Archive for the ‘Pandemics’ Category

Connected World Gives Viruses The Edge

Sunday, June 14th, 2009

“The findings also suggest that as human activity makes the world more connected, natural selection will favour more virulent and dangerous parasites.”

– This quote from the article text below is no surprise to me or to anyone who has looked at the logic of how contagious diseases spread.   You pack more and more people together and the situation begins to favors more and more virulent diseases.   The Black Death in Europe was, perhaps, the first concrete demonstration of this.  The world today is ripe and getting riper for this sort of thing.   We’ve been extremely lucky that some of the very nasty things around like Ebola have not thus far gotten loose in a population center.

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That’s one conclusion from a new study that looked at how virulence evolves in parasites. The research examined whether parasites evolve to be more or less aggressive depending on whether they are closely connected to their hosts or scattered among more isolated clusters of hosts.

The research was led by Geoff Wild, an NSERC-funded mathematician at the University of Western Ontario, with colleagues from the University of Edinburgh.

“Our study follows up on some recent findings that suggest that reduced dispersal of parasites across scattered host clusters favours the evolution of parasites with lower virulence – in the case of influenza, for example, a milder, possibly less deadly, case of flu,” said Dr. Wild.

“Some researchers had contended from this that the parasites were evolving to support the overall fitness of the group,” he added. “The argument for adaptation at the group level is that the parasites become more prudent to prevent overexploitation and hence to avoid causing the extinction of the local host population.”

However, Dr. Wild and his colleagues were not convinced that Darwinian theory – so successful in providing explanations based on the notion that adaptation maximizes individual fitness – was ready for such a major makeover.

The researchers decided to move the arguments from words to harder science. Together they developed a formal mathematical model that incorporated variable patch sizes and the host parasite population dynamics. It was then run to determine the underlying evolutionary mechanisms, the results of which were published in the Nature paper.

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Swine flu pandemic declared

Thursday, June 11th, 2009

LATEST The World Health Organisation has told its member nations it is declaring a swine flu pandemic – the first global flu pandemic in 41 years.

In a statement sent to member countries, WHO said it decided to raise the pandemic alert level from phase 5 to 6, meaning that a global outbreak of swine flu has begun.

The decision was made after the UN health agency held an emergency meeting on swine flu with its experts.

Countries were preparing for tighter swine flu controls as some nations said they had received advance notice of the declaration from the WHO.

Moving to phase 6, the highest level, means a pandemic has begun. It triggers drugmakers to speed up production of a swine flu vaccine and prompt governments to devote more money to containing the virus.

The last pandemic – the Hong Kong flu of 1968 – killed about 1 million people. Ordinary flu kills about 250,000 to 500,000 people each year.

On Wednesday, the WHO reported that the virus has infected at least 27,737 people in 74 countries and caused 141 deaths. Most cases have been in North America, but Europe and Australia have seen a sharp increase in recent days.

Four patients with swine flu were fighting for their lives in Melbourne hospitals, while Thailand’s Public Health Ministry said the country’s case load had nearly tripled to 46, including 17 infected at a disco in the resort town of Pattaya.

Earlier there had been speculation that a  jump in infections in Australia could push WHO to finally announce a pandemic. Australia’s cases reached 1275 by late Wednesday.

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New, Fast-Evolving Rabies Virus Found — And Spreading

Saturday, May 9th, 2009

Evolving faster than any other new rabies virus on record, a northern-Arizona rabies strain has mutated to become contagious among skunks and now foxes, experts believe. The strain looks to be spreading fast, commanding attention from disease researchers across the United States (U.S. map).

It’s not so unusual for rabid animals to attack people on hiking trails and in driveways, or even in a bar—as happened March 27, when an addled bobcat chased pool players around the billiards table at the Chaparral in Cottonwood.

Nor is it odd that rabid skunks and foxes are testing positive for a contagious rabies strain commonly associated with big brown bats.

What is unusual is that the strain appears to have mutated so that foxes and skunks are now able to pass the virus on to their kin—not just through biting and scratching but through simple socializing, as humans might spread a flu.

