6330 – Campylobacter jejuni infection

DBQ: Link to Index of DBQ/Exams by Disability for DC 6330

Definition

Campylobacter is a bacterial species that represents an exceedingly common cause of diarrheal illness worldwide. This infection is associated with undercooked poultry, raw milk, and contaminated water consumption. Patients typically present with a self-limited diarrheal illness lasting 5 to 7 days. 

Etiology

Campylobacter jejuni infection, also known as campylobacteriosis, is primarily caused by the ingestion of food or water contaminated with the bacteria, with raw or undercooked poultry being a common source. Transmission can also occur through contact with infected animals or their feces, and less frequently, from person to person. The bacteria's ability to cause illness is influenced by host susceptibility and the strain's virulence.

Signs & Symptoms

nfection with the bacteria Campylobacter jejuni can cause a range of signs and symptoms, primarily affecting the digestive system. 

Here's a breakdown:

Common symptoms

• Diarrhea: This is the most prevalent symptom and can range from watery to bloody. In infants, bloody diarrhea may be the only symptom.
• Abdominal pain and cramping: Often described as severe, these are also very common.
• Fever: Many people experience fever.
• Nausea: Feeling sick to your stomach is also frequently reported.
• Vomiting: While less common than other symptoms, vomiting can also occur. 

Other important aspects

• Onset and Duration: Symptoms typically appear 2-5 days after exposure to the bacteria and usually last about a week.
• Dehydration: Diarrhea and vomiting can lead to dehydration, so it's essential to drink plenty of fluids.
• Complications: While most cases are mild and resolve on their own, Johns Hopkins Medicine notes that severe complications can occur. These can include:
  • Guillain-Barré Syndrome (GBS): A rare but serious neurological disorder where the immune system attacks the nerves, potentially causing muscle weakness and paralysis.
  • Reactive Arthritis: Some people experience joint inflammation following infection.
  • Bacteremia: In rare instances, the infection can spread to the bloodstream.
  • Irritable Bowel Syndrome (IBS) and Post-Infectious Colitis: These can lead to persistent diarrhea, bloating, and abdominal pain. 

When to seek medical attention

You should contact your healthcare provider if you experience:

• Severe or prolonged diarrhea.
• High fever.
• Bloody stools.
• Signs of dehydration, such as excessive thirst, dizziness, or lightheadedness.
• Severe or persistent abdominal pain.
• Signs of GBS, such as weakness and tingling in the legs that may spread to the arms. 

In cases of infants and young children, consult a doctor if they have a fever above 100.4°F (37.7°C) and diarrhea, diarrhea that doesn't improve within 2 days or worsens, or if they have been vomiting for more than 12 hours (immediately if under 3 months), according to Mount Sinai.

Tests

To detect and diagnose Campylobacter jejuni infections, several laboratory tests are available. 

Here's an overview of the common methods:

• Stool Culture: This is considered the reference method for diagnosing Campylobacter infections. Stool samples are cultured under specific conditions to grow the bacteria, allowing for identification and potentially antibiotic susceptibility testing.
• Rapid Diagnostic Tests: These tests detect the genetic material or specific antigens of Campylobacter bacteria in stool samples. Some common rapid tests include:
  • Nucleic Acid Amplification Tests (NAATs), including PCR (Polymerase Chain Reaction): These tests detect the genetic material (DNA) of the bacteria, offering a rapid and precise method for detection. Multiplex NAAT/PCR tests can simultaneously detect several pathogens, including Campylobacter spp, according to the National Institutes of Health (NIH).
  • Enzyme Immunoassay (EIA) or Enzyme-linked Immunosorbent Assay (ELISA): These tests detect the body's immune response (antibodies) to Campylobacter or the presence of Campylobacter antigens in stool samples. Some rapid immunoassay kits can provide results in less than 30 minutes, notes Techlab.
  • Rapid Membrane Enzyme Immunoassays (such as the QuickVue® TLI Campylobacter Test or CAMPYLOBACTER QUIK CHEK™): These tests detect Campylobacter-specific antigens in stool samples, including C. jejuni and C. coli, and can be used with both preserved and unpreserved fecal specimens, according to QuidelOrtho.
• Blood Tests (Serology): These tests look for antibodies to Campylobacter in the blood. They are rarely used to diagnose typical diarrheal illness. However, blood tests may be ordered if complications like reactive arthritis or Guillain-Barré syndrome are suspected, states UCSF Health.
• Microscopic Examination of Stool: While not as sensitive as culture or rapid tests, microscopic examination of stool smears can reveal white blood cells, indicating inflammation associated with infection. Gram staining can detect the characteristic curved rods of Campylobacter, but its sensitivity is variable. 

