Not the most appetizing of subject but the saying that "travel broadens the mind and loosens the bowels" does make it relevant to airline pilots. In fact, it is the commonest cause of incapacity in air crew, one study suggesting that 29% of all crew suffered at least one incident of incapacitation in flight, and 58 times out of a 100 that incapacitation would be....you've guessed!

Most diarrhoea is caused by ingesting food or water contaminated with faeces or chemicals, such as alcohol or chlorine. "Delhi Belly" is usually acquired in the Tropics or Sub-Tropics where food hygiene is poor and water is polluted by inadequate sewage disposal, though altered diet and sunbathing can be major contributing factors.

Bacteria are the commonest bugs to cause diarrhoea, which can affect half of all travellers, many of whom end up as serious visitors to the toilet and 1% even in the Krankenhaus. E.Coli lives up to its faecal name and is responsible for about half the cases. Shigella, Campylobacter, Salmonella (can cause typhoid) and Vibrio Cholerae are other performers, though the "rice water" stools of the latter are thankfully uncommon amongst present day travellers. Vibrio Parahaemolyticus, although infrequent in the UK, is the commonest form of food poisoning in Japan where seafood forms a high percentage of the staple diet. Viruses are now an increasingly common cause of poisoning from shellfish, and the Protozoa Giardia is responsible for 11,000 reported cases annually in the UK, although most originated abroad. Clay coloured stools suggest viral hepatitis which three in every 1,000 travellers catch unless they have been wise enough to have had their Hep A jab. 

"HOW TO AVOID ILLNESSES CAUSED BY UNSAFE FOOD AND DRINK AND WHAT TO DO IF YOU GET DIARRHOEA!"
This is the sub-heading of a leaflet which arrived in my post recently from the World Health Organisation. Its 8" x 5" size and glossy texture restricts its usefulness but its contents give sound advice. Cooked food should be just that, well cooked and served hot, or cooled to less than 5°C and stored the minimum time before eating. "Keep it hot, keep it cold, or throw it away." The bacteria multiply in it at a prodigious rate if it is left around at room temperature. Observing these precautions can be difficult with aircraft food when there is a delay. Fortunately, there has been a decrease in food poisoning from flight meals, but do the crew still eat different meals these days? Remember that the incubation period for toxic food poisoning can be less than 60 minutes and the ensuing incapacitation could have disastrous consequences even for a short haul crew.

Avoid uncooked food except peeled fruit and vegetables. "Cook it, peel it or leave it." This also applies to Mrs Curry's eggs which should always be well cooked but may slip unsafely into some sauces, mayonnaise, desserts and ice creams.

Shellfish have been a well recognised hazard since Moses decreed "only eat fish with fins and scales" some 2000 BC, though it was not until Pasteur was messing about with wine and beer just over a century ago that anyone began to understand what was going on. Oysters, usually eaten raw, can be particularly tasty and particularly dangerous.

WATER
Your passengers will know what to treat it with but sober air crew will have it boiled, bottled or disinfected and don't forget that ice can be contaminated too. Tea, coffee or fruit juice is often better. Hotel tap water is not always safe and often tastes foul. It's best to take mineral water.

HELP! THE RUNS! WHAT TO DO?"
Most attacks are self limiting and clear up in a couple of days without specific treatment. Drink more fluid as soon as it starts - bottled water, flat coke or 7-up or weak tea - a little and often, at least three litres a day. If it "runs" into the second day, six level teaspoons of sugar and one of salt to each litre of safe water will replace some of the good things that disappear down the pan. There is no need to starve, and readily digestible food in moderate amounts is OK, but if sachets or Rehidrat or Dioralyte are available to make up with water then that is preferable in severe cases. Diarrhoea tablets such as Loperamide (Immodium or Arret) may be used if the diarrhoea persists, but the theory of "let it all come out" still holds favour with many doctors.

If the diarrhoea persists for more than three days then medical advice should be sought. Specimens may be taken and antibiotics sometimes given. With the advent of more powerful antibiotics which fix many of these bacteria there is some controversy whether they should be taken by travellers to prevent infection, but this should not be considered for air crew who might suffer from side effects. A recent, but as yet unpublished study, on British soldiers in Belize suggested that a single dose of the strong antibiotic Ciprofloxacin taken at the onset of diarrhoea could more than halve its duration. Again this would not be appropriate to take while flying. Clearly no-one should contemplate operating an aircraft if suffering discomfort from diarrhoea, or taking drugs to combat it. Finally, remember that if diarrhoea keeps recurring there are other causes which could require investigation. To ignore it could well land you in it!  

Dr S A Goodwin

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