Yersinia Enterocolitica

What is Yersinia Enterocolitica?

Yersinia enterocolitica is a type of bacteria that causes a disease spread between animals and people, known as yersiniosis. Symptoms of this infection can range from acute diarrhea to more severe conditions like mesenteric adenitis (inflammation of lymph nodes in the abdomen), terminal ileitis (inflammation of the end part of the small intestine), pseudoappendicitis (similar symptoms to appendicitis), and even sepsis (a life-threatening infection) in rare cases.

In some parts of the world, these yersinia infections have become more common than other types of bacterial food poisoning, like those caused by shigella and salmonella bacteria. While it’s most common to see individual cases, bigger outbreaks aren’t rare. People can get yersinia from eating contaminated food or through a contaminated blood transfusion.

A unique aspect of yersinia infections is that even after the symptoms have gotten better, the person can still pass the bacteria in their bowel movements for almost 3 months. That’s why it’s so important for doctors to test for yersinia bacteria in stool samples.

What Causes Yersinia Enterocolitica?

The Yersinia group includes 11 different strains, three of which are known to cause diseases in humans. These diseases are caused by Yersinia pestis, Yersinia enterocolitica, and Yersinia pseudotuberculosis. These illnesses are referred to as Yersinioses and are forms of zoonotic infections, which means they are typically spread from animals to humans. However, in this case, humans don’t contribute to the life cycle of the pathogen, meaning they don’t help the bacteria grow and spread.

Yersinia is categorised based on its biochemical characteristics. Out of the six variations, types 2, 3, and 4 are the most commonly found in humans.

Risk Factors and Frequency for Yersinia Enterocolitica

Y. enterocolitica is a type of bacteria that is commonly found in pigs and can spread within a herd. This bacteria can contaminate pig products including neck trimmings, tongue, and tonsils, and even other cuts of meat during slaughter.

Yersinia bacteria are categorized based on their phenotype and serotype, essentially their observable characteristics and their specific sub-group. These bacteria are divided into 6 main groups, but 5 of them (groups 1B and 2-5) are considered harmful to humans. These harmful groups are further classified into more than 57 specific O serogroups, but only a select few are actually pathogenic, or disease-causing.

Notable pathogenic serotypes include O:3 (group 4), O:5,27 (group 2 and 3), O:8 (group 1B), and O:9 (group 2).
In Europe, O:3 and O:9 are the most commonly found in human infections.
Meanwhile, in the United States, O:8 is the more prevalent serotype.

Signs and Symptoms of Yersinia Enterocolitica

Yersinia infections can cause different problems, such as enterocolitis, pseudoappendicitis, reactive arthritis, sepsis, pharyngitis, myocarditis, mesenteric adenitis, or dermatitis. The symptoms of these infections vary and may appear in two primary ways:

Acute Yersiniosis: This illness can cause symptoms like diarrhea, stomach pain, nausea, vomiting, and fever. The diarrhea can last anywhere from 12 to 22 days. This type of infection may be hard to identify because the symptoms are like those of other illnesses that cause acute diarrhea. Specific symptom such as pain in the lower right abdomen can help with diagnosis. Children are more likely to have bloody diarrhea than adults. Sepsis, an extreme bodily response to infection, can occur in babies, people who have weak immune systems, and those with too much iron in their bodies. In these cases, the risk of death is around 50%. Even after the acute infection ends, the bacteria can continue to be present in the stool for around 40 days.
Pseudoappendicitis: This form of acute yersiniosis can seem like appendicitis with symptoms like abdominal pain in the lower right area, fever, vomiting, higher white blood cell counts, and diarrhea. Upon surgery, inflammation is found in the last part of the small intestine and a lymph node in the abdominal region, even though the appendix is normal. This condition commonly occurs in young children, often resulting in appendectomy.
Reactive arthritis is another potential consequence of yersinia. This usually impacts multiple large joints and the symptoms may persist for 30 to 120 days. The joint symptoms usually appear 7 to 14 days after the stomach related symptoms.
Another aspect of Yersinia is erythema nodosum, a skin condition that results in red, tender bumps appearing 2 to 14 days after abdominal pain. These skin lesions are more prevalent in adult women and usually resolve on their own.