Usually the secondary species—in this case, a skunk or fox bitten by a bat—is a dead-end host. The infected animal may become disoriented and even die but is usually unable to spread the virus, except through violent attacks.

(See pictures of infectious animals.)

Skunks have already been proven to be passively transmitting the strain to each other, as documented in a 2006 study in the journal Emerging Infectious Diseases.

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Swine Flu

Tuesday, April 28th, 2009
H1N1 virus

H1N1 virus

Readers, all of you, I’m sure, know that Swine Flu is the BIG story out there just now – and that if we’re unlucky, it may get a lot bigger.

I don’t think there’s much I can add to this subject.   If you are concerned about it, and who’s not, then you’ll be out there looking for breaking news.   I am to.

I wish all of us good luck on this one.

An introduction to global warming impacts: Hell and High Water

Tuesday, April 21st, 2009

– This is a great place to start if you want to get the big overview of Global Climate Change and its consequences.   And recall that this, as big as it is, is only a part of the bigger picture that I’ve been calling The Perfect Storm.

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In this post, I will examine the key impacts we face by 2100 if we stay anywhere near our current emissions path. I will focus primarily on:

  • Staggeringly high temperature rise, especially over land — some 15°F over much of the United States
  • Sea level rise of 5 feet, rising some 6 to 12 inches (or more) each decade thereafter
  • Dust Bowls over the U.S. SW and many other heavily populated regions around the globe
  • Massive species loss on land and sea — 50% or more of all life
  • Unexpected impacts — the fearsome “unknown unknowns”
  • More severe hurricanes — especially in the Gulf

Equally tragic, as a 2009 NOAA-led study found, these impacts be “largely irreversible for 1000 years.”

More… <== Please continue, this is well worth a good read!

Valley fever blowin’ on a hotter wind

Sunday, April 19th, 2009

– I pity the American Southwest where I grew up and where my older son and his family still remain.   It is squarely in the cross hairs of Global Climate Change and one only has to look at Australia to see what the future holds.   10+ million people living in the L.A. basin on what is, at bottom, simply coastal scrub desert that would barely be able to support a few tens of thousands without the massive influx of food and water delivered there daily from elsewhere.  This story about Valley Fever, is just one of many gathering force now for the Southwest.   Can you say, “Water”?

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PHOENIX – It’s high noon, and the 112-degree summer heat – up from a decade ago – stalks Arizona’s Sonoran Desert. By late afternoon, dark clouds threaten, and monsoon winds beat the earth into a mass of swirling sand. Thick walls of surface soil blind drivers on the Interstate.

Some health experts believe new weather conditions – hotter temperatures and more intense dust storms fueled by global warming – are creating a perfect storm for the transmission of coccidioidomycosis, also known as valley fever, a fungal disease endemic to the southwestern United States.

How do cocci spores infect the body? Propelled by winds, thousands of soil particles and cocci spherules are inhaled. People – particularly those older or immune-compromised – may experience flu-like symptoms that can turn into pneumonia. If the infection disseminates, the pathogens can target any organ – mostly the nervous system, skin, bones and joints – and become life threatening.

Each year, according to the American Academy of Microbiology, about 200,000 Americans contract valley fever, and 200 of them die. But some experts believe the disease is vastly underreported. Between 1991 and 1993, healthcare costs for valley fever exceeded $66 million, according to the Pan American Center for Human Ecology and Health.

The group Physicians for Social Responsibility says global warming will multiply the incidence due to increased airborne dust and sandstorms. Higher wind speeds and drought upped Arizona’s yearly count from 33 cases of valley fever per 100,000 in 1998 to 43 per 100,000 in 2001, said Dale Griffin of the U.S. Geological Survey in St. Petersburg, Fla.

The number of cases in Arizona more than quadrupled from 1997 to 2006, according to a Mayo Clinic study. During that same period, incidence rates in California jumped from 2.5 to 8.4 cases per 100,000 people.

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Our Sick Farms, Our Infected Food

Sunday, April 5th, 2009

Yum - antibiotics in excess– One aspect of the world’s increasingly dire problems that one sees over and over again, is how special interest groups push their agendas to the top of the stack to the detriment of the whole.

