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The invisible deadly dangers lurking in your kid's water bottle

May 29, 2024May 29, 2024

THE water bottle your child takes to school every day could be carrying more bacteria than a toilet seat, experts warn.

The harmful germs put youngsters at risk of strep A infections, which often have painful and unpleasant flu-like symptoms.

This can result in a sore throat, an aching body, nausea and vomiting, and requires antibiotics to clear up.

But in more serious cases, microbes can get into the bloodstream and progress to invasive group A strep (iGAS), which can be fatal.

At least 48 children in England have died from the infection since mid-September 2022, UK Health Security Agency data shows.

Doctors this week warned that reusable water bottles are the perfect breeding ground for this type of bacteria, and several others.

Dr Donald Grant, senior clinician at The Independent Pharmacy in Bristol, told BirminghamLive: "A common misconception when it comes to reusable water bottle hygiene is that as you're typically filling it with pure water and it's only coming into contact with your own mouth, so there's little need to clean it often.

"However, every time you drink from the bottle, you're transferring bacteria from your mouth, which can then multiply in the container."

Dr Suhail Hussain, a private GP from Hertfordshire, added: "Anything that is reusable can be prone to accumulating dirt, dust or debris and, as a result, bacteria.

"This is exacerbated by the fact water bottles are the ideal environment for harbouring bacteria due to being moist."

According to a study by, the average container harbours 20.8million colony-forming units (CFUs - the number of viable microbes on a surface) - 40,000 times the number of microbes on a bog seat.

The worst offenders were those with hard-to-reach crevices, such as those with a screw top or flip-up straw.

This is because they can easily develop mould and become contaminated by other sources.

"When you store your bottle in a gym bag, for instance, it can pick up bacteria from the interior of the bag or anything else in it," Dr Grant said.

"You can also transfer bacteria from your hands to your bottle.

"If your bottle has a valve cap, you may need to lift or twist it with your fingers, and this can transfer bacteria you may have picked up from touching other objects or surfaces."

These are primarily commensals - microbes that live on us without causing any harm - like streptococcus and staphylococcus.

But they can become problematic if they accumulate, or if someone is under the weather, Dr Hussain said.

"Bacteria such as E. coli - a common cause of urine and bowel infections - can also often colonise the water bottle following repeated handling, such as taking the cap on and off," he added.

"You may become sick and develop gastric illness, such as diarrhoea or vomiting.

"Gram negative rods - another common bacterium found in unwashed bottles - can lead to urogenital tract infections and pneumonia."

A build-up of mould inside the bottle can also cause allergy symptoms, such as a runny nose, sneezing and red, itchy eyes, which can be more severe in people with asthma.

To minimise your risk of getting sick, experts suggest cleaning your reusable bottle after every use.

But if this seems like a lot, try to do it at least twice a week, Dr Grant added.

All you need to banish potentially-harmful bacteria is hot water and washing up liquid.

Give the lids and straws a good scrub, and leave everything to soak in the hot mixture, Dr Hussain said.

For a deeper clean, put the bottle in a bowl filled with 50 per cent water and 50 per cent vinegar overnight.

Another way to reduce your chances of nasty surprises is to keep bottles away from "germ-rich environments, like your gym locker, sports bag, in direct sunlight or in your car.

"The mixture of warmth and moisture is likely to make bacterial overgrowth worse," Dr Hussain said.

They should also be kept for water only.

"You should avoid filling your bottle with anything other than water, such as protein shakes, energy drinks, or sugar-rich liquids, as sugar can stimulate the growth of bacteria," Dr Grant said.

According to the NHS, Group A Streptococcus bacteria are commonly found on the skin or in the throat.

Under some circumstances, they can cause disease.

Common GAS symptoms include:

Most strep A infections are not serious and can be treated with antibiotics.

But when they become "invasive", they can cause:

Staphylococcus on the other hand may result in skin infections, like lumps, swelling, blisters and sore eyelids.

If you feel as though your child's symptoms are getting worse, you should contact your GP.

If they are having trouble breathing, their skin, tongue or lips are blue, or they are floppy and/or will not stay awake, call 999 or go to A&E.