Leptospirosis: The facts

* Leptospirosis is also known as dairy farm fever, red water disease (in cattle).

* It is one of the most common occupationally acquired diseases caught from animals in New Zealand.

* It is caused by leptospira, long, thin mobile organisms.

* Infection is common in cattle, pigs, possums, rats, mice and hedgehogs. Spread of infection among livestock is very high.

* Transmission is usually by contact with infected urine.

The bacteria enter the body through urine splashed from infected animals through the membranes of the mouth, nose and eyes, through the skin - especially cuts and sores - through bathing in water in which stock may have urinated and by handling infected kidneys.

WHO CAN CATCH IT?

A South Auckland carpet layer has been infected with leptospirosis, Lorene Scott was told. Among other recent victims are people with city occupations, including a security guard.

Anyone who comes in contact with the urine of infected animals, or water contaminated by the urine, could catch leptospirosis. Most of these people will live in rural areas.

Among the occupations most susceptible are dairy farmers, vets, meat inspectors, meat processing workers, service workers, herd testers, and plumbers and drainlayers.

Occupational Safety and Health is now trying to increase awareness that the disease can be caught in a number of different situations.

SYMPTOMS AND TREATMENT

It can incubate for up to 21 days, although in some instances people feel the effects within two days of being exposured to it.

The main symptoms include serious headaches, severe high fever, sensitivity to light, sweating, nausea/vomiting, muscle pain, back pain, loss of appetite, mood changes.

Other symptoms include jaundice, breathing problems, vision problems, diarrhoea, and skin problems.

The disease can come on very rapidly. Patients speak of "crashing," being unable to remember anything before waking up in hospital.

If leptospirosis is suspected, a blood sample should be taken, then treatment with antibiotics should begin immediately.

Another sample should be taken within four weeks, even if symptoms resolve quickly. The diagnosis can be confirmed only through a blood test.

Treatment should begin as soon as the disease is suspected, as delays can lead to more serious illness.

TO PREVENT LEPTOSPIROSIS

* Practise good personal hygiene.

* Cover cuts or scratches with waterproof plasters and replace often.

* Never enter cow sheds or pigsties in bare feet or jandals.

* Consult a vet about a vaccination project for stock.

* Don't run pigs, cattle and deer together.

* Keep recreational water areas free of contamination by infected animals.

* Control rodents.

WHO IS AT RISK?

Leptospirosis has been dubbed "dairy farm fever" because dairy farmers have traditionally been the biggest single group affected by it.

But recent statistics show meat processing workers have proportionally the highest rates of the disease.

"High-risk" occupations now account for 87 per cent of all cases in people aged 15 to 64 and in paid employment.

Those jobs are meat processing workers (165 cases a year per 100,000 workers), livestock farm workers (92 cases) and forestry-related workers (24 cases).

Livestock farmers made up 51.8 per cent of cases between 1990 and 1998, and those involved in meat processing were 29.6 per cent of cases.

If the rates remain static a meat processing worker has a 1 in 20 chance of contracting leptospirosis at some stage in a 30-year working life.

Livestock farm workers have a 1 in 38 chance, and dairy farm workers a 1 in 28 chance, based on 30 years in the business.

* Guidelines for the Control of Occupationally Acquired Leptospirosis will be published by Occupational Safety and Health, in association with ACC, next month.

Information supplied by OSH, Ministry of Agriculture and Forestry.