A survey of infections in United Kingdom laboratories, 1994-1995.
AIMS: To identify the number and type of infections occurring in United Kingdom clinical laboratories during 1994 and 1995, following similar surveys covering 1970 to 1989. METHODS: A retrospective questionnaire survey was undertaken of 397 responding UK clinical laboratories covering 1994 and 1995. A follow up telephone survey was undertaken with each of the laboratories from which a questionnaire had been received indicating a possible or probable laboratory acquired infection during 1994 or 1995. RESULTS: Questionnaires were sent to 659 laboratories or organisations which were thought to have laboratories, of which 557 responded (response rate of 84.5%). Of these, only 397 were from organisations with laboratories. Over 55,000 person-years of occupational exposure were covered, and only nine cases identified, giving an infection incidence rate overall of 16.2/100,000 person-years, compared with 82.7 infections/100,000 person-years found in a similar survey covering 1988 and 1989, reported previously. Infections were commonest in females, in relatively young staff, in microbiology laboratory workers, and in scientific/technical employees. Gastrointestinal infections predominated, particularly shigellosis, but few specific aetiological factors relating to working practices were identified. No hepatitis B cases were reported. CONCLUSIONS: The small number of cases identified indicates high standards of infection control, though there is still room for improvement. Periodic studies of this kind are not adequate for comprehensive monitoring of the incidence of laboratory acquired infections. That will require the introduction of a routine, active surveillance programme or prospective survey which has the support and commitment of the laboratories themselves. (+info)
Recent outbreaks of lymphocytic choriomeningitis in the United States of America.
Lymphocytic choriomeningitis (LCM) has been rarely reported in the American literature since 1960. It is interesting that each of the 3 epidemics reported since then has been associated with exposure to hamsters. In 1973, 48 cases of LCM spanning the years 1971-1973 occurred at the University of Rochester Medical School associated with hamsters implanted with tumour tissues. These tissues were found to be LCM-positive, as in an earlier outbreak in 1965 at the National Institutes of Health. A nationwide outbreak of LCM occurred in late 1973 and early 1974 totalling at least 181 cases in 12 states; all were associated with pet hamsters from a single breeder in Birmingham, Alabama. He was an employee of a biological products firm whose tumour tissues were found positive for LCM and were also incriminated in the 1973 Rochester outbreak. The last outbreak occurred in a graduate school laboratory in New York State involving 7 individuals working with hamster tumours from the same Birmingham biological firm. The nationwide epidemic ended in middle April 1974 following removal of incriminated hamsters from pet shops throughout the country and voluntary cessation of distribution of hamsters from the incriminated breeder. The biological firm notified all laboratories of the possible contamination of tumours and has voluntarily stopped distribution of known positive tumours. (+info)
Formalinized bacterial "antigens" as a potential infection hazard.
It is widely thought that after enteric bacteric have been "formalinized" (treated with an equal volume of 0.6% formalin) for 1 h, the bacteria become "antigens" and are no longer viable. None of the 27 cultures of Salmonella and other Enterobacteriaceae were entirely killed within 1 h after formalin was added, but all 27 were reduced from 10(9) viable cells per ml to less than 10(2) per ml within 7 h. Thus, mouth pipetting of cultures formalinized for only 1 h is a possible infection hazard. (+info)
Biohazards assessment in large-scale zonal centrifugation.
A study was conducted to determine the biohazards associated with use of the large-scale zonal centrifuge for purification of moderate risk oncogenic viruses. To safely and conveniently assess the hazard, coliphage T3 was substituted for the virus in a typical processing procedure performed in a National Cancer Institute contract laboratory. Risk of personnel exposure was found to be minimal during optimal operation but definite potential for virus release from a number of centrifuge components during mechanical malfunction was shown by assay of surface, liquid, and air samples collected during the processing. High concentration of phage was detected in the turbine air exhaust and the seal coolant system when faulty seals were employed. The simulant virus was also found on both the centrifuge chamber interior and rotor surfaces. (+info)
Hepatitis in clinical laboratories: a three-year survey.
