What is Yersinia Pseudotuberculosis?
Yersinia refers to a type of bacteria that is shaped like a rod and can be found in many environments. The Yersinia group includes 17 different varieties, but only 3 types can cause disease in humans. These disease-causing types are Yersinia pestis, Yersinia enterocolitica, and Yersinia pseudotuberculosis. Both Yersinia enterocolitica and Yersinia pseudotuberculosis can lead to an intestinal illness. However, Yersinia pseudotuberculosis is not often seen in humans, while Yersinia enterocolitica is more common.
What Causes Yersinia Pseudotuberculosis?
Yersinia pseudotuberculosis is a type of bacteria that you can get by eating or drinking contaminated food and water. It is often found in the soil and can spread to fresh produce grown on farms, such as root vegetables. This bacteria is also common in many types of animals, including birds, rodents, rabbits, deer, dogs, cats, and cattle.
It typically takes between 5 to 10 days after exposure for symptoms to appear, although it can take up to 20 days in some cases. The most common time for symptoms to appear is 4 days after ingestion.
Risk Factors and Frequency for Yersinia Pseudotuberculosis
The infection caused by Yersinia pseudotuberculosis is found worldwide and doesn’t affect any specific race or ethnic group more than others. While it can occur at any time, most cases take place during winter due to the bacteria’s better growth in cold weather.
In the United States, there are no distinct patterns of Yersinia pseudotuberculosis infection. Most outbreaks of Yersinia are connected to Yersinia enterocolitica rather than Yersinia pseudotuberculosis.
Yersinia pseudotuberculosis infection has been an issue internationally with several outbreaks in places like Russia’s Far East and Japan in the latter half of the 20th century. The outbreaks caused a disease known as ‘Far East Scarlet-like Fever'(FESLF). Its occurrence in Europe, however, is random.
- Yersinia pseudotuberculosis doesn’t show any significant racial or ethnic patterns.
- It tends to affect men more than women, but post-infection complications such as arthritis and erythema nodosum are more common in women.
- About 75% of the cases are seen in children and adolescents between the ages of five and 15 years.
- Even though Yersinia pseudotuberculosis’s fatality rate is low, sepsis-associated problems in patients with existing chronic liver diseases can lead to a mortality rate exceeding 75%.
Signs and Symptoms of Yersinia Pseudotuberculosis
Yersinia pseudotuberculosis is known to cause temporary cases of acute gastroenteritis and mesenteric lymphadenitis, which can often be mistaken for acute appendicitis. Typical symptoms of this infection include abdominal discomfort, fever, vomiting, and diarrhea. This abdominal discomfort is usually focused in the lower right quadrant, leading to it being mixed up with appendicitis.
Additional issues that can accompany Yersinia pseudotuberculosis infection include terminal ileitis and intussusception, with the latter being more common in children. Generally, the enterocolitis caused by this infection lasts between one and three weeks. There can also be various skin and joint conditions, such as erythema nodosum, different types of arthritis, and a skin rash. Other symptoms that have been reported include various skin and eye conditions, such as erythema of the face and neck, conjunctivitis, and strawberry tongue.
Symptoms from the infection caused by Yersinia pseudotuberculosis can be broken down into three main categories:
- Systemic symptoms usually include yellowing of the skin and eyes (jaundice), low blood pressure (hypotension), and swollen lymph nodes (lymphadenopathy).
- Enteric symptoms can include abdominal tenderness, possibly even a specific kind of pain known as rebound tenderness which tends to be in a specific area known as McBurney point.
- Rheumatologic symptoms often include swelling of the joints (joint effusion), joint tenderness, decreased range of movement, and may not be the same on both sides of the body.
People with weakened immune systems or conditions that result in too much iron in the body, such as hemochromatosis, venous congestion, hemolytic anemia, and cirrhosis, are at a higher risk of sepsis from this infection.
Testing for Yersinia Pseudotuberculosis
The diagnosis of Yersinia pseudotuberculosis, a type of bacteria that can cause infections, is typically done in a laboratory by confirming the presence of the bacteria. This confirmation mainly involves analyzing samples from body fluids such as blood, cerebrospinal fluid (fluid surrounding the brain and spinal cord), peritoneal fluid (fluid in the abdominal cavity), synovial fluid (fluid surrounding joints), or from a biopsy of the organs.
However, identifying Yersinia pseudotuberculosis requires attention to certain unique features. They are classified as gram-negative coccobacillus, which refers to their shape and how they respond to a particular staining technique used in microbiology. This bacterium can be distinguished by its ability to break down sorbitol, a type of sugar, and display ornithine decarboxylase activity, an enzyme involved in the metabolism of the amino acid ornithine. These bacteria grow best at temperatures between 20 to 35°C. They can survive in both oxygen-rich and oxygen-poor environments but their growth is slow and best observed between 24-72 hours. Yersinia pseudotuberculosis looks like small gray and transparent colonies and does not ferment lactose, a common habit of some other bacteria.
