Vaccination officially eliminated measles in the United States in 2000, but the global killer still frightens Julia Shaklee Sammons.
As the medical director for infection prevention and control at Children's Hospital of Philadelphia, Sammons is keenly aware that international travel and parental resistance to U.S. immunization practices are renewing the threat of measles.
Orange County, Calif., and New York City have had outbreaks this year, and the U.S. has had 129 confirmed cases of measles though last week - the highest for that period since 1996.
"As more parents refuse to vaccinate their children, measles incidence is rising - a fact that alarms me both as a hospital epidemiologist and as a parent of a vulnerable infant too young to receive the measles vaccine," Sammons wrote last week in an editorial in Annals of Internal Medicine.
Sammons' article aimed to educate physicians. Many doctors may not readily recognize a case of measles because they've never seen one.
She also urged doctors to remind parents "what is at stake."
The measles virus is highly contagious, with a 90 percent transmission rate with direct contact. But it can also be passed indirectly, because the virus can survive as long as two hours in airborne droplets from a sick person's sneeze or cough.
That person is contagious for four days before and four days after the characteristic blotchy red rash appears.
Besides the rash, the classic symptoms are fever, cough, runny nose, pink eye, and slightly raised, white or bluish spots inside the mouth on the cheeks.
Even people with no complications may develop a devastating neurologic illness years later. And children with measles often have complications including diarrhea, earache, pneumonia, and croup. In rare cases, brain inflammation leads to permanent brain damage. Death occurs in 1 to 3 in 1,000 cases.
Worldwide, about 20 million cases occur each year. Before the vaccine era, the U.S. had 500,000 cases yearly - with 500 deaths and 48,000 hospitalizations.
After elimination, the U.S. saw only about 60 cases a year, "but this number is steadily rising," Sammons wrote.
The reasons are clear.
Although national vaccination coverage among children is about 90 percent, 15 states (not Pennsylvania or New Jersey) are below that goal. States that allow parents to opt out because of fears or personal objections have higher rates of unvaccinated children. Anti-vaccine groups continue to claim childhood immunizations are unsafe and ineffective.
Unvaccinated people who travel to a country with endemic measles can become importers of the disease, which then spreads in the U.S.
"For suspected cases of measles, early reporting and rapid control efforts are vital to prevent the spread in health-care facilities" such as doctors' offices and hospitals, Sammons wrote.
Last week, a U.S. Centers for Disease Control and Prevention analysis of the 58 cases in California this year found that 54 were connected to international travel and 11 were transmitted in a health-care setting. Of 25 patients known to be unvaccinated, 19 had philosophical objections to the vaccine.