Leptospirosis

Cause

Many species of Leptospira bacteria can cause this disease.

Description

Leptospirosis is a disease of animals and people. It can also infect some wildlife species, such as rats.

Where the disease occurs

Leptospirosis has a worldwide distribution, most commonly in warm, wet climates. It can occur anywhere in Queensland.

The disease in animals

Leptospirosis affects all farm animal species, dogs and horses. It can be fatal. A range of clinical signs are seen: fever, haemolytic anaemia, abortion, infertility and weak newborns. In cattle, a specific form of mastitis, known as 'milk-drop syndrome', can occur. Horses can develop blindness due to inflammation of eye tissues. Animals can become carriers and shed the bacteria in urine.

Control of the disease in animals

Vaccines are available for the protection of cattle, pigs and dogs. Antibiotics may be used to eliminate infection in carrier animals.

How people can get the disease

Leptospirosis is spread mainly by the urine of infected animals through ingestion of or contamination of cuts and abrasions by the urine of infected animals and is generally not transmitted from person to person. Direct contact with animal urine is a risk. Indirect contact from water (ponds or pools) that has been contaminated with urine is also a risk.

Around 100 cases of leptospirosis in humans are reported in Queensland each year. That is less than four cases per 100,000 of the population. Some level of under-reporting may mean that the disease is a little more common than this. 

Leptospirosis is primarily an occupational disease that affects farmers and other people whose occupation brings them into direct contact with animals. Rats are thought to be a common source of the disease and, historically, cane cutters were infected during manual cutting of cane infested by rats. 

In recent years, the disease has been a problem for dairy farmers because 'herring-bone' dairies have become popular. In a 'herring-bone' dairy, the farmer works below the cows, increasing the risks of urine splashing into the farmer's nose and mouth. Workers on banana farms have also emerged as a higher risk group due to contact with rat urine. Some cases have occurred in people who have swum or waded in water contaminated by the urine of native and wild animals.

Treatments for people

Antibiotic treatment and care in hospital usually leads to recovery.

Preventing the disease in people
  • Exercise good personal hygiene.
  • Avoid situations where contact with animal urine might occur.
  • Wear boots when handling stock.
  • Use rubber or plastic gloves if there is the possibility of contact with urine.
  • Cover cuts and abrasions with waterproof dressings.
  • Vaccinate cattle and pigs regularly as this may reduce the risk of spread from urine.

Further information

Last updated 27 September 2012