In many areas of the world (e.g. Caribbean, Brazil, Africa and Southeast Asia), swimming in slow moving, fresh water rivers, lakes or streams is hazardous due to the risk of contracting schistosomiasis. This microscopic worm can penetrate the skin directly without causing symptoms, only to cause serious illness later. The best protection is to avoid fresh water swimming or bathing in these areas (except for chlorinated pools). If you think you have been exposed, contact the TravelWell staff for a test and evaluation