Norovirus

Clear→ stable

Gastrointestinal

Current NYS Status

Wastewater signal at seasonal baseline. No current outbreaks reported. Norovirus peaks November through April.

Source: NYSDOH wastewater surveillance

What is it?

Norovirus is a highly contagious virus that causes vomiting and diarrhea. It is the leading cause of foodborne illness outbreaks in the United States, responsible for about 21 million illnesses annually. It peaks in winter months but can occur year-round.

How it spreads

Spreads through contaminated food or water, direct contact with an infected person, or touching contaminated surfaces then touching the mouth. Just 18 viral particles can cause infection. Infected people are most contagious while sick and for the first day or two after recovering.

Symptoms

Nausea, vomiting, diarrhea, and stomach cramping that start suddenly, typically 12–48 hours after exposure. Symptoms usually last 1–3 days. Low-grade fever, headache, and body aches are common.

Who is at risk?

Everyone is susceptible. Young children, older adults, and immunocompromised individuals are at highest risk for serious dehydration, which is the primary complication.

What you can do

🛡Wash hands with soap and water — hand sanitizer is NOT effective against norovirus

🛡Stay home from work or school for at least 48 hours after symptoms fully resolve

🛡Disinfect contaminated surfaces with a bleach-based cleaner (1 tablespoon bleach per gallon of water)

⚕️Stay hydrated with water, broth, or oral rehydration solutions — dehydration is the main complication

Tier A — Real-time tracking

Surveillance data updated from government sources daily or weekly. Threat level reflects current wastewater signal or clinical reports.

Seasonality: winter

This information is for general public health awareness and is not a substitute for professional medical advice, diagnosis, or treatment.