Ten Blood Thinners Available On The Market Today

By Michael Monheit

According to BloodThinnerHelp.com, millions of Americans are prescribed blood thinners every year to treat conditions such as clotting disorders and atrial fibrillation. These drugs are also frequently used after knee and hip replacement surgery for the prevention of blood clots. Despite the number of prescriptions written on a daily basis, many are unaware of the potential risks that are associated with the use of blood thinners.

How Do Blood Thinners Work?

Despite the name “blood thinner”, these drugs don’t actually thin the blood. All blood thinners fall into two categories:

Anticoagulants

Drugs that fall into the anticoagulant category work to slow down the speed at which the body forms a blood clot by interrupting the chemical process in the blood which results in a clot. In order to form a clot, the body requires Vitamin K. Anticoagulants actually compete with the Vitamin K, taking its place in the clotting process and disrupting reactions which would normally follow the binding of the vitamin.

Antiplatelets

During the formation of a clot, platelets release thromboxane which acts like a signal to other platelets. This signal results in the platelets sticking together and forming a clot. Antiplatelets work to prevent the release of thromboxane.

The Most Commonly Prescribed Blood Thinners

Drug companies have teams of doctors and scientists who work every day to create new drugs so that doctors will have options when it comes to treating their patients. The most common blood thinners prescribed today include:

Warfarin

Warfarin, which is also known as Coumadin, was first approved for use as a rodenticide in the United States in 1952. It wasn’t until 1954 that the drug was approved for use as a human blood thinner. Reported side effects have included skin necrosis, hair loss, and fatal bleeding events.

Pradaxa

This drug, which falls into the category of antiplatelet, is one of the newer blood thinners on the market. Pradaxa was first approved by the U.S. Food and Drug Administration on October 19th, 2010 for the prevention of stroke and for the treatment of atrial fibrillation. On April 7th, 2014, the drug was also approved for the prevention of deep vein thrombosis (DVT) and pulmonary embolism.

Eliquis

Eliquis, which is also known by its generic name Apixaban, is another one of the newer blood thinners to hit the market. This drug was approved in 2012 for the prevention of stroke and systemic embolism in patients that have been diagnosed with atrial fibrillation. Doctors have reported that adverse bleeding events and spinal hematoma have occurred in patients who have been prescribed the drug.

Plavix

Plavix is an antiplatelet blood thinner. Side effects that have been reported with this drug include nosebleeds, blood in the stool, fever, chest pain, and nausea.

Prasugrel

Prasugrel, also known as Effient, is a platelet inhibitor which is used in combination with aspirin. It is not recommended for patients who are over 74-years-old due to the risk of fatal bleeding. Physicians generally recommend that anyone who is having surgery stop using Prasugrel at least seven days prior to the procedure.

Brilinta

Brilinta, another antiplatelet, is used to prevent strokes and heart attacks. This drug was just recently approved by the FDA on March 30th, 2015.

Cilostazol

This vasodilator is used for claudication - a cramping condition which is often associated with an obstruction of the arteries. Patients using this drug have reported an increase in headaches, swelling in the feet and ankles, fevers, bloody and painful urination, and chest pains.

Aggrenox

This drug, which is actually a combination of aspirin and dipyridamole, is typically prescribed to patients who have previously had a mini-stroke to prevent additional attacks.

Aspirin

Aspirin, which has been around since the 1890’s, is often used to reduce fevers and other pains. It was in the 1960’s that clinical research began to suggest that it could also be used as a blood thinner to prevent strokes and heart attacks.

Xarelto

Xarelto, which has been in the news recently due to the number of lawsuits filed against its manufacturers, is another new blood thinner. Approved in 2011 by the FDA, this blood thinner quickly became popular because the dose used to treat patients was the same for everyone regardless of age, weight, diet, and exercise level. Unfortunately, this drug has also been reported to have a number of serious side effects.

What Is Being Done For Those Who Have Suffered From Side Effects?

One of the most common and arguably most dangerous side effects of any blood thinner is excessive bleeding. Bleeds typically occur in the GI tract, spine, and brain. If the bleed remains uncontrolled, it can be fatal.

In most cases, doctors are able to administer a reversal agent which combats the effects of the blood thinner and allows the blood to form clots. Vitamin K is a reversal agent that is used in many cases. Some drugs, however, like Xarelto, have no known reversal agent and doctors are forced to perform blood transfusions. Sadly, these transfusions don’t work in every case.

