Basics
Description
Yersinia enterocolitica is a gram-negative bacillus that produces an enteric infection characterized by fever, diarrhea, and abdominal pain that may mimic acute appendicitis. ‚
Epidemiology
- Y. enterocolitica is estimated to cause 116,716 infections in the United States annually.
- According to surveillance by the Foodborne Diseases Active Surveillance Network (FoodNet) from 1996 to 2009, the overall annual incidence of Y. enterocolitica infections was 0.5 per 100,000 persons but significantly declined over the time period.
- Most infections occurred in young children; 47% were in children <5 years, and 32% were in infants <1 year.
- Among subgroups, the highest annual incidence was among infants <1 year at 12.3 per 100,000 persons.
- Transmission of Y. enterocolitica
- Occurs through ingestion of contaminated food or water (particularly raw or undercooked pork or unpasteurized milk products) or contact with infected animals (swine are the principal reservoir)
- Fecal " “oral and person-to-person transmission are also possible.
- In the United States, most epidemics have been related to the improper handling of raw pork intestine (chitterlings), most often during winter holiday festivities among African American households in the South.
- Transmission to young children occurs through contact with adult caregivers preparing the chitterlings.
- Transmission through transfusion of contaminated blood products is also possible. The FDA has reported that contamination of the U.S. blood supply by bacteria, although rare, is most frequently due to Y. enterocolitica.
- The incubation period is ¢ ˆ ¼1 " “14 days (average 4 " “6). The mean duration of organism excretion is 42 days; however, asymptomatic carriage can persist even longer.
- Systemic disease or bacteremia occurs more commonly in young infants or those with predisposing conditions, including a clinical state of iron overload or deferoxamine therapy, immunosuppression, diabetes mellitus, malnutrition, and cirrhosis or other liver diseases.
General Prevention
- Infection control
- Contact precautions are indicated for patients with enterocolitis until diarrhea resolves.
- General measures
- Attempts to eliminate reservoirs and reduce frequency of ingesting contaminated foods and beverages are necessary.
- Ingestion of undercooked meats, especially pork and unpasteurized milk, should be avoided.
- Meticulous hand hygiene before and after handling uncooked meat products and avoidance of preparation of meats near or during preparation of infant bottles for feeding are essential.
Pathophysiology
- The portal of entry for Y. enterocolitica is the gastrointestinal tract.
- Y. enterocolitica adheres to epithelial cells and mucus, producing heat-stable enterotoxins, which play a role in the development of watery diarrhea.
- Another cytotoxin then directly injures the distal small and large bowel, producing stools characterized by blood and mucus.
- Release of these toxins leads to the development of an enterocolitis, most commonly in younger age groups.
- Mesenteric adenitis and/or terminal ileitis may lead to a pseudoappendicitis syndrome, typically in the older child or young adult.
- Bacteremia may lead to focal abscesses in a variety of organs, including the lung, liver, spleen, and kidney.
Etiology
- The genus Yersinia consists of 11 species, of which Yersinia enterocolitica, Yersinia pseudotuberculosis, and Yersinia pestis are the 3 most commonly encountered pathogens.
- Y. enterocolitica is a facultative, non " “lactose-fermenting, urease-positive, gram-negative bacillus.
- Over 60 serotypes and 6 biotypes of Y. enterocolitica have been identified. Serotypes O:3, O:5.27, O:8, and O:9 and biotypes 2, 3, and 4 are most commonly isolated from patients. Serotype O:3 is the most common type in the United States.
Diagnosis
Diagnosis depends on elucidation of the pertinent exposure history as well as recognition of typical symptoms and laboratory testing. ‚
History
- Enterocolitis is the most common manifestation of Y. enterocolitica infection in young children and is characterized by fever, abdominal pain, and diarrhea with blood or mucus.
- 25% of patients have hematochezia.
- Typical duration of illness is 1 " “3 weeks but may be longer (up to several months).
- The history taking should include questions regarding exposure to unpasteurized milk products and raw pork or poultry, especially the preparation of pork chitterlings.
- A pseudoappendicitis syndrome due to mesenteric adenitis and/or terminal ileitis predominates in older children and adults and is associated with fever, right lower quadrant abdominal pain, and leukocytosis.
- Yersinia bacteremia is found most commonly in infants <1 year of age or those with predisposing conditions, particularly states of iron overload (e.g., sickle cell disease, thalassemia).
- Extraintestinal manifestations of Y. enterocolitica infection are uncommon and include pharyngitis, suppurative lymphadenitis, pyomyositis, osteomyelitis, abscess, UTI, pneumonia, endocarditis, meningitis, peritonitis, panophthalmitis, conjunctivitis, and septic arthritis.
Physical Exam
Because of the wide range of clinical symptoms, including extraintestinal manifestations, the physical exam is nonspecific for this infection. ‚
Diagnostic Tests & Interpretation
Lab
- Y. enterocolitica can be isolated from blood, sputum, CSF, urine, and bile; these specimens do not require selective culture media techniques.
- Stool samples should be plated on selective media such as cefsulodin-triclosan-novobiocin agar.
- If routine enteric media (MacConkey) are used, a cold enrichment technique will increase recovery of the organism.
- The laboratory should be notified that Yersinia is suspected if not routinely sought.
- Serologic methods (tube agglutination assay, enzyme-linked immunosorbent assay [ELISA]) are available with a rise in titers noted 1 week after onset of symptoms and peak titers observed by the 2nd week of illness. These tests identify IgM, IgG, and IgA antibodies against Y. enterocolitica.