Important Considerations:

• Sensitivity and Specificity: The accuracy of different tests can vary. Rapid tests offer quicker results, but their sensitivity and specificity may be lower than culture or molecular tests like PCR.
• Timing of Specimen Collection: The performance of some tests, particularly antigen detection, is best when performed on fresh stool samples collected during the acute phase of illness (within the first 4-5 days of symptoms), according to www.droracle.ai.
• Antibiotic Use: Prior antibiotic treatment can potentially affect the results of culture and antigen tests.
• Clinical Context: Test results should always be interpreted in conjunction with the patient's clinical presentation, including symptoms and history, notes TECHLAB, Inc.
• Culture-Independent Tests: While offering speed, rapid tests for detecting antigens in stool may not be entirely reliable as standalone diagnostic tools, according to Medscape. Culture remains important for antibiotic susceptibility testing and epidemiological information, says the National Institutes of Health (NIH).

Treatment

Treatment for Campylobacter jejuni infections typically focuses on managing symptoms and, in certain cases, utilizing antimicrobial therapy. 

1. Supportive care

• Hydration and electrolyte replenishment: The primary focus for healthy individuals is to replace lost fluids and electrolytes due to diarrhea. This can be done orally with clear liquids, oral rehydration solutions (like Pedialyte®), or intravenously in severe dehydration cases.
• Antimotility agents: Generally avoid antimotility agents (e.g., loperamide) as they can prolong the infection and should only be used under a doctor's guidance. 

2. Antibiotics

Most Campylobacter infections are self-limiting and resolve within a week without antibiotics. Antibiotics may be necessary for severe cases, prolonged illness (more than 7 days), systemic spread, or in high-risk patients such as those with weakened immune systems, very young children, older individuals, or pregnant women. 

• Antibiotic choices:
  • Azithromycin: Often preferred, especially in areas with high fluoroquinolone resistance.
  • Erythromycin: An alternative.
  • Fluoroquinolones (e.g., ciprofloxacin): Not recommended as first-line due to increasing resistance.
  • Other options: Carbapenems or aminoglycosides may be used for specific cases, and tetracyclines are an option but should be avoided in pregnancy and children.
• Antimicrobial susceptibility testing: Testing the bacteria for antibiotic effectiveness is advised, particularly for resistant infections.

Residuals

Post-infection residuals of Campylobacter jejuni

While most Campylobacter jejuni infections are self-limiting and resolve within about a week, some individuals may experience post-infectious sequelae or residual effects that can impact their health long-term. These complications can range in severity and affect various body systems. 

Potential post-infectious complications

• Neurological disorders:
  • Guillain-Barré syndrome (GBS): This is a rare but serious autoimmune disorder where the immune system attacks the peripheral nerves, leading to muscle weakness and potentially paralysis. C. jejuni infection is a recognized trigger for GBS, believed to be caused by molecular mimicry between bacterial lipooligosaccharides and nerve cell gangliosides.
  • Miller Fisher syndrome (MFS): A variant of GBS affecting eye muscles and coordination.
• Musculoskeletal disorders:
  • Reactive arthritis: Some individuals may experience joint inflammation following the infection, usually affecting a single joint or a few joints (oligoarticular) and often the knees. This is more common in individuals with the HLA-B27 phenotype and typically resolves within a few months, according to Marler Clark.
• Gastrointestinal disorders:
  • Post-infectious irritable bowel syndrome (PI-IBS): Some individuals may develop IBS symptoms, such as abdominal pain, bloating, and changes in bowel habits (diarrhea, constipation or both) that persist after the acute infection has resolved. Factors like the severity of the initial infection, age, anxiety, depression, and genetic predispositions can increase the risk of developing PI-IBS.
  • Inflammatory bowel disease (IBD) and microscopic colitis: Some research suggests a possible link between C. jejuni infection and an increased risk of developing IBD (Crohn's disease or ulcerative colitis). Some patients with PI-IBS also exhibit mucosal abnormalities in the colon similar to microscopic colitis.
• Other complications (rare):
  • Bacteremia: The infection can spread to the bloodstream, which is more likely to occur in individuals with weakened immune systems.
  • Cardiovascular complications: In rare cases, the infection may spread to the heart or brain, notes Mount Sinai. 

Mechanism of action

• Molecular mimicry: In the case of GBS, C. jejuni bacteria have a surface structure (lipooligosaccharides) similar to gangliosides found on nerve cells. The immune system, in its effort to fight the infection, may mistakenly attack the nerves.
• Immune dysregulation and inflammation: C. jejuni infection can trigger an inflammatory response that may become dysregulated or misdirected, potentially contributing to the development of post-infectious complications like reactive arthritis and PI-IBS. Chronic low-grade inflammation and changes in the gut microbiota are thought to play a role in PI-IBS development.