Listeriosis: are we at risk?

GILLIAN KLAWANSKY

Listeriosis is a bacterial disease that people contract when eating food contaminated with the bacterium, listeria. While it’s preventable and treatable, in severe cases it can be life-threatening. According to Dr Juno Thomas, head of the Centre for Enteric Diseases at the National Institute for Communicable Diseases (NICD), new cases are steadily being reported.

Furthermore, the number of cases – and of deaths – is likely to be higher than reported as the outcomes of only 30% of reported patients are known.

“Listeriosis only became notifiable on December 15,” explains Dr Thomas. “Up until then, healthcare facilities, workers and laboratories weren’t obligated to report cases.”

According to Dr Thomas, to date about 35% of overall cases have been reported from the private healthcare sector. This proportion is higher than one would expect, she says, considering that only about 17% of the population has access to private healthcare. “To us, this means that the listeria is present in a food item that’s consumed by people across a broad range of socio-economic groups.”

While no one is immune, Linksfield-based family GP Dr Tracy Paiken hasn’t seen any cases to date and argues that those in the middle- to upper-income groups are unlikely to be affected because of their awareness of personal and food hygiene.

But until the contaminated food item causing the current outbreak is identified, everybody is advised to take extra precautions in ensuring food is hygienic. “In many homes, from the poshest to the poorest, food safety is often neglected because people don’t understand enough about it,” says Dr Thomas.

Protect yourself and your family by adhering to the following guidelines, suggests Dr Paiken:

• Wash foods such as fruit and vegetables properly before using them.
• Don’t go to places that don’t have good refrigeration as listeria can grow in the fridge.
• Wash your hands, especially when preparing and eating food.
• If you’re reheating food, ensure that it’s properly heated.
• Don’t eat food that’s been standing outside for a while.

Apart from adhering to basic food safety principles, in the midst of the current listeriosis outbreak, it may be prudent for those in high-risk groups to avoid some foods that have been implicated in past outbreaks, suggests Dr Thomas. These include soft cheeses and ready-to-eat processed meat products like polony, cold meats and sausages – food that isn’t cooked, but rather, is eaten straight from the fridge.

Together with relevant government departments, the NICD is currently working to identify the exact source of the outbreak, explains Dr Thomas. This is done through interviews with patients, testing their food and testing samples from major food production concerns. “Because listeriosis is linked to meat products, dairy products, fresh and frozen fruits, vegetables and sprouts, as well as ready-to-eat products, there’s nothing that’s above suspicion at this stage,” she says.

Before you panic, consider the following. Listeriosis is only contracted by eating contaminated food. “The only other way it’s spread is from a mother to her unborn child during pregnancy, otherwise it isn’t spread from person to person,” explains Dr Thomas.

What’s more, in most otherwise healthy people, even if you eat food that’s contaminated, you won’t become severely ill – you may just contract a form of gastro, some fever and diarrhoea that will soon pass on its own.

“However,” adds Dr Thomas, “people who belong to one of the vulnerable risk groups are at much higher risk of getting severe disease if they eat food contaminated with listeria.” These include:

• pregnant women;
• people over the age of 65;
• babies under the age of one month; and
• anyone with a weak immune system, for example, those with HIV, diabetes, cancer, kidney or liver disease, etc.

“In these risk groups, the serious complications that can occur include bacteria entering the bloodstream and causing a generalised infection or sepsis throughout the body, or travelling to the brain and causing meningitis,” says Dr Thomas.

“Another danger is in the case of pregnant women, when the bacteria enters the bloodstream and infects the unborn child. This  can have serious consequences for the foetus.”

If you’re in one of the identified risk groups, see your doctor immediately if you exhibit the following symptoms:

• fever;
• flu-like symptoms, including generalised tiredness with weakness of the body;
• muscle and joint aches and pains; and
• diarrhoea or vomiting.

If doctors are concerned, they will send a stool sample for testing or take some bloods to diagnose listeriosis, explains Dr Paiken.

Adds Dr Thomas: “Listeriosis is treated with a widely available antibiotic called ampicillin. It isn’t a drug-resistant organism, and people can be treated very quickly.

“If listeriosis is diagnosed during pregnancy, you also go on antibiotic treatment. In most cases, this results in the treatment of the foetus as well, preventing severe complications. However, because this organism tends to attack those who have vulnerable immune systems to begin with, even if it’s diagnosed early and treated correctly, patients may still die in severe cases.”

Being aware, proactive and cautious is therefore essential.