– It is a short sightedness that happens over and over and over again.   And again, ‘No single raindrop thinks that it is responsible for the flood’.

– Here’s a story about American farms and how a decision that was for all of our benefits was pushed quietly aside by the Farm Lobby.

– Their profits will hold up a bit better over the next few years because of their actions, but all of us will suffer badly in the long run.

– When we do this sort of thing to ourselves over and over again, how can anyone have any real hope that we’re suddenly going to wake up and save ourselves collectively from the impending global environmental and climatic crises?

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Congress and the FDA must upend the nation’s agricultural policies to keep its food supply safe

Agriculture has fueled the eruption of human civilization. Efficiently raised, affordable crops and livestock feed our growing population, and hunger has largely been banished from the developed world as a result. Yet there are reasons to believe that we are beginning to lose control of our great agricultural machine. The security of our food supply is at risk in ways more noxious than anyone had feared.

The trouble starts with crops. Orange groves in Florida and California are falling to fast-moving blights with no known cure. Cavendish-variety bananas the global standard, each genetically identical to the next will almost certainly be wiped out by emerging infectious disease, just as the Cavendish’s predecessor was six decades ago. And as entomologists Diana Cox-Foster and Dennis vanEngelsdorp describe in “Saving the Honey bee,” on page 40, a mysterious affliction has ravaged honeybee colonies around the U.S., jeopardizing an agricultural system that is utterly dependent on farmed, traveling hives to pollinate vast swaths of monoculture. The ailment may be in part the result of the stresses imposed on hives by this uniquely modern system.

Plants and animals are not the only ones getting sick, however. New evidence indicates that our agricultural practices are leading directly to the spread of human disease.

Much has been made in recent years of MRSA, the antibiotic-resistant strain of Staphylococcus bacteria, and for good reason. In 2005, the most recent year for which figures are available, about 95,000 MRSA infections caused the deaths of nearly 19,000 Americans. The disease first incubated in hospitals the killer bacterium is an inevitable evolutionary response to the widespread use of antibiotics but has since found a home in locker rooms, prisons and child care facilities. Now the bacteria have spread to the farm.

Perhaps we should not be surprised. Modern factory farms keep so many animals in such a small space that the animals must be given low doses of antibiotics to shield them from the fetid conditions. The drug-resistant bacteria that emerge have now entered our food supply. The first study to investigate farm-bred MRSA in the U.S. amazingly, the Food and Drug Administration has shown little interest in testing the nation’s livestock for this disease recently found that 49 percent of pigs and 45 percent of pig workers in the survey harbored the bacteria. Unfortunately, these infections can spread. According to a report published in Emerging Infectious Diseases, MRSA from animals is now thought to be responsible for more than 20 percent of all human MRSA cases in the Netherlands.

In April 2008 a high-profile commission of scientists, farmers, doctors and veterinarians recommended that the FDA phase out the nontherapeutic use of antibiotics in farm animal production, to “preserve these drugs to treat sick animals, not healthy ones” in the words of former Kansas governor John Carlin, the commission’s chair. The FDA agreed and soon announced that it would ban the use of one widespread antibiotic except for strictly delineated medical purposes. But five days before the ban was set to take effect, the agency quietly reversed its position. Although no official reason was given, the opposition of the powerful farm lobby is widely thought to have played a role.

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Is China Making Its Bird-Flu Outbreak Worse?

Sunday, March 15th, 2009

– Scary stuff.  here’s a quote from within this story:

 Dr. Lo Wing-Lok, an adviser to the Hong Kong government on communicable diseases, said the mainland had not been forthright about the spread of bird flu in poultry. “There’s no doubt of an outbreak of bird flu in China, though the government hasn’t admitted it,” he told Bloomberg.

