Explainer: Low immunization rates and global epidemics promote the spread of measles in the United States

(Reuters) – A measles epidemic that has struck at least 225 people in New York since October began with a traveler who visited Israel during the Jewish summer holidays and returned to a predominantly ultra-poor neighborhood. orthodox county of Rockland.

A similar pattern took place three months later and nearly 4,800 km apart, when a person who visited Eastern Europe returned to a community with close ties to a local religious group located in Vancouver, Washington State. More than 50 people got sick there.

In both cases, US travelers caught measles in foreign countries where the highly contagious disease reigned and brought it back to places where vaccination rates were too low by US public health standards, triggering the worst epidemics observed in these states for decades.

The US Centers for Disease Control and Prevention report that the New York outbreak has recorded the highest number of imported cases since measles was declared eradicated in the United States in 2000.

According to health officials, the two epidemics are shrinking, after concerted efforts to identify the origins, isolate and inoculate exposed but unprotected people and educate parents who have resisted vaccines.

The disease is especially prevalent among school-aged children whose parents have refused to be vaccinated. Most cited philosophical or religious reasons, or concerns – refuted by medical science – that three-way vaccines against measles, mumps and rubella (MMR) could cause autism, the researchers said. authorities.

Dr. Howard Zucker, commissioner for health in the state of New York, said that another key factor was simple "complacency" at a time when the potential ravages of measles are unknown to parents who reached adulthood after the introduction of the vaccine in 1957.

In Rockland County, Manhattan's northern suburbs, which accounts for most of the cases, the state has vaccinated 15,000 children since the epidemic began last fall, Zucker said. The Brooklyn district of New York was another hot spot.

However, according to officials, the measles crisis in the states of New York and Washington offers a lesson on the importance of maintaining a minimum level of "collective" vaccination against dangerous and preventable diseases such as measles.

It also highlights the global nature of the fight against the disease, in which a hot spot of infection in one country can trigger a distant epidemic in a weak point of vaccination, said Dr. Scott Lindquist, the largest epidemiologist in Washington.

Here are some key facts about measles and vaccination, according to public health experts and the CDC.

WHAT VACCINATION RATES ARE IDEAL?

A vaccination rate of 95% is necessary to ensure adequate protection of the "herd" in a given population. Rates as low as 60% have been found in areas of New York where measles has spread, said Zucker.

HOW CAN THE MESSES BE OBTAINED?

Symptoms usually include high fever, cough, runny nose and watery eyes, followed by tiny white spots inside the mouth and a red rash that may cover the body.

Serious and life-threatening complications, especially in young children and pregnant women, may include pneumonia and swelling of the brain. Ear infections affect approximately 10% of children with measles and can lead to permanent hearing loss.

Subacute Panencephalitis (SSPE) is a rare but life-threatening complication that can attack the central nervous system seven to ten years after measles recovery.

How mice are contagious?

Measles is spread by accidental contact with the virus, which can persist and remain contagious in the air of an enclosed space up to two hours after its expiration by the carrier of the disease. The transmission rate from an infected person to another person nearby who lacks immunity is about 90%.

ORIGINS OF THE LAST SPARKS?

Health authorities have indicated that the strain of virus identified in the state of Washington is consistent with that widely circulating in Ukraine since last year. The New York epidemic has been followed up, leading to separate outbreaks of measles in Israel and Eastern Europe.