Major disease outbreaks around world becoming more common

[Al-khiyal]

Major disease outbreaks around world becoming more common

February 21, 2008 -- Major outbreaks of disease have become more common around the globe in the past 40 years, according to the largest ever investigation into emerging infections.

Diseases such as Ebola and Sars, which originally spread from animals, are an increasing threat to human health, and many infections have now become resistant to antibiotics, researchers said.

The international team of scientists warned that tropical regions are likely to become a future hotspot for new diseases, and called for early warning systems to be set up in countries to spot outbreaks before they become unmanageable.

Researchers from the Zoological Society of London, the Wildlife Trust and Columbia University analysed databases of outbreaks and found 335 cases of emerging diseases between 1940 and 2004. Of these, 60.3% were infections which also affected animals, and 71.8% were known to have triggered disease in humans after spreading from wildlife.

The research, published in Nature, identifies "hotspots" where new diseases are expected to come from wildlife, driven by the proximity of dense human populations and high levels of biodiversity.

The global pattern of diseases was closely linked to regions with high rainfall and biodiversity, alongside rapid growth in the human population. Europe and North America have experienced high numbers of outbreaks, but much of that is because those regions have invested heavily in detecting early signs of disease. Other countries, scientists fear, are less able to spot new diseases as they arise.

More diseases emerged in the 1980s than any other decade, according to the study. This was likely to be because of the emergence of HIV, which put vast numbers of people at risk of contracting other diseases. The great majority of outbreaks were triggered by bacteria and viruses, with 20% caused by antibiotic-resistant microbes.

Dr Kate Jones, of the zoological society, said areas of rich biodiversity harboured pools of pathogens, which were readily able to spread. "Humans are impacting on these areas and developing them, coming into contact with wildlife through bushmeat, farming, domestication of animals. We're increasing our human impact on these areas and exposing ourselves to potential pathogens."

Preserving wildlife-rich areas could help to protect people from new diseases, in the same way that conservation ensures cleaner water supplies and helps soak up carbon emissions.

[Al-khiyal]

WHO says frontal assault needed as drug-resistant TB cases rise

February 26, 2008 -- Rates of drug resistant tuberculosis continue to rise, reaching alarming levels in parts of the former Soviet Union, according to a new World Health Organization report released Tuesday.

Worrisome spread of multi-drug resistant tuberculosis and extensively drug resistant TB is also occurring in other parts of the world - notably China and parts of Africa, said the report, the first estimate of the scope of drug-resistant TB issued by the WHO since 2004.

The Geneva-based agency's head of TB control suggested that if aggressive action isn't taken, drug resistant strains could become the dominant circulating strains of the bacteria - a nightmare situation which would make it harder and harder to treat a bug one-third of the people on the planet are believed to carry in active or latent form.

"If we don't act now, we're going really to risk a disaster of enormous proportion here," Dr. Mario Raviglione, director of the WHO's Stop TB program, said from Washington.

With a growing proportion of new multi-drug resistant cases occurring in people who have never before taken TB drugs, it is clear that drug resistant strains are able to compete with non-resistant bacteria in nature.

At one point it had been thought that TB bacilli that were drug resistant would be wimpier - less fit in the words of science - than regular viruses and would be less likely to spread from person to person.

But the report showed that 22 per cent of multi-drug resistant cases in Baku, Azerbaijan were in newly diagnosed people. And 19.4 per cent of MDR TB cases in Moldova were new cases.

"You don't want drug resistant strains to become the dominant latent strains," warned Dr. Ross Upshur, director of the University of Toronto's Joint Centre for Bioethics. Upshur, who was not involved in the writing of the WHO report, has been following closely the emergence of MDR and extensively drug resistant or XDR TB.

"This is a global health disaster in the making," said Upshur. "It's not looking good.... And we have only worse to come if we don't take concerted collective action."

Raviglione said the concern is real, noting mathematical modelling done by the WHO suggests these difficult-to-treat strains could in theory take over. "That's not impossible. It's mathematically at least possible."

He said averting that situation may be possible, noting that Estonia and Latvia - hotspots of drug resistant TB a decade ago - have succeeded in driving down rates through aggressive action. But those countries had MDR TB rates in the range of about 10 per cent.

"When you have levels of around nine, 10 per cent I think things are addressable and we can actually get it down. And the Baltics show that this is possible," Raviglione said.

"When you have levels of 20, 22 per cent ... if this is not frontally addressed, if it is not taken extremely seriously with the investment of the necessary resources and the human resources . . . then we might be in a very troublesome situation."

The WHO estimates US$4.8 billion is needed to fight TB in low and middle income countries this year, US$1billion of which would be needed for MDR TB and XDR TB control alone. But the agency has raised only about half of what it needs for the job.

The report, the fourth from the WHO on this issue, is based on data from 81 countries covering the years 2002 to 2006.

It estimates nearly half a million new cases of multi-drug resistant tuberculosis are arising each year, and 110,000 people a year are dying from this form of TB.

Some of these cases are triggered by failure of infected people to follow the long course of antibiotic treatment properly or fully. In other cases, the newly infected person contracted a drug-resistant strain of the bacterium.

The report estimates 40,000 new cases of the highly worrisome XDR TB - a type which is virtually untreatable in parts of the world without sophisticated medical care - are developing each year.

