Disease outbreak associated with international adventure race

October 29, 2000

After grueling, non-stop days of biking over mountains, crawling through caves and kayaking down rivers, the racers in the 2000 Eco-Challenge in Borneo thought their struggle against Mother Nature ended at the finish line. For many it didn't. Researchers at the Centers for Disease Control and Prevention (CDC) report that at least 25% of the participants from that race developed a severe disease, leptospirosis, after returning home, highlighting yet another risk in the increasingly popular sport of adventure racing. They report their results at the annual meeting of the American Society of Tropical Medicine and Hygiene.

It started about a week after the race ended in early September. The CDC received a few sporadic reports of leptospirosis from Idaho, San Diego and Los Angeles. All the cases, though, had one thing in common. The patient had just finished participating in the Eco-Challenge.

"Putting all this information together it became clear that many Eco-Challenge participants had developed this illness. The reports we were receiving suggested there were a lot of ill individuals," says Dr. Jim Sejvar of the meningitis and special pathogens branch at the CDC. "Based on those initial results we initiated a telephone survey. Through a collaborative effort we tried to reach as many of the participants as possible, gather information on any illness or symptoms they had experienced and identify risk factors associated with illness."

They were eventually able to reach and interview just under half of the 308 race participants. Of those they interviewed approximately 44% had experienced symptoms consistent with leptospirosis infection. The researchers believe the cause might have been in the river water.

"Several of the events including kayaking, swimming in the river and spelunking appeared to be risk factors for infection," says Sejvar. "The only independently significant risk factor, though, was swimming in the river. There were a number of participants who became ill who did not report swimming in the river, but it's possible they were exposed to river water during one of the other events."

Leptospirosis is caused by a bacterium and is usually transmitted to humans through water contaminated with urine from infected animals. It may take as long as one month for symptoms of illness to develop among persons infected with the bacterium responsible for leptospirosis. The most common symptoms of leptospirosis include fever, chills, red eyes, abdominal discomfort, vomiting, and diarrhea. In rare instances, severe disease can result in damage to the liver, kidneys, and lungs.

Antibiotics are useful in both the prevention and treatment of leptospirosis. Several studies show that taking the antibiotic doxycycline just before or after exposure will not necessarily prevent infection, but can significantly reduce the severity of symptoms.

The Eco-Challenge experience is not an isolated incident in the adventure travel - leptospirosis link, as evidenced by other reports at the same meeting. For instance, researchers from the University of Utah reported on the case of a young woman who developed leptospirosis after a 2-week kayaking trip in Ecuador. As the popularity of eco-tourism and adventure travel increase and more people participate in activities where leptospirosis is prevalent this type of outbreak has the potential for occurring more often, says Sejvar. That doesn't mean people should avoid adventure travel, though. After all, part of its allure is its inherent risks. But, adventure travelers should investigate and learn as much about the location to which they are traveling as possible, so that they can be fully aware of the infectious disease risks that they may encounter.
The American Society of Tropical Medicine and Hygiene (ASTMH) is the principal organization in the United States representing scientists, clinicians, and others with interests in the prevention and control of tropical diseases through research and education. Additional information on the meeting can be found at http://www.astmh.org/presskit.html.

American Society for Microbiology

Related Infection Articles from Brightsurf:

Halving the risk of infection following surgery
New analysis by the University of Leeds and the University of Bern of more than 14,000 operations has found that using alcoholic chlorhexidine gluconate (CHG) halves the risk of infection in certain types of surgery when compared to the more commonly used povidone-iodine (PVI).

How plants shut the door on infection
A new study by an international team including University of Maryland scientists has discovered the key calcium channel responsible for closing plant pores as an immune response to pathogen exposure.

Sensing infection, suppressing regeneration
UIC researchers describe an enzyme that blocks the ability of blood vessel cells to self-heal.

Boost to lung immunity following infection
The strength of the immune system in response to respiratory infections is constantly changing, depending on the history of previous, unrelated infections, according to new research from the Crick.

Is infection after surgery associated with increased long-term risk of infection, death?
Whether experiencing an infection within the first 30 days after surgery is associated with an increased risk of another infection and death within one year was the focus of this observational study that included about 660,000 veterans who underwent major surgery.

Revealed: How E. coli knows how to cause the worst possible infection
The discovery could one day let doctors prevent the infection by allowing E. coli to pass harmlessly through the body.

UK study shows most patients with suspected urinary tract infection and treated with antibiotics actually lack evidence of this infection
New research presented at this week's European Congress of Clinical Microbiology & Infectious Diseases (ECCMID) in Amsterdam, Netherlands (April 13-16, 2019) shows that only one third of patients that enter the emergency department with suspected urinary tract infection (UTI) actually have evidence of this infection, yet almost all are treated with antibiotics, unnecessarily driving the emergence of antimicrobial resistance.

Bacteria in urine doesn't always indicate infection
Doctors should think carefully before testing patients for a urinary tract infection (UTI) to avoid over-diagnosis and unnecessary antibiotic treatment, according to updated asymptomatic bacteriuria (ASB) guidelines released by the Infectious Diseases Society of America (IDSA) and published in Clinical Infectious Diseases.

Subsidies for infection control to healthcare institutions help reduce infection levels
Researchers compared three types of infection control subsidies and found that under a limited budget, a dollar-for-dollar matching subsidy, in which policymakers match hospital spending for infection control measures, was the most effective at reducing the number of hospital-acquired infections.

Dengue virus infection may cause severe outcomes following Zika virus infection during pregnancy
This study is the first to report a possible mechanism for the enhancement of Zika virus progression during pregnancy in an animal model.

Read More: Infection News and Infection Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.