EID

Andy pointed out a couple of relevant studies in the latest Emerging Infectious Disease journal issue:

Predicting Hotspots for Influenza Virus Reassortment
The influenza pandemics of 1957 and 1968 were deadly; each killed about 1 million people. Both pandemics resulted from the mixing of genetic material of 2 types of closely related flu viruses, called reassortment. This occurs when both viruses infected the same host at the same time. This mixing produced a virus that was more lethal than either alone. This mixing could also happen again. Studies in mice have raised the possibility that mixing of the human seasonal flu virus and the bird flu virus could produce a novel virus that could spread rapidly and kill many people. To determine where such mixing is most likely to occur, researchers evaluated livestock densities and agricultural practices (looking for areas with human and bird flu viruses and high concentrations of pigs). They concluded that the areas at highest risk for a future flu pandemic are coastal and central China and the Nile Delta region of Egypt.

MRSA Infection Risk among HIV-infected Adults
Methicillin-resistant Staphylococcus aureus (MRSA) infections has emerged as an important public health problem. HIV-infected persons are at increased risk for infection and colonization (carrying the bacteria without signs of infection).  Because colonization increases risk for MRSA infection, prevention should be aimed at decreasing colonization. But where and how?  To learn where on the body these bacteria are most likely to colonize, researchers collected samples from HIV-infected patients and monitored these patients over time. Although the nose is consid­ered the primary reservoir of S. aureus, in this study the groin was also frequently colonized with MRSA, and those with groin colonization were more susceptible to developing active MRSA infection later. These data suggest that to prevent active MRSA infections, HIV-infected persons should maintain good general hygiene which includes groin hygiene and take steps to avoid potential MRSA exposures (e.g., by not sharing personal items that may become MRSA contaminated such as towels, bedding, and razors and by keeping cuts and scrapes clean and covered).

Untreatable

‘Totally drug-resistant’ tuberculosis spreads in South Africa as researchers warn global outbreak would be ‘untreatable’
The world is facing outbreaks of “totally drug-resistant” tuberculosis if explosions of the bacteria in South Africa and other poorer nations are not addressed, according to a new papers published in Emerging Infectious Diseases. At this point, researchers are working to determine how the bacteria gains its invincibility, and how to isolate it.

Like the situation in India the argument over whether the South African strains are 'extensively drug-resistant or 'totally' drug resistant is beside the point. Extensively drug resistant tuberculosis (XDR-TB) is already a big enough problem. Here are some statistics from an earlier post comparing different strains of TB.

Tuberculosis (TB)

• Cost of drug treatment: $10-$20
• Course of treatment: 6 months
• Side effects of treatment: generally minor but may include vomiting, nausea and loss of appetite.

Multi-drug-resistant Tuberculosis (MDR-TB)

• Cost of drug treatment: up to $5,000 - $20,000
• Course of treatment: 2 years
• Side effects of treatment: side-effects are more serious and include hepatitis, depression and hallucinations.

Extensively drug-resistant Tuberculosis (XDR-TB)

• Cost of drug treatment: cases have been dealt with individually - some have cost $500,000
• Course of treatment: as long as it takes, many patients die
• Side effects of treatment: severe, in South Africa many patients discontinued treatment stating that they would rather die.

Ask a lawyer

An interesting question in class today - can you sue the hospital if you get a hospital acquired infection?

Just googling any version of this query brings up a lot of similar questions and links suggesting this is a pretty popular question.

Lets ask a lawyer:

Can I sue a hospital if I contract MRSA while in the hospital?

Answer (from an Ohio 'MRSA lawyer' !):


In order to sue a medical provider in Ohio and in many other states, you have to show that the hospital or medical facility had a duty to keep you safe, was negligent in that their treatment standard of care fell below that of an ordinary hospital in the area, and that as a result of their negligent and careless acts, you contracted MRSA or did not get treated quickly or effectively with negative consequences.

As any competent MRSA lawyer / attorney will tell you, if you want to sue a hospital or medical provider after you contract MRSA, you have to basically show they did something wrong that led to you contracting MRSA or not get treated correctly for MRSA.  As you can see these cases depend on the specific facts of each case. This breaks down to basically several theories of negligence? I will discuss four of them here.

Negligence / Failure to protect you from danger of catching MRSA
Delay in diagnosing MRSA
Delay in treatment of MRSA
Using wrong drugs to treat MRSA

So the key issue is negligence which can be difficult, but not impossible, to prove. Getting an infection and proving it came from the hospital is not sufficient. You need to prove the hospital was, in some way, negligent. The fact that some individuals have won big settlements has attracted a swarm of lawyers who are eager for cases. (I found this on one site: 'hospital infections are said to be the next asbestos'. The good news is that this may lead hospitals to improve their practices. The bad news is that it will further drive up medical costs.

