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Biological Warfare : Biological Terrorism : Emerging Diseases

In one New Guinea hilltop village the message was rooted deep in lore: If you hunt in the valley below and sleep there overnight, evil spirits will possess you, you'll become sick, and you'll die.

It was a homespun kind of malaria control in the highlands of this western Pacific island, long free of the disease-bearing mosquitoes that plague the hot and humid nights of its lowlands, said Dr. Ivo Mueller, a lead scientist at the Papua New Guinea Institute of Medical Research.

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As the Earth warms, however, "malaria epidemics in the highlands are now basically happening every year," Mueller said.

The threat of collapsing ice sheets and super-hurricanes dominates many discussions at the annual U.N. climate conference now under way in Bali, Indonesia. On the litany of ills linked to climate change, the slow spread of warm-weather diseases is more a quiet scourge, one whose ultimate cost remains incalculable.

"What is going to be the burden on the health care infrastructure of poor, developing countries?" asked Hannah Reid, of London's International Institute for Environment and Development, opening a panel session Wednesday in Bali on the health impacts of climate change.

Forecasting those impacts can be controversial, both politically and scientifically.

In Washington this October, for example, The Associated Press reported that the Bush administration, which opposes mandatory international action to rein in warming, expurgated pages discussing such negative health effects from a U.S. official's congressional testimony.

At the technical level, researchers in poorer nations like Papua New Guinea often cannot find the reliable health statistics or, sometimes, historical temperature readings they need to reach scientific conclusions.

"Not having quality health data that spans many decades makes the long-term assessment of climate change impact on health...

Researchers in New York believe they have solved one of the great mysteries of the flu: Why does the infection spread primarily in the winter months?

The answer, they say, has to do with the virus itself. It is more stable and stays in the air longer when air is cold and dry, the exact conditions for much of the flu season.

“Influenza virus is more likely to be transmitted during winter on the way to the subway than in a warm room,” said Peter Palese, a flu researcher who is professor and chairman of the microbiology department at Mount Sinai School of Medicine in New York and the lead author of the flu study.

Dr. Palese published details of his findings in the Oct. 19 issue of PLoS Pathogens. The crucial hint that allowed him to do his study came from a paper published in the aftermath of the 1918 flu pandemic, when doctors were puzzling over why and how the virus had spread so quickly and been so deadly.

As long as flu has been recognized, people have asked, Why winter? The very name, “influenza,” is an Italian word that some historians proposed, originated in the mid-18th century as influenza di freddo, or “influence of the cold.”

Flu season in northern latitudes is from November to March, the coldest months. In southern latitudes, it is from May until September. In the tropics, there is not much flu at all and no real flu season.

There was no shortage of hypotheses. Some said flu came in winter because people are indoors; and children are in school, crowded together, getting the flu and passing it on to their families.

Others proposed a diminished immune response because people make less vitamin D or melatonin when days are shorter. Others pointed to the direction of air currents in the upper atmosphere. But many scientists were not convinced.

“We know one of the largest factors is kids in school — most of the major epidemics are traced to children,” said Dr. Jonathan McCullers, a flu researcher at St. Jude Children’s Research Hospital in Memphis. “But that still does not explain wintertime. We don’t see flu in September and October.”

As for the crowding argument, Dr. McCullers said, “That never made sense.” People work all year round and crowd into buses and subways and planes no matter what the season.

“We needed some actual data,” Dr. McCullers added.

But getting data was surprisingly difficult, Dr. Palese said.

The ideal study would expose people to the virus under different conditions and ask how likely they were to become infected. Such a study, Dr. Palese said, would not be permitted because there would be no benefit to the individuals.

There were no suitable test animals. Mice can be infected with the influenza virus but do not transmit it. Ferrets can be infected and transmit the virus, but they are somewhat large, they bite and they are expensive, so researchers would rather not work with them. ...

From meat, poultry and milk to potatoes, onions and leafy greens, everything consumed on the world's dining tables is feeling the heat from climate change, scientists say.

Researchers are trying to establish the extent to which global warming will affect livestock, plant life and staple crops such as rice to bolster their resistance to disease and breed stronger varieties.

The world's billion poor, whether producers or consumers, will bear the brunt, warned scientists who ended a conference Saturday on agriculture and climate change in Hyderabad, southern India.

"In some ways, the time for doing things is already past," said John McDermott, deputy director of research at the Nairobi-based International Livestock Research Institute. "The changes are already happening."

As an example, rift valley fever, a deadly virus transmitted to sheep, cattle, camels and humans by mosquito bites, is being fuelled by climate change, the scientist said.

The virus is manifesting itself in broader swathes of East Africa and the Middle East because of climate variability in dry regions that helps vectors such as mosquitoes, tsetse flies and ticks to breed and spread, he said.