This is why it is important to always discuss your lifestyle and any medications you are on with a doctor before beginning a blood thinner. This way, they can identify any risk factors and decide which drug will work best for you. It is also important to pay close attention to any warnings released by the FDA regarding the drug you have been prescribed, like those for the blood thinner Xarelto.

FDA Warnings For Xarelto

In order to provide additional safety information for patients and the medical community, the FDA has also released several warnings regarding Xarelto.

A black box warning was issued informing doctors that patients who discontinued the drug too quickly may suffer from clot formation, DVT, and spinal hematomas.

A second black box warning was issued in March of 2014, which informed the public and medical community that anyone who was scheduled to undergo a procedure involving the spine should wait until the drug was completely out of their system. 

An Adverse Reaction Report was released which informed users that Xarelto could cause thrombocytopenia.

Ongoing Litigation

Many patients who have suffered from side effects such as heart attacks, spinal hematoma, stroke, and excessive bleeding have decided to pursue legal action against the manufacturers of Plavix, Eliquis, and Xarelto. In cases where the patient passed away because of a side effect, their loved ones have pursued a wrongful death complaint.

The largest of these involves more than 5,000 lawsuits which have been filed against Bayer AG and Johnson & Johnson regarding the drug Xarelto. So many complaints have been filed that the Judicial Panel on Multidistrict Litigation decided to consolidate all federally-filed lawsuits into MDL 2592. This consolidation placed the lawsuits in the Eastern District of Louisiana to be overseen by the honorable Judge Eldon E. Fallon. In each of these cases, a plaintiff alleges that the drug Xarelto caused serious harm to a patient to whom it was prescribed.

Did The Manufacturers Conceal Data?

Additionally, a writer for the New York Times published an article which reported that Johnson & Johnson and Bayer Inc may have concealed specific data when their clinical studies were being reviewed by a peer reviewer at the New England Journal of Medicine. The information that was allegedly withheld involved the device used to monitor the blood levels of the patients involved in the clinical trial and the fact that it had been recalled for inaccurate readings.

Plaintiffs are hoping that the combination of their legal efforts and the reviews into how safety testing is done for new drugs will push pharmaceutical companies to change their testing methods. 

Zika - explained with new graphic

Emily Maynard has provided an interesting graphic on the Zika virus (via MPH online).

The graphic is displayed below:

Posted by Dr. Tim Sandle

Human Activity Affecting Microbes in Soil

New research from an Iowa State University ecologist shows that agricultural inputs such as nitrogen and phosphorous alter soil microbial communities, which may have unintended environmental consequences.

Adding nitrogen and phosphorous, commonly used as fertilizers, to the soil beneath grasslands shifts the natural communities of fungi, bacteria and microscopic organisms called archaea that live in the soil, said Kirsten Hofmockel, an associate professor in the ISU Department of Ecology, Evolution and Organismal Biology.

For instance, some soil microbes change the form of nitrogen in the soil. Ammonia-oxidizing archaea feed on ammonia and then convert it into nitrate. Hofmockel said the research shows that those ammonia oxidizers grow as more nitrogen is introduced, essentially because those organisms have access to more food. As a consequence, increasing amounts of nitrate may leach into waterways.

Generally, the researchers found nutrient additions favored fast-growing bacteria and decreased the abundance of fungi that share a symbiotic relationship with grassland plants.

For further details see: “Consistent responses of soil microbial communities to elevated nutrient inputs in grasslands across the globe.”



Posted by Dr. Tim Sandle

Women need More Truvada than Men to prevent HIV Infection

Women need daily doses of the antiviral medication Truvada to prevent HIV infection, while men only need two doses per week due to the way the drug accumulates in different body tissues, says a research. Truvada is the only drug approved by the FDA as a daily administration drug to help prevent the infection from spreading. It was approved in 2012, but the new findings show that one dose does not fit all.  

Read more 

Posted by Dr. Tim Sandle

Guideline on the sterilisation of the medicinal product

The European Medicines Agency has introduced a new draft guideline entitled "Guideline on the sterilisation of the medicinal product, active substance, excipient and primary container."  The document was issued in April 2016.

As the introduction to the document states: “Sterility is a critical quality attribute for all sterile products. Sterility of the medicinal product cannot be assured by testing; it needs to be assured by the use of a suitable and validated manufacturing process. Sterility is dependent on several factors such as the bioburden of the formulation components, the sterilisation procedure, the integrity of the container closure system, (abbreviated as container in this document), and in the case of aseptic processing, the use of satisfactory aseptic technique.”

