Planning a winter vacation in the tropics this year? A new study of tourists who brought home an infection as a souvenir of their travels has found malaria and typhoid fever topped the list of diseases acquired abroad by American travelers.
The finding, published online in the American Journal of Tropical Medicine and Hygiene, indicated travelers who visited Western Africa or India were particularly vulnerable to infection.
"While diagnosis and treatment of malaria and typhoid fever and many other tropical diseases have improved greatly over the years, people still can die from them if they are not treated quickly after their symptoms begin," said University of Oslo researcher Mogens Jensenius, M.D., who analyzed 15 years of data involving more than 80,000 travelers who sought medical care for illnesses after returning home.
"Doctors and nurses in Western countries need to be vigilant in considering these potentially life-threatening tropical infections in recently-returned travelers with fevers, and identify and treat them quickly."
For the study, Dr. Jensenius and fellow researchers at the U.S. Centers for Disease Control and Prevention and several other universities throughout Europe, Israel, Australia, and the United States examined medical charts of 82,825 ill travelers from Europe, North America, Israel, Japan, Australia, and New Zealand. The travelers sought care at clinics from June 1996 through August 2011 for illnesses contracted during travel to the tropics.
Among the findings:
• About 3,000 (4 percent) were affected by malaria, typhoid fever, and other potentially life-threatening tropical diseases;
• More than 3,650 patients — 4.4 percent of the total — had one of 13 life-threatening diseases;
• There were a total of 13 deaths, 10 of which occurred in patients with malaria;
• Malaria — spread by mosquitoes — was by far the most common condition, making up 76.9 percent of the diagnoses;
• Fevers such as typhoid fever — contracted from contaminated food and water in areas with poor sanitation — were found in 18.1 percent of the patients;
• Leptospirosis, a rare bacterial infection usually caused by exposure to contaminated water, was diagnosed in 2.4 percent of the ill travelers; and
• Not a single traveler contracted the highly contagious and lethal Ebola virus, which is typically one of the tropical diseases most feared by travelers.
Every year, some 50 million Western travelers visit tropical countries in Central and South America, Africa, Oceania, and Asia, and their numbers are expected to grow, according to the World Tourism Organization.
"While tropical illnesses are rare in the Western world, these findings remind us that infectious disease pays no attention to geographic borders and affects the world at large," said David H. Walker, M.D., president of the American Society of Tropical Medicine and Hygiene and chair of the department of pathology at the University of Texas Medical Branch in Galveston.
Health experts urge visitors to tropical regions to seek pre-travel advice on vaccinations and medications required for the countries they plan to visit, take precautions to prevent insect bites, and drink bottled water while traveling.
Tourists who become ill with fever or flu-like illness while traveling or soon after returning home from high-risk areas should seek immediate medical attention and share their travel history with their physician.
"Nearly all the diseases identified in our paper presented with a fever and an incubation period of just a couple of weeks," noted Dr. Jensensius.