THE RECENT REPORTED death of an adult along with the identification of nine cases of listeriosis has prompted a ‘voluntary precautionary recall’ of over 200 ready-made products ‘due to a link with the outbreak.’

The Food Safety Authority of Ireland (FSAI) has confirmed an adult died with the rare bacterial infection while the HSE’s Health Protection Surveillance Centre (HPSC) is investigating the death. The authority said that no further information can be disclosed to protect the person’s medical confidentiality.

The recalled products are sold in Tesco, Supervalu, Centra and Aldi among other outlets.

The affected meals include chicken curries, lasagnes, bolognaises, pasta bakes, cottage pies and chow meins. Side dishes also being recalled, including readymade mashed potatoes, carrots and peas, green cabbage and pilau rice.

Consumers are being warned not to eat these products as they may be contaminated with the bacteria Listeria monocytogenes.

The recalled products are produced by food manufacturer Ballymaguire Foods which specialises in the production of freshly prepared meals. All batches and all best before dates are included. The products are marketed under the private label brands of its customers.

The FSAI has issued a full list of the recalled products here. The authority has requested that retailers remove the implicated products from sale and display recall notices at point-of-sale. They have also advised caterers not to use these products.

What is listeriosis?

Listeriosis is an infection caused by the bacterium Listeria monocytogenes. It is usually acquired by eating food contaminated with this bacterium. The bacteria are widely distributed in nature. They can be found in soil, water, vegetation and the faeces of some animals — all of which can predispose to contamination of foods.

Anyone who eats food contaminated with the bacterium can become ill but certain groups are at increased risk of infection including pregnant women; newborns; adults with weakened immune systems and the elderly.

Infection in a healthy adult is usually without symptoms or causes a mild flu-like illness. In immunocompromised and elderly people, the infection can occasionally spread to the central nervous system causing meningitis and /or septicaemia, with symptoms such as headache, stiff neck, confusion, loss of balance or convulsions.

Infected pregnant women may have no symptoms or experience a mild flu-like illness. However, infection during pregnancy can lead to premature labour, meningitis in the newborn or even miscarriage.

Diagnosis is usually made by culture of blood or cerebrospinal fluid (the fluid bathing the brain and spinal cord). During pregnancy, a blood test is the most reliable way to find out if symptoms are due to listeriosis.

How does a person get listeriosis?

Infection occurs mainly through contaminated food, as with this recent outbreak. The incubation period (the time between initial infection and the appearance of symptoms) can range between 3 and 70 days, with an average of about three weeks.

If a woman eats contaminated food during pregnancy, the infection can be passed across the placenta to the baby. The World Health Organisation (WHO) report that when infection occurs during pregnancy, prompt administration of antibiotics prevents infection of the foetus or newborn.

How does Listeria get into food?

Listeria monocytogenes is widespread in the environment and can be found in soil and water. Vegetables can become contaminated from the soil or from manure used as fertiliser. Animals can carry the bacteria without appearing ill, and meat or dairy products from these animals can be contaminated. Foods may also be contaminated after processing, such as cheese.

As with this outbreak, the foods most often associated with infection are ready-to-eat refrigerated and processed foods such as: pre-prepared cooked and chilled meats, soft cheeses, cold cuts of meat, pâtés and smoked fish. Outbreaks of listeriosis associated with fresh products- particularly fresh vegetables that undergo little or no heat treatment are reported by the HPSC as becoming more frequent.

The WHO report that foodborne listeriosis is one of the most serious and severe foodborne diseases. It is relatively rare with 0.1 to 10 cases per million people per year depending on the countries and regions of the world. Although the number of cases is small, the high rate of death associated with infection in vulnerable people makes it a significant public health concern.

The HPSC reported 19 cases of listeriosis in Ireland in the last 52 weeks the majority (84%) of whom were 65 years or over.

Globally, the WHO report previous outbreaks included ready-to-eat products such as frankfurters, paté, smoked salmon, dairy products including soft cheese, unpasteurised milk and ice cream; and prepared salads including coleslaw and beans sprouts; as well as fresh vegetables and fruits.

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Unlike many other common foodborne disease-causing bacteria, the WHO report that L. monocytogenes can survive and multiply at low temperatures usually found in refrigerators. Eating contaminated food with high numbers of the bacteria is the main route of infection.

Treatment of listeriosis is with antibiotics. However, even with treatment, infection can be severe and may result in death, especially in older people.

How can I protect myself from listeriosis?

Protecting yourself against listeriosis is particularly important for pregnant women, infants, the elderly and those with weakened immune systems.

As with other foodborne illnesses, there are several measures, the HPSC report that can be taken to reduce the risk of infection.

• Keep foods as short a time as possible and follow story instructions including ‘use by’ and ‘eat by’ dates

• Cook food thoroughly, especially meat, ensuring that it is cooked through to the middle

• Keep uncooked meats separate from vegetables and from cooked and ready-to-eat foods

• Wash hands, knives and cutting boards after contact with uncooked food

• Make sure fridge is working correctly

• When heating in a microwave, follow heating and standing times recommended by the manufacturer

• Throw away leftover reheated food. Cooked food that is not eaten immediately should be cooled as rapidly as possible and then stored in the fridge

• Pregnant women, the elderly and people with weakened immune systems should avoid eating high-risk foods such as raw (unpasteurised) milk or foods made from raw milk; soft or mould-ripened cheeses (feta, Brie, Camembert, blue-veined cheeses), pâté or smoked salmon

• If contact with ewes at lambing time is unavoidable for pregnant women, the elderly or people with weakened immune systems, washing of hands after handling animals should reduce any possibility of infection.

Listeriosis is a serious but preventable and treatable disease. Pregnant women, the eelderly,or individuals with a weakened immune system are at greatest risk of severe invasive disease and should avoid high-risk foods.

High-risk foods include deli meat and ready-to-eat meat products such as cooked, cured and/or fermented meats and sausages, soft cheeses and cold-smoked fishery products.

During this instance, if any of the items that have been recalled by the FSAI are sitting in your fridge, discard them immediately and talk to a health professional if you have concerns.

Dr Catherine Conlon is a public health doctor in Cork and former director human health and nutrition, safefood.