Dr Jules Eden, dive medicine specialist and founder of e-med, answers divers' questions - as published in Sport Diver magazine:
Q - I've been stationed out in Vietnam with work for a year, and whilst here I've been enjoying all the natural pursuits the country has to offer - amongst them, diving in inland lakes as well as off the coast, caving, longboating up the river etc. Recently I had what I though was just a cold/cough, with the usual symptoms of fever, shivers, muscle pains and a sore throat. It went after 4 or 5 days, but someone mentioned a condition called Weil's disease, and that it was common here and I might have picked it up from the water? Is this possible and what should I do to find out if I've got it?
A - Adolf Weil first described ďan acute infectious disease with enlargement of spleen, jaundice and nephritisĒ in 1886. This bacterial illness, known as leptospirosis, is usually acquired via water contaminated with animal urine coming into contact with eyes or unhealed breaks in the skin. Surfers, rowers, farmers and sewage workers are examples of your at-risk groups; leptospirosis has even been seen in golfers who have become infected while retrieving balls from stagnant pools. Thankfully itís rare, as itís a pig to diagnose. Symptoms vary from none at all to almost anything, but typically an initial flu-like illness resolves before a second phase of meningitis, liver damage and renal failure kicks in. Diagnosis is via blood tests and cultures but can be hit and miss unless there is access to a lab with sophisticated equipment. High doses of antibiotics are required to deal with the bacteria, but handily doxycycline is a good prophylactic (in addition to its similar function as an antimalarial). As usual, the golden rule is to try to stop yourself getting it in the first place, so avoid any rat-infested swimming pools if you can.
Q - I am planning on taken part diving in the Thames & other British fresh water sites both rivers & lakes. I would like to know of any health risk's that might be involved in diving such sites & any preventative measures I can take to protect myself. Also if you can advise me of any vaccinations that might be advantagous I would be grateful.
A - I think you should be fine in our joyous clean waters here in the UK. The only real issue is that of an interesting illness called Weil's disease or leishmanisis. This is a bug transferred into fresh water from rat's urine. However it's mostly really found in still water like in wells or small ponds where the only divers are from the supermarkets retrieving their trolleys. If you are diving big lakes or quarries like Stoney then there is little chance of getting this interesting condition. As for rivers, they are pretty clean, even in London as the number of cormorants visible from Chelsea Bridge proves.
What immunisations? Well, you should always keep up to date with tetanus and polio, which are every 10 years anyway. That's about all you need look out for but if you are diving near unprocessed sewage get a Hepatitis A shot too, but nowadays most of the Capital's number 2's are clean enough to drink after processing by the water authorities. Well that's what they tell us anyway!