Leptospirosis

Leptospirosis is primarily an occupational disease that affects farmers and other people whose occupation brings them into direct contact with animals. It can also infect some wildlife species, such as rats. 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.

Cause

Many species of Leptospira bacteria

Distribution in Queensland

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

Affected animals

cattle; pigs; sheep; dogs; horses; farm animals

Hosts

Cattle, sheep, dogs, horses

Symptoms

Leptospirosis can be fatal. A range of clinical signs are seen:

  • fever
  • haemolytic anaemia
  • abortion
  • infertility
  • 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.

How it is spread

Leptospirosis is spread mainly through ingestion of or contamination of cuts and abrasions by the urine of infected animals. It 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.

Approximately 100 cases of leptospirosis are reported in humans each year in Queensland. That is less than 4 cases per 100,000 people.

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.

Control

Prevention

Vaccines are available for the protection of cattle, pigs and dogs.

People can prevent infection through:

  • good personal hygiene
  • avoiding situations where contact with animal urine might occur
  • wearing boots when handling stock
  • using rubber or plastic gloves if there is the possibility of contact with urine
  • covering cuts and abrasions with waterproof dressings.
  • vaccinating cattle and pigs regularly as this may reduce the risk of spread from urine.

Treatment

Antibiotics may be used to eliminate infection in carrier animals. For people antibiotic treatment and care in hospital usually leads to recovery.

More information