The report does not offer an estimate of the number of deaths annually that are attributable to XDR TB, saying too little is known yet about this type of TB. But it said 45 countries worldwide have reported at least one case of XDR TB.

Canada has recorded two cases of extensively drug resistant tuberculosis, according to statistics from the Public Health Agency of Canada. One was in 2003 while the other is currently in Toronto's West Park Hospital receiving treatment.

The Public Health Agency estimates about 15 to 25 people a year in this country test positive for multi-drug resistant TB.

India and China account for about 50 per cent of drug-resistant TB cases, the report said, but countries in the former Soviet Bloc are also registering staggering rates of infections in outbreaks fuelled by overcrowded prisons.

Upshur called the statistics on infection rates in these countries "evidence of an unfolding cataclysm."

In Baku, 56 per cent of cases were resistant to at least one TB drug.

The report acknowledges that the true scale of the problem remains unknown. Much of Africa, for instance, cannot do the testing to look for cases of drug-resistant TB. Data from only six African countries were included in the report.

Given the tragic synergy of drug-resistant TB and HIV-AIDS, people concerned about this issue wait with dread to learn what might be lurking in sub-Saharan Africa in the countries known as the "HIV belt."

Upshur said the world needs to address the problem of drug resistant tuberculosis while it can.

"What we've seen is a stable growth of MDR. And with it, on its tail we'll see a stable growth of XDR. And what we don't want to see five years from now is the emergence of complete drug resistance."

[amalgamate]

yalateef

[Bent_Bladi]

exactly... ya lateef...

Those are some pretty nasty diseases... death by the most painful abnormal way ever.

I remember when I was in middle school- one of our morbid science teachers showed us a disturbing documentary about an ebola outbreak that happened a while ago. Putting aside the creepy background music and the narrators deep solemn voice - the stuff I learned that day scared the living daylights out of me... A3uthu billah from such a disease - I swear I couldn't sleep for a week straight after that.... kept thinking that I had it

[Cheba_Mami]

Yes true, but pharma companies are trying to make medicine in some ranges in advance so that there are still antibiotics in case needed..

i know it sounds weird, and let's hope it will work.

[Al-khiyal]

WHO says frontal assault needed as drug-resistant TB cases rise

L'essor de la tuberculose pharmacorésistante

[Al-khiyal]

Epidemics: Scientists to hunt down new viruses before they strike

June 15, 2008 -- Scientists are preparing to hunt down the planet's last remaining viruses capable of triggering new diseases in humans. Several hundred new varieties may still be lurking in the wild or in remote populations, it is believed.

In recent years, deadly outbreaks of diseases such as Sars and Ebola have caused major health scares and officials are anxious to use modern gene-hunting technology to pinpoint pathogens before they can get a chance to spread through populations.

Among those backing the project is the company behind web search engine Google, which has launched a 'predict and prevent' programme aimed at setting up a network for forecasting emerging threats 'before they become local, regional, or global crises'.

'Some of these viruses have very limited impact but others can trigger pandemics,' said Dr Mark Woolhouse, of Edinburgh University's centre for infectious diseases. 'The purpose of this initiative is to identify viruses before they get a chance to spread among humans.' Woolhouse has been invited to work with the US National Academy of Sciences, which will hold a meeting next week aimed at drawing up plans to tackle the problem of emerging diseases.

'We are in the middle of a revolution in gene technology,' said Woolhouse. 'For the first time, we have the means to trace any pathogen that has infected a human or is capable of infecting a person.'

In recent years, biologists have developed chips that can identify every known human virus from blood or tissue samples and have designed machines that can unravel the genetic make-up of new organisms in minutes. As part of the virus-hunting programme, scientists would study remote populations and test individuals to detect previously unknown viruses in their blood. Other researchers would study animals in order to test if any carry viruses capable of infecting humans.

'Viruses infect men and women if they carry pieces of protein capable of unlocking receptors on the surfaces of human cells,' added Woolhouse. 'Testing animal viruses to see if they have protein sections that could easily mutate and open up our receptors would be one priority for the project.'

In a recent Royal Society paper, a team led by Woolhouse calculated that since 1960 an average of two to three new viruses affecting humans have been discovered every year. Most are transmitted to humans from other mammals. A smaller but significant number come from birds and wildfowl.

Recent examples include the 2002 outbreak of Sars virus, which killed hundreds of people, the Ebola virus - linked to fruit bats - which has caused several disease outbreaks since 1976, and the Sin Nombre virus, linked to the deer mouse, which caused deaths in the US in 1993.

As roads are built across Africa and South America, more people are encountering animals with which mankind has had little previous contact. In addition, pets have been linked to disease outbreaks, such as the Gambian pouched rat that was blamed for an outbreak of monkeypox in the US in 2003.

In other cases, changes in farming practices have triggered unexpected outbreaks. In Malaysia in 1999, more than 100 people died of a form of encephalitis that was traced to the Nipah virus. This outbreak was attributed to a decision by pig farmers to plant fruit trees on their land to boost income. Fruit bats, which were subsequently found to carry Nipah, came to the trees for food, dropped excrement on pigs below and the disease was then transmitted to humans.

However, the worst known outbreak caused by such viruses - known as zoonotic organisms - is the HIV/Aids epidemic. Tens of millions of people could die of the illness, which scientists believe was caused by a disease in chimps that was passed to humans in Cameroon in the Thirties. Pinpointing another HIV-like disease before it reaches humans is the key motivation for the new project.