Testing for Yersinia Enterocolitica

When you have a severe case of diarrhea, your doctor might check your blood and stool. Even though the blood test may not show anything unusual, a stool test can identify whether the ‘Yersinia’ bacteria is causing your symptoms. If Yersinia is detected, you will need to take precautions to prevent the infection from spreading through contact with stool.

Even though ‘Yersinia’ bacteria can sometimes be identified in a blood test, this is typically not the case. Depending on the organ system affected, other tests may be necessary. Imaging tests like ultrasound or a CT scan may also be needed to determine if you have appendicitis or pseudoappendicitis, a similar condition. A diagnosis can sometimes be confirmed from positive cultures taken from specific areas of your body, like lymph nodes in your gut, throat secretions, fluid from the abdomen, or your blood.

There are other tests for Yersinia used in Japan and Europe, such as enzyme-linked immunosorbent assays (ELISA) and immunoblotting. These tests detect proteins called antibodies that your body produces in response to the infection. However, these tests are not commonly used in the United States. There are also tests which use a technique called polymerase chain reaction and immunofluorescence, but these are not commonly used either.

A colonoscopy is not typically performed for Yersinia infection, but in some cases it might be done. This procedure involves using a flexible tube to examine your colon. If you have a Yersinia infection, the doctor might find small, shallow sores and ulcers in the lower portion of your small intestine, called the terminal ileum, during the colonoscopy. Most of the time, the bacteria usually affects the right side of your bowel.

Treatment Options for Yersinia Enterocolitica

When dealing with Yersinia, a bacterial infection, maintaining hydration and good nutrition is essential. Depending on the individual case, specific medications like aminoglycosides or trimethoprim-sulfamethoxazole may be used. There are other effective medications as well, including tetracycline (but it’s not recommended for children), quinolones, and cephalosporins. In some situations, such as when there is an abscess in the abdomen, surgery might be necessary.

One potential complication is when it’s hard to tell the difference between pseudoappendicitis and actual appendicitis. Pseudoappendicitis is when the symptoms appear to point towards appendicitis, but the appendix itself is not inflamed. In these cases, even detailed medical examinations and scans might not be able to reliably distinguish between the two. This can sometimes lead to unnecessary appendix removal surgeries, where it’s discovered during the procedure that the appendix is actually healthy. Instead, the cause of the symptoms is swollen lymph nodes in the abdominal region, which is a condition known as mesenteric adenitis.

It’s generally advised for patients with diarrhea to steer clear of medications that alter intestinal movement, as it could potentially worsen the infection. Antibiotics are usually reserved for particular patients, such as those who are older, have compromised immune systems, or have diabetes. If children become severely dehydrated or develop a severe systemic infection known as sepsis, they might have to be admitted to the hospital. Occasionally, some patients may require hospital admission if it’s unclear whether they have appendicitis.

Preventing Yersinia infection involves good hygiene practices like washing hands after handling animals, eating food that’s been cooked and handled safely, and specifically avoiding the consumption of raw pork and related products. Ensuring clean, disinfected water and screening blood products for the bacterium are also effective preventive measures.

