The Virginia Health Department issued an advisory Thursday, cautioning the public that they may have been exposed to a measles-infected child at Dulles International Airport on Sunday and in several other places in Northern Virginia a few days later.

Alison Ansher, health director for the Prince William Health District, said the case was not related to a current outbreak in several parts of the United States. She said the child, who was sick and infectious, had left the United States, contracted the highly contagious disease, and returned. Ansher, citing confidentiality rules, also said she could not identify the exact flight the child was on or give the child’s sex and age.

The agency said it is trying to identify people who came into direct contact with the infected child and urged any unvaccinated people who may have crossed paths with the child at those locations to get in touch with a health-care provider. The agency said the infected child was at the following locations at the following times:

  • Washington Dulles International Airport in Terminal A and the baggage-claim level on Sunday from 5:30 to 8:30 p.m.
  • Novant Health UVA Health System Haymarket Medical Center, 15225 Heathcote Blvd., Haymarket, Va., in the emergency department on Sunday from 11 p.m. through early Monday at 4:30 a.m.
  • Inova Fair Oaks Hospital, 3600 Joseph Siewick Dr., Fairfax, Va., in the emergency department, including the waiting area, on Tuesday from 3 to 5:30 p.m.

Ansher said the virus that carries the potentially fatal disease can remain in an area for up to two hours after the infected person has left. People who have been infected could develop symptoms as late as June 25, Ansher said.

The agency’s warning — which was reported earlier by WTOP — comes as the United States has experienced a sharp increase in measles cases. The outbreak has been spurred at least in part by the anti-vaccine movement that claims that there is a link between vaccines and autism, despite repeated studies showing no such correlation. There have been more than 1,000 reported cases of measles in the United States. The total for just the first five months of 2019 was the highest since 1992, when 2,126 cases were reported for the entire year.

Measles is a highly contagious but preventable disease. It can be spread through coughing, sneezing and contact with droplets from the nose, mouth or throat of an infected individual, the agency said. Symptoms begin with a fever of more than 101 degrees and other cold- or flulike symptoms such as a runny nose, watery red eyes and a cough. A rash appears three to seven days later, appearing first on the face and spreading to the rest of the body.

People who have had a documented case of measles are immune for life, Ansher said. People who received two doses of measles vaccine — either the measles, mumps and rubella (MMR) vaccine or a measles-only vaccine — need not worry, the agency said. Those who have received only one dose of a measles vaccine are probably not at risk, but a second dose would ensure complete immunity.

However, those who have never been vaccinated and have never had a documented case of measles are at risk. The agency further advised that if symptoms appear, a person should seek immediate medical care from a doctor or local health department. The agency also urged people with symptoms to call ahead to alert the staff that they could be infected with measles.