The document looks at the following processes:

• Steam sterilisation
• Dry heat sterilisation
• Ionisation radiation sterilisation
• Gas sterilisation
• Sterile filtration
• Aseptic processing

The document can be found here.



Posted by Dr. Tim Sandle

Tuberculosis: the disease, its treatment and prevention

Public Health England has issued a new fact sheet, intended for a general audience, about tuberculosis.

TB (tuberculosis) is an infectious disease that usually affects the lungs, although it can affect almost any part of the body. TB is not easily caught – you have to be in fairly prolonged close contact with someone with TB (for example, living in the same household) – but everybody should be aware of the symptoms of the disease so they can seek treatment as soon as possible.

Mycobacterium tuberculosis (MTB) is transmitted from person to person, usually by mucous droplets i.e. cough, sneezes, laugh, sings or even breath. The size of particles are an estimated 1–5 mm, for prolonged time periods normal air currents can keep them airborne when it is inhales by a susceptible person these droplet nuclei traverse the mouth or nasal passages reach to the alveoli of the lungs. The infections depend on duration of exposure to infectious droplet nuclei and its concentration

This leaflet gives information on the disease tuberculosis (TB), how it can be treated, and its prevention, and it can be accessed here.



Posted by Dr. Tim Sandle

Cleaning and disinfection of cleanrooms (new edition)

A second, revised and expanded, edition of the CDC Handbook has been issued. The new edition contains revised information on biocidal products regulations, an expansion on the types of disinfectants and their validation requirements, and greater detail on contamination control.

The book is aimed at anyone working with cleanrooms in the pharmaceutical, healthcare or medical device sectors.

Contamination control is of great importance to healthcare facilities and to pharmaceutical cleanrooms. With healthcare, the more immediate concern is with protecting the patient from infection (infection prevention practices aim to eliminate the risk of the transmission of pathogens between patients and between patients and the health care worker). With pharmaceuticals the concern is with avoiding contamination of the product being prepared so that the product is safe for use. Both healthcare facilities (from hospital wards to pharmacy units) and pharmaceutical facilities share a number of similarities, from the importance of hand sanitization to the control of cleanrooms.

With cleaning and disinfection, there is often ambiguity about how such agents should be used including questions of ‘how often should I use this?’, ‘how do I dilute it?’, ‘how long do I leave it for?’ coupled with confusion over cleaning methods and techniques. “The Cleaning and Disinfection Handbook” addresses such issues.

The book is available from Amazon worldwide, such as:

Amazon   

Amazon U.K. 

The book is available in print or e-book format.

The book’s editor and main contributor, Dr Sandle says: ‘The use of detergents and disinfectants is a critical part of the contamination control approach. There are a myriad of different agents, but not all are suitable for cleanrooms, hands or hospital wards. Also, there is a sometimes bewildering choice of different chemicals with different modes of action, many of which are incompatible with one another. There is often ambiguity about how such agents should be used including questions of 'how often should I use this?', 'how do I dilute it?', 'how long do I leave it on for?' coupled with confusion over cleaning methods and techniques. In relation to these issues it became clear that there was no handbook which addressed these issues for those concerned with keeping hospitals and cleanrooms clean. In light of this, the idea for this book - "The Cleaning and Disinfection Handbook" - was born.’

‘In putting this book together, some of the leading experts in the field of contamination control, working either in healthcare or the pharmaceutical industry, were approached. In agreeing to contribute to this book each person has written a high quality chapter and has helped to put together what is a unique book on cleaning and disinfection. The book is subtitled "a handbook" and this is the operative word that, as editor I would most like to see applied. This is not a book intended to sit on a shelf and gather dust, it is a book intended to be read and discussed by those with the very important task of keeping cleanrooms, hospitals and the hands of staff, clean. If "The CDC Handbook" becomes an established part of the educational resources available to the workforce who aim to keep critical areas clean, then the aims and intentions which shaped this book will have been a success.’

Posted by Dr. Tim Sandle

Carbon Dioxide Dependent Microorganisms

When growing microorganisms, several conditions including incubation time, temperature, pH, adequate moisture and sufficient nutrients (such as carbon and nitrogen) must be considered to ensure successful results.

Microbiologics have an interesting paper on those organisms that require a carbon dioxide rich atmosphere and the paper provides tips for cultivating these organisms using chocolate agar.

