Weil’s Disease and Leptospirosis
Weil’s Disease (Leptospirosis) is a term applied to diseases caused by microorganisms of the genus Leptospira. They arise in the urine of rats and farm animals and are quite frequently found in the cave environment in water and mud. The organisms can easily enter the body of the caver and can lead to flu like
illness, which may well be fatal in as many as 2% of cases.
Treatment is possible at the early stage of the infection but the average GP will neither be aware of the illness nor be able to differentiate the symptoms from those of many flu bugs. A blood sample is necessary and the laboratory must be instructed to look for traces of leptospirosis (ELISA test).
What is Leptospirosis ?
Leptospirosis is a term applied to diseases caused by microorganisms of the genus Leptospira. It may range from being a mild flu-like illness to full-blown Weils Disease, which is a very serious and often fatal condition.
The Leptospira serogroup, which causes the most serious illness, is usually icterohaemorrhagiae, but other serotype, especially canicola, may cause serious or fatal disease.
The incubation time varies between extremes of 7 – 26 days but is usually 7 to 13 days, the average being 10 days. In many cases, infection with the organism does not produce any symptoms at all and they may be totally unaware that they have been infected. The illness in its mildest form is very like influenza.
The onset is usually very sudden and often the patient is able to give the exact time that the started to feel unwell. They may have a headache, feel chilled, shiver have vague muscular pains and a sore throat and temperature. They may feel nauseous and not want to eat. After a few days to a week the symptoms disappear and the patient fully recovers believing they had a touch of the flu.
In more severe cases the patient may experience a blinding headache (often of sudden onset) with rigors and a temperature of up to 40C (104F). Muscle pains especially in the calves of the legs may be so intense that the patient cannot bear to be touched. The patient may have a sore throat, chest pain with respiratory distress and cough up blood. They may have respiratory difficulty because of a headache and neck stiffness and a mild rash. Vomiting is common and tends to get worse as the disease progresses, constipation is usual (although diarrhoea may occur) and abdominal pain is present in most cases in the first few days.
This is the first phase of the disease and usually lasts about a week after which the symptoms abate and the patient feels better. Slow recovery may take place at this stage but usually after 2 – 3 days relief the second stage begins.
The symptoms are varied but often similar to the first phase accompanied with fever and symptoms of meningitis. After this there is a slow recovery usually between the second and fourth week during which fever and aching may recur or the disease may progress to full-blown Weils disease.
Sources of Infection
The usual source of infection is wet clay, mud or water, which has been contaminated with the urine of an infected rat. Other animals such as dogs and farm animals, especially cattle, may also be a source of infection and in some
instances may constitute the major source.
The route by which the infection enters the body is through cuts and abrasions, through the membranes of the mouth, nose and eyes. It is debatable that the organism may enter through soft wet skin. The organism is particularly sensitive to acid conditions and will die quickly in very acidic water or soil, but will
survive for months or longer in mild alkaline conditions.
Therefore a cave offers an ideal site – particularly one with stagnant pools.
This is probably best thought of as being a very severe type of leptospirosis. The mortality rate is about 5 – 10%. The symptoms at onset are as before or considerably worse.
The headache may be so bad as to require morphine and muscular pain is also severe. The eyes become bloodshot and may ooze. In many of these already severe patients the disease may progress to a second stage of liver and kidney failure. The skin begins to turn yellow and the bloodshot eyes acquire an orange
The patient’s condition worsens rapidly and as the jaundice deepens the skin becomes intensely yellow. There is anorexia and continuous vomiting. Bleeding may occur internally into the gut, brain and lung cavity and externally from the nose and other orifices. Heart and brain may also be affected. As the kidneys begin to fail the patient may cease to pass urine; the amount of urine may greatly reduce or cease altogether.
The patient may be extremely anxious but more commonly is apathetic and semi-stuporose and if the condition does not improve the urine flow increases by the second week they slip into a coma and die.
If the illness begins to lessen, the patient begins the slow road to recovery though even in this phase symptoms may recur and there may be a temporary impairment of vision.
This is usually with some antibiotic (penicillin, streptomycin, tetracycline and erythromycin) and in severe cases, kidney dialysis may be necessary.
Care should be taken when entering caves – particularly dry caves with stagnant water. Caves with farmyard run-off can also harbour the bacteria.
Always wear rubber gloves and good boots and wash and clean any cuts and grazes with antiseptic immediately on leaving the cave.