BANGKOK — The deaths of 72 tigers in two animal parks for tourists in northern Thailand shouldn't be a major concern for the public, officials said Tuesday, because they were caused by a virus not known to affect humans, rather than bird flu.
No one has shown any symptoms so far, but authorities were nonetheless monitoring the health of people who had recently come into contact with the animals.
''There has not been an animal-to-human infection case,'' Public Health Minister Pattana Promphat said at a news conference at Government House in Bangkok.
The tigers in the parks in Mae Taeng and Mae Rim districts in Chiang Mai province became sick and died during a roughly 10-day period between Feb. 8-18.
On Friday, the Chiang Mai regional livestock office announced in a statement that autopsies of the animals found genetic material of canine distemper virus, or CDV, and traces of bacterial infection, but no avian influenza type A virus, also known as bird flu.
''If we detect any sick persons, we will prepare for a nationwide monitoring measure," said Monthien Khanasawat, director-general of the Public Health Ministry's Disease Control Department. "This will include contact tracing and treatment as necessary.''
Monthien spoke at the news conference in an apparent effort to reassure the public that the tigers' deaths didn't come from bird flu, which has been resurgent in parts of Asia. Thailand saw 17 deaths among 25 infected patients from poultry-caused influenza from 2004 to 2007, according to the Public Health Ministry.
CDV, infectious for both dogs and felines, can cause stronger symptoms in cats and tigers and can be spread through bodily fluids and air. Thai authorities said that tigers in confined environments, and which are already affected by stress and inbreeding conditions, could be particularly vulnerable to the viral infection.