Measles is a viral infection that primarily targets the respiratory tract but can affect many parts of the body, leading to a range of early symptoms and potentially serious complications. Here’s what it does to the body, broken down clearly. Direct effects and initial course
- Viral infection of the respiratory tract: The measles virus enters through the nose or throat and replicates in the upper respiratory tract and later in the lungs. This can cause fever, cough, runny nose, red watery eyes, and the characteristic rash as the immune system responds. These early signs typically appear about 10–14 days after exposure.
- Rash and immune response: A maculopapular rash usually starts on the face and spreads downward over several days, driven by the body’s immune response to the virus. The rash and fever are common hallmarks of the infection.
- Immune system impact: Measles temporarily impairs immune function, reducing the body’s ability to fight other infections for weeks to months after the illness. This suppression increases susceptibility to other illnesses during and after measles.
Common complications (vary by age and health status)
- Ear infections (otitis media): One of the most frequent complications, which can affect hearing in young children if recurrent.
- Diarrhea and dehydration: Gastrointestinal symptoms are common and can contribute to dehydration, especially in young children.
- Pneumonia: The most serious measles complication in children; can be viral or secondary bacterial pneumonia. Pneumonia is a leading cause of measles-related death worldwide.
- Encephalitis: In roughly 1 in 1,000 cases, measles can cause inflammation of the brain, which may occur during the acute illness or weeks to months later. This can result in seizures, cognitive impairment, or long-term neurological damage in severe cases.
- Other respiratory inflammation: Measles can cause laryngitis, bronchiolitis, tracheitis, or croup-like symptoms due to inflammation of airways.
- Less common organ involvement: In rare cases, measles may affect the liver, heart, or other organs, particularly in those with weakened immune systems or severe disease.
Pregnancy and high-risk groups
- Pregnancy: measles during pregnancy can pose risks to both the pregnant person and the fetus, including miscarriage, preterm birth, or low birth weight. Pregnant individuals without immunity should seek guidance to minimize risk if exposure occurs.
- Higher risk individuals: Infants under 1 year, people with weakened immune systems, and those without prior vaccination are at higher risk for severe disease and complications.
Prevention and implications
- Vaccination is the best protection: Two doses of the measles-containing vaccine provide about 97% effectiveness at preventing measles and are recommended for routine childhood immunization with a second dose to ensure near-complete protection in the community.
- Public health impact: High vaccination coverage reduces the spread of measles, protects vulnerable populations, and lowers the likelihood of severe complications and outbreaks.
If you’re seeking guidance for a specific situation (e.g., symptoms in a child, concerns about vaccination, or exposure and risk assessment), share details and a tailored overview can be provided.
