THURSDAY, May 1 (HealthDay News) -- There were 64 confirmed cases of measles in the United States from January through April 25, the highest number of cases in that time period since 2001, U.S. health officials said Thursday.

Cases have been reported in nine states, and measles outbreaks are continuing in Arizona, Michigan, New York and Wisconsin. Another eight cases have been reported in Washington state since April 25, according to the U.S. Centers for Disease Control and Prevention.

"Many people have forgotten about measles, but it causes about 20 million infections around the world every year," Dr. Anne Schuchat, director of CDC's National Center for Immunization and Respiratory Diseases, said during a teleconference.

"Measles have been increasing in the United States, mostly due to importation from Europe and Israel," Schuchat added. Belgium, China, Japan, India and Italy are also sources of the measles virus, she said.

"These cases of measles are coming particularly from outbreaks that are occurring in Switzerland and Israel," she said. "In Switzerland, there have already been more than 2,000 cases and in Israel more than 1,000."

The U.S. outbreaks have primarily affected people not vaccinated against the disease. Recently, some parents have been concerned that vaccines -- such as the measles, mumps and rubella (MMR) vaccine -- can cause autism or other diseases, and have decided against vaccination for their children. This trend has left children vulnerable to diseases that had virtually disappeared in the United States, Schuchat said.

"In the U.S. outbreaks this year, two-thirds of children who are old enough to be immunized but are not turned out not to be immunized because of personal belief or religious exception," Schuchat said. "This is a new trend, and I am concerned these communities may be growing," she said.

There have been 15 reported measles cases in Arizona, 12 in California, three in Hawaii, one in Illinois, four in Michigan, 22 in New York City and one in New York state. There's also been one case in Pennsylvania, one in Virginia and four in Wisconsin, Schuchat said.

She noted that even states not on this list should be alert to the possibility of measles cases.

The best protection against measles is vaccination, which is 99 percent effective, Schuchat said. "In the United States, about 97 percent of kindergartners have gotten their measles immunization," she said.

That doesn't mean there aren't pockets of unimmunized children and adults around the country, Schuchat said.

The 64 people with measles ranged in age from five months to 71 years. Fifty-nine were U.S. residents and 54 cases were linked to measles brought from other countries. Sixty-three of the patients were not vaccinated or their vaccination status was not known. One patient had had two doses of the vaccine, the CDC reports.

Schuchat noted that the 64 cases are only those that have been confirmed. She believes that there may be many more cases that have not been reported and more cases yet to come.

The 64 cases reported from January to April 25 of this year compare with 55 cases reported in all of 2006 and 66 cases reported in all of 2005, Schuchat said. "This year does appear to have more simultaneous ongoing outbreaks from different places among children who have not been immunized," she said. "I am really concerned that we have not seen the end of this."

Among the unvaccinated patients, 13 were under one year of age and thus too young to be vaccinated. "At least one of these children acquired the disease in a doctor's waiting room," Schuchat said. "Other cases have been acquired in hospital emergency rooms from health-care workers."

Seven of the infected children were 12 to 15 months old, but not yet vaccinated. Twenty-one others were 16 months to 19 years old, and 14 of those children had not been vaccinated due to religious or personal beliefs or had missed their vaccinations, Schuchat said.

For those measles patients older than 20 years of age, 14 had undocumented vaccination status and two had gotten the disease in Europe.

Among the 64 patients, 14 were hospitalized and none have died, according to the CDC.

Schuchat said it's especially important to be sure that your measles immunization is up to date if you are traveling outside the United States. "Measles is an ongoing risk," she said.

According to the CDC, measles is an infectious viral disease that occurs most often in late winter and spring. It begins with a fever that lasts for a couple of days, followed by a cough, runny nose, and conjunctivitis (pink eye). A rash starts on the face and upper neck, spreads down the back and trunk, then extends to the arms and hands, as well as the legs and feet. After about five days, the rash fades in the same order it appeared.

While measles itself can be unpleasant, the complications are potentially dangerous. Six percent to 20 percent of people who get the disease will get an ear infection, diarrhea, or even pneumonia. One of every 1,000 people with measles will develop inflammation of the brain, and about one out of 1,000 will die, the CDC said.

More information

For more on measles, visit the U.S. Centers for Disease Control and Prevention.

SOURCES: May 1, 2008, teleconference with Anne Schuchat, M.D., director, National Center for Immunization and Respiratory Diseases, U.S. Centers for Disease Control and Prevention, Atlanta; May 2, 2008, Morbidity and Mortality Weekly Report, CDC

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