To access the paper, see Microbiologics

Posted by Dr. Tim Sandle

Neisseria gonorrhoeae: Combating a Multidrug-Resistant Organism

Microbiologics have an interesting white paper on Neisseria gonorrhoeae.

Here is an extract:

Gonorrhea is a globally prevalent infection caused by N. gonorrhoeae, a Gram-negative bacterium. According to CDC, approximately 820,000 new gonorrheal infections occur in the U.S. annually. However, recent statistics show fewer than half of the new infections are usually reported to the organization likely because many cases of gonorrhea are symptom-free. In 2014, 350,000 gonorrhea cases were reported to CDC. Between 2010 and 2014, the rate of gonorrhea infections in men was particularly alarming with an increase of 27.9%. During the same time, the rate of infection in women decreased 4.1%.

Although most women with gonorrhea do not have any symptoms, the STD can be especially harmful to women if the infection spreads to the uterus and fallopian tubes increasing the risk of pelvic inflammatory disease (PID) and infertility. If a pregnant woman has gonorrhea she can give the infection to the baby during childbirth.

The paper can be accessed here.

Posted by Dr. Tim Sandle

Acinetobacter spp. bacteraemia

Public Health England has published data relating to resistance to more than one antibiotic among Acinetobacter baumannii and A. lwoffii bacteraemia.

The key points are:

the incidence rate of Acinetobacter spp. bacteraemia has decreased over the eight year period from 2008 to 2015 the country with the highest incidence rate in 2015 was Northern Ireland (1.6 per 100,000 population) within England, the English region with the highest incidence rate was Greater Manchester (1.8 per 100,000 population), while Anglia and Essex had the lowest (1.0/100,000);

Infants have the highest rate of Acinetobacter spp. infection (8.2 per 100,000 population);

Individuals aged 75 years and over also having a relatively high rate (3.7 per 100,000 population), variation is noted by Acinetobacter species in 2015, 50% percent of neonatal Acinetobacter spp. bloodstream infections occurred in infants less than 7 days old (18/36) there were more Acinetobacter spp. reports for females than males with rates of 1.4 and 1.3 per 100,000 population respectively (432 and 381 reports respectively);

Organisms A. lwoffii and A. baumannii continue to be the most common species of Acinetobacter in 2015 from blood isolates (38% and 20% respectively), accounting for over half of all isolates the level of resistance to colistin has fallen to a five year low (2%);

However the proportion of Acinetobacter spp. bacteraemia tested for colistin susceptibility remains below 13% in England, Wales and Northern Ireland in 2015 resistance to a carbapenem (meropenem and/or imipenem) has decreased over the last 5 years a reduction in the proportion of resistant Acinetobacter spp bloodstream isolates was noted between 2011 and 2015 for each of the following antimicrobials: gentamicin, ciprofloxacin, tobramycin and amikacin of 42 isolates of A. baumanii (29) and A. Iwoffi (13) tested, there was no (0%) multidrug resistance to gentamicin, ciprofloxacin, carbapenem and colistin.

The full report can be read here.



 Posted by Dr. Tim Sandle

ISO 13485:2016 – new medical devices standard

ISO 13485 sets out the requirements for a quality management system specific to the medical devices industry. It has recently been revised to respond to the latest developments in quality management, technology and regulatory requirements that relate to the industry.

With the standard applicable to so many types of products, the revision was no easy task. A medical device is any product intended for use in the diagnosis, prevention and treatment of medical conditions. They range from simple products like wound dressings to dentist chairs, cardiac pacers, life-support machines and even in vitro diagnostic reagents.

Improvements in the new version of the standard include broadening its applicability to include all organizations involved in the life cycle of the product, from concept to end of life, greater alignment with regulatory requirements and a greater focus on post-market surveillance including complaint handling.

There is also a greater emphasis on having the appropriate infrastructure, particularly for the production of sterile medical devices, and more focus on risk management.

For more details, see: ISO.



 Posted by Dr. Tim Sandle

Microbiological safety of medicines discussed in Oxford

The safety of medicines is of great importance, needing to be of the required formulation and contamination free. Recently, in Oxford, U.K., pharmacists and microbiologists came together to review best practice.

The event, held on March 2 and 3, 2016, was hosted by the Pharmaceutical Microbiology Interest Group (Pharmig.) Day one of the event was more general, and it looked at the best strategies for ensuring the environments within which medicines are prepared and put into final containers is safe. The second day was more specific, assessing an important subject of avoiding bacterial and fungal spores entering into products. A unifying theme with the second day was the use of special, highly aggressive disinfectants called as "sporicides."

