By Dr Eddy Bajrovic*
The recent death of a three-year-old child in Victoria after drinking ‘raw’ or unpasteurised milk should also serve as a reminder to Aussies travelling overseas to choose milk and other dairy products with care.
While you can get a food-borne illness from many different foods, raw milk is among the most risky – at home or abroad.
But, haven’t people drunk raw milk for centuries, you ask?
That’s true, and when it’s consumed straight after the animal was milked, it is relatively safe. It is in the hours between the milking and when the raw milk is packaged and transported to the point of sale that harmful, potentially fatal, bacteria or other pathogens in it can multiply rapidly.
Raw milk is an ideal medium for a range of bacteria such as Brucella, Campylobacter, Listeria, Mycobacterium bovis (a cause of tuberculosis), Salmonella, Shiga toxin-producing Escherichia coli (E. coli O157), Shigella, Yersinia to grow. Raw milk can also carry parasites like Giardia and viruses such as norovirus.
Any organisms that find their way into raw milk multiply quickly unless killed by heat, which is what happens when raw milk is pasteurised. For instance, E. coli can go from 10 cells – enough to make you sick – to 100 million cells in just over 6 hours at 30°C.
Chilling milk slows bacterial growth, but unlike pasteurisation, doesn’t actually stop it.
Some travellers at higher risk of severe illness
Getting sick from raw milk can mean many days of diarrhoea, stomach cramping, and vomiting: Not much fun if you’re on holiday in a foreign country.
Less commonly, the more severe illnesses related to raw milk can lead to kidney failure, paralysis, chronic disorders or, as we’ve now seen in Victoria, death.
Each person’s symptoms can differ, depending on the type of germ, the amount of contamination, and just how well their immune system’s defences respond.
The risk of severe illness from drinking contaminated raw milk is higher for infants and young children, the elderly, pregnant women, and people with weakened immune systems, such those with cancer, and organ transplant, or HIV/AIDS.
The smart travel solution? UHT
So, what are the safer dairy choices for travellers? We asked an expert, Dr David Everett, Associate Professor in Food Science at New Zealand’s University of Otago.
His advice: NEVER drink raw milk – even if the owner of the cow/goat/sheep/buffalo it comes from swears it’s safe. Instead, opt for long-life milk – especially in developing countries.
“Personally, I’d never buy milk outside of a supermarket in any country, but I’d be particularly wary in Asia, Africa, or Latin America,” he said.
“Long-life milk is available just about everywhere overseas. It is often called UHT (ultra-high temperature) milk and effectively it’s sterile and therefore safe to consume anywhere in the world.
“It is heat-treated at around 130-145 degrees under high pressure for 2-3 seconds. It can be stored at room temperature for about 6 months, but must be refrigerated after opening.”
First, eat with your senses
As always when it comes to food safety, eat with your eyes first.
Order dairy products – especially desserts – only in better restaurants where you feel confident about the level of hygiene and sanitation.
“Still, it’s hard for travellers to be certain when it comes to dairy – or any food for that matter,” Professor Everett said.
“Even if a dairy product reaches you chilled, it may have thawed much earlier, which allows bacteria to multiply.
“Subsequent refrigeration slows bacterial growth but does not kill any organisms already in the item.
“And, many poorer countries experience regular power outages and lack reliable cool room storage facilities and refrigerated trucks.”
The safer dairy choices
The safest choices for travellers include:
Packaged butter
Hard cheeses
Hard cheeses are the safest of all dairy products because of their low-level acidity, low water and high salt content, cool storage temperature, hard rind or plastic wrap, and the preserving lactic acid bacterial culture that helps preserve them.
Yoghurt
Despite its high moisture content and the absence of preserving salt, freshly made yoghurt straight from the fridge is a fairly safe choice.
“I am a bit more cautious about yoghurt than cheese, because it can easily spoil,” Professor Everett said. “But, if it has been freshly made and kept refrigerated I would consume yoghurt made in-house when travelling.”
He was quick to add that food poisoning is not restricted to developing countries.
“My own personal experiences with food poisoning were due to mayonnaise on a salad in Amsterdam, undercooked hamburger in Cape Town, and ice cream left out on a shelf all day to make it softer to scoop into iced coffees in Newcastle, Australia.”
Death prompts change to milk laws
It is illegal to sell raw milk for human consumption in Australia.
The tragic death of one child from Victoria’s Mornington Peninsula and the sickening of 4 others after drinking raw milk late last year saw the state government last week act to strengthen existing laws covering the sale of raw milk, which is sold here as ‘bath milk’ or ‘cosmetic milk’. The legislation requires all raw milk products to be pasteurised or have a bitter gag-inducing agent added before it can be sold.
Victoria's Chief Health Officer, Dr Rosemary Lester is concerned unpasteurised milk was intentionally being given to children despite being labelled not for human consumption.
“There are two issues that concern me - one is the movement out there that people think that something raw must be wholesome and better for you, which is clearly not the case,” Dr Lester told the media.
“No matter what precautions are taken by dairy farmers during milking, there can be no guarantee that the milk will be free from harmful bacteria, making pasteurisation essential.”
Pasteurisation – a public health milestone
Like vaccination, pasteurisation is a victim of its own success. Introduced in Australia in the 1950s, pasteurisation has virtually eliminated the illnesses that were once commonly associated with milk.
Indeed, all 9 outbreaks of disease linked to milk in Australia between 1997 and 2008, which led to 117 cases of illness, were the result of drinking raw milk. In the USA, there were 2384 illnesses, 284 hospitalisations and two deaths associated with the consumption of raw milk in 13 years to 2011, according to the CDC.
So why do people choose to drink raw milk? Advocates of raw milk often claim it is healthier and more nutritional because it has not undergone further processing.
But, the reality is that heating milk just long enough to kill disease-causing germs leaves it with all its nutritional benefits, but none of the potential disease risks of raw milk.
Pasteurisation remains an important public health measure that ensures we can enjoy safe milk and other dairy products – at home or away.
Read more about safe food choices. For more advice on healthy travel for your next overseas trip call Travelvax Australia’s free advisory service on 1300 360 164.
* Dr Bajrovic is the Medical Director of Travelvax Australia.