VCOM Carolinas Research Day 2023

Clinical Case-Based Reports

Yersinia enterocolitica infection in an elderly patient complicated by anemia and new-onset atrial fibrillation Alexis Eastburn OMS-III and Lindsey Tjiattas-Saleski DO, MBA, FACOEP Haywood Regional Medical Center, Clyde, NC and Edward Via College of Osteopathic Medicine – Carolinas Campus

Abstract # CBR-18

Hospital Course

Discussion

Abstract Background

Yersinia enterocolitica is a gram-negative zoonotic bacilli that most commonly presents as a benign, self-limiting acute enteritis, most often seen in children. Hospitalizations due to the infection are rare, and most often occur in children or adults over 60 years old (1). The typical disease course includes fever and watery diarrhea with or without blood, or alternatively can present as right lower quadrant abdominal pain that may mimic appendicitis (1-3). Handling or consuming raw or undercooked pork has been identified as the most common source of Y. enterocolitica infection (4). Consuming raw milk and handling the feces of household pets have also been cited as common sources of infection (5,6). Despite evidence that Yersiniosis is more common and causes more severe disease in geriatric patients, there are a limited number of cases in the literature describing the infection in this age group (7). This report aims to contribute an example of Yersiniosis in an elderly patient with no significant preexisting comorbidities and demonstrate the severity of illness it can cause in this patient population. Initial Presentation: • An 86-year-old male presented to the emergency department by ambulance after suffering a presyncopal episode and subsequent fall. • The fall was witnessed and the patient did not suffer any trauma. • Patient admitted to a 3-week history of weakness, fatigue, and diarrhea (1-week of hematochezia). • Patient was normotensive and afebrile. • Past medical history was notable for hypertension and distant colon cancer 20+ years prior with a partial bowel resection. • Past social history: former smoker for 15 years but quit over 30 years prior, occasional alcohol use denied any illicit drug use. • He lived independently at home with his wife. Initial workup: • Fecal occult test was positive • Complete blood count demonstrated a low hemoglobin of 8.1 (13.7-17.5), with macrocytosis and an elevated reticulocyte count of 2.1 (0.5-1.8). • Iron was low at 14 (65-175), with a high ferritin of 887.4 (26.0-388.0), evidence of an anemia of chronic disease (Figure 1). The patient was afebrile. CT of his head, chest, and abdomen and pelvis all revealed no acute findings. His troponin and uranalysis were unremarkable. Initial Patient Presentation

• Had only traditional stool culture methods been performed on this patient’s stool, Yersinia enterocolitica infection may have gone undetected, potentially leading to unnecessary additional invasive procedures and delay of susceptible antibiotic therapy. • This case thus provides evidence for the importance of CIDT in order to detect a wider array of organisms.

Day 1: The patient developed new onset atrial fibrillation with RVR, with heart rates from the 90s 140s. His atenolol dose was increased from his home dose of 25mg to 50mg for rate control, and an echocardiogram was ordered. Anticoagulation was withheld at this time due to current bleeding. Day 3: An Esophagogastroduodenoscopy (EGD) was performed. The procedure revealed a healthy upper GI tract with no actively bleeding ulcers or varices. The results of the stool sample ordered on admission came back positive for Yersinia enterocolitica (Figure 1). It was now presumed that the source of bleeding was infectious diarrhea. A five-day antibiotic course of oral trimethoprim/sulfamethoxazole was initiated.

Sources of Infection: • Raw or undercooked pork is the most common source of Yersinia enterocolitica infection (4). • Pigs are the major reservoir for human pathogenic strains, with the bacteria able to colonize healthy pigs (1,6). • Raw or improperly pasteurized milk has also been reported as a source of infection (5). • Household pets have also been found to be infected with Yersinia enterocolitica (6). • Pets shed the bacteria in their feces, and the bacteria can then spread to humans who handle their stool.

