Hepatitis C virus infection in healthcare workers: risk of exposure and infection.

OBJECTIVES: To determine the incidence of hepatitis C virus (HCV) infection among healthcare workers (HCWs) at a university hospital, the proportion of HCWs having non-A, non-B hepatitis (NANBH) who were anti-HCV positive, and the rate of HCV transmission following a HCV-positive needlestick injury. DESIGN: Longitudinal analysis of a dynamic (cohort) population. MEASUREMENTS: From 1980 through 1989, HCWs who had clinical NANBH were identified, and from 1987 through 1989, HCWs who reported a blood or body fluid exposure and the patients who were the source of the exposure were screened for antibodies to HCV. SETTING: A 732-bed, university hospital and outpatient clinics. RESULTS: Over the 10-year period, six cases of occupationally acquired NANBH were observed, for an incidence of 21 cases per 100,000 HCWs per year (standardized incidence ratio, 2.96; 95% confidence interval [CI95], 1.83 to 4.36). Four of the six cases were confirmed to be HCV infection. From 1987 through 1989, 176 (12.7%) of 1,387 patients who were the source of an exposure were anti-HCV positive. Exposures that occurred in the emergency department were more likely to be anti-HCV positive than were exposures from all other locations (relative risk [RR] = 1.7; P = 0.009). Of HCWs who had an HCV-positive needlestick injury and whose serum had been tested for anti-HCV at least 5 months after the exposure, 3 (6.0%) of 50 seroconverted. From 1987 through 1989, the incidence of HCV infection among HCWs was 54 cases per 100,000 HCWs per year. CONCLUSION: The incidence of clinical NANBH among HCWs in this study is approximately three times higher than that of non-HCWs. HCWs are at significant risk for exposure to and acquisition of HCV.

Decline of clinical hepatitis B in workers at a general hospital: relation to increasing vaccine-induced immunity.

Hepatitis B is a well-recognized occupational hazard of health-care workers that can be prevented with vaccination. However, because data on the current epidemiology of hepatitis B virus (HBV) in this population are limited, no consensus exists regarding the requirement for immunization. In 1980-1989, 4,908 exposures of health-care workers to patients' blood and/or other body fluids were reported and evaluated at a general hospital. During this period, 4.8% of patients to whom health-care workers were exposed were positive for hepatitis B surface antigen (HBsAg). In exposed workers, the rate of protective immunity to HBV (measured by antibody to HBsAg) increased from 14% in 1980 to 55% in 1989. Hepatitis B vaccine became available at this hospital in 1983. The increase in antibody to HBsAg was not associated with an increase in antibody to HBV core antigen; this finding suggests that the increase in immunity was primarily vaccine induced. The incidence of reported clinical hepatitis B in health-care workers decreased from 82/100,000 in 1980-1984 to zero in 1985-1989 (odds ratio = 20.06; P = .0012). Thus, in this study, a program of hepatitis B immunization for health-care workers was associated with a significant decline in clinical HBV infection despite continued exposure to patients positive for HBsAg.

Yersinia enterocolitica infections in hospitalized patients: the problem of hospital-acquired infections.

OBJECTIVE: To study the epidemiology of Yersinia enterocolitica infections in hospitalized patients and to determine the frequency of hospital-acquired infection and the modes of transmission within the hospital. DESIGN: Descriptive study in which the clinical microbiology laboratory reported all positive Yersinia cultures to the infection control department; each case was investigated to determine the source of infection. SETTING: A 700-bed university teaching hospital. PARTICIPANTS: All patients who were culture-positive for Y enterocolitica after admission to the University of Cincinnati Hospital during the 4-year period between 1987 and 1990. RESULTS: Of 18 patients who were diagnosed with Yersinia infections, 8 (44%) were community-acquired. These patients were admitted with gastrointestinal symptoms and had their first positive cultures between days 1 and 5 of their hospitalizations. Five patients (28%) had hospital-acquired infections, having developed diarrhea after admission for unrelated problems, and became culture-positive between days 18 and 66. The remaining 5 patients could not be classified as either community- or hospital-acquired. These patients had gastrointestinal symptoms at the time of admission, but these could have been explained by other diseases. Their first positive stool cultures were not obtained until the second week or later during hospitalization, and 3 of these patients had negative stool cultures prior to a positive culture. CONCLUSIONS: Although Y enterocolitica has not previously been recognized as a common hospital problem, at least 28% of our patients acquired their Yersinia infections in the hospital. In some cases, cross infections, transmitted by healthcare workers, occurred between patients. Four of the 18 infections occurred in patients with acquired immunodeficiency syndrome.

Prolonged hospital epidemic of salmonellosis: use of trimethoprim-sulfamethoxazole for control.

The occurrence of a foodborne outbreak of Salmonella drypool, an uncommon serotype, led to the recognition of hospital-acquired cases occurring over a 5-year period. In late 1981, a catered luncheon resulted in an epidemic of S. drypool, and in retrospect, cases were found to have been occurring in hospital patients from 1977 until 1981. Over the next 4 months, patients, employees, and 50% of the kitchen workers became infected, despite repeated culture surveys of the staff and removal of all infected workers. Food and environmental cultures failed to reveal the source of infection, but infected workers were observed to have multiple negative cultures over several months and then to become positive again. Closing of the kitchen for 2 weeks failed to stop the epidemic. Finally, all kitchen employees, both infected and uninfected, were treated with trimethoprim-sulfamethoxazole for 2 weeks. After treatment, no new kitchen workers became infected, although two workers who had had positive cultures earlier in the epidemic began to excrete S. drypool again, and the epidemic ended.