Evidence-based biosafety: a review of the principles and effectiveness of microbiological containment measures

Abstract

We examined the available evidence on the effectiveness of measures aimed at protecting humans and the environment against the risks of working with genetically modified microorganisms (GMOs) and with non-GMO pathogenic microorganisms. A few principles and methods underlie the current biosafety practice: risk assessment, biological containment, concentration and enclosure, exposure minimization, physical containment, and hazard minimization. Many of the current practices are based on experience and expert judgment. The effectiveness of biosafety measures may be evaluated at the level of single containment equipment items and procedures, at the level of the laboratory as a whole, or at the clinical-epidemiological level. Data on the containment effectiveness of equipment and laboratories are scarce and fragmented. Laboratory-acquired infections (LAIs) are therefore important for evaluating the effectiveness of biosafety. For the majority of LAIs there appears to be no direct cause, suggesting that failures of biosafety were not noticed or that containment may have been insufficient. The number of reported laboratory accidents associated with GMOs is substantially lower than that of those associated with non-GMOs. It is unknown to what extent specific measures contribute to the overall level of biosafety. We therefore recommend that the evidence base of biosafety practice be strengthened.

FIG. 1.

Context of biosafety measures. Based on a risk assessment, wild-type biological agents and GMOs are assigned to one of four risk categories. Work is subsequently performed under conditions that reflect increasing containment demands, i.e., BSL-1 to -4. Risks are contained by a set of measures employing biological and physical barriers and laboratory practices.