How to keep your family safe from gastro

The threat of a quick-spreading gastro outbreak will spur any household into action to avoid vomiting and diarrhoea. Here’s how you can help prevent it.

Gastro can affect people of all ages, particularly children attending school or child care, where it can spread like wildfire.

And while keeping safe from infections can be difficult outside the home, there are a number of steps you can take to protect your household from gastro.

What is gastro?

Gastroenteritis, or gastro, occurs when there is an inflammation on the digestive system such as the stomach and intestines.

It is typically caused by viruses, parasites or bacteria, which can spread from person to person.

“What we most frequently see during winter is viral gastroenteritis – so viruses such as the rotavirus or norovirus infections, which spread very readily,” NSWH Health’s director of communicable diseases Dr Vicki Shepherd says.

Gastro tends to spread fast in highly populated places such as child care centres, aged-care facilities and hospitals, where infection control is hard to implement.

What are the signs and symptoms of gastro?

Common symptoms of gastroenteritis can include abdominal cramps, diarrhoea and vomiting.

Others may also experience the following:

  • Loss of appetite
  • Bloating
  • Nausea
  • A feeling of being generally unwell, including lethargy and body aches

In some severe cases, those infected may experience other signs and symptoms such as dehydration, blood stools, or fever.

Why did gastro cases surge in Australia this year?

Infectious diseases expert Professor Paul Griffin says people socialising more again following limited interaction during the height of the pandemic was likely contributing to the increase in gastro cases in 2023.

“We did a really good job in preventing the spread of Covid, staying apart, but perhaps people have relaxed, so we have seen a number of infections have rebounded, including gastro outbreaks,” Prof Griffin says.

“With all mitigations we saw a reduction in flu, RSV (respiratory syncytial virus) and gastro infections.

“Those basic infection control principles – staying away from others and washing hands – works for so many infections.”

Prof Griffin says an element of complacency around hygiene practices and social distancing may have played a role in the increased spread of gastro.

“We always had to have a return to normal after Covid,” he says.

“It is unrealistic to expect all those things to continue, but isolating yourself from others if unwell and keeping up hand hygiene in particular – these remain the best tools at preventing infection.”

How long does gastro last?

Dr Shepherd says symptoms usually only last 24 to 72 hours, but they can take a huge toll on our bodies.

“In very small children and in older people, it can hang around longer,” she says.

Meanwhile Dr Shepherd tells The House of Wellness radio team: “If you’re vomiting it can be in the vomit, but if you have diarrhoea it’s definitely there.”

If you have acute gastroenteritis, symptoms can last less than a week, but most people feel better within three days.

How does gastro spread so quickly?

GP Dr Billy Stoupas says the gastro virus is spread from faecal-oral contamination.

This means rapid spreading can occur from directly touching an infected person or a surface contaminated by someone with gastro.

“If someone doesn’t wash their hands after going to the toilet and then touches the door handle, then you go to the toilet and touch that door handle, you risk contamination,” Dr Stoupas says.

How long is gastro contagious?

Dr Stoupas says it is important to keep in mind a person can remain infectious for 24 to 72 hours after their last episode of diarrhoea, so remain vigilant even once the sick person starts to feel better.

A person with gastro is contagious if they have symptoms and up to two weeks after they have subsided.

Those infected are recommended to undergo a short incubation period of around 24 to 48 hours.

However, this can be extended up to 72 hours for those with gastro caused by norovirus.


How to prevent gastro at home

Sanitation of your home and handwashing are key actions in preventing the spread of gastro.

“Do try and isolate anybody who has symptoms and use a separate bathroom if available,” Prof Griffin says.

“Wash hands really well – consider using soap and water as it is more effective than alcohol rubs – and ensure lots of good cleaning, especially around areas that might have come in contact with the virus.”

Parents should make sure their babies are vaccinated against rotavirus at six weeks and four months of age.

“We’ve been using that vaccine for a decade now and it’s been highly successful in reducing the number of infants admitted to hospital with gastroenteritis,” Dr Shepherd says.

How to treat gastro

“Generally, you do just have to let the symptoms pass through, and while that is happening the biggest thing is pushing fluids and keeping hydrated,” Dr Stoupas says.

He says consuming electrolytes, whether as a drink or an icy pole, is an efficient way to replace those you’re passing with the illness.

In severe cases, medication and hospitalisation may be required to help stop vomiting and prevent dehydration.

Getting enough fluid and signs of dehydration

While there is a general formula for how much fluid someone might require depending on their size, Dr Stoupas recommends simply trying to hydrate as much as possible.

For young children, frequent sips are easier than consuming large amounts all at once.

It is also important to recognise the signs of dehydration, which include:

  • Headaches
  • Dark yellow or brown urine
  • Fewer wet nappies in babies
  • Not going to the toilet as much
  • Dry lips, tongue, or mouth
  • Looking pale
  • Lethargy
  • Extremely thirst

When to see a GP for gastro

While gastro can generally be managed with fluid replacement and rest, there are some situations when it’s best to seek medical advice, including if:

  • You’re experiencing ongoing diarrhoea for more than seven days
  • You’ve been travelling and have diarrhoea
  • You’ve got young kids and they can’t keep any fluids down and are dehydrate
  • You have a baby under six months with a fever
  • You’re experiencing recurrent episodes of the same illness every few weeks

If you’re unsure, Dr Stoupas says parents, especially, should listen to their instincts.

What should you eat after having gastro?

Dietitian Susie Burrell says people should be careful about reintroducing food after a bout of gastro.

“The gut has a series of antennae-like functions and (gastro) destroys that, so everything you eat can go through you,” she says.

Avoid dairy and fruit, because sugars and fibres will exacerbate gastro symptoms and prevent you from absorbing nutrients.

Susie suggests rebuilding the gut after gastro with simple foods like white bread and Vegemite, which contains replenishing B-group vitamins and salt.

Sports drinks and flat soft drinks can also be good before plain foods are reintroduced, she says.

“Gradually increase the complexity of what you’re eating, so maybe a plain chicken soup or some chicken breast with plain, reasonably low-fibre vegetables like carrots,” Susie says.

Then consider taking a probiotic to rebuild the gut and compensate for any medication you may have been on while ill.

For more on keeping your loved ones safe and healthy:

Written by Sarah Marinos and Claire Burke.

First published August 2018. Last updated October 2023.