The key here was warning not to micturate ("P" silent as in bathing) In the waters mentioned there dwells a tiny crustacean, that homes in on the stream of warm water, and enters the male urethra, and has backwards direct spines so it cannot be removed on the spot. If it got into bladder, in old days, death frequently ensued. Equally horrible alternative when only partway up male urethra, was amputation just above that point. A potent reason for not polluting the Amazon. wwh