Epidemic Hazards / Diseases & Climate Change

Earth Watch Report – Friday August 31st, 2012

Epidemic Hazards / Diseases

‘Virtually Untreatable’ Tuberculosis Threat Rising, Study Finds

Makiko Kitamura and Adi Narayan

Aug. 30 (Bloomberg) — Almost half of tuberculosis patients who received prior treatment were resistant to a second-line drug, suggesting the deadly disease may become “virtually untreatable,” according to a new study.

Among 1,278 patients who were resistant to two or more first-line tuberculosis drugs in Estonia, Latvia, Peru, Philippines, Russia, South Africa, South Korea and Thailand, 43.7 percent showed resistance to at least one second-line drug, according to a study led by Tracy Dalton at the U.S. Centers for Disease Control and Prevention. The findings were published in the Lancet medical journal today.

About 1.4 million people died from TB, the second-deadliest infectious disease globally after AIDS, and 650,000 cases were multi-drug resistant in 2010, according to the World Health Organization. Rising infection rates prompted the U.K. to announce in May it will require pre-entry tuberculosis screening for migrants from 67 countries seeking to enter the country for more than 6 months.

“The global emergence of extensively drug-resistant tuberculosis heralds the advent of widespread, virtually untreatable tuberculosis,” the study authors said in the published paper.

Previous treatment with second-line drugs was the strongest risk factor for resistance to these drugs, the authors said.

Alcohol Abuse

The prevalence of drug resistance, which ranged from 33 percent in Thailand to 62 percent in Latvia, also correlates with how long second-line drugs have been available in each country.

South Korea and Russia had the longest histories of availability — more than 20 years — and the highest rates of resistance. In contrast, Thailand, Philippines and Peru, where second-line drugs were introduced 10 years ago or less, had the lowest resistance rates.

Unemployment, alcohol abuse and smoking were also associated with resistance to second-line injectable treatment across countries.

This is one of the few studies that have followed patients with the multi-drug-resistant form of TB for several years, Justin Denholm, an infectious disease epidemiologist at the Royal Melbourne Hospital, said in a phone interview.

Patients not taking their medicines properly is a major driver for resistance, said Denholm, who is studying TB transmission patterns in Australia’s Victoria state.

Individualized Treatment

The WHO’s current strategy for tackling TB is called Dots, short for “directly observed treatment, short course.” Under Dots, patients are required to show up at a clinic three times a week to be supervised when taking their medicine to be sure they complete the treatment.

“The reality is that this one-size-fits-all approach is a major part of what’s led to this drug resistance issue,” Denholm said. “I think individualized treatment is what we should be aiming for.”

Scientists are also researching new treatments. In a study published last month in the Lancet, researchers from Stellenbosch University in Cape Town said an experimental three- drug combination killed 99 percent of the bacteria within two weeks. As the combination doesn’t contain isoniazid or rifampicin, the two main medicines used against TB, it may also provide a much-needed weapon against drug-resistant strains, the researchers wrote.

China Survey

India and China, which have the world’s highest numbers of tuberculosis cases, weren’t included in Dalton’s study as they hadn’t begun pilot programs for increasing access to second-line drugs until after the study began.

In a 2007 national survey in China, 27 percent of multi- drug-resistant tuberculosis cases showed resistance to the antibiotic fluoroquinolone, according to the Lancet report. In India, a 2006 population-based survey in the western state of Gujarat reported fluoroquinolone resistance in 24 percent of cases.

The U.K. Border Agency this month began requiring TB screening for Indians applying for a settlement visa and will extend the rule to those obtaining a work visa from Sept. 10. The new requirement replaces screening at airports.

TB is at the highest level in 30 years in the U.K. In London, 84 percent of the 3,302 people infected in 2010 were foreign-born, according to the Health Protection Agency.

30.08.2012 Epidemic Hazard USA State of Colorado, [Cimarrona Campground, Archuleta County] Damage level Details

Epidemic Hazard in USA on Wednesday, 29 August, 2012 at 15:48 (03:48 PM) UTC.

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Updated: Thursday, 30 August, 2012 at 03:20 UTC
Description
A camper near Pagosa Springs has contracted bubonic plague. The Durango Herald reports that the person contracted the plague during a family outing in the Cimarrona Campground. The San Juan Basin Health Department did not give the victim’s age or gender. Warning signs are being posted in the campground, The Centers for Disease Control and Prevention reports an average of seven cases of plague each year across the country. Most human cases tend to occur in rural areas in the Southwest. Symptoms of plague begin two to six days after a person is bitten by an infected flea, rodent or cat. The plague can be successfully treated if diagnosed promptly.

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Climate Change

Thawing permafrost frees millions of tons of carbon: study

ICE WORLD

by Staff Writers
Paris (AFP)

A vast outcrop of the Arctic Siberian coast that had been frozen for tens of thousands of years is releasing huge carbon deposits as rising temperatures thaw parts of its coastline, a study warned Wednesday.

The carbon, a potential source of Earth-warming CO2, has lain frozen along the 7,000-kilometre (4,400-mile) northeast Siberian coastline since the last Ice Age.

But atmospheric warming and coastal erosion are gnawing at the icy seal, releasing about 40 million tonnes of carbon a year — 10 times more than previously thought, said a study in the journal Nature.

About two-thirds of the carbon escapes into the atmosphere as carbon dioxide (CO2) and the rest becomes trapped in higher layers of ocean sediment.

About half the carbon pool in soil globally is held in permafrost in the Arctic, a region that is experiencing twice the global average of climate warming, said the study led by researchers at Stockholm University.

Earlier this week, US scientists said the sea ice in the Arctic Ocean had melted to its smallest point ever.

The region covered by the Nature study, called Yedoma, is twice the size of Sweden but has been poorly researched because it is so remote.

The finding touches on a vicious circle, or positive feedback in climate parlance.

Under this, man-made warming caused by the burning of fossil fuels releases naturally-occurring stocks of CO2 that have been stored in permafrost since the last Ice Age, called the Pleistocene.

The released gases in turn add to global warming, which frees even more locked-up carbon, and so on.

“Thermal collapse and erosion of these carbon-rich Pleistocene coastline and seafloor deposits may accelerate the Arctic amplification of climate warming,” the paper warned.

The atmospheric leakage from Yedoma is equivalent to the annual emissions of around five million passenger cars, on the basis of average carbon output (five tonnes per year) of vehicles in the United States.

In a separate study also in Nature, researchers in Britain, the Netherlands and the United States used computer models to estimate there could be as much as four billion tonnes of methane under Antarctica’s icesheet.

Methane is 25 times more efficient at trapping solar heat than carbon dioxide.

Before it froze over, the region teemed with life whose organic remains became trapped in sediment later covered by ice sheets.

“Our modelling shows that over millions of years, microbes may have turned this old organic carbon into methane,” which could boost climate warming if released by icesheet collapse, the researchers said in a statement.

The collapse of the Antarctic icesheet is considered an extremely remote scenario by most climatologists, and some studies have suggested that parts of it could be thickening, due to localised increases in snowfall.

Related Links
Beyond the Ice Age

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