U.S. Weekly Flu Report
for every state in America

Weekly Flu Report
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Influenza and pneumonia rank among the most deadly illnesses in the United States. Influenza—the flu—is caused by a virus, with symptoms including coughing, fatigue, and fever.

While the flu is not typically fatal, it is highly contagious and can be deadly to children, seniors, and other vulnerable populations. Pneumonia, a serious condition in which the lungs fill with fluid, commonly results from a flu infection.

The most effective way to avoid the flu is to get vaccinated before flu season every year. In addition to getting a flu shot, there are many habits that can help prevent the flu and similar illnesses. Some of these health habits include: avoid close contact with someone who is sick, cover your mouth and nose, and clean your hands.

Weekly Flu Snapshot

Virologic Surveillance Trend

There are four types of influenza viruses: A, B, C and D. Human influenza A and B viruses cause seasonal epidemics of disease almost every winter in the United States. The emergence of a new type A virus can cause an influenza pandemic.

Both A and B viruses are tracked across the United States by the CDC's virologic surveillance system. Approximately 100 public health and over 300 clinical laboratories located throughout all 50 states, Puerto Rico, Guam, and the District of Columbia participate in virologic surveillance for influenza. These laboratories gather respiratory specimens—such as throat and nasal swabs—and report how many test positive for influenza each week to the CDC.

Outpatient ILI Trends in the United States

Each week, approximately 2,200 outpatient healthcare providers around the country report data to the CDC on the total number of patients seen for any reason and the number of those patients with influenza-like illness (ILI). For this system, ILI is defined as fever (temperature greater than 100°F [37.8°C]), a cough, and/or a sore throat without a known cause other than influenza. 

Annual Mortality Trends in the United States

On the national scale, influenza and pneumonia deaths gradually decreased between 1999 and 2017, falling from 23.5 deaths per 100,000 people (age-adjusted) in 1999 to 14.3 deaths in 2017.

The severity of the flu varies depending on the person, the flu season, and the flu virus active that year. The most at-risk populations include seniors and young children as their immune systems are more likely to be compromised. Serious cases of the flu can result in hospitalizations. Even more serious cases result in death.

How To Avoid Getting the Flu

• Get a Flu Shot

• Washing hands

• Avoid close contact with people who are sick

• Stay home when you are sick

• Covering your mouth and nose when coughing and sneezing

What To Do When You Get the Flu

Most people who get the flu experience mild illness and will want to stay home and avoid close contact with others as much as possible. Despite this, those who are at high risk of flu-related complications or are concerned about their symptoms should contact their health care provider.

This video from the Centers for Disease Control and Prevention (CDC) explains steps to protect yourself and your family from the flu. 

About the Data

Mortality data for influenza and pneumonia was queried from CDC Wonder based on the following parameters: Underlying Cause of Death, ICD-10 codes: J10-J16, J18. Data may not be available for all counties. The CDC does not report rates with numerators of fewer than 20 deaths.

• Weekly flu data for both virology and outpatient visits is from the CDC's Flu Activity and Surveillance