By Charlene Porter
Washington File Staff Writer

Washington – The death of 17-year-old Thai youth from the H5N1 strain of avian influenza is confirmed by the World Health Organization (WHO) July 26 as researchers and health officials continue efforts to contain the disease in the hop of quelling a possible human pandemic.

The case marks the first appearance of the disease in humans in Thailand since December 2005. The Southeast Asian nation has confirmed a total of 23 human cases of H5N1, resulting in 15 deaths. The largest wave of cases came in 2004, and diminished sharply after Thai animal and human health authorities waged an aggressive campaign to bring avian influenza under control.

In the current case, a young man from the Phichit province in the north developed symptoms on July 15 and died by July 24, according to a WHO report. The victim is known to have had contact with dead chickens, and the disease has been detected in poultry populations in Phichit.

The Thai Ministry of Agriculture and Cooperatives reported to the World Organisation for Animal Health (OIE) July 24 that the H5N1 viral strain had re-occurred in poultry for the first time since November 2005.

In March, the Thai authorities filed what they called a final report with OIE, after 140 days had elapsed without the detection of a single animal case.

In May, the Food and Agriculture Organization of the United Nations (FAO) issued a report entitled Thailand Share Secrets of Success, which details the “unprecedented campaign” the nation conducted to beat the H5N1 flu strain.

Thirteen government ministries participated in containment efforts, said the FAO, including army personnel and police officers who helped agricultural agents cull birds in infected areas and control the movement of animals, poultry products and people.

Dr. Oraphan Pasavorakul, of the Thai Bureau of Disease Control, said the three most important steps Thailand took to control the outbreak “were intense and constant surveillance – we call it X-ray surveillance - fair compensation for culled birds, continuous poultry inspection and control of all poultry movement in the country.”

Controlling the disease in animals is critical to preventing a broader spread among humans. In the overwhelming majority of cases, the virus infects humans after direct contact with sick birds or their habitat. If the virus mutates further to become easily transmissible among humans, health experts warn the disease could sweep the world because people have no immunity to the virus.

PROGRESS IN VACCINE DEVELOPMENT

The United Kingdom-based pharmaceutical company GlaxoSmith-Kline (GSK) reported July 26 that a clinical trial has produced positive results for a low-dose vaccine to protect against H5N1 infection.

Previous efforts to develop a vaccine have produced notable immune responses in subjects, but only at very high doses of the vaccine. It is acknowledged widely that the pharmaceutical industry lacks the capacity to produce massive amounts of vaccine in a short time, as would be needed in a pandemic. So these earlier trials, while hopeful, left considerable practical problems.

GSK attributed the success of its trial vaccine to the use of a proprietary adjuvant, a substance used to boost the effectiveness of the active ingredient.

So far, the trial vaccine has been tested in 400 adults, aged 18 to 60, with 80 percent developing an immune reaction to H5N1 when injected with the vaccine.

A GSK executive calls the finding a “significant breakthrough,” but acknowledges that a great deal of work remains to develop the product and present it to regulatory agencies.

DISEASE COMMUNICATION PLAN GAINS MOMENTUM IN AMERICAS

Animal health experts and poultry producers know the appropriate response to an outbreak of highly pathogenic avian influenza in a bird population. Destroying the birds, quarantining the area, controlling movement of birds and disinfection of the affected farms and facilities all are widely accepted steps.

Whether those actions are successful depends on how rigorously they are applied and how effectively people are informed about the need to take them. 

In the Western Hemisphere, no trace of the H5N1 viral strain has appeared, so there is been no need for control measures, but a broad range of animal and human health officials in the region are starting to work on the communications side of the equation to achieve better effectiveness of the control actions when and if their time should come.

In a Washington meeting July 25, representatives from a range of international health and development organizations endorsed a plan to step up efforts to communicate the threat of H5N1.

“We must take advantage of the experience of other regions to inform and prepare our own region,” said Director Mirta Roses of the Pan American Health Organization (PAHO).

Participants at the meeting endorsed the Inter-Agency Communication Framework for Avian and Human Influenza in the Americas, which sets forth a common approach for communicating with the media, government officials, the private sector and the general public as part of ongoing efforts to prevent and prepare for avian and pandemic flu.

Recognition of the linkage between animal and human health and the need to support the improvement of veterinary capabilities in developing countries have been important priorities expressed at high level international meetings on the pandemic threat. (See related article.)

The full text of Thailand Shares Secrets of Success is available on the FAO Web site. The full text of the press release on the framework agreement is available on the PAHO Web site.

For ongoing coverage, see Bird Flu (Avian Influenza).