Antibiotic-Resistant Bacteria in meat

The title of this post at Wired's Superbug blog says it all:

Antibiotics and Antibiotic-Resistant Bacteria in Meat: Not Getting Better

The Pew Campaign on Human Health and Industrial Farming (of the Pew Charitable Trusts) has been tracking this data year to year, and this year retrieved some additional data from the human side of the pharma industry to use as a comparison. They found that human-use antibiotics totaled 3.5 million kilograms, or 7.7 million pounds, in 2011.

It’s worth noting that this continued antibiotic use, and continued and rising appearance of resistant bacteria on meat, is happening as the FDA has abandoned attempting to regulate livestock producers’ use of antibiotics, and has switched to a voluntary approach. Given the trend, I think it’s worth asking how well that voluntary approach is going to work.

New antibiotics

A recent Op-Ed in the New York Times addressed the topic of antibiotic resistance and why drug companies aren't developing new antibiotics.
Let’s Gang Up on Killer Bugs.

What makes the rapid loss of antibiotics to drug resistance particularly alarming is that we are failing to make new ones. We are emptying our medicine chest of the most important class of medicines we ever had. 

One of the big problems is the economics of drug development today.

Historically, the drug industry thrived on antibiotics. But if an antibiotic is useful against only one type of bacterium, relatively few people need it during its patent life. And if an antibiotic is “broad spectrum,” meaning it works on many different types of bacteria, wider use shortens its commercial life because it quickens the pace at which bacteria develop resistance. Moreover, antibiotics are designed to cure an acute disease — not to palliate a chronic one — so people need them only for a limited time. Compared with drugs that are used for years to treat widespread conditions like high cholesterol or asthma, antibiotics pale as a corporate investment.

The article contains some suggestions for a better way forward from collaborative drug research to a different economic model.

There are, however, other ways for drug makers to profit beyond using monopoly to protect prices. As Thomas Pogge of Yale and Aidan Hollis of the University of Calgary have pointed out, an intergovernmental fund for drug discovery could reward drug makers for products in proportion to their impact in reducing the loss of healthy years of life. The lower the cost of a lifesaving drug, the greater the number of people who could use it; the more lives protected, then, the greater the monetary reward. An investment of $20 billion a year could encourage more open-lab collaborations to find new medicines in challenging settings like antibiotic discovery and make them accessible to all who need them.

What's in a name?

This time last year I reported on news from India  that a new, even more resistant, strain of Tuberculosis had been isolated and that the name TDR-TB (totally drug resistant TB) was being used. Even at the time the Indian Government was disputing whether the strain is totally or merely 'extensively' drug resistant.

A year later the debate rumbles on. The World Health Organisation (WHO) does not approve of the term TDR or Totally Drug Resistant tuberculosis and the term XXDR or Extra Extensively Drug Resistant Tuberculosis is being used in some places.

The WHO has a fairly extensive explanation of why they don't consider a strain of Tuberculosis that is resistant to all known antibiotics in use to be totally drug resistant. Their arguments seem very weak:

1) A strain of TB that shows itself to be totally resistant to antibiotics in lab tests may in fact be susceptible to  them in the human body.

2) New drugs are under development, and their effectiveness against these “totally drug resistant” strains has not yet been reported.

Sampling the antibiotic resistome

Remember the soil bacteria Streptomyces I mentioned as being the source of several of our antibiotics? You will probably not be surprised to find that this bacteria is also the source of resistance genes. A paper from the end of 2006 shocked many people though when it was discovered just how many antibioticsStreptomyces was resistant to.

In the paper, they isolated 480 different strains of the bacteria from soil samples and then exposed them to 21 different antibiotics to see if they could survive. The average strain was resistant to between seven and eight antibiotics and two particularly hardy ones were resistant to 15 drugs. The danger is that these genes will pass from harmless soil bacteria such as Streptomyces into more deadly bacteria. This is known to happen, for example the genes that allow some harmful bacteria to resist vancomycin, one of the last lines of antibiotic defense, originally came from soil-dwelling bacteria.

"The chances that these genes will end up in a disease-causing organism at some future point is high," microbiologist Abigail Salyers, University of Illinois at Urbana-Champaign.

MRSA day

On Tuesday it was announced that October 2nd will be the Fourth Annual World MRSA Day(and October is  World MRSA Awareness Month)  and the theme this year is 'The MRSA Epidemic – A Call to Action'.

This event is organized annually by the MRSA Survivors Network and there's a lot of useful information at their website.

MRSA Survivors Network was founded in early 2003. MSN was the first consumer organization in the U.S. to raise the alarm concerning the MRSA epidemic and other multi-drug resistant healthcare-acquired infections. MSN has been the key catalyst for change on an international and national front with its groundbreaking crusade and mission to stop MRSA deaths and infections. MSN partners with healthcare professionals, healthcare companies and consumer organizations.