Day 4: Watery diarrhea continued, however evidence of blood in his stool resolved. Hemoglobin levels had stabilized. Day 5: The patient developed new onset confusion and became only oriented to self. He also developed shortness of breath. A chest x-ray was completed which showed mild bilateral pleural effusions. Volume overload from the fluid resuscitation on admission was suspected. The patient was started on IV Lasix. Day 7: The dyspnea had improved and a repeat chest x-ray demonstrated a decrease in size of the pleural effusions. Rate control of his atrial fibrillation had also been achieved and maintained with the increased dose of atenolol. Day 8: The patient was still becoming increasingly confused. A urinalysis was performed and was negative. A thorough neurologic exam did not show any focal deficits. With no other identifiable cause, hospital acquired delirium was suspected. The patient was discharged to a skilled rehab facility.

Figure 3. Common sources of Yersinia enterocolitica infection, including (from left to right, top to bottom) chitlins, raw milk, dog feces, and raw or undercooked pork.

˜ • Despite obtaining a thorough history, it was never determined where the patient obtained his infection. Treatment Guidelines: • Most cases do not require antibiotic treatment as the disease course is usually self-limited. • There are currently no controlled trials demonstrating the efficacy of antibiotic therapy in mild cases of acute, uncomplicated Yersiniosis (10). • The decision to utilize antibiotic therapy is based on clinical judgement of severity and underlying comorbidities (10). • Current recommendations include a fluoroquinolone, or alternatively doxycycline or trimethoprim-sulfamethoxazole. • In cases of complicated GI or extraintestinal infections, doxycycline or trimethoprim sulfamethoxazole are preferred. • Y. enterocolitica is typically resistant to first generation cephalosporins, penicillin, ampicillin, and macrolides. • A 5-day course of oral therapy is recommended if using antibiotics for cases of enterocolitis. • Here a 5-day course of oral trimethoprim-sulfamethoxazole was utilized as the case was deemed a complicated severe case of enterocolitis. • Improvement in the patient’s hematochezia and hemoglobin levels was seen within 24 hours of initiating antibiotic therapy. • This case thus provides further clinical evidence for the utilization of antibiotic therapy in severe complicated cases of Yersiniosis. Prognosis: • The prognosis of Yersinia enterocolitica infections is generally good, with a relatively low mortality rate (6). • Among 1,355 cases in the United States between 1996-2007, only 1.1% resulted in death (11).

Figure 2: Gastrointestinal Panel PCR study, ran on the patient’s stool sample, which identified the Yersinia enterocolitica infection.

Discussion

Clinical Presentation: • Infection most commonly presents as fever and watery diarrhea with or without blood (1). • Cases may also present as right lower quadrant abdominal pain, that in some patients may mimic appendicitis (2,3). Epidemiology: • According to the CDC, an estimated 640 hospitalizations due to Yersinia enterocolitica infection occur per year in the United States, with 35 resulting in death (3). • While more commonly seen in the pediatric population, Yersiniosis has been reported in all age groups (1). • Children under 3 years old and adults over 60 years old have been found to be more likely to have a severe illness requiring hospitalization (8). How to diagnose: • Y. enterocolitica infection can be diagnosed using culture methods or culture-independent diagnostic tests (CIDTs) (6). • Y. enterocolitica can grow on most routine laboratory media, however the bacteria grows slower than most other GI flora bacteria, and therefore growth of Y. enterocolitica may be inhibited by overgrowth of natural GI flora organisms (9). • In this case the infection was detected using a CIDT, specifically a PCR gastrointestinal panel ran on the patient’s stool, which tested for a variety of bacteria, parasites, and viruses (Figure 1).

ED Stay: • 4 hours into being in the emergency department the patient became hypotensive with a blood pressure of 77/47. • A transfusion of 1 unit of packed RBCs and a bolus of normal saline was administered. • Pantoprazole was given due to concern for a GI bleed. • The patient was admitted to the ICU with diagnosis of a probable GI bleed with associated anemia requiring transfusion.

References

Acknowledgements

Thank you to the patient and all involved with his care. There are no relevant financial affiliations or conflicts of interest to report.

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Figure 1. Charts of the patient’s complete blood count, iron studies, reticulocyte count ferritin on the day of admission.

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