Dangers in Freshwater

In many travel destinations, there is an increased risk of pathogens or other health hazards in freshwater. Rivers, lakes, ponds, and poorly maintained swimming pools may contain germs that can enter the body through the skin, mucous membranes, nose, or open wounds.

Especially in warm regions – often in the Global South, but also in many other areas – it is therefore recommended to avoid swimming, wading, or washing in freshwater (lakes, rivers, ponds, waterholes).

The risks associated with freshwater exposure can vary greatly depending on the region. Travelers should therefore assess each situation individually and take local conditions into account.

Infectious diseases caused by parasites and bacteria, such as:

• Schistosomiasis: A worm infection that often begins without noticeable symptoms and therefore can remain undetected for a long time. An early symptom may be an itchy skin rash which appears shortly after freshwater exposure (“swimmer’s itch” or bathing dermatitis). 2–12 weeks after contact, other symptoms such as fever, general malaise, headache, body aches, or abdominal pain may develop (“Katayama fever”). If left untreated, the infection can cause chronic issues such as diarrhea, painful or bloody urination, or persistent abdominal pain and in severe cases, may cause organ damage in the gastrointestinal or urinary tract. In some cases, chronic inflammation may even lead to certain cancers.
  
  
• Leptospirosis: A bacterial infection that occurs more frequently after flooding. Transmission happens through contact with water contaminated by the urine of infected animals (mainly rats). The course of illness can vary widely, from mild flu-like symptoms to life-threatening organ failure.
  
  
• Amoebas, Giardia, and diarrheal pathogens: Parasitic or bacterial infections contracted by swallowing contaminated water. Typical symptoms include diarrhea, nausea, and stomach cramps.
  
  
• Bloodsucking leeches: These parasites are found worldwide, especially in the shallow waters of stagnant or slow-flowing rivers and lakes in tropical and subtropical regions. Leeches can attach to the skin and feed on blood. This is usually harmless but unpleasant, and it may cause minor bleeding or local skin irritation.

Environmental toxins and water pollution

• Wastewater from cities and industries

• Pesticides

• Garbage

Physical hazards

• Currents, shallow water (beware of jumping from rocks)

• Risk of injury from glass, metal, or stones

• Sudden weather changes (e.g., flash floods, thunderstorms)

• Find out about local health risks and heed posted warnings, e.g., regarding schistosomiasis, leptospirosis, or other waterborne diseases.
• Avoid contact with untreated freshwater (lakes, rivers, ponds) in known endemic areas.
• Use only officially approved and monitored swimming sites.
• Wear water shoes, especially on unfamiliar or muddy ground.
• Shower immediately after swimming and dry off thoroughly to reduce the risk of infection.
• Avoid getting water into your mouth, nose, or eyes, and do not swim with open wounds or if you have a weakened immune system.