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One thing is certain about avian influenza: it’s deadly. All three people who contracted the H5N1 strain of the virus in China last year died. In the first six weeks of 2009, eight people have come down with bird flu, and five have died. Another thing is that while the disease has yet to go pandemic, as many doctors fear it could, it remains worrisomely persistent. Every year since 2003, about 100 people in Asia, the Middle East and Africa contract the disease. Last year, in a rare exception, the number dropped below 50.

But bird flu, it seems, is back. Last month’s five deaths — one of the highest tallies of bird-flu deaths China has ever recorded in a month — were in locations as far removed from one another as Beijing in the north, Xinjiang in the west, Guangxi in the south, Hunan in the center and Shandong in the east. “From a disease-control perspective, the increase in cases in China is notable, as is the wide geographic spread,” says Dr. Hans Troedsson, the World Health Organization’s representative in China. There is still no evidence that the virus has mutated to spread easily between humans, he says. But while such a nightmare scenario, which could set off a global flu pandemic that could kill millions, has shown no signs of being an immediate threat, serious concerns remain. “The fact that this is the highest number for a single month in China reminds us that the virus is entrenched and circulating in the environment,” Troedsson says. (See pictures of the resurgence of bird flu.)

On Feb. 10, authorities in the far-Western region of Xinjiang culled more than 13,000 chickens in the city of Hotan after 519 died in a bird-flu outbreak. But until this week, China had reported no widespread outbreaks of the virus among bird populations, prompting concerns among some public-health experts that mainland health and veterinary authorities could be missing — or even concealing — the spread of the disease through poultry and wild birds. Hong Kong, where the first human cases of H5N1 infection were found in 1997, reported finding a dozen birds with the deadly strain of the virus earlier this year — a strong indication that the virus is very likely present in adjacent Guangdong province. But so far, Guangdong has reported no bird cases. Equally unusual is that after such a busy month of infections in China, reports of human cases have gone silent. “It’s a surprise for me, since in January, the human cases, you have so many, but in February it suddenly stops,” says Dr. Guan Yi, a virologist from the University of Hong Kong. (Read “Is Hong Kong’s Bird-Flu Vaccine Failing?”)

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Fresh bird flu outbreak in India

Saturday, December 20th, 2008

Authorities in the eastern Indian state of West Bengal say they have identified the deadly H5N1 strain of bird flu in thousands of dead chickens.

Tests on poultry from two villages around Englishbazar town in the Maldah district have returned positive results, a health official said.

He “few thousand” birds in the area will be slaughtered, he said.

The H5N1 strain of bird flu is regarded as highly pathogenic and can also cause disease and death in humans.

Bird flu has returned to West Bengal after an outbreak in 14 districts of the state in January this year.

Separately, authorities in the north-eastern state of Assam say they have finished culling of more than 300,000 chickens and ducks to control the spread of bird flu in the state.

Poultry in seven districts in the state have turned up cases of bird flu.

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– Just go to the search box at the upper left and enter “Bird Flu” for more of the same.

China cull amid bird flu outbreak

Friday, December 19th, 2008

More than 370,000 chickens have been culled in China’s eastern province of Jiangsu after an outbreak of the H5N1 strain of bird flu, say officials.

The outbreak is thought to be the first in mainland China since June.

Meanwhile, a man has reportedly contracted the virus in Cambodia, while Taiwan is investigating suspected infection among birds.

The death of a teenage girl from H5N1 was announced in Egypt on Tuesday, and a bird cull is also under way in India.

More than 200 people in a dozen countries have died of the virus since it resurfaced in Asia in 2003, say global health authorities.

Experts fear that the virus could mutate into one that is easily transmissible from human to human.

Migrating birds blamed

China’s Ministry of Agriculture said it received notification that the H5N1 virus had been found in two areas of Jiangsu on Monday.

The usual precautions have been imposed: birds have been slaughtered in the surrounding area, farms quarantined and disinfected, and the transport of fowl banned.

But no information has been released about the scale of the outbreak – how many birds were found to be carrying the H5N1 strain of the virus and how many of them died.

Officials say they think migrating birds might have been the source of the disease.

They are currently testing samples of the virus to check it has not mutated into a form that would pose a risk to human health, reports the BBC’s Chris Hogg in Shanghai.

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