118 Control measures include elimination of anthrax in farm animals, high
standards of personal hygiene including the covering of cuts with waterproof dressings and information and training.
12.4.2 Leptospirosis Hazard group 2
The main form of leptospirosis is Weil‟s disease which is a potentially life threatening illness caused by the Leptospira bacteria passed from rats via
urine. Symptoms include flu-like symptoms such as fever, headache, vomiting, muscle pains, pneumonia and possible kidney failure and death.
The disease may be transmitted through contact with rat‟s urine or watercourses contaminated with it. It may enter the body through abrasions,
cuts in the skin and through the lining of the mouth, nose and conjunctiva. At risk occupations include farmers, farm workers, fish farmers, construction
workers, water industry workers, leisure industry workers, sewer workers and laboratory workers.
12.4.3 Salmonellosis
Salmonellosis is the name given to an infection caused by any of the Salmonella group of bacteria. Salmonella bacteria may be carried by most
types of farm animal. Infections are usually associated with ingestion of contaminated food or may result from contact with farm animal dung e.g.
using contaminated hands to eat, drink or smoke. Symptoms develop suddenly about 12 to 24 hours after infection and include
malaise, headache, nausea, abdominal pain, diarrhoea and fever. Symptoms normally last 2 to 3 days but can persist longer. Dehydration or septicaemia
blood poisoning may also occur.
12.5 Moulds
Moulds are microscopic fungi that grow in the form of branching threads or filaments. They reproduce by means of microscopic spores which can give
rise to new mould growth which in turn can produce millions of spores.
119 If inhaled, fungal spores may cause allergic rhinitis or other allergic responses
such as alveolitis. Moulds can be found wherever there is moisture, oxygen and a source of
nutrients. They grow on dead organic matter such as on rotting vegetation and dead leaves, especially in moist shaded areas.
In industrial situations bakeries, breweries, dairies and greenhouses are examples of ideal places for moulds to grow. Any areas where fresh food is
stored are also potential sites where mould growth is possible. Well documented examples include grain stores or silos, particularly if the grain
has been stored slightly damp. Indeed, in any indoor environment, mould may grow in damp places such as
in poorly ventilated basements, bathrooms, and humidifier and air-conditioning units. Indeed they can thrive in any area where surfaces or materials are
damp. Reduction of moisture and humidity levels is the most important factor in mitigating mould growth.
12.6 Pandemics
A pandemic can be defined as an epidemic of an infectious disease that spreads over a wide geographic area several countries, a continent or even
worldwide and affects a large proportion of the population. A pandemic can start when the following conditions occur:
Emergence of a disease, or a particular strain of a disease, new to a population
The agent affects humans, causing serious illness The agent spreads easily and sustainably among humans.
There have been many pandemics in the past including those caused by typhoid, cholera, bubonic plague and influenza viruses. Bubonic plague killed
tens of millions of people in Europe in the middle ages. The most severe influenza virus pandemic recorded occurred between 1918 and 1920 when
„Spanish Flu‟ was estimated to have killed at least 40 million people. More
120 recently „Hong Kong Flu‟ was estimated to have resulted in about 1 million
deaths in the late 1960‟s.
New strains of the influenza virus continue to emerge in animals with the potential that any particular new strain could cause a future pandemic. These
new strains of the influenza virus occur when they are transmitted to humans from another animal species such as pigs, chickens or ducks.
A recent example of a new variant strain of influenza virus is H5N1 „Bird Flu‟ which was found in 2004 in birds in Vietnam. By 2007 numerous cases had
been found across Asia and much of Europe. There have been human fatalities among people who have had close contact with infected birds. There
has been no, or limited, transmission of the disease from person to person. H5N1 bird flu is not categorized as a pandemic as the virus cannot yet spread
easily or sustainably among the human population. However, if the virus combines with a human influenza virus strain a new sub-type may evolve that
could be highly contagious in humans. Another concern related to pandemics is that many micro-organisms are
becoming resistant to many of the antibiotics currently in use. These antibiotic resistant micro-organisms sometimes terme
d „superbugs‟ may contribute to the re-emergence of many diseases which are currently well controlled e.g.
tuberculosis. A range of common bacteria are also becoming more resistant to antibiotics
leading to a rise in the number of healthcare acquired infections. A well known example of this is methicillin-resistant Staphylococcus aureas or
MRSA.
12.7 Genetic modification