MRSA news

The good news is that MRSA rates in hospitals and in the community have declined in a recent survey. The authors suggest that a change in hospital reporting laws may have provoked the decrease.

Trends in Invasive Infection with Methicillin-Resistant Staphylococcus aureus,Connecticut, USA, 2001–2010
We examined trends in incidence of methicillin-resistant Staphylococcus aureus (MRSA) infections in Connecticut, with emphasis on 2007–2010, after legislation required reporting of hospital infections. A case was defined as isolation of MRSA from normally sterile body sites, classified after medical record review as hospital onset (HO), community onset, health care–associated community onset (HACO), or community-associated (CA). Blood isolates collected during 2005–2010 were typed and categorized as community- or health care–related strains. During 2001–2010, a total of 8,758 cases were reported (58% HACO, 31% HO, and 11% CA), and MRSA incidence decreased (p<0.05) for HACO and HO, but increased for CA. Significant 3- to 4-year period trends were decreases in all MRSA (–18.8%), HACO (–12.8%), HO (–33.2%), and CA (–12.7%) infections during 2007–2010, and an increase in CA infections during 2004–2006. Decreases in health care–related isolates accounted for all reductions. Hospital infections reporting may have catalyzed the decreases. 

Latest 'superbug' - NDM-1

Here's a nice example of how I hope this class can help you understand the science behind the headlines a little better.

If you read the news you may have come across references to the latest 'superbug' NDM-1. But this is misleading, and confusing, because NDM-1 is actually just the name of an enzyme (New Delhi metallo-beta-lactamase-1). Several problematic bacteria have now acquired the ability to manufacture this enzyme (and you now know how they probably acquired this ability - especially if I tell you it is often carried on a plasmid).

Why is this enzyme important? Because it can break down beta-lactam antibiotics called Carbapenems that were developed to be more resistant to the beta-lactamase enzymes that many bacteria now have. Carbepenem antibiotics are extremely powerful and often used to fight highly resistant bacteria when other antibiotics have failed.

Bacteria that can produce NDM-1 are sometimes referred to as superbugs because infections caused by them are difficult to treat but NDM-1 is the name of the enzyme, not a specific bacteria.

For more information see: NDM-1 — A Cause for Worldwide Concern in the New England Journal of Medicine.

Pigs on pills

Agricultural use of antibiotics for growth promotion is back in the news this week because of a paper published in PNAS this week: In-feed antibiotic effects on the swine intestinal microbiome
This comes hot on the heels of the failure of the FDA to take a harder line against big business on the topic. In fact the Atlantic has an article on this subject today: The Rise of Antibiotic Resistance: Consequences of FDA's Inaction
By allowing big food to self-regulate when it comes to using antibiotics as a growth promoter in animals, the FDA is setting us up for disaster.

Bad news everyone..

 Hitting the news today is a report on a new strain of gonorrhea that is resistant to all available antibiotics.

Here's a link to the MSNBC article quoted below, but you can find hundreds of news reports on the story via google news.

For several years, public health officials have been concerned that gonorrhea, one of the most prevalent STDs in the world, might become resistant to the last widely available antibiotics used to treat it, a class of drugs called cephalosporins.  


Now, it has.

In the space of one week, infectious disease specialists have received a one-two punch of bad news that confirms those fears, including the discovery of a new, cephalosporin-resistant strain of the bacteria.

The Rise of Superbugs

From an article in The Atlantic last week. Well worth a read:

The Rise of 'Superbugs': Time to End a Decades-Long Problem By Frances Beinecke
We've known since the mid-'70s that feeding animals antibiotics is dangerous—but we haven't changed our ways

All 27 EU nations have already successfully stopped using antibiotics for growth promotion. Denmark, the world's largest pork exporter, ended the practice over a decade ago, and industry data have shown a sustained decrease in overall antibiotic use and the amount of drug-resistant bacteria found in livestock and meat products. At the same time, livestock production has grown and prices have remained stable.

The American National Academy of Sciences estimated in 1999 that if we were to take similar steps in the U.S. to eliminate all non-therapeutic use of antibiotics in livestock, it would cost grocery shoppers less than $10 annually. That's less than $13.50 per year in today's dollars. 

Making a difference

Antiobiotic resistance is a real and growing problem. If you were wondering what you could do about it individually then the CDC is happy to help with information and suggestions.

I think one of the problems is that although we should minimize inappropriate antibiotic use, in cases where it is appropriate then you should finish your prescription as indicated by the doctor. Taking fewer pills, even with the best of intentions, does not help and, in fact, is likely to make both you, and the problem, worse.

