Norovirus is a highly contagious virus that commonly causes acute gastroenteritis, an inflammation of the stomach and intestines. This illness is often referred to as the “stomach flu,” though it is not related to influenza. While most people recover within one to three days, understanding its mortality rate and identifying those most at risk is important.
Norovirus Mortality Rates
Globally, norovirus causes an estimated 685 million illnesses and 200,000 to 212,000 deaths annually. About 99% of these deaths occur in developing countries, particularly in Southeast Asia and Africa, due to limited access to healthcare, rehydration therapies, and sanitation. In developed countries, the mortality rate is considerably lower. In the United States, norovirus causes an average of 900 deaths annually, primarily among adults aged 65 and older. Despite the lower risk, it remains a public health concern due to its widespread incidence.
Who is Most Vulnerable
Certain populations face a higher risk of severe illness and death from norovirus infection. Infants and young children, especially those under five years old, are particularly susceptible to norovirus. They are more prone to rapid dehydration due to vomiting and diarrhea, which can quickly become dangerous. Older adults, especially those aged 65 and above, also experience a heightened risk of severe outcomes, including prolonged symptoms and death. Their increased vulnerability is often due to underlying health conditions and reduced physiological reserve. Immunocompromised individuals, such as those with chronic diseases, organ transplant recipients, or cancer patients undergoing treatment, are also at increased risk. Their weakened immune systems make it harder to fight off the infection, leading to more severe and prolonged illness.
How Norovirus Can Become Fatal
Norovirus primarily leads to death through severe dehydration and electrolyte imbalance. The intense vomiting and diarrhea from norovirus can cause rapid loss of fluids and essential salts. If not replaced, the body’s systems fail. Severe dehydration can lead to a drop in blood pressure, reducing blood flow to vital organs like the kidneys, heart, and brain. This can result in acute kidney failure or other organ damage. Electrolyte imbalances, such as low potassium (hypokalemia) or low sodium (hyponatremia), can disrupt normal bodily functions, causing irregular heart rhythms or heart failure. In weakened patients, other complications like aspiration pneumonia can occur if vomit is inhaled into the lungs.
Reducing the Risk of Death
Preventing death from norovirus focuses on prompt rehydration and supportive care. Oral rehydration solutions (ORS) are preferred for replacing lost fluids and electrolytes, especially in children. They contain the correct balance of sugars and salts for effective water absorption. Broths, diluted fruit juices, and plain water also help maintain hydration.
Seeking medical attention is important for severe dehydration symptoms like decreased urination, dry mouth, dizziness, or unusual sleepiness. Hospitalization for IV fluids may be necessary to rapidly correct dehydration.
Basic hygiene also prevents virus spread, reducing exposure and infection risk. This includes thorough handwashing with soap and water, especially after using the restroom and before preparing food, as alcohol-based sanitizers are less effective. Disinfecting contaminated surfaces with bleach-based cleaners helps control outbreaks.