The four biosafety levels were developed to protect against a world of select agents. These agents include bacteria, fungi, parasites, prions, rickettsial agents and viruses, the latter being probably the largest and most important group. In many instances the work or research involves vertebrate animals, everything from mice to cattle. When vertebrates are involved, additional precautions and safety requirements are necessary.
Using the most infectious agents also means extensive security measures are in place, not only because of their virulence but also because of their potential for use in bioterrorism. Biosafety level one, the lowest level, applies to work with agents that usually pose a minimal potential threat to laboratory workers and the environment and do not consistently cause disease in healthy adults.
Research with these agents is generally performed on standard open laboratory benches without the use of special containment equipment. BSL 1 labs are not usually isolated from the general building. Training on the specific procedures is given to the lab personnel, who are supervised by a trained microbiologist or scientist.
Standard microbiology practices are usually enough to protect laboratory workers and other employees in the building. These include mechanical pipetting only no mouth pipetting allowed , safe sharps handling , avoidance of splashes or aerosols, and decontamination of all work surfaces when work is complete, e.
Decontamination of spills is done immediately, and all potentially infectious materials are decontaminated prior to disposal, generally by autoclaving. Standard microbiological practices also require attention to personal hygiene, i. PCR has the additional advantage of being more rapid, potentially providing results in a matter of hours rather than days. However, the process shares the limitation with B virus culture that sample collection must be delayed until symptoms appear.
A quantitative, real-time PCR method has been developed by the National B virus Resource Center and is being evaluated for use as a clinical diagnostic. While a PCR diagnostic assay would substantially reduce the risk to diagnostic laboratory workers, the samples tested could contain viable B virus and need to be handled with appropriate caution. Skip directly to site content Skip directly to page options Skip directly to A-Z link.
B Virus herpes B, monkey B virus, herpesvirus simiae, and herpesvirus B. Section Navigation. Facebook Twitter LinkedIn Syndicate. Laboratory Testing and Diagnosis. Two publications in science magazines have provided recent information about LAIs. The current Ebola crisis reveals that priority must be given to infectious diseases because of the potential consequences to individuals and society [ 6 ].
Some researchers argue for the need to increase research on Ebola virus to develop treatments, while others focus on recent incidents in biosafety facilities and the possible dissemination of these dangerous pathogens in the general population [ 6 ].
A recent example, in , was the mishandling of the severe acute respiratory syndrome virus that resulted in tertiary infections and the death of an attending physician in China [ 7 ]. Lipsitch found that government data on US biosafety labs reveal accidents estimated to be between and potential releases of pathogens each year in labs that deal with select agents between the years and ; however, these reports include banal accidents like spills and record-keeping errors, and very few workers were infected [ 8 ].
However, until now, the true risk posed to laboratory workers after potential exposure to an infectious agent has been difficult to determine, in part because of the lack of systematic reporting of laboratory infections.
It may vary greatly according to the pathogen and also the type of exposure considered. Currently available data are limited to retrospective and voluntary postal surveys, anecdotal case reports, and reports about selected outbreaks with specific microorganisms. The aim of this survey was to gather information on LAIs in biosafety level 3 and 4 laboratories around the world and to assess possible underlying causes of these infections, in order to identify real current risks and to propose preventative procedures.
In this study, private or public institutions with notified containment level 3 or 4 laboratories were contacted by email to complete a survey about LAIs. The mailing list was established by investigators in Marseille. In total, 15 questions were addressed to each respondent, consisting of single-answer questions and multi-answer questions, most of the questions being mandatory see below. We also performed a literature analysis. To determine the worldwide number of LAIs, a systematic review of articles published during the period — was performed.
The inclusion criterion was the presence of an accidental infection in workers or students in research laboratories working with French select agents. X, director of a laboratory dealing with rickettsial diseases in the United States, pointed out that he had not had any laboratory infections with biosafety level 3 rickettsial agents since He specified that he had personal experience with laboratory infections with rickettsial agents particularly Rickettsia in the USA, but these infections generally occurred before the implementation of biosafety level 3 laboratories and the exclusive handling of infectious agents in class II biosafety cabinets.
He remembered one C. However, at present, all work with C. The laboratory coordinates European and international networks, and serves as a leader in research on several infectious diseases, including rickettsial diseases, Q fever, and arboviral diseases, and is directly involved in defense against bioterrorism and highly contagious diseases.
In the s, the laboratory had three LAI cases from skin wounds caused by the manipulation of glass tubes broken after centrifugation of an infectious suspension. The involved biological agents were Rickettsia species including R. The persons exposed received appropriate antibiotic treatment and recovered without sequelae. These incidents occurred before the publication of regulatory procedures for biosafety level 3 and 4 laboratories and good laboratory practices. A total of 23 of the contacted laboratories accepted to participate to this survey, of which five were biosafety level 4 laboratories.
As shown in Fig. Worldwide repartition of the laboratories that responded to the survey. Only four of the 23 surveyed laboratories reported 15 LAIs caused by four different pathogenic organisms.
The remaining case was caused by a biosafety level 2 virus foamy virus. It should be noted that laboratory technicians are more numerous than researchers worldwide, and also probably more often exposed to biological agents. Fortunately, no deaths were reported.
In none of the LAIs was the infection transmitted to another person. Half of the cases were related to technical failures in equipment and infrastructure. However, these cases occurred in a single laboratory where the environment was not safe. Consequently, the laboratory was closed after this incident. For the remaining cases, three contaminations occurred because of not wearing personal protective equipment.
Other incidents leading to LAIs were animal bites and scratches two cases , splashes one case , inadequate compliance with safety rules one case , and spills one case Fig. Not respecting certain biosafety practices eight cases , lack of attention six cases , lack of appropriate equipment and materials four cases , and insufficient training four cases seem to be the principal causes of LAIs Fig. LAIs represent an occupational hazard unique to laboratory workers, especially those working in microbiology laboratories.
Before the introduction of regulations concerning biosafety levels in laboratories and good laboratory practices, laboratory manipulations, including the handling of cultures of human pathogens, took place on the bench, without any specific protection. For example, it was permissible to smoke, eat, or drink in such laboratories, to conduct an olfactory examination of the cultures, or to perform mouth pipetting of infectious suspensions, all practices that are now well known to be associated with a high risk of laboratory infections.
Therefore, many LAIs occurred, as described by Pike [ 1 ]. The actual risk of LAIs is difficult to quantify because there is no systematic reporting system. Because of this lack of information, control measures are proposed and implemented by competent authorities, and regulations are increasing dramatically, which, in turn, profoundly affect research [ 9 ].
The additional, sometimes draconian, measures for laboratories working with highly pathogenic microorganisms have been implemented without solid evidence that they will provide additional public or laboratory safety. However, with the strengthening of regulations, we believe that some laboratories are reluctant to expose their accidents. South Africa was the first to report this variant to the WHO. CDC has issued a Health Alert Notification HAN to inform physicians about this situation and provide recommendations for public health departments, testing laboratories, healthcare providers, and the general public.
The information in this announcement is based on current knowledge at the time of publication. Please share this message with your networks and invite them to opt in to LOCS to receive future updates. Skip directly to site content Skip directly to page options Skip directly to A-Z link.
Section Navigation. Facebook Twitter LinkedIn Syndicate.
0コメント