By: Alison Young, USA TODAY

Federal health officers logged more than 3,000 cases of potentially infectious diseases among travelers in the past year, including airline passengers with tuberculosis, whooping cough, measles, mumps and typhoid fever, according to Centers for Disease Control and Prevention data obtained by USA TODAY.

The reported cases, a fraction of illnesses carried by travelers, show the importance of up-to-date vaccinations and getting medical advice before going abroad, says Nina Marano, chief of the CDC’s quarantine branch.

“I think a very high percentage of these cases are preventable,” Marano says, noting that shots, pills and careful food and water choices can prevent diseases such as malaria, typhoid, cholera and measles, along with other vaccine-preventable diseases.

There is no law that generally prohibits sick people from traveling, though health officials can take action to prevent travel or isolate individuals with dangerous diseases. Many sick travelers aren’t officially diagnosed before their trips.

Reports to the CDC of sick travelers were up significantly in the past year, largely because of increased reporting of flulike symptoms in the wake of the H1N1 pandemic, data show.

Since 2007, the CDC’s regional quarantine stations — centers at 20 airports and other ports of entry that monitor air, sea and land travelers’ illnesses — have received about 7,000 reports of potentially infectious diseases, records obtained under the Freedom of Information Act show. Reports come from airlines, cruise ships, immigration officials and CDC staff, as well as local health departments that learn of sick travelers after trips are over.

The initial diagnoses include thousands of cases of flulike illness and gastrointestinal disease, as well as:

  • Tuberculosis— 662 reports, most involving air travel. A 23-year-old woman with multidrug-resistant TB and a persistent cough flew Dec. 22 from Poland to Chicago. Travelers who sat near her were contacted and the CDC has found no evidence she spread the disease, Marano says.
  • Chicken pox and shingles — 518 reports, most involving cruise ship passengers.
  • Measles— 78 reports. On April 19, a 24-year-old woman arrived in Los Angeles aboard a flight from the Philippines.
  • Mumps — 56 reports, including a 22-year-old man who arrived June 2 in Des Moines on a flight from Chicago.
  • Whooping cough — 41 reports, mostly on airlines. An 11-year-old girl flew Oct. 25 from San Diego to Dallas-Fort Worth.
  • Typhoid fever — 19 reports. A 37-year-old man flew Dec. 20 from Haiti to Miami. The life-threatening illness is often spread by bacteria-contaminated food and water.
  • Lassa fever — One report. A 47-year-old man flew Jan. 14 from Brussels to Atlanta, then to Philadelphia, where he was treated for the viral hemorrhagic fever. Passengers who sat near him were contacted and none was infected, Marano said.It’s possible for fellow passengers to catch these diseases, but the greatest risk is to the individual who has them, says William Schaffner, a Vanderbilt University infectious disease expert. A growing number of parents are choosing not to vaccinate their children, he says. Recent measles outbreaks have been linked to unvaccinated children who had traveled to Europe, where the disease is more prevalent.”The global village is getting smaller and smaller,” Schaffner says. “We must protect ourselves here in order to avoid the reintroduction and spread of these diseases, which many young parents today have forgotten.”Beyond routine shots, many international travelers fail to protect themselves from more exotic diseases. Only 36% of travelers flying to Latin America, Asia and other destinations sought health advice before their trips, and only 46% headed to areas with malaria carried pills to prevent the disease, Bradley Connor found in a 2004 study.

    “People going to high-risk areas were grossly undervaccinated, and most weren’t even aware to seek travel health advice,” says Connor, head of the New York Center for Travel and Tropical Medicine.

    U.S. residents visiting friends or family abroad are among those at greatest risk, yet they often wrongly believe they’re immune to local diseases because they grew up there, says David Freedman of the International Society of Travel Medicine. “They don’t stay at the Sheraton. They stay in the local village. They’re not eating at restaurants frequented by tourist travelers,” Freedman says.

    Although the odds are in travelers’ favor they won’t catch a serious disease, some will if they don’t get vaccinated and take other precautions, Freedman says. “I always tell my patients it’s an insurance policy,” he says.