Instructions for monitoring health of laboratory workers
and for destroying influenza A (H2N2) samples

This is an official CDC Health Update
Distributed via Health Alert Network
April 15, 2005 12:20 EDT (12:20 PM EDT)
CDCHAN-00228-05-04-15-UPD-N

On April 13, 2005, CDC issued a Health Advisory describing the inadvertent distribution of influenza A (H2N2) samples to domestic and international laboratories and recommending that those samples be destroyed immediately. This update provides instructions for 1) monitoring for and reporting influenza-like illness among laboratory workers who might have been exposed to the A (H2N2) samples and 2) destroying influenza A (H2N2) samples by use of autoclaves, incineration, or chemical decontamination.

Monitoring and reporting influenza-like illness among laboratory staff
Testing of laboratory personnel who may have worked with the influenza A (H2N2) panels is not recommended in the United States at this time. The biosafety level 2 (BSL-2) precautions required for this agent would be expected to protect workers from exposure and infection, and therefore the risk of transmission is considered low.

However, CDC is recommending that laboratories with workers with relatively recent exposure (within the last 10 days) to the H2N2 test samples monitor their worker's health for influenza-like-illness (i.e., temperature of greater than or equal to 100 degrees F and cough or sore throat).

If a laboratory worker with recent exposure to the H2N2 samples develops such symptoms, clinical specimens should be obtained and tested for influenza A. Commercially available rapid test kits for influenza and other methods for rapid detection of influenza virus, such as indirect fluorescent antibody assay, direct fluorescent antibody assay, and polymerase chain reaction should be used. If the sample is positive for influenza A virus, contact your state health department and CDC immediately at (770)-488-7100.

Instructions for destroying influenza A (H2N2) samples
Laboratories have been advised to immediately destroy and treat as potentially infectious and hazardous all materials retained or derived from the influenza A (H2N2) proficiency testing panels created by Meridian Bioscience and sent out by the College of American Pathologists (CAP), the American Association of Bioanalysts, the American College of Family Physicians, or the American College of Physician Services.

These materials may be destroyed by autoclave, incineration, or chemical disinfection

To autoclave:

* Autoclave with moist heat at 121 degrees C (15-19
pounds of pressure) for at least 20 minutes or
* Autoclave with dry heat at 170 degrees C for 1 hour
or 160 degrees C for 2 hours or 121 degrees C for at least 16 hours.

To chemically disinfect:
Any of the following liquid disinfectants can also be used to destroy the virus; however, with the exception of the alcohols, these should not be used with autoclaving due to the chemical fumes that would result. The length of exposure time required to kill the virus depends on the disinfectant used, but overnight exposure would be adequate for all of them.

* 200 ppm fresh sodium hypochlorite (a freshly made
1:10 dilution of household bleach should provide this level of free
chlorine)

* 60%-95% ethanol or isopropryl alcohol
* 5% phenol
* 3% lysol

Other agents that may be used but that have toxic or irritant properties include

* 5-8% formalin
* 2% alkaline glutaraldehyde

Other Instructions:
If the autoclave/incinerator is offsite, the material should be sealed in an impervious bag while being transported. If the bag will be shipped, it must conform with all International Air Transport Association <http://www.iata.org/about/index> and Department of Transportation <http://www.dot.gov/> requirements regarding packaging and labeling of infectious substances
(http://www.cdc.gov/ncidod/srp/specimens/DOT%20Final%20Rule%208-14-02.pdf).

CDC and HHS remain in close communication with the World Health Organization, as well as the College of American Pathologists and other providers of proficiency testing panels, about the identification and destruction of the H2N2 panels of concern and will provide additional information as it becomes available.