Norovirus and Toxoplasma

Birth of a pathogen, part IV Norwalk, Ohio J. Infect. Dis. 119:668-673 (1969)

Genome is single-stranded RNA Two capsid proteins 7-8 kb Genome is single-stranded RNA Two capsid proteins Virion is 60-sided, 180 capsid proteins Hyde et al., J. Virol. 83:9709.

Norovirus Reservoir: us (foods: human contact) Incubation time: ~1-2 days Disease: Nausea, projectile vomiting, diarrhea (12-60 hours) Millions to billions particles shed per individual; Shedding may continue weeks after becoming asymptomatic. Immunity lasts ~6-14 weeks barfblog.org

Norovirus Infectious dose ~ 18 viral particles; Resistant to: Heating to 140 oF Drying (for week) Soil and water (for months) Human norovirus cannot be cultured; Detection by PCR-based methods Treatment: oral hydration; Disinfect area (bleach) carefully, wash clothes, wash your hands constantly.

Detection of Norovirus Immunoassays Poor sensitivity Reverse transcriptase PCR RT-PCR Often targeting polymerase From Wikipedia

Interviews with Jimmy John’s employees revealed that four of the employees had missed work during the week before the KDA inspection on December 18 due to gastrointestinal illness.

Chipotle explained it may be at a higher risk of food-borne illness than some competitors due to its "use of fresh produce and meats rather than frozen" and "reliance on employees cooking with traditional methods rather than automation." http://www.cnbc.com/2015/12/08/chipotle-new-illnesses-look-like-norovirus-not-e-coli.html

Toxoplasma gondii bradyzoites “definitive host” vs. “intermediate host” tachyzoites

Three largest concerns YOPI Brain, heart, skeletal muscles; May become chronic; Congenital toxoplasmosis 10% fetal death, 30% brain/heart/developmental issues Increasing importation of wild boar/wild game meat