spores on 18 out of 46 test strips. A shut-down of the autoclaves and a massive investigation failed to identify any mechanical, physical, or human failures. However, after 48 hours, it was found that the broth used as growth medium contained a contaminant, Bacillus coagulans, that resulted in broth turbidity at 55 degree C. Incubating an uninoculated tube of trypticase soy broth (TSB) for quality control at 55 degree C in addition to the usual 37 degree C quality check is a recommended safeguard against such occurrences.

Significance of fever in hospital employees

Hospital employees are exposed to a variety of occupationally related hazards that can be categorized as infectious or noninfectious. Lost work time often results from these problems. Infection control practitioners receive many telephone calls of inquiry about these employees in terms of their transmissible infections. Little has been written concerning fever in the employee health setting. To determine the frequency of febrile illness in hospital employees, we conducted a prospective study of the employee health service from January to December 1987. Winthrop-University Hospital is a 533-bed community teaching hospital with approximately 2400 employees. During 1987, 2974 visits were made to the employee health service. Of these, 879 (30%) were for occupationally related illness or injury. Oral temperatures of greater than or equal to 100 degrees F were noted in 25 (2.8%) of the 879 visits. Fever occurred predominantly in employees with infections. Upper respiratory tract infection accounted for 268 of 544 (49%) visits for infection. In addition, 11 of 22 (50%) febrile episodes were related to upper respiratory tract infections. A total of 963 work days were lost because of illness or injury. Of these, 743 (77%) were related to an infectious illness; 67 sick days (7%) were attributed to infections with a febrile response. We conclude that fever is uncommon in our employee health care population and that upper respiratory tract infections were the single most common cause of fever. When an employee had a febrile illness, the lost work time was 9% of the total time loss because of infection.

Caring for the Infectious Patient: Risk Factors During Pregnancy

Health care personnel are exposed to infectious diseases in the community as well as in the health care setting when they care for patients with transmissible conditions. Pregnant nurses, physicians and others face an additional risk--that of exposing their unborn children to some of these infections. Risk factors vary greatly between diseases and it is, therefore, important that each be evaluated and acted upon realistically. We will discuss and compare the risk of infections such as hepatitis, cytomegalovirus, tuberculosis, chickenpox, and others. With this knowledge, administrators and personnel involved will be able to make decisions about which patients should not be cared for by pregnant personnel, and which areas pose too high a risk for the mother and child so that a temporary transfer may be advisable. We address the multiplicity of preventive measures available for the prevention of maternal infections.

Excessive levels of gram-negative bacteria in hemodialysis machines because of inadequate cleaning guidelines.

The possibility of sepsis or pyrogenic reaction increases in hemodialysis patients as coliform or other gram-negative counts in the dialysis water reach levels greater than or equal to 1000 colonies/ml. After the introduction of Cobe Century II dialysis machine (Cobe, Lakewood, Colorado), routine testing of dialysis water samples revealed gram-negative bacteria in concentrations up to 45,000 colonies/ml. An epidemiologic investigation was performed to determine the source of the bacterial contamination. The amounts of disinfectant solution were increased, but bacterial counts remained unacceptably high. A study of the fluid path within the machines revealed that part of that path was not reached at all by the disinfectant. In addition, the disinfectant was automatically and improperly diluted. Therefore, increased bacterial counts could not be reduced satisfactorily by using the manufacturers disinfection guidelines.

Preventing the spread of infectious disease. Precautionary measures for the office setting.

PreviewExposure to an infectious disease is possible in any setting, but in the physicians office the likelihood is greatly increased. The authors discuss methods to help safeguard healthcare workers (and patients), reviewing the latest information from the Centers for Disease Control and other sources, and give a summary in tabular form that can be posted for quick and easy reference.