Three key publications summarize our calicivirus results for this year
on this project. These were studies done by Dr. Wang who finished her PhD in
December 2005. We developed improved methods (1) for detection of noroviruses (NoV)
and for differential diagnosis of human from animal NoV infections. We conducted
an epidemiologic survey of caliciviruses in swine herds from Ohio, Michigan and
North Carolina and a slaughterhouse in Ohio and found that sapoviruses are most
common in all age pigs (62%) and noroviruses were present but less so in swine
(20%). Surprisingly Noroviruses were only found in older finisher pigs
suggesting a completely different epidemiology for them, similar to the
prevalence of noroviruses in mainly adult cases of food-borne disease and
outbreaks. We are trying to find out the basis for these differences in age
susceptibility between the 2 viruses as part of next year’s goal.
We found that one genotype of porcine norovirus was genetically and antigenically related to human noroviruses and replicated in gnotobiotic pigs (3). These results raise concerns of whether subclinically infected adult swine may be reservoirs for emergence of new human noroviruses or if porcine/human GII recombinants could emerge.
Finally and most germaine to ABIG, we developed a new microwell hybridization assay and an internal control RNA for the RT-PCR detection and differentiation of porcine noroviruses and sapoviruses by reverse transcription-PCR (2). This is the test that we suggest could be commercialized, but no marketing analysis was done as of this writing.
1. Wang, Q-H., K-O. Chang, M.G. Han, S. Sreevatsan, L.J. Saif, 2006. Development of a new microwell hybridization assay and an internal control RNA for sthe detection of porcine noroviruses and sapoviruses by reverse transcription-PCR. J. Virological Methods 132: 135-145.
2. Qiu-Hong Wang, Menira Souza, Julie A. Funk, Wei Zhang, and Linda J. Saif, 2006. Prevalence of Noroviruses and Sapoviruses in Swine of Various Ages Determined by Reverse Transcription-PCR and Microwell Hybridization Assays, Journal of Clinical Microbiology 44(6):2057–2062.
3. Qiu-Hong Wang, Myung Guk Han, Sonia Cheetham, Menira Souza, Julie A. Funk, and Linda J. Saif, 2005. Porcine Noroviruses Related to Human Noroviruses, Emerging Infectious Diseases • www.cdc.gov/eid • Vol. 11(12):1874.