The CDC site also has information for doctors and the title of their video indicates one of the problems doctors face:
CDC Commentary: Don't Give In and Give Those Antibiotics!   Tips on how to communicate with patients about appropriate antibiotic use for upper respiratory infections.

Super Bacteria Survive Without Genetic Resistance

It turns out that genetic resistance is not the only way that bacteria are able to survive antibiotics, according to a new study by The Journal of Medical Microbiology. So called, "Persister Cells" are created in very low numbers, but have an exceptional ability to survive in the presence of all common antibiotics, without having developed a genetic resistance.

When small quantities of these persistent cells remains after antibiotic treatment has taken care of most bacteria, the infection still has a chance of coming back. Studies have even shown that the amount of persister cells shows a relationship to the presence of antibiotics. n one study, the amount of persister cells created was lower when the bacteria showed a resistance to the present antibiotics.

This may suggest that the production of persistent cells is another method of survival for bacteria, acting as a Noahs's Arc for the infection to survive even when most of the bacteria is destroyed by antibiotics. Scientist hope to develop a new form of infection treatment which combines antibiotics with other drugs to combat regular, and persistent bacteria all at once.

Unfortunately, not enough research has been done and the mechanism for bacterial persistence is still unknown. If researchers are able to break the secret of persistence and develop a treatment to counter it, it could mean a great increase in the frequency with which active infections are completely eradicated.

http://www.sciencedaily.com/releases/2011/01/110105194838.htm

The antiotic resistance

Although we will generally proceed forward in this course at a steady pace, covering a new disease and topic each week, there are some topics that overlap. For example in week 6 we will discuss nosocomial, or hospital acquired, infections. As we will see then the problem is made much worse by the problem of antibiotic resistance. This cartoon is correct - the best place to find antibiotic resistant strains of bacteria is in hospitals.

This little piggy

You will find a LOT of information on the web about antibiotics and, especially, antibiotic resistance. A lot of people are increasingly concerned about this topic and websites such as SaveAntibiotics.org and KeepAntibioticsWorking.com contain a lot of useful information, videos and links.

Currently the hot topic is pending changes that would restrict the use of antibiotics in the meat industry to when animals are actually sick.
eg New York Times article from last October: Meat industry unhappy over limiting the use of antibiotics
For decades, factory farms have used antibiotics even in healthy animals to promote faster growth and prevent diseases that could sicken livestock held in confined quarters.
The benefit: cheaper, more plentiful meat for consumers.
But a firestorm has erupted over a federal proposal recommending antibiotics only when animals are actually sick.

Better late than never....

Mon Jun 28, 2010 from Reuters: FDA recommends new limits on livestock drugs:

To prevent development of drug-resistant bacteria that could infect people, the U.S. Food and Drug Administration recommended on Monday that livestock farmers use the drugs solely to cure or prevent disease in animals, phasing out their use to promote growth.

FDA said research showed mixing antibiotics in livestock rations or feedlot water supplies "is not in the interest of protecting or promoting public health." Over-the-counter antibiotics have been routinely used for decades to promote livestock growth and feed efficiency.

Emergence of antibiotic-resistant bacteria poses a serious public health threat, said FDA, so it is looking for ways to reduce overuse of the drugs.

Antibiotics including penicillin and tetracyclines should be used only under the supervision of veterinarians to prevent or treat illness in livestock, FDA said in its 19-page draft.

FDA made its recommendations in a first-round version of a "guidance" document, which represents the agency's current thinking on an issue. Guidance does not carry the weight of law but generally is adopted by industry.

Gram-negative infections

Deborah sent me this link to a New York Times article from last week Rising Threat of Infections Unfazed by Antibiotics .

The article describes the problems caused by the rising prevalence of some gram-negative infections like Acinetobacter.

Doctors treating resistant strains of Gram-negative bacteria are often forced to rely on two similar antibiotics developed in the 1940s — colistin and polymyxin B. These drugs were largely abandoned decades ago because they can cause kidney and nerve damage, but because they have not been used much, bacteria have not had much chance to evolve resistance to them yet.

“You don’t really have much choice,” said Dr. Azza Elemam, an infectious-disease specialist in Louisville, Ky. “If a person has a life-threatening infection, you have to take a risk of causing damage to the kidney.”

Animal antibiotic use

Over the last two nights Katie Couric on CBS News had a two part series on the use of antibiotics on farm animals. You can watch the videos here or read the transcripts.

Part 1: Animal Antibiotics a Threat? (video) and transcript
Public health officials are worried that the widespread use of antibiotics on healthy animals may be putting people at risk. Katie Couric investigates this potential health threat.

Part 2: Antibiotic-free animals (video) and transcript
American farmers use more growth-promoting-antibiotics than any other place in the world. Katie Couric reports on a possible alternative in Denmark, which bans antibiotic use in livestock.