What’s inside a stream? Plunging into rivers, lakes and streams has its enormous charm and every year as soon as the heat becomes pressing there are many people who walk on the mountain paths to find some refreshment in the wild nature. But you have to be very careful. The dark side of the bucolic experience exists and is not very nice.
In those waters, in fact, there can be several bacteria, viruses and protozoa. Among the former, the most common are those present in the stool released into the water by humans and animals, such as Escherichia coli. For the same reason, salmonella or vibrio (which causes cholera) may also be present in the water. But there may also be viruses such as that of hepatitis A or some rotaviruses (which cause gastroenteritis). In addition, the waters of mountain streams can be the transmission vehicle of some parasites such as entamoeba histolytica, a species of amoeba that causes dysentery, giardia (a parasite of the intestine) or Cryptosporidium, a parasite that infects many vertebrates.
There is not much to do to completely avoid these dangers, common sense however suggests not to swim in waters close to pastures and areas intended for frequent passage of animals. Or in stagnant waters. And to inquire with the locals before diving somewhere.