Measles outbreaks spur caution as a forgotten foe returns

Physicians and public health officials are concerned that populations with low vaccination rates could let the disease take root here again.

Physicians and public health officials are concerned that populations with low vaccination rates could let the disease take root worldwide again.Last January, a 24-year-old woman became feverish on a flight from the Philippines to New York and later broke out in a red rash.Diagnosis: measles.She has since recovered. But some public health officials have not experienced the same relief. Instead, they see this incident and a few others as sounding an alarm that this illness may re-emerge after years of decline.”It’s a cautionary note,” said Steve Cochi, MD, MPH, deputy director of the American National Immunization Program at the Centers for Disease Control and Prevention. “Measles is always on our doorstep.”Experts point out that there is an unsettling reminder offered by this case — the first of 39 reported to the NIP this year — as well as this past summer’s large outbreak in the Marshall Islands. According to a September report in the CDC’s Morbidity and Mortality Weekly Report, hundreds of people in this former American territory, a jurisdiction that maintains strong economic ties to United States, became ill and three died because of a possible importation of measles from Asia. Because the virus is endemic to much of the world, it may always be just one flight away.”The resurgence of measles is related to the influx of people who are not immune, and it’s the imported cases which pose the threat to the those people who are not vaccinated or have waning immunity,” said Kurt Cullamar, MD, an internist and infectious disease specialist who is a geriatrics fellow at Maimonides Medical Center in New York. He knows this truth firsthand because he happens to be the brother-in-law of the woman who became ill on the airplane. Fortunately, it does not appear that his sister-in-law transmitted the virus to anyone else. In the Marshall Islands’ outbreak, though, the virus traveled as far as Hawaii and Guam.”Let Hawaii’s experience be a wake-up call to the rest of the country about how closely we are connected to areas that have measles,” said Paul Effler, MD, MPH, state epidemiologist at the Hawaii Dept. of Health.Even Arkansas initiated a vaccination program in response because of its significant Marshallese population. No cases were recorded there.Maintaining vaccine coverage key:Measles seems to be creeping in ever closer.Europe is experiencing growing numbers of cases because of declining rates of immunization. Coverage has dropped so low in Great Britain that Dr. Simon Murch, the pediatric gastroenterologist who originally suggested that there might be a link between the measles-mumps-rubella vaccine and autism, wrote a letter to The Lancet stating that the purported link and related vaccine fears were unfounded while concerns about the illness were very real.Only vaccination rates near 100% would entirely eliminate measles from the U.S. “There is now unequivocal evidence that MMR is not a risk factor for autism. … [But] unless vaccine uptake improves rapidly, major measles epidemics are likely in the UK this winter,” he wrote.For the most part, the United States has vaccination rates that likely would prevent measles from spreading widely. For instance, 91% of 3-year-olds have received one dose of MMR. This number jumps to 95% by the time children enter school. Still, according to the National Immunization Program, two-thirds of cases are imported or directly linked to importation, and measles is so contagious that experts believe only vaccination rates near 100% would entirely eliminate the disease from U.S. shores.”Importation is not going to lead to a large outbreak as long as we maintain the high vaccine coverage levels that we enjoy,” Dr. Cochi said. “But we face that danger if we let our guard down.”And that’s why clusters of illness become a concern, especially in areas of the country that may have less than optimal vaccination rates. In Montana, only 85% of 3-year-olds have received at least one MMR dose. Doctors say the kids sometimes slip by either because of parental objections or the chaos of life. Regardless, these young patients would be in jeopardy.”Our goal should be to approach 100% immunization, and if we’re seeing a resurgence of measles, that is all the more reason that we should do that,” said Kurt Kubicka, MD, president of the Montana Medical Assn., and a family physician in Helena.But even those who follow the recommendations to the letter may be at risk. Some children may fall into an unprotected zone — too young to receive the shot, but too old to still retain their mother’s antibodies. And although measles is generally thought of as a childhood disease, adults are also at risk. A quarter of the cases in the Marshall Islands were among adults. Two of the three deaths were among people older than age 20.Another reason for worry is that some adults may have come of age after the two-dose vaccine recommendation came into play. Experts maintain, though, that a vast majority of these people would have at least some immunity even if it waned over time.”The second dose is really to pick up that 5% who may not have responded to the first dose,” said Samuel Katz, MD, professor of pediatrics at Duke University in Durham, N.C., and co-chair of the National Network for Immunization Information. Still, he adds, “were I an individual who had only one dose and there were a little cluster of cases in my community, I might be susceptible.”And some adults may have never received the shot in the first place. The woman who flew to New York thought she had received the vaccine, but she had no proof.Physicians and public health officials concede that measles, because it is so highly contagious, must be controlled worldwide to actually get at the problem — to achieve the Healthy People 2010 goals of zero cases per year. In October, health officials from around the world gathered at the Global Measles Forum in Cape Town, South Africa, and pledged to work towards reducing measles deaths. Last year the United Nations also agreed to work towards halving measles deaths, which currently tally 745,000 globally every year. More than half occur in Africa.”The most important thing we can do right now is to reduce the measles burden in the rest of the world,” Dr. Cochi said. “That will continue to lower the risk of U.S. citizens coming down with measles.”(Source: Victoria Stagg Elliott, AMNews American Medical Association November 2003)