Measles is caused by a virus from the paramyxovirus family and is among the most contagious diseases in existence. An infected person can transmit the virus to up to 15 other people, mainly through respiratory droplets released when coughing, sneezing or even speaking.

Stories like Mariana's, who took her 8-month-old son to the emergency department with high fever and reddish spots on the skin that seemed to belong to the past of Brazilian medicine, have started happening again.

"The data and clinical case cited in this article are fictitious and are merely illustrative, serving to facilitate understanding of the topic addressed."

Measles never really went away

The virus survives in the air and on surfaces for up to two hours, which facilitates transmission in enclosed environments such as schools, public transport and waiting rooms.

Brazil received the measles elimination certificate in 2016, but lost that status in 2019, after the virus returned to circulate sustainably in the country. In November 2024, the certificate was recovered. Nevertheless, isolated cases continued to appear, mainly linked to international travel and declining vaccination coverage in some regions.

The cases that are concerning now

This year, the state of São Paulo has already confirmed more than a dozen cases, concentrated in the capital, in Guarulhos and in São Bernardo do Campo.

Among the patients are:

  • Babies under 1 year old
  • Adults between 20 and 50 years old

These age groups depend directly on being up to date with their vaccinations, since younger babies have not yet completed their vaccination schedule and many adults have never received the two recommended doses.

Given this, from 3 August to 1 September, vaccination against measles is being offered to the entire population aged 6 months to 59 years in these three municipalities, regardless of whether they have already been vaccinated before. In the other municipalities in the country, the recommendation follows the national vaccination calendar, with updating of the vaccination card whenever there is a missed dose.

How measles presents itself

The first signs usually appear between 7 and 14 days after contact with the virus, and for this reason often go unnoticed as a common cold at first. The typical presentation follows more or less this order:

  • High fever, which increases over the first few days
  • Dry cough, runny nose and conjunctivitis (red eyes and sensitive to light)
  • White spots inside the mouth, near the molars, known as Koplik spots — considered a quite characteristic sign of the disease
  • Reddish spots on the skin, which appear a few days later, starting on the face and behind the ears, and spreading down to the trunk and limbs

The period of transmission begins even before the appearance of spots on the skin, which makes outbreak control more difficult.

What is the prognosis

In most healthy children and adults, measles progresses to complete recovery in a few weeks. But this is not a disease without risks: measles can be severe and, in some cases, fatal.

The risk is higher for:

  • Children under 5 years old
  • Pregnant women
  • Immunocompromised people
  • Individuals with malnutrition

It is precisely because of this potential for severity that surveillance around any increase in cases is taken so seriously by health authorities.

Possible complications

Among the complications most associated with measles are:

  • Otitis media (ear infection)
  • Pneumonia, one of the leading causes of death associated with the disease
  • Diarrhoea and dehydration
  • Encephalitis (inflammation of the brain), which can leave neurological sequelae
  • Subacute sclerosing panencephalitis, a rare, serious and late-onset neurological complication, which can appear years after the initial infection
  • In malnourished people, increased risk of blindness

Why the vaccine remains the answer

The triple viral vaccine, which protects against measles, mumps and rubella, is available free of charge through the SUS and is part of the national vaccination calendar.

Recommended vaccination schedule

  • First dose: at 12 months of age
  • Booster: at 15 months (at this age, often already combined with protection against varicella, in the quadrivalent vaccine)

In cities with confirmed circulation of the virus, the Ministry of Health also recommends the so-called zero dose for babies between 6 and 11 months, as extra protection until they reach the age of the routine dose.

For adolescents and adults

Adolescents and adults who do not have proof of two doses of the vaccine should also seek a health service to update their vaccination schedule.

The return of cases that did not exist for years in Brazil is directly related to the decline in vaccination coverage in some regions, and reversing this depends on each person being vaccinated, not just children.

If you are unsure about your own vaccination card or your children's, it is worth checking before any travel or exposure to places with higher circulation of people.

Important notice: This content is for informational purposes and does not replace a medical consultation. Seek a healthcare professional for individual evaluation, vaccination guidance and management of suspected symptoms.

Dr. Rebeca Soares Andrade CRM - GO 39335