Stomach Bug Season: What's Going On?

The U.S. is experiencing a significant increase in norovirus cases, commonly referred to as the stomach bug. According to recent data from the Centers for Disease Control and Prevention (CDC), this highly contagious virus causes vomiting and diarrhea, posing a substantial health risk.

Rising Positivity Rates

• Mid-November 2023: Almost 14% of tests for norovirus were positive.
• August 2023: Only about 6.5% of tests were positive.

This stark increase indicates a wider spread of the virus during the colder months.

Impact and Vulnerability

Norovirus is the leading cause of food poisoning in the U.S., affecting millions annually. Key statistics include:

• 2,500 outbreaks each year.
• Over 100,000 hospital visits.
• Around 900 deaths annually.

High-risk groups include:

• Older adults
• Young children
• Individuals with weakened immune systems

Seasonal Trends and Recent Outbreaks

Norovirus is most prevalent from November to April. The winter of 2022-2023 saw a 25% positivity rate in January 2023. Recent incidents include:

• A middle school in Michigan closed for a day to disinfect after multiple students fell ill.
• Nearly 100 people on a cruise ship contracted norovirus in October.

Tracking and Symptoms

The CDC monitors norovirus through test positivity rates, though these can fluctuate based on testing volume. Data is collected from labs, hospitals, and health departments, providing valuable insights despite limitations.

Common symptoms include:

• Nausea
• Stomach pain
• Vomiting
• Diarrhea

Most people recover within 1 to 3 days, but the virus's high contagion rate leads to frequent outbreaks.