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Weil's Disease

What is it?

Infection with the Leptospira bacterium is called Leptospirosis or Weil's Disease. It is a reasonably rare condition with a low infection rate, but can be highly dangerous if not treated correctly or in time. The Leptospira bacterium is carried by rats (and other infected animals) which excrete the organism Leptospira ictero-haemorrhagiae in their urine. If the urine enters areas of freshwater, lakes, streams, rivers (or sewage works/pipework) that commonly made home by rats, the bacteria survives in the water and is able to infect animals and humans who enter/work with it.

How is it caught and what happens?

The bacterium enters the body through breaks in the skin (cuts, blisters, abrasions) and via the lining of the nose, throat and alimentary tract. The incubation period for the disease can last anything from 3 - 15 days (though cases over 30 days and under 48 hours have been recorded). Symptoms include fever, chills, muscular aches and pains, loss of appetite and nausea. In its starting stages it can be commonly mistaken for influenza, meningitis or a fever of unknown origin. The infection becomes more violent in its later stages with symptoms such as bruising of the skin, sore eyes, anaemia, nose bleeds and jaundice. The fever can last for around five days followed by a marked deterioration. Most people will recover completely with treatment, but there are cases where the illness causes serious damage to internal organs and can lead to death. Weil's disease is commonly treated by antibiotics. Recovery from the condition (once the serious stages are passed) can take from 6 to 12 weeks.

Anyone experiencing fever after exposure to high risk water should contact their GP immediately. Always tell your doctor you suspect Weil's disease to avoid miss-diagnosis (many urban GP's may not have seen the disease before so alert them to the possibility). If you think you have flu and then develop the later symptoms after exposure to water at risk of contamination, go directly to a hospital and tell them you suspect Weil's disease.

Who is at risk from Weil's Disease?

The rats that spread the disease commonly live near water and places where there is easy access to food such as farms and stables. Those at high risk include sewage workers, abattoir workers, farm workers, miners and those who have an increased contact with water such as cavers and water sports enthusiasts. The Leptospira bacteria does not live long in dry conditions but can survive in fresh water up to a month (in salt water the bacteria only survives for a few hours). If you work (or play) with water that has a high risk of rat infestation take great care not to ingest the water or let any wounds come into contact with it.

Protecting yourself from infection

The most effective way to protect yourself from Weil's disease is to avoid contact with infected water. However, there are steps you can take to lower your risk of infection if you have to come into contact with water in lakes, streams, rivers or sewage works/pipework:

  • wear splash-proof clothing and gloves;
  • if you have cuts do not allow them to be submerged in the water;
  • if you have cuts or grazes and enter the water, you must cover them in a waterproof dressing;
  • never swallow water unsuitable for drinking;
  • do not immerse your head;
  • those who have to enter the water need to wear oversuits and gloves;
  • as soon as you are out of the water take a shower in clean water as soon as possible;
  • wash all equipment and clothing in clean water;
  • clothing that can withstand bleaching should be disinfected or bleached to kill the bacteria;
  • if you have a wound always use clean fresh water to clean wounds as soon as possible;
  • those who have to enter water at a high risk of infection on a regular basis can take doxycycline as a form of protection. 

It is always prudent to remember that any water course can be infected with any number of harmful organisms, so use your common sense and don't take risks that can lead to exposure.