July 11 (Bloomberg) -- The Netherlands confirmed a case of Marburg hemorrhagic fever, a highly infectious disease that can kill within a week, in a Dutch tourist who visited Uganda.

The 40-year-old woman is in a critical condition after contracting the virus last month while visiting caves in the Maramagambo Forest in which she had contact with a bat, the World Health Organization said in a statement on its Web site.

``As a precaution Dutch authorities have alerted the tour operator to avoid visits to the caves until further information is available,'' the Geneva-based organization said in the statement.

Health officials are checking for signs of sickness in people with whom the woman had contact before she developed symptoms. The case illustrates how global travel is helping spread infectious diseases, which are emerging at an ``unprecedented rate,'' the WHO said in a report last year.

There were 831 million international air passengers last year, and that number is expected to grow at an average 5.1 percent until 2011, according to the International Air Transport Association.

Marburg is related to the Ebola virus. Victims suffer high fever, vomiting and severe bleeding, and die within a week of contracting the illness. The disease is named after a city in Germany where the first known human cases occurred in 1967, spreading to people from monkeys imported from Uganda.

The virus is one of at least 39 new pathogens identified during the past 40 years, the WHO said in its 2007 World Health Report. The others include HIV, Ebola and SARS.

The Dutch woman returned to the Netherlands on June 28 in good health, developed symptoms on July 2 and was admitted to hospital on July 5, the WHO said. She suffered liver failure and severe hemorrhaging on July 7.

To contact the reporter on this story: Simeon Bennett in Singapore at sbennett9@bloomberg.net

Last Updated: July 10, 2008 22:32 EDT