Disinfection is one of the last major steps in emergency poultry disease response as shown in the USDA APHIS recommendations: “When HPAI outbreaks occur in poultry, the preferred eradication and control methods are quarantine, enforcement of movement restrictions, and depopulation (culling) of all infected, exposed, or potentially infected birds, with proper disposal of carcasses and rigorous cleaning and disinfection of farms and surveillance around affected flocks. ”

The University of Delaware has been involved in laboratory and field evaluation of disinfectants for poultry diseases. The laboratory evaluations include comparison of different avian influenza strains with a select list of disinfectants (Experiment 1) and testing of alternative disinfection agents (Experiment 2). Field evaluations include equipment disinfection (Experiment 3, see side bar).

Disinfectants have to be label rated for specific agents. It is expensive to test a disinfectant against all possible viruses. One question was whether a disinfectant that had been tested with low pathogenicity avian influenza (LPAIV) would be effective against high pathogenicity avian influenza (HPAIV) or human influenza. In this experiment, four disinfectants (1% citric acid, 1% Virkon S, 350 ppm sodium hypochlorite, and 1:256 dilution of quaternary ammonia) were tested with LPAIV, HPAIV, and PR8. The results showed consistency across viruses and a disinfectant that inactivated LPAIV also inactivated HPAIV and PR8. The one disinfectant that was not effective (350 ppm sodium hypochlorite) was not effective on any of the three influenzas tested.

Although disinfectants have to be label rated for specific viral agents, it is possible to for emergency exceptions to be made (i.e. Section 18 approval). There are a number of generic chemicals with disinfectant ability, however, individual companies rarely pay for the appropriate testing required for label rating. In this experiment, a number of common, easily obtained chemicals were tested in the laboratory for their ability to inactivate LPAIV. The chemicals tested included acetic acid (1%, 3%, 5%), citric acid (1%, 3%), calcium hydroxide (1%), calcium hypochlorite (750 ppm), sodium carbonate (4%), sodium hypochlorite (750 ppm), sodium hydroxide (1%, 2%), and laundry detergent with and without peroxygen bleach. Laundry detergent was concentration dependent and the detergent with peroxygen bleach was more effective than detergent without bleach. Acetic acid (1%, 3% and 5%), citric acid (1% and 3%), sodium hydroxide (2%), calcium hydroxide (1%), calcium hypochlorite (750 ppm), and sodium hypochlorite (750 ppm) inactivated LPAIV on hard, non-porous surface. Citric acid was also effective on porous surfaces.

In addition, disposal and composting is included Emergency Poultry Disease Response certification course.