"What you see are diseases moving into areas where they have not been before, which means sometimes animals are exposed where they haven't been for a long time," he said.

"That leads to more outbreaks," McDermott added.

For the poor, livestock offers a livelihood as well as a savings bank they can tap, selling off their cows or chickens to deal with a health or family emergency.

"These are the people who don't make much of an impact on the ecological footprint of the world," said McDermott.

But they are also the people most at risk from damage wrought on livestock by diseases that could be aggravated by climate-related phenomena.

Scientists are also studying cropping and disease patterns in vegetables -- potatoes and tomatoes to cabbage and spinach, onion and garlic -- to see how they can cope with the stresses brought by global warming and its side-effects.

"If you make it a given that temperatures will go up, water will be a problem -- that will be your worst-case scenario," said Jackie Hughes, deputy director of research at the Shanhua, Taiwan-based World Vegetable Centre.

"You're going to have typhoons, cyclones and hurricanes," she said, adding vegetable growers may have to grow different varieties, use grafting techniques to address flooding and devise rain and insect protection for their crops.

"Probably, it will mean a shift of where crops are grown -- onions moving a little bit in one direction and tomatoes, cabbages coming out of very, very dry areas," she added.

Success in tackling the impact of climate change on crops is important as the world is host to a billion people who are already underweight and under-nourished, Hughes said.

The average adult is required to consume 74 kilogrammes of vegetables a year and "most don't reach that," she added.

Scientists are also concerned about the potential effect of climate change on potato blight, a weather-driven disease that takes a heavy toll on potato crops. ...

Government health regulators recommended adding label precautions about neurological problems seen in children who have taken flu drugs made by Roche and GlaxoSmithKline.

The Food and Drug Administration on Friday released its safety review of Roche's Tamiflu and Glaxo's Relenza. Next week, an outside group of pediatric experts is scheduled to review the safety of several such drugs when used in children.

FDA began reviewing Tamiflu's safety in 2005 after receiving reports of children experiencing neurological problems, including hallucinations and convulsions.

Twenty-five patients under age 21 have died while taking the drug, most of them in Japan. Five deaths resulted from children "falling from windows or balconies or running into traffic."

There have been no child deaths connected with Relenza, but regulators said children taking the drug have shown similar neurological problems.

While FDA said it isn't clear whether the problems are directly related to the drugs, it recommends adding language about the possible side effects to labeling for physicians who prescribe Tamiflu and Relenza....

An outbreak in Europe of an obscure disease from Africa is raising concerns that globalization and climate change are combining to pose a health threat to the West.

Nearly 300 cases of chikungunya fever, a virus that previously has been common only in Africa and Asia, were reported in Italy — where only isolated cases of the disease had been seen in the past.

"We were quite surprised," said Stefania Salmaso, director of Italy's Center for Epidemiology at the National Health Institute. "Nobody was expecting that such an unusual event was going to happen."

While the outbreak was largely the result of stronger trade and travel ties, some experts believe it is a sign of how global warming is creating new breeding grounds for diseases long confined to subtropical climates.

Officials at the European Centre for Disease Prevention and Control said the particularly mild winter in Italy allowed mosquitoes to start breeding earlier than usual, giving the insect population a boost.

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"This outbreak is most important as a warning signal," said Diarmid Campbell-Lendrum, a climate change expert at the World Health Organization. "Climate change affects the breeding of every mosquito on earth."

More mosquitoes will mean more disease. With warmer temperatures in the future, Europe and North America might be hit by outbreaks of diseases usually confined to southern continents.

"With more movement of people and a changing climate, there will be shifting patterns of disease," Campbell-Lendrum said. "We need to be prepared for more surprises like this in the future."

Italian officials first grew suspicious in July, when dozens of people in the country's northeast complained of fevers, joint pain, headaches and rashes. Local doctors thought they had been bitten by sandflies, but lab tests confirmed chikungunya fever, a disease spread by mosquitoes.

Officials believe the virus arrived when a tourist from India brought the virus to the Italian province of Ravenna. The Asian tiger mosquito, which can spread the disease, had reached Italy nearly two decades earlier.

Experts are also nervous because the Asian tiger mosquito might be capable of spreading more dangerous diseases like dengue fever and yellow fever.

"Dengue would certainly be more worrying than chikungunya," said Dr. Denis Coulombier, the European Centre for Disease Prevention and Control's head of preparedness and response. "It is something we need to keep an eye on, because the possibility is there."

Most scientists think Europe's advanced health systems and high living standards will help avert widespread disease. Malaria was once endemic in much of Europe but disappeared once the swamps that bred mosquitoes were replaced by buildings and medicines to treat malaria became widely available.

But development doesn't deter all mosquitoes. Certain species prefer artificial breeding sites like rain-filled gutters and plastic containers. "If the climate gets suitable enough, then even very high living standards won't necessarily protect you," Campbell-Lendrum said....