In a survey of laboratories where members of the Association of Clinical Pathologists worked, hepatitis was reported from 5 percent of 244 in 1970, 7 percent of 215 in 1971, and 2 percent of 337 in 1972. Of the 36 laboratories reporting hepatitis, a modest excess tested specimens from haemodialysis, transplant, and haemophilia units and performed tests for HB Ag. The average annual attack rate for staff of all types was 111 per 100,000 with higher rates for biochemists (268 in science graduates and 204 in technicians) and medical haematologists (258). Tests for HB Ag were positive in 17 cases ans negative in 15; nine were untested. No case was fatal and only 10 of the 41 required admission to hospital. Fourteen had a history of contract with 'high-risk (haemodialysis) specimens' but the most frequently suspected source of infection was personal contact with jaundiced or HB Ag-positive individuals and only in three cases were laboratory accidents suggested as the suspected source of infection. The findings indicate a need for caution and sensible safety precautions but not for exaggerated alarm. (+info)
Exposure of guinea pigs to Rickettsia rickettsii by aerosol, nasal, conjunctival, gastric, and subcutaneous routes and protection afforded by an experimental vaccine.
Guinea pigs were inoculated with Rocky Mountain spotted fever by the aerosol, conjunctival, subcutaneous, intragastric, and intranasal routes. Rickettsial infection was produced by all routes except intragastric. All animals with clinical signs of disease developed agglutinating antibody, and most developed a cell-mediated immune response. Disease produced by all experimental routes (except intragastric) was indistinguishable. The tissue culture-derived inactivated vaccine produced in this laboratory protected guinea pigs against an aerosol challenge. (+info)
Laboratory-acquired parasitic infections from accidental exposures.
Parasitic diseases are receiving increasing attention in developed countries in part because of their importance in travelers, immigrants, and immunocompromised persons. The main purpose of this review is to educate laboratorians, the primary readership, and health care workers, the secondary readership, about the potential hazards of handling specimens that contain viable parasites and about the diseases that can result. This is accomplished partly through discussion of the occupationally acquired cases of parasitic infections that have been reported, focusing for each case on the type of accident that resulted in infection, the length of the incubation period, the clinical manifestations that developed, and the means by which infection was detected. The article focuses on the cases of infection with the protozoa that cause leishmaniasis, malaria, toxoplasmosis, Chagas' disease (American trypanosomiasis), and African trypanosomiasis. Data about 164 such cases are discussed, as are data about cases caused by intestinal protozoa and by helminths. Of the 105 case-patients infected with blood and tissue protozoa who either recalled an accident or for whom the likely route of transmission could be presumed, 47 (44.8%) had percutaneous exposure via a contaminated needle or other sharp object. Some accidents were directly linked to poor laboratory practices (e.g., recapping a needle or working barehanded). To decrease the likelihood of accidental exposures, persons who could be exposed to pathogenic parasites must be thoroughly instructed in safety precautions before they begin to work and through ongoing training programs. Protocols should be provided for handling specimens that could contain viable organisms, using protective clothing and equipment, dealing with spills of infectious organisms, and responding to accidents. Special care should be exercised when using needles and other sharp objects. (+info)
Exposure of laboratory workers to Francisella tularensis despite a bioterrorism procedure.
A rapidly fatal case of pulmonary tularemia in a 43-year-old man who was transferred to a tertiary care facility is presented. The microbiology laboratory and autopsy services were not notified of the clinical suspicion of tularemia by the service caring for the patient. Despite having a laboratory bioterrorism procedure in place and adhering to established laboratory protocol, 12 microbiology laboratory employees were exposed to Francisella tularensis and the identification of the organism was delayed due to lack of notification of the laboratory of the clinical suspicion of tularemia. A total of 11 microbiology employees and two persons involved in performing the patient's autopsy received prophylactic doxycycline due to concerns of transmission. None of them developed signs or symptoms of tularemia. One microbiology laboratory employee was pregnant and declined prophylactic antibiotics. As a result of this event, the microbiology laboratory has incorporated flow charts directly into the bench procedures for several highly infectious agents that may be agents of bioterrorism. This should permit more rapid recognition of an isolate for referral to a Level B laboratory for definitive identification and should improve laboratory safety. (+info)