The Pharmaceutical Journal
Vol 268 No 7204 p934
29 June 2002

Pharmacists and prevention of zoonoses

Earlier this year the European Union published a discussion document focusing on the need for better control and prevention of zoonoses. The list of diseases communicable between animals and humans is significant and includes salmonellosis, rabies, toxoplasma, Lyme disease and (although rare in humans) foot and mouth disease. The risk is not restricted to those in contact with infected animals, because disease may be transmitted via food or contact with a contaminated surface or liquid.

The EU document makes early reference to the need for a "concerted multidisciplinary approach". Subsequent sections reflect the opportunities facing pharmacists, who are in a front-line position to contribute to recording and reporting possible food borne infections, while working closely with the medical profession. The document refers to under-reporting of infections and "patients failing to present to health services". Some patients will probably have presented at a pharmacy with alimentary tract symptoms and will have been appropriately advised or referred to their GP, especially should the condition persist.

What is required is a recognition of pharmacy's special position and its unique scope for acting as a link between medical and veterinary professionals. Also required is co-ordination, notably at primary care level, as well as a culture of working with veterinarians and other relevant groups, which in rural locations could include farming communities.

The issues involved affect not only specialist veterinary pharmacists but to varying degrees all practising pharmacists. An estimated half of the United Kingdom's 23 million households owns a pet, and the cat and dog population is about 14 million. In addition there are at least two million other small pet animals, 10 million racing and show pigeons and about three-quarters of a million horses — all capable of transmitting disease, especially when hygiene and routine prophylactic health care are neglected.

Although the risk of serious zoonoses in the UK is low, there is much public ignorance and worry, particularly when the media make alarmist comments following, for example, outbreaks of salmonellosis.

Lyme disease

At its 1999 annual conference, the British Veterinary Association advised that "the increasing distribution of Lyme disease, particularly in the New Forest, means that pharmacists [there] are likely to receive enquiries about 'flu-like symptoms and joint swelling resulting from infected tick bites, possibly many months after tick bites."

More than 500 cases of Lyme disease have been reported in the UK since 1985, but laboratory confirmation can be difficult. The infection is caused by the bacterium Borrelia burgdorferi, transmitted by the two-host tick Ixodes ricinus. The main reservoir hosts are believed to be small mammals, especially rodents, but dogs and deer are potential hosts too. Humans initially experience a spreading red ring around the tick bite along with intermittent fever and 'flu-like symptoms that can last a few weeks. The infection responds to antibiotics, but if left untreated, arthritis, heart, skin and nervous symptoms may develop over a period of weeks or months.

Human infection is best prevented by ensuring that vulnerable areas of skin, such as the legs, are covered and the bottoms of trouser legs are sealed. Risk may be further minimised by examining skin and clothing and inspecting accompanying dogs, which may have been exposed to opportune ticks. (See also PJ, 27 April, p593)

Ringworm

One common zoonosis affecting the public, as well as among those involved with handling animals, is ringworm. Most pharmacists have at some time been asked to advise on what might be ringworm, which may be transmitted among schoolchildren by physical contact. An eight-year-old schoolgirl does not have to have been to riding lessons to contract ringworm.

Ringworm is caused by fungi of the genera Trichophyton and Microsporum. The transmission risk to humans is from contact with contaminated buildings as well as direct contact with infected animals. The human disease manifests itself as characteristic round, inflamed areas on exposed skin. Fortunately, a number of effective antifungal preparations are available.

Main zoonotic infections

The Moredun Research Institute has recently published through the Moredun Foundation two booklets listing the main zoonotic infections affecting humans, which are primarily associated with keeping cattle and sheep. The alphabetical listings are as follows (causative organism in brackets): cattle — anthrax (bacteria), bovine spongiform encephalopathy (TSE prion), brucellosis (bacteria), Escherichia coli O157 (bacteria), cryptosporidiosis (protozoa), leptospirosis (bacteria), ringworm (fungus) and tuberculosis (bacteria); sheep — campylobacteriosis (bacteria), chlamydiosis (bacteria), cryptosporidiosis (protozoa), hydatidosis (tapeworm), listeriosis (bacteria), louping ill (virus), Lyme disease (bacteria), orf (virus), Q fever (rickettsia), salmonellosis (bacteria) and toxoplasmosis (protozoa).

Obviously the risk of acquiring toxoplasmosis from sheep is much less than the risk from cats. However, toxoplasma readily infects humans and it is estimated that 30 per cent of the human population is infected, but clinical illness is relatively much less common. Most human infection is a result of eating raw or lightly cooked meat containing toxoplasma tissue cysts or from exposure to an environment contaminated with toxoplasma oocysts. There may be a serious threat to an unborn infant if the mother becomes infected with toxoplasma for the first time during pregnancy. The rate of congenital infection varies considerably from one country or even region to another, but is estimated at between 1 and 6 per 1,000 pregnancies in the UK.

Conclusion

This short report aims to draw attention to what appears to be an important but commonly ignored aspect of health care in which good hygiene standards are crucial if the risk of disease is to be minimised. For examples, pregnant women should, if possible, not deal with cat faeces and should certainly wear disposable gloves where a risk exists.

The wider question could be: Does seamless health care, as applied to pharmacy, adequately recognise and include issues related to zoonoses? Many zoonoses are food-borne and others can be acquired on from pets, but who is helping to ensure that the risks are known and minimised? Can pharmacists play a part?

There is now a Food Standards Agency whose remit includes "the ensuring of animal and human health", and imminently, an Infection Control Agency. Record keeping and reporting are increasingly on the health care agenda. Are pharmacists sufficiently prepared to contribute and get the recognition they deserve? The EU should take seriously the need for better control and prevention of zoonoses.
— By Dr Michael H. Jepson, FRPharmS, a member of the Veterinary Pharmacists Group Committee.