The two day meeting drew over 50 delegates, over 20 exhibitors and specialist speakers. The meeting was held in a new hotel — The Oxfordshire — which overlooks the sprawling delights of Oxfordshire, the epitome of the English countryside (Digital Journal has also reviewed the hotel and its facilities in a separate article.)

A view from The Oxfordshire hotel.

Tim Sandle

The first day, facilitated by the chair of Pharmig David Keen (from GlaxoSmithKline), began with a presentation from Tim Sandle (speaking in an independent capacity). Dr. Sandle compared the differences between U.S. and European guidances for assessing contamination in cleanrooms. A cleanroom is a specially designed, contained room, with filtered air (through a HEPA filter) and a high level of air-changes, so that any contamination is (in theory) removed from the room. The problem with cleanrooms arise when people are placed in them, for people continually shed skin detritus and some of these very small particles (on the micronmeter scale) act like rafts, carrying bacteria.

Pharmig's David Keen addresses the meeting.

Tim Sandle

The key difference between U.S. and European regulations, Dr. Sandle explained, is for the cleanest areas the U.S. approach is to count non-zero events and to react to adverse trends; whereas the European approach is to react to actual counts, and assess the individual impact of each.

The second presentation was from David Keen, which looked at a strategy for rolling out an environmental monitoring program. Of particular use was looking at where points of microbial contamination are likely to occur and ensuring samples are taken in these locations, rather than putting out agar plates away from where work is actually going on. This may seem like common sense, but Mr. Keen pointed out, from his experience of visiting different pharmaceutical manufacturing sites, there is a bewildering array of practices.

Conference delegates assemble in-between presentations, at The Oxfordshire Hotel, Oxford.

Tim Sandle

Dr. Sandle presented again for the third presentation. This looked at the best methods to capture both bacteria and fungi. This is not straightforward because the organisms — from two different microbial kingdoms — prefer growing on different media. The trick is to develop an incubation strategy, examining the factors of time and temperature. Dr. Sandle outlined a recent paper he had written, which recommended using a lower temperature first (20-25 degrees Celsius), which encourages fungal growth and does not kill bacteria, and then incubating at a higher temperature (30-35 degrees Celsius). The risk of not doing so could lead to a destruction of lytic cellular enzymes, which can kill some fungi.

Conference delegates discussing new technologies with exhibitors, at the Pharmig event.

Tim Sandle

The fourth presentation was delivered by pharmaceutical consultant Julie Roberts. This looked at how to identify microorganisms recovered from the environment and the differences between phenotypic technology (which looks at how an organism interacts with its environment) and genotypic methods, which look at the microbial genome. The presentation also discussed how many identifications should be performed in order to create a meaningful picture of the production environment.

Global audit specialist Julie Roberts discusses best practices for microbiological identification at the conference.

Tim Sandle

This was followed by a presentation by Erika Notman (a pharmaceutical sector consultant.) This presentation consider case studies for investigating high microbial counts and the sorts of things to look for, such as poor cleaning techniques or environmental control failure.

The final presentation from day one was delivered by Julie Roberts and this touched on the subject of data integrity. Readers of Digital Journal will be aware about this subject as it touches on either the mis-recording of data or even the falsification of data, designed to make a drug product appear safe when it is, in fact, adulterated.

At the end of the first day, delegates had the opportunity to walk the hotel grounds. Too late for a round of golf (for those interested in the small ball and stick sport); the views were nevertheless impressive.

The golf course at the conference venue - The Oxfordshire hotel.

Tim Sandle

The second day was orientated more towards the health sector and hospital pharmacy units. There were aspects, however, of interest to the pharmaceutical sector as well. The day was chaired by Tim Sizer, who is the Regional Pharmaceutical Quality Assurance Officer South West.

Tim Sizer, the Regional Pharmaceutical Quality Assurance Officer South West, chairs day two.

Tim Sandle

In preparation for the second day, folders ready, PowerPoint presentation loaded.

Tim Sandle

The aim was to provide an updated overview of the risks associated with bacterial and fungal spores within the aseptic preparation environment (where medicines intended to be sterile are formulated and filled.) The day also set out to review recent incidents causing harm to patients and to discuss new guidance, such as the Medicines and Healthcare products Regulatory Agency (MHRA) — the U.K. medicines regulator — new "Guidance to Specials Manufacturers."

