Is contaminated water making people sicker during monsoon? Doctor explains rising risk of Diarrhoea, Typhoid and Hepatitis
New Delhi: As heavy rain, flooding and overflowing drains raise the risk of sewage entering water supplies, contaminated water can become an invisible carrier of infection. Dr Prashant Sinha, Senior Consultant and HoD, Department of Emergency Medicine, PSRI Hospital, New Delhi, explains why monsoon stomach illnesses deserve more attention – and when diarrhoea can become dangerous.
The monsoon brings relief from the heat, but it can also bring a less visible health threat: contaminated water. When heavy rainfall overwhelms drainage systems, floods low-lying areas or damages water pipelines, sewage and other pollutants can find their way into drinking-water sources. The water may look perfectly clear, yet still carry bacteria, viruses or parasites capable of causing disease.
According to Dr Prashant Sinha, Senior Consultant and HoD, Department of Emergency Medicine, PSRI Hospital, New Delhi, this is one reason hospitals commonly see patients with diarrhoea, vomiting and other gastrointestinal illnesses during the rainy season.
“During the monsoon, cases of diarrhoea, vomiting, typhoid, hepatitis A and E, cholera, and other gastrointestinal infections often increase,” Dr Sinha says.
The concern is not limited to the glass of water people drink. Contaminated water can enter the food chain through washing, cooking, ice-making and food preparation. WHO notes that unsafe water and inadequate sanitation are associated with diseases including cholera, diarrhoea, dysentery, hepatitis A and typhoid.
How does monsoon water become contaminated
Heavy rain can cause sewage overflows, flooding and runoff from contaminated areas. Where water and sanitation infrastructure is damaged or overwhelmed, faecal contamination can reach drinking-water supplies.
Flooding is particularly concerning because it can contaminate water facilities and expose communities to water- and food-borne infections. WHO recommends protecting water sources and ensuring that drinking and food-preparation water is chlorinated or boiled after flooding.
The danger is that appearance is not a reliable safety test.
A change in colour, smell or taste is certainly a reason to stop using questionable water and report the problem. But water that looks, smells and tastes normal can still contain infectious organisms. The CDC, for example, notes that sewage overflows and polluted stormwater can contaminate water with hepatitis A virus.
It is not just about drinking water
A common misconception is that people become infected only when they drink contaminated water. In reality, the faecal-oral route can involve food and hands as well.
Unsafe water can be used to:
- wash fruits and vegetables;
- prepare salads, chutneys and other uncooked foods;
- make ice;
- prepare beverages;
- wash utensils;
- prepare infant feeds; or
- cook food.
That creates several opportunities for pathogens to reach the mouth.
WHO says diarrhoeal infections can spread through contaminated food or drinking water as well as person-to-person transmission when hygiene is poor. Unsafe household water storage and handling can also contribute to risk.
Which illnesses are linked to contaminated water?
The list is broader than what is commonly called “food poisoning”.
Diarrhoeal disease: A range of bacteria, viruses and parasites can cause diarrhoea. These include organisms such as E. coli, Salmonella, Shigella, Campylobacter, norovirus, rotavirus, Giardia and Cryptosporidium.
Cholera: Caused by Vibrio cholerae, cholera is particularly dangerous because severe watery diarrhoea can result in rapid fluid and electrolyte loss. WHO says untreated severe cholera can become fatal within hours.
Typhoid: Typhoid fever is caused by Salmonella Typhi and is usually transmitted through contaminated food or water. Prolonged fever, headache, fatigue, nausea, abdominal pain and diarrhoea or constipation can occur. Unlike many uncomplicated diarrhoeal illnesses, typhoid requires appropriate antibiotic treatment once diagnosed or strongly suspected by a clinician.
Hepatitis A: The hepatitis A virus spreads primarily through ingestion of food or water contaminated with faeces. Symptoms can include fever, fatigue, nausea, abdominal discomfort, diarrhoea and, particularly in symptomatic adults, jaundice.
Hepatitis E: Hepatitis E is also transmitted mainly through the faecal-oral route, particularly contaminated drinking water. WHO says contaminated water can lead to large-scale outbreaks.
What symptoms should people watch for
For common gastrointestinal infections, symptoms may include:
- loose or watery stools;
- abdominal cramps or pain;
- nausea;
- vomiting;
- fever;
- weakness and fatigue; and
- loss of appetite.
When hepatitis A or E affects the liver, symptoms may also include jaundice, dark urine, nausea, vomiting and marked loss of appetite.
But the most immediate danger from significant diarrhoea is often dehydration.
Every episode of diarrhoea causes the body to lose water and electrolytes. If those losses are not replaced, dehydration can progress to severe weakness, shock and other complications. WHO identifies dehydration as the major danger associated with diarrhoeal disease.
Dr Sinha cautions that persistent diarrhoea should not be dismissed as an ordinary monsoon illness.
“Most mild stomach infections improve with adequate fluids and rest, but persistent diarrhoea can quickly cause dehydration,” he says.
When is it time to see a doctor
Warning signs include:
- extreme thirst;
- very little urine;
- dry mouth;
- dizziness or marked weakness;
- unusual sleepiness or lethargy;
- repeated vomiting;
- blood in the stool;
- high or persistent fever;
- inability to drink or keep fluids down; or
- jaundice.
Young children, older adults, pregnant women and people with compromised immunity can be particularly vulnerable to complications from dehydration or infection.
How to protect yourself during the monsoon
The simplest protection is also the most important: make sure the water used for drinking and food preparation is safe.
If contamination is suspected, use bottled or otherwise verified safe water. Water can also be made safer by appropriate boiling or disinfection. CDC guidance recommends boiling questionable water for at least one minute; WHO similarly recommends boiling or chlorinating water following flooding.
During periods of questionable water quality:
Drink safe water: Use safe water not only for drinking but also for brushing teeth, preparing food, making ice and preparing infant feeds.
Be careful with raw food: Avoid raw salads, cut fruits, chutneys and other foods that may have been washed with unsafe water.
Think twice about ice: Ice is safe only when it has been made from safe water.
Eat food hot and fresh: Proper cooking can reduce the risk from many foodborne pathogens, while food that is exposed or improperly stored can become contaminated again.
Wash hands: Use soap and water after using the toilet and before eating or preparing food. Good hand hygiene remains one of the most important ways to interrupt faecal-oral transmission.
Store water safely: Keep stored water in clean, covered containers and avoid repeatedly dipping hands or dirty utensils into it.
Be extra cautious with uncertain sources: Families dependent on tankers, borewells or stored water should pay particular attention to water safety after heavy rainfall or flooding.
Dr Sinha puts the message simply: “Prevention begins with safe drinking water.”
Monsoon-related stomach illness is common, but it should not automatically be dismissed as routine “food poisoning”. Contaminated water can play an important role in transmitting diarrhoeal infections, typhoid, hepatitis A, hepatitis E and cholera, particularly when flooding, sewage contamination or inadequate sanitation compromise water safety.
As Dr Sinha warns, “Monsoon-related stomach illness should not be dismissed as routine food poisoning.”
The message for families is straightforward: when the rains arrive, water safety becomes healthcare.