Diagnosing this bacterium from stool samples can be tricky because it grows slowly. However, using certain techniques like cold enrichment, special culture media, or an alkali treatment can help with extraction from stool samples. Similarly, it’s also possible to find the organism in blood, peritoneal fluid, synovial fluid, and pharyngeal exudate (a substance discharged from the throat).
Another diagnostic method includes serology, a blood test that detects antibodies, proteins your body produces to fight off infections. Enzyme-linked immunosorbent assay and agglutination tests are two types of serological tests that can be used. These antibodies tend to appear soon after the infection starts and can last for two to six months. However, these antibody tests can sometimes give false-positive results if there is a cross-reaction with antibodies from other organisms.
In patients showing symptoms of swollen lymph nodes in the abdomen (mesenteric lymphadenitis), computed tomography (CT) scans or ultrasound may reveal enlarged mesenteric lymph nodes and other signs like inflammation of the appendix and terminal ileitis (an inflammatory condition in the last part of the small intestine).
If someone is experiencing symptoms like pneumonia or sepsis (a severe infection that spreads in the bloodstream), a chest x-ray may show infiltrates, which are marks indicating acute pneumonia. In rare cases, if the patient has Izumi fever, a condition similar to Kawasaki disease, abnormalities in the electrocardiogram (ECG) could show signs of reduced blood supply to the heart due to possible aneurysms, which are bulges in the blood vessel walls. This situation is especially concerning in children.
Treatment Options for Yersinia Pseudotuberculosis
Infection with Yersinia pseudotuberculosis, a type of bacteria, often resolves on its own. However, in severe cases where toxins cause intense symptoms like sepsis (a life-threatening response to infection) or severe dehydration, hospitalization may be required for support and care.
Antibiotics, which are medicines used to treat bacterial infections, aren’t always needed for less severe infections. However, if a person has a weakened immune system or chronic liver disease and is experiencing severe symptoms like sepsis, the use of antibiotics may be necessary.
Research has shown that the fluoroquinolone group of antibiotics (medications that kill bacteria or prevent them from growing) are the most effective in treating Y. pseudotuberculosis infections. While other types of antibiotics weren’t as effective in stopping bacterial growth, some like ampicillin, ceftriaxone, doxycycline, and gentamycin have successfully treated this infection and its complications in the past.
In some rare cases, if complications such as severe gastrointestinal (relating to the stomach and intestines) bleeding or intestinal blockage occur, it may be necessary to perform an exploratory laparotomy. This is a surgical procedure where a large incision is made in the abdomen to identify and treat the problem. However, this type of intervention is not common.
What else can Yersinia Pseudotuberculosis be?
There are several health conditions that may share similar symptoms with each other. Here are some of these conditions:
- Appendicitis
- Pancreatitis
- Inflammatory bowel disease
- Gastroenteritis
- Scarlet fever
- Toxic shock syndrome
- Leptospirosis
What to expect with Yersinia Pseudotuberculosis
Most cases of Yersinia pseudotuberculosis, a type of bacterial infection, are mild and go away on their own. However, for people with weakened immune systems and those who have chronic liver disease, this condition can be deadly. These patients are at risk of developing a severe form of the disease that can result in sepsis (a life-threatening infection that can spread throughout the body) and widespread involvement of the intestine.
Possible Complications When Diagnosed with Yersinia Pseudotuberculosis
Common Side Effects:
- Reactive arthritis – a condition causing inflammation, redness, and swelling in the joints.
- Septic arthritis – an infection causing severe discomfort in the join
- Uveitis – inflammation of the middle layer of the eye
- Acute tubulointerstitial nephritis – an inflammation condition affecting the kidneys.
- Terminal ileitis – inflammation of the end part of the small intestine.
- Severe gastrointestinal (GI) bleeding – potentially life-threatening blood loss in the digestive tract.
- Intussusception – a serious condition where one part of the intestine slides into an adjacent part.
- Intestinal abscess – pus-filled area in the intestines caused by infection.
- Intestinal obstruction – blockage that prevents normal flow of food or liquids through your intestines.
- Sepsis – a life-threatening condition caused by the body’s response to an infection.
- Death – the most severe outcome.
Recovery from Yersinia Pseudotuberculosis
Patients suffering from diarrhea, fever, and loss of appetite may continue to experience these symptoms for several days or even weeks. During this time, doctors generally advise patients not to eat or drink anything by mouth, a practice referred to as NPO (nil per os). Additionally, patients are typically given fluids through a vein (IV hydration) to ensure they remain well-hydrated and nourished during this period.
Preventing Yersinia Pseudotuberculosis
The patient should be informed about the importance of maintaining cleanliness and safety in handling food, as the disease-causing organism can tolerate cold temperatures. Regrettably, there isn’t a vaccine available yet to counteract this organism.