Identifying the correct diagnosis requires a comprehensive history, thorough physical exam, and supportive lab and imaging results. Several conditions can appear similarly to this disease. They include:

Acute diarrhea, which can be caused by a variety of organisms, including viruses, bacteria, fungi, and protozoa
Inflammatory bowel disease
Diverticulitis
Appendicitis
Colitis related to medication
Ischemic colitis, which is inflammation and injury of the large intestine resulting from inadequate blood supply
Infections like HIV, influenza, dengue fever, or malaria, especially in developing countries
Radiation colitis, which can happen after radiation therapy for cancer
Diversion colitis that occurs after surgery to create a temporary or permanent bypass (diversion) of the large intestine
Solitary rectal ulcer syndrome
Cancer of the colon or small bowel

What to expect with Yersinia Enterocolitica

Yersiniosis, a type of infection, generally has a good prognosis or outcome. Data from a U.S. study show that only 1.2% (18 out of 1373 patients) died after being diagnosed with Yersiniosis. In another study from Norway, only 2 out of 458 patients diagnosed with yersiniosis passed away.

However, it’s important to note that Yersiniosis can lead to various other health problems, including:

* Pseudoappendicitis: a condition that mimics appendicitis
* Erythema nodosum: a skin condition causing red, painful lumps
* Pharyngitis: inflammation of the back of the throat
* Mesenteric adenitis: inflammation of the lymph nodes in the abdomen
* Glomerulonephritis: inflammation in the kidneys
* Myocarditis: inflammation of the heart muscle
* Dermatitis: inflammation of the skin

Also, conditions that break down red blood cells and release iron can increase the risk of a full-body infection. And, using deferoxamine, a medication that removes excess iron from the body, can also increase the risk of Yersinia enterocolitis, a type of intestinal infection.

Possible Complications When Diagnosed with Yersinia Enterocolitica

Complications related to Yersiniosis can occur in the gastrointestinal region as well as outside of it (extraintestinal).

Gastrointestinal Complications:

Perforation of the bowel
Inflammation of the peritoneum, the tissue that lines the inner wall of the abdomen
Serious inflammation and ulcers in the ileum and colon
Intussusception, where one part of the intestine slides into an adjacent part
Paralysis of the ileum, a part of the small intestine
Inflammation of the bile duct
Blood clot in the mesenteric vein
Enlargement and inflammation of the colon, also known as toxic megacolon
Death of the tissue in the small bowel

Extraintestinal Complications:

Liver abscess, a pus-filled mass inside the liver
Abscess in the spleen
Bloodstream infection, also known as septicemia
Abscess in the kidney
Infection in the bone, known as osteomyelitis
Lung abscess
Inflammation of the inner layer of the heart, known as endocarditis
Inflammation and pus formation in the lymph nodes, known as suppurative lymphadenitis
Skin infection
Abnormal dilation of a part of a blood vessel, known as a mycotic aneurysm
Infections related to foreign objects like catheters and prostheses
Inflammation of the heart muscle, known as myocarditis
Inflammation of the kidney’s tiny filtering units, known as glomerulonephritis
Liver failure

Preventing Yersinia Enterocolitica

If you have a simple case of diarrhea, it’s important to stay hydrated and make sure you’re getting enough electrolytes. This can often be managed at home.

To avoid getting sick in the first place, make sure to handle food properly, wash your hands frequently, and avoid eating raw pork products. These preventatives measures can help reduce your risk of infection.

If you start experiencing severe symptoms like a fever, bloody stools, a swollen abdomen, looking unwell, or decreased pee, you should get medical help right away. These could be signs of a more serious problem.

Frequently asked questions

Yersinia enterocolitica is a type of bacteria that causes a disease known as yersiniosis.

Yersinia enterocolitica is commonly found in pigs.

