Thai concerns about reporting of H5N1

Thai Bird Flu Case Suggests Under-Reporting in Fowl (Update1)

Aug. 4 (Bloomberg) -- A 17-year-man who died of bird flu in Thailand last week, the country's first case this year, suggests the virus is being under-reported in poultry, the influenza team at the European Centre for Disease Surveillance and Control said.

The youth from a northern province was hospitalized on July 18 suffering fever, cough and headache and died six days later, the Thai Bureau of General Communicable Diseases said in a July 26 report. A week before his symptoms appeared he buried 10 dead chickens, touching the carcasses with his bare hands. His phlegm tested positive for the H5N1 avian flu strain.

The case ``could be an example of the phenomenon of a sentinel human already seen in other countries, where it is only the severe illness or death of a person from H5N1 that triggers detection or reporting of H5N1 in poultry,'' the team in Stockholm said in a report. ``This suggests under-detection or under-reporting of poultry deaths.''

Thailand widened the search for avian flu patients and improved surveillance for the virus in poultry as a result of the death of the youth. New cases create chances for H5N1 to mutate into a pandemic form and world health authorities are tracking the disease for signs it's becoming more contagious.

The virus is known to have infected 232 people in 10 countries, killing 134 of them. Most infections occurred in Asia through contact with birds. The disease may kill millions should it start spreading easily between people, researchers have said.

Respiratory Symptoms

Thailand is awaiting laboratory tests on 259 people with respiratory symptoms, of whom 32 are from Phichit, the same province where the teenager died last week, the country's Bureau of General Communicable Diseases said on its Web site today.

So far this year, Thai health authorities have investigated more than 2,300 clinical influenza or pneumonia patients as part of routine surveillance. Only one of these has been found to be infected with H5N1.

Thai health officials recorded 65,100 cases of seasonal influenza in the first seven months of this year. Of those patients, 370 died, Thawat Suntrajarn, director general of the health ministry's disease control department, told reporters in the capital, Bangkok, today.

``Our biggest concern is the outbreak of seasonal flu in Pichit, where the bird flu virus is still active'' in poultry, and in nearby provinces, Thawat said. The initial symptoms of both avian and seasonal influenza are similar, he said.

Health officials are concerned that people may contract H5N1 flu while they're infected with seasonal influenza. The dual infections might allow the H5N1 to mutate into a pandemic form, Thawat said.

`Very Lethal'

``Bird flu is very lethal with a high fatality rate among infected patients, while seasonal flu is easily transmitted between humans,'' he said. ``Any combination of both viruses in a person would be very dangerous.''

Laboratory tests on a 9-year-old girl, who died earlier this week in Lop Buri province, showed she had seasonal flu, not the H5N1 strain, Paijit Warachit, director general of Thailand's Medical Science Department, said in a telephone interview today.

Tests on two suspected avian flu patients in Chachoengsao also showed they have seasonal flu and not H5N1, Thawat said.

Concern of fresh outbreaks of the disease have been fanned by reports of new infections in poultry. Laos, Thailand's northeastern neighbor, said the virus killed thousands of poultry in several farms owned by a commercial producer near the capital, Vientiane, last month.

``There remains a constant risk of outbreak reoccurrence'' because of the large numbers of free-range poultry that haven't previously been exposed to the virus, and the movement and mixing of fighting cocks, the influenza team at the ECD said in its report.

Wild Birds

``There is also the additional risk from wild birds mixing with the free-grazing birds,'' the team said. The report was published yesterday in Eurosurveillance, an online journal of peer-reviewed information on communicable diseases.

In Vietnam's Kien Giang province on the Cambodian border in the Mekong Delta, a man was hospitalized with damaged lungs and high fever about a week after eating duck, the Tuoi Tre newspaper reported yesterday.

Tests on the man were negative for H5N1, said Nguyen Thi Kim Tien, director of the Pasteur Institute in Ho Chi Minh City.

The Nguoi Lao Dong newspaper reported today that he virus was found in storks in the Suoi Tien district of Ho Chi Minh City, and in ducks from two flocks in the southern province of Tay Ninh.

Tests on the duck flocks were negative for the H5 avian flu subtype, said Nguyen Xuan Binh, deputy head of the Ho Chi Minh City regional center for animal health, which is responsible for carrying out tests on animal samples from southern provinces.

``We have just received samples from the stork flock in Suoi Tien today, and tests are underway,'' Binh said.

A swan found dead in Dresden zoo in eastern Germany was infected with H5N1, the first such infection in the country in almost three months, Agence France-Presse said yesterday, citing local authorities.

To contact the reporters for this story:
Jason Gale in Singapore at  j.gale@bloomberg.net;
Anuchit Nguyen in Bangkok at at anguyen@bloomberg.net

Last Updated: August 4, 2006 06:10 EDT