The first presentation of the day was from Tim Sandle. Here Dr. Sandle provided an overview of spores, both bacterial and fungal, and explained why they are so resistant to common disinfectants. With bacteria, this is due to a three-layered spore coat, and the ability of some spores to stick together. For fungi, the problems are with the sheer number and the ability of some to secrete an enzyme that can inactivate disinfectants. While the use of a potent sporicidal disinfectant is important, the key message from the presentation was to focus on a good biocontamination control strategy.

A conference delegate peruses Pharmig literature, during a mid-session break.

Tim Sandle

The second presentation of the day was delivered by Tim Sizer. This ran through some of the more recent pharmaceutical and pharmacy contamination events. These included the infamous New England Compounding Center (NECC) issue, where contaminated vials of a steroid were distributed across the U.S. The case count is still being tallied up, and stands at almost 800 infected and over 70 deaths.

The third address was from Mark Oldcorne, who is the All Wales Quality Assurance Specialist Pharmacist. In this presentation the advantages gained in reducing contamination events from different types of disinfection were discussed. Data was presented showing sanitization by gassing to be the most effective, followed by the use of spraying and wiping or a sporicidal chemcial. Without wither of these two measures, other data indicated a low but ever present microbial contamination risk.

A key part of many conferences is the opportunity to discuss test kits and disinfectants with suppliers. The photograph shows delegates interacting with suppliers.

Tim Sandle

The fourth presentation was delivered by Rachel Blount, who is the Global Validation Manager of the company Ecolab. The presentation was designed to enable the user to interpret the methods adopted to validate disinfection efficacy. Here Rachel Blount explained the different international standards for testing disinfectants to show that they actually work.

The next presentation was again by Tim Sandle. In this second presentation, Dr. Sandle set out to consider the types of sproicidal agents available on the market and the limitations of their use. The choice of sporicides is quite narrow, once health and safety issues and ease of use have been considered. These are either chlorine based (such as chlorine dioxide, hypochlorus acid, chloramine, or hypochlorite) or oxidizers like peracetic acid or hydrogen peroxide. Dr. Sandle was keen to emphasize that the claims of manufacturers should not be taken at face-value and laboratory studies were needed to confirm biocide effectiveness.

The day also included a workshop, where delegates simulated disinfecting and transferring vials. Here there was a variety of different practices, indicating that a common standard was required. Based on this, the pharmacists present undertook to continue to develop best practice for the transfer disinfection process and potential alternatives.

Delegates undergoing a practical exercise to learn about good disinfection practices.

Tim Sandle

The practical including advice on how to disinfect the outer surfaces of vials, used to store medicine, correctly.

A pharmacy technician learns the correct procedure for disinfecting a vial of medicine.

Tim Sandle

There was also an opportunity learn about spraying disinfectants, with a view to getting the right quantity onto a wipe.

A delegate practices the application of a disinfectant onto a cleaning cloth.

Tim Sandle

The final presentation was from Mark Oldcorne, which considered some best practices from aseptic processing, focusing on materials being transferred into and out of controlled environments.

The two day Pharmig event was well organized and helped to reinforce best practices and the appropriate standards for microbiological contamination control.

A sign for the Pharmig event at The Oxfordshire Hotel, Oxford.

Posted by Dr. Tim Sandle

Foodborne illness in humans

An outbreak is an incident in which two or more people, thought to have a common exposure, experience a similar illness or proven infection (at least one of them having been ill).

A general outbreak is an outbreak affecting members of more than one household or residents of an institution.

In relation to the U.K., Public Health England have a compilation of interesting statistics. The various reports can be found here.

 Posted by Dr. Tim Sandle

Listeria Strains Are Not One and the Same

It is now recognised that not all strains of Listeria monocytogenes cause disease. Pathogenicity (the ability of an organism to cause disease) for humans is generally confined to certain strains of L. monocytogenes. One particular strain causes 40% of foodborne outbreaks.

Current research is now focussing on understanding why certain strains of L. monocytogenes are more pathogenic than others. Research has revealed that certain genes are more commonly found in pathogenic strains of L. monocytogenes and are absent in less pathogenic strains. This may eventually allow the development of tests to further distinguish pathogenic and non-pathogenic strains. However, this is complicated since the severity of disease i.e. virulence, is linked to individual immunity and certain people are more likely to contract listeriosis than others.

On this subject, Dr Paul Gibbs (Leatherhead Food Research/emeritus) has written an interesting article for Rapid Microbiology. The article can be found here.

Posted by Dr. Tim Sandle