Apologies for re-opening this thread, but I have been offline for a while. Still I feel a need to comment on the tap-water in Chile.
erizzo said:
And I hope I didnt ofend you eather Rasmus.
Nope, you certainly didn't offend me, even though I wasn't too pleased about the part that has now been changed. As said, it has been changed, so I see no reason to comment further on that.
First, in case my previous post left any doubts, birding in Chile is amazing and well worth the trip. I believe most who have visited Chile will agree on this part.
Originally, I made my comment on tap-water on basis of personal experience as a visitor (last time I visited Chile was ~1½ year ago) and what guide-books say. I obviously don’t think “European stomachs” are different than “South American stomachs” (and there were certainly absolutely NO racism intended in case anybody misunderstood this; I genuinely love South America and have spend roughly 50% of the last three years in this part of the World). I used "European stomachs" as a fast and non-scientific way of explaining that tolerance (immunity) towards various bacteria etc. is different, often resulting in the well-known travellers' diarrhoea for people who visit far-away countries. As I wanted to be able to elaborate the following further I asked an uncle of mine who has a Ph.D. in Tropical Medicine and also practice as such on the largest hospital in Denmark; Rigshospitalet. It should be menioned that Tropical Medicine is a poor term as it is in no way limited to “tropical”; in reality it covers the various types of diseases that are not normally associated with the country of residence (Denmark). He was kind enough to give a lengthy explanations filled with numbers so we have something to relate to. I have tried to keep the scientific language at a fair level, so it should be digestible and not
that boring
:
Water in Chile generally relatively clean especially in larger cities where it usually is heavily treated with chemicals to kill various viruses (vira) and bacteria. For this reason north Europeans may think it taste a bit “weird” compared to the tap-water we are used to, however it is generally considered harmless. This is not unique to Chile, but is common practise in large cities throughout Latin America. Via this chemical treatment, the amount of pathogenic bacteria and viruses often is no higher than in northern Europe. However, the amount of pathogens is not the problem. The actual problem is that the strains (“variations”) found in Chile are not the same found in northern Europe. This means that we, North Europeans, don’t have a natural resistance (as the locals do) to these viruses or bacteria. This is especially obvious in bacteria with a high rate of mutations such as E. coli, Salmonella, Shigella, Yersinia and Clostridium; all of which can give diarrhoea in humans. Furthermore, achieved immunity (Ig-based) against viruses normally is specific without cross-resistance, meaning that even small variations can be of great importance rendering the “original” immunization largely useless. In terms of travellers' diarrhoea many groups are important, but worth mentioning are the various Rota Virus, Norfolk Virus("-group") and the enterotoxins from E. coli (= not the bacteria itself; the toxins it produce). A relatively small amount is needed of the above to make you ill and for this reason they are considered a risk in tap-water. Furthermore, none of them are removed efficiently via the usual treatment of water, be that chemical or mechanical. For these reasons a large percentage of travellers' diarrhoea are the results of exposure to those groups. It should be mentioned that in normal, healthy adults these pathogens usually don’t cause serious illness that needs treatment - just a few days in bed. But… if you visit
beautiful Chile for the typical 10-14 days, do you really want to spend two or three days in bed? The most recent numbers (1995-99) indicate that 26% of north Europeans (survey included people from Denmark, Norway, Sweden, Germany, Switzerland, Holland & England) who visit Chile will get travellers’ diarrhoea. For comparison the average for visits to Latin America is significantly higher at 38%, while visits to the Mediterranean region results in travellers’ diarrhoea in between 3 and 18% (depending on the exact region). Obviously many of these cases are not due to pathogens in the tap-water. There appear to be four main reasons why people get travellers’ diarrhoea: 1) Pathogens in food, 2) Pathogens in water, 3) Direct transfer of pathogens via contact with other humans & 4) Different food and drinking habits than we are used to (i.e. not pathogen related).
As a traveller you
will need to eat, you
will need to shower, you
will have contact with other humans and the food/drinks
will be different from what you are used to. But why not
remove the risk from tap-water? Especially as it is easily done by buying certified water on bottles - this also being recommended by guide-books. Even more so as birders usually spend a significant time away from cities in areas where treatment of tap-water is minimal or even non-existent. In such areas Chile has had recent sporadic cases of Cholera (so far very localized in Chile, but apparently on the rise throughout South America) and Typhoid (relatively widespread, esp. December-March); both of which to a large extent are spread by contaminated water. Both of these are also mentioned on the homepage of the Foreign & Commonwealth Office (
http://www.fco.gov.uk) under "travel advice - health" for Chile.
Above should not deter anybody from visiting Chile, and, as obvious from the figures given (combined with previous comments in regards of Dengue, Malaria etc.), Chile is significantly safer than Latin America in general - not that pathogens present a large problem anywhere in Latin America as long as you take the needed precautions...