What Are the Symptoms of Measles? 107 Cases Confirmed Across 21 States

More than 107 people in the U.S. have been diagnosed with measles this year, according to health officials.

The Centres for Disease Control and Prevention stated cases were reported across 21 states: Arkansas, California, Connecticut, Florida, Illinois, Indiana, Kansas, Louisiana, Maryland, Michigan, Missouri, Nevada, New Jersey, New York, North Carolina, Oklahoma, Oregon, Pennsylvania, Tennessee, Texas, and Washington.

The majority of cases involved individuals who were not vaccinated against the condition.

The number of cases fell slightly compared with 2017, when 118 cases were reported in 15 states and the District of Columbia.

Measles is caused by a highly contagious virus that inhabits the nose and throat mucus of an infected person. It is passed on when they cough or sneeze.

After a person is infected, it can take between a week to 14 days for symptoms to develop. These include a fever hitting 104F, a cough, runny nose and red watery eyes. Around two or three days later small white spots can appear inside the mouth, followed by a rash of flat, red spots on the skin by around day five.

First appearing on the face at the hairline, the rash can spread downward to the feet. As it develops, bumps may appear on the spots as they begin to "join." Measles usually clears at around seven to 10 days.

The virus can lead to serious complications, which children under the age of five and adults above the age of 20 years old are most likely to suffer. Complications include pneumonia, the most common cause of death from measles in children. One in 1,000 children will develop swelling of the brain known as encephalitis, which can cause deafness and developmental disabilities, causing as many as 2 in 1,000 to die.

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There is currently no treatment for measles, but medical care can be given to deal with the symptoms and complications.

In the decade prior to 1963 when the vaccine was rolled out, almost all children in the U.S. developed measles by the age of 15, infecting as many as an estimated four million people each year. The disease killed up to 500 people a year, 48,000 were hospitalized and 1,000 suffered encephalitis.

Thanks to vaccination programs rolled out in the last century, cases of measles dropped by 80 percent in 1981 on the previous year. By 2000, health officials declared measles had been eliminated in the U.S.

But in 2014, the U.S. saw a record number of measles cases at 667 across 27 states: the greatest numbers since it was eliminated in 2000. Scientists warned in a 2017 study that hesitancy to vaccinate contributed to the spike in cases.

"Even small declines in vaccination coverage in children owing to vaccine hesitancy may have substantial public health and economic consequences that will be larger when considering unvaccinated infants, adolescents, and adults," the authors from Stanford University and Baylor College of Medicine wrote.

Dr. Paul Sax, clinical director of the division of infectious disease, Brigham and Women's Hospital, told Newsweek there is no doubt that vaccine hesitancy, and so called 'non-medical vaccine exemptions,' have led to an increase in cases of measles.

"The measles vaccine is one of the greatest advances in the history of medicine. It is safe and highly effective, preventing a highly contagious childhood disease that can lead to permanent complications or, in severe cases, even death," he said.

"From a public and personal health perspective, all parents should follow national vaccine guidelines and allow their children to be vaccinated. Not doing so risks not only their child's health, but also the health of others, in particular those with weakened immune systems, who are especially vulnerable to severe measles."

Dr. Paul Duprex, Jonas Salk chairperson for Vaccine Research at the University of Pittsburgh, agreed vaccine hesitancyis a major contributing factor for the resurgence of measles, with states that have more non-medical exemptions being more likely to experience outbreaks.

"Measles is the most transmissible human virus known so given the number of people traveling around the country its hardly surprising that 21 out of 50 states have outbreaks," he told Newsweek.

"This is sure to continue unless sense prevails and vaccination rates increase in these pockets. Spread of this virus in the U.S. is a tragedy, first because the vaccine works and it's one of the safest we have and second, because measles is far from a benign disease."

This article has been updated with comment by Dr. Paul Sax and Dr. Paul Duprex.