Reply to “Studies on Influenza Virus Transmission between Ferrets: the Public Health Risks Revisited”

Lipsitch, Marc; Inglesby, Thomas V.

Moreover, while U.S. labs working with select agents show no reports of accidental viral infections in 2004 to 2010, accidental LAIs have occurred in or from BSL3, BSL3 agricultural (BSL3Ag), or BSL4 laboratories in China, Singapore, the United Kingdom, Russia, and Taiwan (8) . Finally, underreporting of LAI is internationally the rule rather than the exception, in part because serosurveillance is not routinely performed in many highcontainment labs, and in part because reporting systems, if they exist, are inadequate. The Netherlands has been singled out as notable for inadequate surveillance and reporting of LAI (9) . Also, as a general principle, it is self-evident that the number of potentially serious laboratory exposures is greater than the number of actual confirmed laboratory infections. For example, the CDC has reported a number of potentially serious laboratory exposures this year, but none of them would have been factored into LAI calculations. At the time of this writing, it is unclear whether the exposure of a CDC technician to Ebola virus due to an error of switching live and inactivated samples has resulted in infection; whatever the outcome, this incident reinforces the idea that accidental exposures are possible in the best virologic laboratories.