Dialysis Patients May be at Higher Risk for Listeria Food Poisoning

By Peter Laird, MD

The news over the last month chronicles the still increasing death toll from a deadly bacteria called Listeria Monocytogenes. The culprit in this attack stems from cantaloupe at a farm in Colorado (here).  There are now over 28 confirmed deaths since the outbreak of listeriosis became evident in the middle of August. Listeria is one of the most feared bacteria due to its unique method of invading other cells, it is rocket powered: 

The gram-positive bacterium Listeria monocytogenes is the causative agent of listeriosis, a
severe food-borne infection characterised by abortion, septicaemia, or meningoencephalitis. L. monocytogenes causes outbreaks of febrile gastroenteritis and accounts for up to 10% of community-acquired bacterial meningitis in humans. It is the primary cause of central nervous system infection in domestic ruminants. Listeriosis has one of the highest hospitalisation (90%) and mortality rates of all food-borne infections.

Dialysis patients may be at an increased risk of this infection according to prior studies. In one study from 1984, patients on hemodialysis who received multiple blood transfusions causing elevated iron uptake had several cases of Listeria compared to dialysis patients who had not received blood transfusions. 

Listeriosis in patients with long-term hemodialysis and transfusional iron overlaod

Over a four-year interval, four cases of Listeria monocytogenes bacteremia were observed among a population of 127 patients undergoing long-term hemodialysis. None had an underlying malignancy or were recently receiving immunosuppressive medications. A search for a predisposing factor suggested a relationship to transfusional iron overload. Although still a rare infection, the possibility of listeriosis must be kept in mind by physicians caring for patients undergoing hemodialysis, particularly those requiring blood transfusions.

This may be more relevant today now that EPO recommendations are to increase the reliance of blood transfusions in chronic hemodialysis patients who are not candidates for transplant (here). Another population that may be at risk is the peritoneal dialysis patients. There have been several outbreaks of Listeriosis from contaminated PD solutions documented over the years.

Listeria Monocytogenes Peritonitis in a Peritoneal Dialysis Patient with Severe Heart Failure

Listeria monocytogenes has rarely been reported to cause peritonitis in peritoneal dialysis (PD) patients. Listeriosis is usually a severe disease with a mortality rate of 20 to 40% in humans despite early antibiotic treatment. In this report we present the first case in Greece of peritonitis caused by L. monocytogenes, in a chronic PD patient with severe cardiac failure. The patient received prolonged antibiotic therapy with vancomycin and netilmicin which resulted in peritonitis resolution. Unfortunately however, the listeria infection caused decompensation of the patient’s cardiac failure and led to his death, despite appropriate antibiotic treatment. When peritoneal fluid cultures yield gram positive rods in an immune-compromised patient or on a patient with severe underlying diseases who regularly consumes dairy products, the clinical suspicion of this rare infection must be immediately evaluated. Listeriosis can be fatal despite effective antibiotic therapy, since it affects patients with severe underlying pathologies.

Listeria is a lethal pathogen that rears its head in many different settings and is difficult to treat and at times difficult to diagnose due to its similar features to other "gram positive" bacteria. With its unique mode of rocket powered propulsion, it is not only a deadly invader, it is one of the marvels of God's creation. Truly, there is nothing new under the sun as Solomon stated over 3000 years ago.