Measles

What is measles?

Measles is one of the most contagious infections known, spreading through the air and remaining infectious in a room for up to two hours after an infected person leaves. It is not a mild childhood illness; it causes pneumonia, encephalitis and death, and it suppresses immune memory for years afterwards. Two doses of vaccine give around 97 percent protection.

Causes

• Measles virus, a paramyxovirus
• Airborne spread by respiratory droplets and aerosols
• Extremely high transmissibility in unvaccinated groups

Symptoms

• High fever
• Cough, runny nose and red watery eyes
• Koplik spots inside the cheeks before the rash
• Red blotchy rash starting at the hairline and spreading downward
• Rash appearing three to five days after first symptoms
• Light sensitivity
• Diarrhoea

Risk factors

• Being unvaccinated or incompletely vaccinated
• Travel to areas with active outbreaks
• Vitamin A deficiency
• Infancy before vaccination age
• Weakened immune system
• Pregnancy

Diagnosis

• Clinical recognition of fever with characteristic rash
• Measles specific IgM serology
• PCR testing of throat swab or urine
• Immediate notification to public health authorities
• Contact tracing of exposed individuals

Treatment

• Vaccination for prevention, given as MMR
• Supportive care with fluids and antipyretics
• Vitamin A supplementation, which reduces severity and mortality
• Isolation for four days after rash onset
• Treatment of complications such as pneumonia
• Post exposure vaccine or immunoglobulin for susceptible contacts

Self care

• Rest and keep fluids up
• Use paracetamol for fever and discomfort
• Keep lights dim if the eyes are sensitive
• Stay away from others for four days after the rash appears
• Tell your clinic before attending so others are not exposed
• Take vitamin A if prescribed

When to see a doctor

Book an appointment if:

• Any suspected measles, ideally by phone first
• Fever lasting beyond four days after the rash appears
• Ear pain or discharge
• Worsening cough or breathlessness
• Poor fluid intake
• Exposure during pregnancy or with reduced immunity

Some symptoms need emergency care rather than an appointment. See the warning signs listed above.

Prevention

• Two doses of MMR vaccine, which give around 97 percent protection
• Catch up vaccination for anyone unvaccinated at any age
• Post exposure vaccination within 72 hours for susceptible contacts
• Immunoglobulin for high risk contacts
• Maintaining high community coverage to protect infants

Outlook

Most previously healthy children recover within two to three weeks. Complications including pneumonia, ear infection and encephalitis are not rare, and measles suppresses immune memory for years afterwards, raising susceptibility to other infections. It remains a significant cause of childhood death where vaccination coverage is low.

Related conditions

Common questions