Hold the Gourmet Cheese! Listeria outbreak results in Whole Foods recall
Specific organisms are a significant part of the Infectious Diseases portion of the Internal Medicine (ABIM) board exam syllabus. Below we review Listeria monocytogenes by examining the recent outbreak and subsequent recall of infected cheese.
In late summer 2011, it was cantaloupe from Colorado. This summer, the food item that’s harboring a deadly strand of Listeria monocytogenes is specialty cheese produced in Wisconsin. On Friday, national food retailer Whole Foods Market announced that it is recalling the particular brand of cheese–Crave Brothers Les Freres–that has been implicated in the outbreak. Prior to the recall, it had been sold in at least 30 states and Washington D.C.
The infection has taken the life of one person and hospitalized four others, the U.S. Food and Drug Administration reported this week. The multi-state outbreak currently involves Illinois, Indiana, Minnesota and Ohio. No infants or adolescents have been affected thus far as the patients’ age ranges from 31 to 67 years.
Six species of the gram-positive Listeria exist but only one, L. monocytogenes, is able to infect and produce symptoms in humans. Therefore, this is the one to know about when reviewing for the the Internal Medicine (ABIM) board exam. In addition to raw vegetables and unpasteurized milk products, leftover beef and poultry have been contaminated in the past. A rare but serious illness, Listeriosis can cause fever, myalgias, diarrhea or other gastrointestinal issues. Complicated cases, especially in the elderly, can involve the central nervous system and lead to meningitis, encephalitis and brain abscess.
As we recall from medical school lectures, some of the most vulnerable patients to be affected by Listeria are pregnant women, who have a 10-fold increased risk of becoming ill. Indeed, one of the infected persons in the recent series of cases was pregnant and unfortunately suffered a miscarriage due to the infection. Like many infections, people at the extremes of age and those with hampered immune systems are especially at risk of acquiring Listeriosis.
The CDC reports that individuals above the age of 65 are four times more likely than others to be infected and often suffer more severe cases. Consistent with the recent outbreak, about 20% of Listeria infections are deadly. Similarly, the 2011 Listeria cantaloupe outbreak sickened 147 and killed 33 people.
Supportive care and replenishing fluid is the mainstay of treatment for Listeria gastroenteritis. However, when systemic symptoms develop suggesting bacteremia, ampicillin for 14 days is the first-line therapy. Brain abscess and meningocephalitis cases can require around 4-6 weeks of antibiotics. In severe cases, gentamicin may be added for the first week of treatment in non-pregnant patients.
Listeria’s long incubation period–sometimes as long as 70 days–has traditionally presented a challenge to public health authorities to collect data as many people may not recall having ingested the tainted product. With the recent news reports, those of you practicing in the midwest may witness a spike in the number of patients presenting with the chief complaint of “Recent cheese ingestion.” The US FDA is asking those who experienced a fever within 2 months after eating Les Frères, Petit Frère, and Petit Frère with Truffles cheeses manufactured by Crave Brothers Farmstead Cheese Company to contact their doctor.
Dr. Bhatia is a practicing Internist at the Kaiser Permanente Medical Center in Fremont, CA
You can find other posts by Dr. Bhatia on the Knowmedge Blog. You can also find additional topics and questions directly from the Knowmedge Internal Medicine ABIM Board Exam Review Questions QVault. Ravi Bhatia