Variola major, the causative agent of
smallpox, has been eradicated from nature. However, stocks still exist; thus, there is a need for relevant decontamination studies, preferably with nonpathogenic simulants. Previous studies have shown a similarity in response of vaccinia virus and
variola major to various decontaminants and thermal inactivation. This study compared
vaccinia and fowlpox viruses under similar conditions, using
disinfectants and temperatures for which
variola major data already existed. Most
disinfectants showed similar efficacy against
vaccinia and
fowlpox, suggesting the utility of
fowlpox as a decontamination simulant. Inactivation kinetics studies showed that
fowlpox behaved similarly to
variola major when treated with 0.1%
iodine and 5.7% polyethyleneglycol nonylphenyl
ether, 0.025%
sodium hypochlorite, 0.05%
sodium hypochlorite, and 0.1%
cetyltrimethylammonium chloride and 0.05%
benzalkonium chloride, but differed in its response to 0.05%
iodine and 0.3% polyethyleneglycol nonylphenyl
ether and 40%
ethanol. Thermal inactivation studies demonstrated that
fowlpox is a suitable thermal simulant for
variola major between 40 degrees C and 55 degrees C.