Rainfall and Diarrhoea: How to Protect Your Family
By Dr Joann

Diarrhoea and stomach infections in children tend to rise during Malaysia’s heavy rainfall months, even though many parents may not immediately realise the connection. While rainy days can sometimes feel like a refreshing break from the heat—or a nuisance w

hen flash floods appear—they also create conditions that allow harmful germs to spread more easily.

When rainfall is frequent, water flowing through drains, soil, and flooded areas can pick up viruses and bacteria, increasing the chances of contamination in the environment and water supply. This leads to more cases of vomiting, diarrhoea, tummy cramps, and dehydration among young children during these seasons.

Understanding why this happens and how to protect your child can make a big difference in keeping your family healthy during Malaysia’s rainy months.

Why Does Heavy Rain Increase the Risk of Diarrhoea?

During periods of continuous rainfall, our environment changes in ways that favour the spread of viruses, bacteria, and parasites. When rainwater flows, it often picks up contaminants from soil, drains, animal waste, and sewage systems. All these microorganisms can enter the water supply or settle in areas where children play, making infections more likely.

Among the common germs that cause acute gastroenteritis during this time are rotavirus, norovirus, E. coli, Salmonella, Shigella, and Campylobacter.

Children—especially toddlers and young preschoolers—are naturally curious, touch everything, and have weaker immune systems compared to adults. They are also more prone to dehydration when diarrhoea occurs, making prevention even more important.

 

1. Ensure Clean and Safe Drinking Water

One of the main ways diarrhoea spreads is through contaminated drinking water. Even if your home uses tap water, cracks in pipes, old plumbing, or contamination during flooding can increase risk. To reduce this threat, simple habits at home can make a big difference:

Use boiled water for drinking and preparing milk

Boiling water kills harmful microorganisms effectively. If your child still drinks formula or expressed breast milk, always prepare it using fully boiled and cooled water.

Sterilise baby bottles before every use

This is especially important for infants under 12 months. During rainy seasons, the risk of bacterial contamination is higher, so proper sterilisation—whether through steam, boiling, or sterilising tablets—helps protect your baby.

Avoid sharing cups and water bottles among siblings

Infections spread easily within households. Even if one child has mild symptoms, sharing bottles or utensils can transmit viruses to others.

Consider using a water filter—and maintain it properly

A filter can help, but only if the cartridges are changed as scheduled. A poorly maintained filter can become a source of contamination instead of protection.

Store drinking water in clean, covered containers

Leaving water uncovered exposes it to dust, insects, and environmental contaminants. Use containers with lids and keep them away from direct sunlight.

2. Practice Strict Hand Hygiene

If there’s one habit that has shown time and time again to drastically reduce infections, it is proper handwashing. During rainy periods—when the spread of germs is higher—hand hygiene becomes even more crucial.

Teach your children to wash their hands with soap at important moments:

• • Before eating or handling food

  • After using the toilet

  • After outdoor play or contact with soil

  • After touching pets 🐈 🦮

For younger children who may struggle to wash thoroughly, parents or caregivers should assist. Babies and toddlers should also have their hands cleaned before meals and after diaper changes. Using gentle, baby-safe wipes can help when soap and water aren’t immediately available.

3. Safe Food Handling: A Must During Rainy Seasons ☔

Foodborne illnesses spike during periods of heavy rain, often because bacteria multiply more quickly in warm, humid conditions.

Avoid leaving food at room temperature

Bacteria thrive in warm, moist environments. Cooked food should be consumed within two hours or stored in the refrigerator promptly.

Reheat cooked food thoroughly

Leftovers must be heated until steaming hot—not just warmed. Partial heating may not kill bacteria effectively.

Wash fruits and vegetables well

Fresh produce can be contaminated during harvesting, transport, or storage. Washing under running clean water helps remove dirt and potential microbes.

Avoid street food during flood seasons

While usually enjoyable, street food may be exposed to rainwater splashes, flies, or inconsistent hygiene practices. During high-risk periods, it is safer to choose home-prepared meals.

4. Prevent Contamination Inside the Home

Even if you practise good hygiene, your child can still be exposed to germs through floors, toys, or household surfaces—especially when rainwater enters the property.

Keep floors dry and clean

Wet surfaces collect bacteria and mould. Clean spills quickly and mop using child-safe disinfectants.

Do not let children play in floodwater or dirty puddles

Young children may not understand the dangers, but floodwater can contain sewage, animal waste, and chemicals. Even a small cut or accidental splash into the mouth can cause infection.

Wash toys that may have been contaminated

If any toys touch dirty water, they must be cleaned and disinfected before your child uses them again. Soft toys may need to be washed and sun-dried or temporarily removed if they cannot be cleaned properly.

Dispose of diapers safely

Used diapers contain germs. Wrap them securely before throwing them away, and wash hands thoroughly afterward.

5. Keep Sick Children at Home to Prevent Spread

Rotavirus, norovirus, and other diarrhoeal viruses spread very easily between children—especially in daycare centres, kindergartens, or crowded indoor spaces.

If your child has vomiting or diarrhoea:

• Keep them home until at least 24 hours after the last episode

• Encourage rest and hydration

• Clean frequently touched surfaces

• Avoid sending them to school or allowing playdates during the infectious period

A note about the rotavirus vaccine

The rotavirus vaccine is given only to infants under a certain age. It does not completely prevent all diarrhoea, but it significantly reduces severe cases—and also reduces the spread within households. Vaccinated babies are less likely to bring the virus home to siblings or parents.

Bottom Line: Small Daily Habits Make a Big Difference

Heavy rainfall is part of our environment, but the illnesses associated with it are often preventable. Clean water, clean hands, and safe food handling remain the strongest lines of defence against diarrhoea in children.

By staying mindful, making small changes at home, and recognising symptoms early, you can protect your little ones—especially the most vulnerable infants and toddlers—from unnecessary illness and dehydration.

Rainy seasons may be unavoidable, but diarrhoea doesn’t have to be. With the right habits and awareness, families can stay healthy, confident, and well-prepared all year round.

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