(Bloomberg) — Apathy toward the pandemic risk posed by bird flu is one of the greatest threats to public health and may undermine efforts to improve disease detection and control systems in developing countries, a World Health Organization official said.

Health authorities have been monitoring the H5N1 strain of avian influenza for more than a decade for any sign that it is becoming as contagious as seasonal flu. While millions of birds have been infected, fewer than 400 people are reported to have contracted the illness, including 36 this year.

“The threat of a pandemic, of a virus jumping from animals into humans, is still there, but the biggest threat that we have now is `flu fatigue’,” Dr. Julie Hall, deputy regional adviser on communicable disease surveillance and response with the WHO’s Western Pacific region, told reporters in Sydney today.

Misconceptions that the pandemic threat is “a storm in a teacup” may sap investment in surveillance for bird flu as well as other infectious diseases, particularly in parts of Asia, where systems are “very weak,” Hall said. Donor governments and organizations such as the World Bank have pledged more than $2 billion the past three years to help poorer nations stem bird flu’s spread and prepare for any pandemic it spawns.

“These systems are useful for many different things — from naturally occurring diseases through to manmade and bioterrorism threats,” Hall said in a telephone interview. “It should be seen as a long-term investment for multiple purposes that one day will most definitely be needed.”

More money to fund global preparedness programs will be sought next month, when Egypt hosts an international ministerial conference on avian and pandemic influenza.

Growing Threat

The world is closer to another influenza pandemic than at any time since 1968, when the last of the previous century’s three pandemics occurred, according to the Geneva-based WHO. The H5N1 virus has spread to more than 60 countries and caused at least 6,500 poultry outbreaks since 2003.

“There has been a lot of hype about pandemic influenza and a fair amount of investment into strengthening surveillance and response systems, but I believe now this new disease called flu fatigue is setting in,” Hall told a meeting hosted by the Australian Science Media Centre.

“We haven’t seen a pandemic, but the H5 virus and all the other influenza viruses are still out there,” she said. “Nipah virus is there causing problems and changing. Dengue is on the rise.”

Population density, increasing poultry production, natural disasters and global warming may spur the emergence of undiscovered diseases in Asia as more people move or are displaced and have closer contact with animals, she said.

An outbreak of nipah virus in Malaysian pigs in 1998 that killed 105 people is one of the most significant epidemics to have occurred anywhere in the world during the past 15 years, according to the Centers for Disease Control and Prevention.