The Centers for Disease Control and Prevention (CDC), USA, is warning people aged 50 years or more to reheat their cold meat before eating, to avoid listeriosis – listeria infection. For those over 50, and especially over 65, such meats as hot-dogs, cold cuts, luncheon and deli meats should be heated to at least 165 degrees, what the CDC describes as “steaming hot”.

The CDC adds that any opened package of sliced meat should be thrown out within five days.

Listeria is much less common than salmonella or E. coli. However, it can be extremely deadly.

As Spring advances and the days get warmer, there are more group gatherings and a higher consumption of processed meats.

The problem with listeria is that it does not hold back in cold temperatures – put the cold meat in the fridge and it will continue to reproduce. The CDC says the concern over listeriosis in the USA is not new; it seems people are just not paying attention.

Listeriosis is an illness resulting from infection caused by consuming food tainted with Listeria monocytogenes, a bacterium. It is not very common in humans.

The CDC says that listeriosis is a major public health concern in the USA.

The majority of listeriosis cases are non-invasive; patients experience slight flu-like symptoms, such as an elevated body temperature, muscle pain, and some diarrhea. However, those with weakened immune systems and the elderly are more vulnerable to invasive listeriosis.

Invasive listeriosis requires immediate hospitalization and aggressive treatment with antibiotics. Approximately 35% of patients with invasive listeriosis die due to complications.

Infected pregnant women have a significantly higher risk of miscarriage, premature delivery, stillbirth, or life-threatening infection of the newborn.

Listeria is named after Joseph Lister (1827-1912), an English surgeon and apostle of antisepsis.

According to a study by the University of Florida last week, cold cuts and listeriosis were the third worst combination of a food with pathogen in the burden placed on public health, costing approximately $1.1 billion in medical costs and lost productivity.

Latest reports reveal that about 1,600 people have listeriosis each year in the USA, and 260 die.

Written by Christian Nordqvist