Norovirus - the global hitchhiker

Norovirus image

Vomiting, often in projectile form, diarrhoea, muscle and head aches and a churning stomach which lasts a day or two - the symptoms of Norovirus, arguably one of the most common human pathogens on the planet and for which there is no known treatment or vaccine. Norovirus is particularly prevalent during Winter months and highly infectious as exposure to as few as 17 virus particles can lead to infection in comparison to almost 1,000 which are needed for influenza to take hold.

For an RNA virus, Norovirus is very resilient being able to withstand most chemical detergents, freezing and heating up to 600C. It can also survive for up to 2 weeks on hard surfaces such as doorknobs and  tablecloths. There are around 40 identified strains. One study in 2009 the Netherlands which examined a jamboree which had been over-run by Norovirus found that for every person who fell sick, fourteen others were infected. These are startling rates of transmission and account for the speed at which Norovirus epidemics can quickly move to pandemics. Norovirus has two main groups (termed genogroups) which afflict humans - GI and GII - within each of these are viral variants with GII.4 currently having the greatest mutation capacity.  The mutation capability of Norovirus is what makes it hard for the immune system to identify the pathogen  and attack it.

With the Winter season now in full swing in the Southern Hemisphere, the global hitchhiker is bound to make its appearance. In 2012, Novovirus GII.4 Sydney progressed to world -wide infection with a substanial impact on the United Kingdom.

Online medical diagnosis - harnessing a 'world-wide' audience

The expansion of interactive websites on the internet has led to a wide range of online tools in the health sector which assist with self diagnosis or to facilitate patient and clinician understanding. With the increasing recent use of crowd sourcing for fund-raising, suspect identification and IT tasking, it was only a matter of time until health also started to make use of the wider community for diagnosis, whether only a specific segment or a wider general call. With over 7,000 known rare diseases there is a large market of people who either suffer from an undiagnosed condition or one which has been misdiagnosed. Two such new emerging health websites are CrowdMed and FindZebra.

CrowdMed promotes its' function by stating:  

“Instead of relying on individual physicians, CrowdMed harnesses the collective intelligence of hundreds of Medical Detectives (MD’s) to produce astonishingly accurate diagnostic suggestions in just hours. As a CrowdMed Medical Detective (MD), you can use your personal experience, intuition, and online research skills to help solve the world's most difficult medical cases. You can not only win cash, prizes, and status, but also help save lives"

CrowdMed does not require a medical degree or any health qualifications at all. Participants on the website bet on a patient's diagnosis from lists of suggestions and the top three are given to a patient to discuss with their physician.

In contrast, FindZebra provides an index of articles from rare disease databases. The website contains a condition of use stating:

"FindZebra should only be used by medical professionals. Although the articles indexed by the system have been written by medical professionals or reviewed by medical associations, it is strongly recommended that, as a patient, you consult your local health care provider. FindZebra does not replace professional health care, and cannot be held responsible for erroneous use of the information provided through the system".

As with all website data, it is a case of buyer beware. Both these websites can be found by clicking the links below:

CrowdMed

FindZebra

Mesothelioma - the emerging new sinister cause of erionite

erionite

The deadly lung cancer known as Mesothelioma is usually associated with exposure to asbestos, a term commonly associated with various commercial industrial and building products. However in recent years there has been a growing awareness that there are other sources of the deadly fine, durable dust which constitutes the asbestos hazard and these sources of lung disease are far more widely dispersed around the world. Asbestos, in fact, is a common name given to six similar silicate compounds which may be either sodium, magnesium, calcium or iron.  A widely found silicate is termed 'erionite' and is caused by the action of water on volcanic ash with deposits of this substance found in mountainous or rocky areas worldwide including Europe, Australia and New Zealand. The threat of erionite has already been proven with extraordinary mesothelioma mortality rates being found in the Cappadocia region ot Turkey where the silicate occurs naturally in vast tracts of rock and throughout the mountains where people live. As a consequence it is also found in the buildings people occupy in that region. In the early studies of recent years, including animal studies, erionite is found to be more likely to cause cancer than asbestos and in fact does. There is little information about erionite and cell biology interaction and hence the capacity to assess at-risk communities remians poor.

A new contagion - drug resistant bacteria in the wild

Under the microscope - MRSA

Health authorities, medical research institutions and pharmaceutical companies across the world have, for several years, been concerned with the increase of drug resistant bacteria materialising in hospitals, primary health care facilities and in geographic regions where there is a measurable level of social/economic deprivation. In fact, the increase of medically acquired infections in hospitals has led to changes in clinical pathways with an emphasis on discharging patients to their homes for recuperation as quickly as possible to avoid continued hospital stays and the heightened risk of infection. There has always been a question as to the degree of spread which may occur given diseases such drug resistant malaria and drug resistant tuberculosis already exist in regional and urban environments. The so-termed and best known superbug, MRSA or Methicillin-resistant Staphylococcus aureus continues to be a menace in hospitals and nursing homes.

Research from the Antarctic coast has shown that a quarter of the samples of seawater taken from locations close to Chile's research stations on the ice continent contained e-coli bacteria with genes which produce an enzyme which can destroy most antibiotics (such as penicillin, cephalosoporins etc).  The enzyme, ESBL is found mainly in people and the bacteria appear to be able to survive in the wild without their hosts. How long will it be before this situation leads to wildlife in the region becoming a reservoir for the drug resistant superbugs?

Update on H1N1

The recent information on the spread of swine flu indicates that the new virus is dominating over the existing main flu virus H3N2. More than 98% of the flu cases genotyped in the US during June 2009 were swine flu and a similar statistic exists for the state of Victoria in Australia where 99% of all flu cases which were genotyped were H1N1. A similar results exists for Argentina and Chile where over 90% of cases of flu were found to be swine flu. There are also indications that Tamiflu resistant swine flu has already evolved although at this stage, the number of cases is very small.

Opinion - Swine Flu H1N1

The latest animal to human virus mutation, the Mexican Swine Flu or H1N1 again demonstrates the capacity of viruses to mutate and literally jump species with relative ease. New Scientist (2 May 2009) points out that the virus was genetically stable until 1976 as a mild, purely swine flu. In that year it affected people at a military camp in New Jersey and by 1998, the virus had hybridised with human and bird flu viruses. The current version of H1N1 in Mexico has surface proteins from Swine flu virus, five swine flu genes, two avian flu genes and one human flu gene (shown above). The surface protein being the swine version means that human antibodies will not recognise it.

The other matter which comes to mind is the use of antibiotics in animal husbandry - the use of antibiotics is widespread in farming and while it prevents animals from becoming sick, it does not prevent initial infection nor the transmission of disease. Connected to this aspect is the potential risk of an infection becoming antibiotic resistant as large scale farms become in effect, incubation laboratories.

An example which springs to mind is 'Golden staph' or Staphylococcus aureus which is mostly associated with hospital acquired infections, mainly post-operative. Since the mid 1990s antibiotic resistant 'Golden Staph' has been detected in abattoirs in the meat and livestock industry and also in site sampling in the general community.

The high use of antibiotics with animals has been in use for decades but with some bacterium common to various species and also humans and some viruses developing the capacity to leap between species, how long will it be before such a step takes place and humans face an infection (viral or bacteria), created in farming and resistant to any treatment?