The signs and symptoms of Yersinia enterocolitica, also known as acute yersiniosis, can include: - Diarrhea: This can last for 12 to 22 days and may be accompanied by stomach pain, nausea, and vomiting. - Fever: A high body temperature is a common symptom of Yersinia infections. - Abdominal pain: Pain in the lower right abdomen can be a specific symptom that helps with diagnosis. - Bloody diarrhea: Children are more likely to experience bloody diarrhea than adults. - Sepsis: In severe cases, sepsis can occur, especially in babies, individuals with weak immune systems, and those with excess iron in their bodies. The risk of death in these cases is around 50%. - Pseudoappendicitis: This form of acute yersiniosis can mimic appendicitis, with symptoms such as abdominal pain in the lower right area, fever, vomiting, higher white blood cell counts, and diarrhea. However, upon surgery, the appendix is found to be normal, and inflammation is present in the last part of the small intestine and a lymph node in the abdominal region. - Reactive arthritis: Yersinia infections can lead to reactive arthritis, which typically affects multiple large joints. The joint symptoms usually appear 7 to 14 days after the initial stomach-related symptoms and may persist for 30 to 120 days. - Erythema nodosum: Yersinia can also cause erythema nodosum, a skin condition characterized by red, tender bumps. These skin lesions typically appear 2 to 14 days after abdominal pain and are more common in adult women. Fortunately, they usually resolve on their own.

Yersinia enterocolitica can be obtained by consuming contaminated pig products, such as neck trimmings, tongue, tonsils, and other cuts of meat during slaughter.

The other conditions that a doctor needs to rule out when diagnosing Yersinia Enterocolitica are: - Acute diarrhea caused by various organisms - Inflammatory bowel disease - Diverticulitis - Appendicitis - Colitis related to medication - Ischemic colitis - Infections like HIV, influenza, dengue fever, or malaria - Radiation colitis - Diversion colitis - Solitary rectal ulcer syndrome - Cancer of the colon or small bowel

The types of tests that are needed for Yersinia enterocolitica include: - Stool test to identify the presence of Yersinia bacteria - Blood test to check for any unusual findings, although this may not always show the presence of Yersinia - Imaging tests such as ultrasound or CT scan to determine if there are any complications like appendicitis or pseudoappendicitis - Positive cultures taken from specific areas of the body, such as lymph nodes, throat secretions, fluid from the abdomen, or blood, to confirm the diagnosis - Other tests like enzyme-linked immunosorbent assays (ELISA) and immunoblotting, which detect antibodies produced in response to the infection, although these tests are not commonly used in the United States - Polymerase chain reaction and immunofluorescence tests, although these are also not commonly used - Colonoscopy in some cases to examine the colon and identify any sores or ulcers in the lower portion of the small intestine, known as the terminal ileum - In some situations, surgery may be necessary, especially if there is an abscess in the abdomen.

Yersinia enterocolitica is treated by maintaining hydration and good nutrition. Depending on the individual case, specific medications like aminoglycosides or trimethoprim-sulfamethoxazole may be used. Other effective medications include tetracycline (not recommended for children), quinolones, and cephalosporins. In some cases, surgery might be necessary, especially when there is an abscess in the abdomen.

When treating Yersinia enterocolitica, there can be potential side effects or complications. These include gastrointestinal complications such as perforation of the bowel, inflammation of the peritoneum, serious inflammation and ulcers in the ileum and colon, intussusception, paralysis of the ileum, inflammation of the bile duct, blood clot in the mesenteric vein, enlargement and inflammation of the colon (toxic megacolon), and death of the tissue in the small bowel. There can also be extraintestinal complications such as liver abscess, abscess in the spleen, bloodstream infection (septicemia), abscess in the kidney, infection in the bone (osteomyelitis), lung abscess, inflammation of the inner layer of the heart (endocarditis), inflammation and pus formation in the lymph nodes (suppurative lymphadenitis), skin infection, abnormal dilation of a part of a blood vessel (mycotic aneurysm), infections related to foreign objects like catheters and prostheses, inflammation of the heart muscle (myocarditis), inflammation of the kidney's tiny filtering units (glomerulonephritis), and liver failure.

The prognosis for Yersinia enterocolitica is generally good. Data from studies show that the mortality rate for yersiniosis is low, with only 1.2% to 0.4% of patients dying after being diagnosed with the infection. However, it's important to note that Yersinia enterocolitica can lead to various other health problems and complications.

A general practitioner or primary care physician.

Diarrhea Infectious Disease Mesenteric Adenitis Pseudoappendicitis Terminal Ileitis