- Cross-reactivity between Y. enterocolitica and Brucella abortus, Rickettsia species, Morganella morganii, Salmonella species, and thyroid tissue antigen make serodiagnosis of limited usefulness.
Imaging
Abdominal ultrasound can be used to distinguish pseudoappendicitis from acute appendicitis through demonstration of bowel wall edema in the terminal ileum and cecum. ‚
Differential Diagnosis
- Y. enterocolitica should be considered in all patients with fever, abdominal pain, and stools with blood or mucus as well as in patients with the extraintestinal manifestations described earlier.
- Pitfalls
- Not all bacterial colitis presents with bloody or mucus-appearing diarrhea. Therefore, suspicion should exist if the diarrhea is prolonged or environmental exposures pose a risk for developing infection.
- The possibility of Y. enterocolitica bacteremia should be considered in blood transfusion " “related illnesses, thalassemia, or prior history of liver disease.
Treatment
General Measures
- The benefit of treatment of uncomplicated enterocolitis, mesenteric adenitis, or pseudoappendicitis has not been established in immunocompetent hosts.
- Antimicrobial therapy has been shown to benefit patients with systemic infections, focal extraintestinal infections, and enterocolitis in an immunocompromised host.
- For most isolates, trimethoprim/sulfamethoxazole, chloramphenicol, aminoglycosides, tetracycline or doxycycline, fluoroquinolones, and 3rd-generation cephalosporins are effective treatment options.
- Y. enterocolitica is usually resistant to most penicillins and 1st-generation cephalosporins.
Ongoing Care
Follow-up Recommendations
- Symptoms of enterocolitis usually abate within 2 weeks of the onset of illness.
- Shedding of the organism in stool can last more than 6 weeks after diagnosis.
- For extraintestinal manifestations, the expected course depends on the specific organ system involved.
Prognosis
- The prognosis is usually quite good, as most infections are gastrointestinal.
- Systemic disease (i.e., septicemia with subsequent secondary spread) has higher morbidity and mortality. Mortality related to septicemia can be as high as 50%.
Complications
- Postinfectious sequelae may occur 1 " “2 weeks after gastrointestinal symptoms and include erythema nodosum as well as reactive arthritis involving weight-bearing joints. These complications are seen most often in adults, particularly those with HLA-B27 antigen.
- Reactive arthritis syndrome, myocarditis, glomerulonephritis, erysipelas, chronic diarrhea persisting for months, and hemolytic anemia have also been reported.
- Intestinal perforation and ileocolic intussusception are possible.
Additional Reading
- Abdel-Haq ‚ NM, Asmar ‚ BI, Abuhammour ‚ WM, et al. Yersinia enterocolitica infection in children. Pediatr Infect Dis J. 2000;19(10):954 " “958. ‚ [View Abstract]
- Guinet ‚ F, Carniel ‚ E, Leclercq ‚ A, et al. Transfusion-transmitted Yersinia enterocolitica sepsis. Clin Infect Dis. 2011;53(6):583 " “591. ‚ [View Abstract]
- Natkin ‚ J, Beavis ‚ KG. Yersinia enterocolitica and Yersinia pseudotuberculosis. Clin Lab Med. 1999;19(3):523 " “536. ‚ [View Abstract]
- Ong ‚ KL, Gould ‚ LH, Chen ‚ DL, et al. Changing epidemiology of Yersinia enterocolitica infections: markedly decreased rates in young black children, Foodborne Diseases Active Surveillance Network (FoodNet), 1996 " “2009. Clin Infect Dis. 2012;54(Suppl 5):S385 " “S390. ‚ [View Abstract]
- Scallan ‚ E, Hoekstra ‚ RM, Angulo ‚ FJ, et al. Foodborne illness acquired in the United States " ”major pathogens. Emerg Infect Dis. 2011;17(1):7 " “15. doi:10.3201/eid1701.091101p1. ‚ [View Abstract]
Codes
ICD09
- 027.8 Other specified zoonotic bacterial diseases
- 005.89 Other bacterial food poisoning
ICD10
- A04.6 Enteritis due to Yersinia enterocolitica
- A05.8 Other specified bacterial foodborne intoxications
SNOMED
- 80960004 Infection by Yersinia enterocolitica
- 240334006 Yersinia enterocolitica food poisoning (disorder)
FAQ
- Q: How long is a child considered infectious with Y. enterocolitica?
- A: Although the typical course of enterocolitis is ¢ ˆ ¼14 days, shedding of the organism in the stool can last 6 weeks or longer. Strict adherence to hand hygiene should be discussed with the child 's parent or caregiver, particularly for those with incontinent or diapered children, to ensure infection control.
- Q: If there is no history of stools with blood or mucus, can you exclude Y. enterocolitica as the likely infectious agent in a child with diarrhea?
- A: No. In fact, early in the course of illness, the diarrhea is more likely to be watery owing to the enterotoxins produced (see "Pathophysiology ").
- Q: How is the diagnosis of Y. enterocolitica determined if you are unable to isolate the organism from a clinical specimen?
- A: When a diagnosis cannot be made during acute infection or in the clinical setting of postinfectious complications, a serologic titer of >1:128 is suggestive of previous infection of Y. enterocolitica. Keep in mind the possibility of cross-reactivity with Brucella, Rickettsia, Morganella, and Salmonella species as well as thyroid antigens.