It started as a self-sacrificing trip to Romania to perform missionary work at an orphanage.
But when a rural Indiana family returned home in 2005, the voyage ended in a horrible twist: Thirty-four people in the West Lafayette area came down with measles, a highly infectious disease brought home from Romania by the family's teenage daughter, who hadn't been vaccinated against it.
Although she wasn't feeling well, the girl attended a church function, where several unvaccinated members of the community became exposed to her germs. (Her family has asked that its name be withheld for privacy reasons.)
The family's story highlights a growing concern, according to a report published in today's issue of the New England Journal of Medicine. Although vaccines are designed to protect those most vulnerable to infections -- children -- an increasing fear of vaccines could make more towns ripe for the spread of measles and other vaccine-preventable diseases, such as mumps and whooping cough, also known as pertussis.
Why do some people choose not to vaccinate their kids? In 1998, the Lancet, a British medical journal, published an article that claimed that the MMR (measles-mumps-rubella) vaccine caused autism in children. The article has since been retracted, but the worry has remained.
As a result, even though vaccines are required for school attendance, many parents have opted out, claiming that vaccination violates their personal or religious beliefs. It appears this view is especially prevalent among parents who home-school their children. And this, in turn, puts children and their communities at a growing risk of spreading preventable epidemics.
"Most parents today have never seen the physical and emotional devastation caused by vaccine-preventable diseases and have a skewed view of the perceived risks associated with vaccines versus the actual risks of the diseases the vaccines are designed to prevent," said Dr. Gary L. Freed, chairman of the U.S. National Vaccine Advisory Committee and director of the Pediatrics and Child Health Evaluation and Research unit at the University of Michigan Healthcare System.
In the Indiana measles outbreak, 71 percent of the children who contracted measles were home-schooled. Experts agree that anecdotal evidence suggests that families who home-school tend to have nontraditional health care beliefs and are less interested in conventional medicine.
The outbreak could have been worse. The majority of residents in this community had been immunized against measles, so an epidemic was prevented. Also, the New England Journal report noted that swift action among local, state and federal agencies helped contain the disease.
The decision not to vaccinate affects not only the individual family but puts everyone in a community at risk for contracting a disease, doctors said.
Even if vaccinated, if a person has an immune system-suppressed condition -- like cancer, HIV or organ transplantation -- he or she is at risk of catching an infectious disease that is potentially deadly.
Pastor Del Broersma of the Upper Room Christian Fellowship in West Lafayette, said the outbreak had a tremendous impact on the Indiana community.
People who had small children who had not been immunized were asked to not come to church. Sunday school and the meal after services were suspended for three weeks.
"We asked those families who had the measles to honor a self-imposed quarantine at the suggestion of the health department," he said.
After the outbreak, many families decided to immunize their children, while other families remained unconvinced about the low risk of autism, Broersma said, noting it was not church policy to withhold immunizations.
The only adult in the community to contract measles, Scott Schneider, 46, didn't know he hadn't been vaccinated.
"They don't call these childhood diseases for nothing. It'll take your life," he said. "I was totally out of commission for three months."
Vaccines have dramatically improved the health of the world, but only smallpox has been eradicated -- measles, polio, mumps and rubella still pop up from time to time, said Dr. Samuel L. Katz, chairman emeritus of pediatrics at Duke University and one of the inventors of the measles vaccine.
In the United States, many doctors have never had the opportunity to see some of these diseases firsthand, which means it can take longer to diagnose them properly.
That doctors are unfamiliar with diagnosing vaccine-preventable diseases is a "testament to the success of vaccinations," said Dr. Lance Rodewald, director of immunization services at the Centers for Disease Control and Prevention.
Still, in the rest of the world, diseases like measles are widespread. There were an estimated 530,000 deaths in 2003 from measles, and it remains the leading cause of vaccine-preventable death among children worldwide, according to the CDC.
The Indiana case shows how easily a disease can be brought into the United States.
"This issue is very real and can come to your community as easily as imported cheese," said Dr. Jeff Durchin, chief of communicable disease control for the Seattle Public Health Department.
For example, in 2004, Liz Parker and Norvin Leach adopted a baby girl from China. They had no idea that a measles outbreak was rampant in the orphanage.
But two days after coming home to Seattle, their daughter had a 105.5 degree fever. At first, the doctors at the hospital thought it was SARS, since none of them had ever seen measles before, and the girl had a rash that didn't look like measles. It took 10 days to correctly diagnose her.
The couple had traveled with 11 other families, and when they all returned stateside, measles had spread to Washington, Maryland, Florida, New York and Alaska. One college student in Washington contracted the measles from exposure to one of the children on an airplane.
"The measles was not an isolated incident for our daughter," Parker said. "It will always be part of her medical history and looming over her head, as there can be potential complications that will be with her for the rest of her life."