Legionnaires' disease: case report with special emphasis on electron microscopy and potential risk of infection at autopsy

Design and Construction of a Biosafety Level 3 Autopsy Laboratory

CONTEXT.—

Autopsy pathologists, including medical examiners, provide valuable public health support for infectious disease deaths through surveillance for deaths of public health concern including emerging infections, identifying causative organisms for unexplained deaths, and providing insights into the pathology and pathogenesis of novel or unusual infections. However, autopsy poses biosafety risks to workers within and outside the laboratory. The highest rates of laboratory-acquired infections occur in autopsy workers.

OBJECTIVE.—

To design and construct an appropriately biosafe autopsy laboratory.

DESIGN.—

We conducted a biosafety risk assessment for autopsy workers using the process developed by the US Centers for Disease Control and Prevention and National Institutes of Health and applied these findings as the basis of laboratory design and construction.

RESULTS.—

Autopsy workers are unpredictably exposed to a variety of infectious organisms, including hepatitis C virus, HIV, and Mycobacterium tuberculosis. Hazardous autopsy procedures include using and encountering sharp objects and the generation of aerosols from dissection, fluid aspiration, rinsing tissues, and dividing bone with an oscillating saw.

CONCLUSIONS.—

Exposure to blood-borne and airborne pathogens from procedures that can cause cutaneous inoculation and inhalation of aerosols indicates that human autopsies should be performed at biosafety level 3. We designed a large, entirely biosafety level 3 medical examiner autopsy laboratory using design principles and characteristics that can be scaled to accommodate smaller academic or other hospital-based autopsy spaces. Containment was achieved through a concentric ring design, with access control at interface zones. As new autopsy laboratories are planned, we strongly recommend that they be designed to function uniformly at biosafety level 3.

Biosafety considerations for autopsy

An autopsy may subject prosectors and others to a wide variety of infectious agents, including bloodborne and aerosolized pathogens such as human immunodeficiency virus, hepatitis B and C viruses, and Mycobacterium tuberculosis. Other hazards include toxic chemicals (e.g., formalin, cyanide, and organophosphates) and radiation from radionuclides used for patient therapy and diagnosis. These risks can be substantially mitigated through proper assessment, personal protective equipment, appropriate autopsy procedures, and facility design.

What's new in managing health hazards in pathology departments

Health hazards related to activities performed in pathology departments have represented, in recent years, an increasing concern among pathologists and pathology technicians. The major occupational health problems encountered in pathology departments are reviewed. They include biological hazards (tuberculosis, hepatitis, HIV, other infectious diseases), chemical hazards (formaldehyde, xylene(s), aromatic amines, methacrylates, glutaraldehyde, latex) and physical hazards (cut injuries, accidental fires, radiation). Current data suggest that infections (particularly, tuberculosis and hepatitis) still represent the more relevant risk. Exposure to HIV and Creutzfeldt-Jakob agent may be highly harmful but containment measures have been proven to be effective. The actual adverse effects due to chemicals seem to be less alarming than was previously believed. Attaining a safe work environment is an inherent element of good quality assurance management. This task is largely a matter of information, education, organization and common sense. Well-designed premises, efficient equipment and well-trained personnel are the keys to preventing and minimizing hazardous exposures. In order to provide current information that may be used by pathology staff to implement the functional quality of the workplace, organizational and preventive measures are described.

The detection of blood on nonporous environmental surfaces: an approach for assessing factors contributing to the risk of occupational exposure to blood in the autopsy suite

A simple and inexpensive method to assess the contamination of environmental surfaces and the associated potential risk of exposure of autopsy room personnel to potentially hazardous materials is described. Blood was selected as a marker of contamination and HEMASTIX reagent strips were used to determine its presence on selected surfaces. The surfaces selected for examination typically do not come into direct contact with cadavers or tissues during a routine postmortem examination and thus are not included in routine cleanup. We documented the presence of blood on a variety of environmental surfaces in the autopsy suite and suggest that the contamination resulted from a breakdown in good work practices, most probably the indiscriminate handling or touching of materials and equipment with contaminated gloves. The risk of exposure to blood by the indirect route was deemed significant. The results of this study underscore the importance of establishing and consistently following good work practices and cleanup procedures to minimize the risk of exposure to blood before, during, and after postmortem examinations.

An outbreak of Legionnaires' disease in Sweden: report of sixty-eight cases

From August 27 to September 21, 1979, 58 patients fell ill with Legionnaires' disease (LD) in the town Västerås, Sweden. All patients had been staying in the town some time during 2 weeks preceding their illness, as had 10 LD patients who fell ill from mid-June to mid-August the same year. Clinically, high fever, headache, dizziness and gastrointestinal symptoms were dominating. Respiratory symptoms were moderate, radiologically verified pneumonia was seen in 59 of 64 patients examined. One patient died. The diagnosis was verified by serology, using the IFL method, in all cases. Legionella pneumophila serogroup 1 was isolated from a closed lung biopsy from 3 patients. Isolates of identical strains were made from the cooling tower on the roof of an indoor shopping centre in Västerås, visited by 57 of the patients during the incubation period.

Lack of airborne spread of infection by Legionella pneumophila among guinea pigs

Many investigators find no spread of Legionnaires disease from person to person. The present study examined the question of airborne transmission of infection by Legionella pneumophila serogroup 1 from guinea pigs inoculated nasally with the agent to healthy guinea pigs. The nasal inoculation produced confluent peribronchiolar pneumonia similar to the pulmonary lesions observed in humans, but by techniques of clinical observation, serology, culture, and pathology, there was no evidence of airborne spread of infection from 26 inoculated guinea pigs to 64 uninoculated guinea pigs. The results, compatible with epidemiological studies of Legionnaires disease that fail to demonstrate airborne person-to-person transmission of the illness in humans, are useful for scientists who work with animal models of Legionnaires disease.

Immunoperoxidase staining of Legionella pneumophila

Immunoperoxidase staining has been applied to sections of pneumonic lung from a previously published case of Legionnaires' disease. Specific staining of Legionella pneumophila was accomplished with sub-group I antiserum, which also revealed staining of phagosomes, and in some areas diffuse background staining of 'soluble' antigen. Some organisms remained unstained with the specific antiserum, and these were revealed by progressive haemalum staining. In other sections, some organisms stained specifically with anti-mu chain serum but not with anti-gamma chain serum, this result suggesting that the organisms were coated with patient's IgM specific antibody.