Campylobacter Infection: Symptoms, Types, Causes and Treatment

Campylobacter infections are among the most common causes of bacterial gastroenteritis globally. While most cases are self-limiting, some can lead to serious complications and long-term health effects. This article explores the symptoms, types, causes, and treatment options for Campylobacter infection, synthesizing the latest evidence and research to provide an accessible and authoritative overview.

Symptoms of Campylobacter Infection

Campylobacter infection, also known as campylobacteriosis, typically presents with a range of gastrointestinal symptoms, but the clinical picture can vary depending on age, underlying health, and the infecting strain. Recognizing these symptoms is essential for timely diagnosis and management.

Symptom	Description	Age/Group Most Affected	Source
Diarrhea	Watery or bloody stools	All ages; bloody: infants	1 4 5
Abdominal pain	Cramping, sometimes severe	Children >3 years, adults	1 5
Fever	Mild to moderate	Most patients	1 4
Nausea/Vomiting	Accompanies GI symptoms	Variable	4 5
Malaise	General unwell feeling	All ages	4
Asymptomatic	No notable symptoms	Some cases	4
Complications	Reactive arthritis, Guillain-Barré syndrome, IBS	Rare, post-infection	1 2 3 4

Table 1: Key Symptoms

Common Gastrointestinal Symptoms

• Diarrhea is the hallmark of Campylobacter infection, often beginning as watery and sometimes progressing to bloody stools, particularly in infants and young children. Adults and older children may experience cramping abdominal pain, which can be severe enough to mimic appendicitis 1 4 5.
• Fever, nausea, and vomiting frequently accompany diarrhea, but the severity varies. In some young infants, bloody diarrhea may be present without fever 4 5.
• Malaise and a general sense of being unwell are also reported by many patients 4.

Age-Related Presentation

• Infants and Young Children: More likely to have bloody diarrhea without fever as the sole symptom. Watery diarrhea is more common in children over 1 year, while abdominal pain is prominent in children over 3 years 5.
• Adults: Typically present with diarrhea, abdominal pain, fever, and malaise. The disease course is usually self-limited, lasting about a week 1 5.

Asymptomatic and Mild Cases

Not all individuals infected with Campylobacter develop noticeable symptoms. Asymptomatic infections are possible, particularly in regions where exposure is more common 4.

Complications and Long-Term Effects

Most cases resolve without incident, but a minority may develop complications:

• Reactive Arthritis: Joint pain and swelling may occur after infection, with Campylobacter patients at higher risk than those with other bacterial gastroenteritis 3.
• Guillain-Barré Syndrome: A rare but serious post-infectious complication characterized by progressive muscle weakness 1 4.
• Irritable Bowel Syndrome (IBS): Persistent bowel habit changes and IBS-like symptoms can follow infection, especially with toxin-producing strains 2.
• Bacteremia: Rare, but more likely in children or immunocompromised patients 4 11.

Types of Campylobacter Infection

Campylobacteriosis is not a one-size-fits-all disease. Several Campylobacter species can cause infection, and the disease spectrum varies widely depending on the species, strain, and host factors.

Type/Species	Typical Disease Manifestation	Prevalence/Distribution	Source
C. jejuni	Acute gastroenteritis; post-infectious sequelae	Most common, global	1 6 7 10
C. coli	Gastroenteritis, similar to C. jejuni	Less common, some regions	6 7 10
C. fetus	Systemic infections, bacteremia	Rare, immunocompromised	6 10
C. lari, C. upsaliensis	Mild GI symptoms or asymptomatic	Rare, emerging pathogens	6 10
Mixed Infection	Coinfection with other GI pathogens	Not uncommon in children	5 6

Table 2: Types and Species of Campylobacter Infection

Campylobacter jejuni

• C. jejuni is responsible for the vast majority of human cases worldwide. It commonly causes acute gastroenteritis and has been linked to complications such as reactive arthritis and Guillain-Barré syndrome 1 6 7 10.
• Genetic diversity exists within C. jejuni, with various capsular polysaccharide (CPS) types identified. Some strains carry virulence determinants, such as the type-6 secretion system (T6SS), though their presence does not necessarily predict more severe disease 7.

Campylobacter coli

• C. coli is the second most common species causing human disease. The symptoms generally mirror those of C. jejuni, though some studies indicate it may be less frequently associated with severe complications 6 7 10.

Emerging and Less Common Species

• C. fetus, C. lari, and C. upsaliensis are less commonly implicated in human disease. C. fetus tends to cause systemic infections, particularly in immunocompromised individuals, the elderly, or neonates 6 10.
• Newer species are being identified with advances in diagnostics and genomics, highlighting the evolving landscape of Campylobacter infection 10.

Mixed Infections

• Especially in children, Campylobacter infection may coexist with other enteric pathogens (e.g., E. coli, Salmonella, Rotavirus), potentially complicating diagnosis and management 5 6.

Disease Spectrum

• The clinical spectrum ranges from asymptomatic carriage to severe systemic illness, with most cases presenting as self-limited gastroenteritis 4 10.
• Severity may be influenced by species, strain virulence factors, and host immune status 7 10.

Causes of Campylobacter Infection

Campylobacter infections are primarily foodborne, but there are multiple pathways for transmission. Understanding the causes helps guide prevention and risk reduction strategies.

Cause	Description/Examples	Relative Importance	Source
Undercooked Poultry	Eating/handling raw or undercooked chicken	Major source	1 4 8 9 14 15
Contaminated Water	Drinking contaminated or untreated water	Common in developing world	4 6 8 9 15
Raw Milk	Consuming unpasteurized milk	Recognized risk	4 9
Salad Vegetables	Cross-contamination, improper washing	Emerging risk	8
Animal Contact	Direct contact with pets, livestock, animal feces	Notable, especially children	4 8 11
Bottled Water	Some studies show association	Possibly significant	8
Person-to-Person	Fecal-oral route, less common	Occasional	4

Table 3: Main Causes and Transmission Routes

Foodborne Transmission

• Poultry is the leading source of Campylobacter infection worldwide. The bacteria colonize the intestines of chickens without causing disease, resulting in frequent contamination of raw poultry meat 1 4 8 9 14 15.
• Other Meats and Eggs: Undercooked red meat and eggs can also be sources, though less commonly than poultry 4.

Water and Milk

• Contaminated Drinking Water: In many developing regions, untreated or improperly chlorinated water is a significant source of outbreaks 4 6 8 9 15.
• Raw (Unpasteurized) Milk: Milk can become contaminated during collection or via fecal contamination, making pasteurization a key preventive measure 4 9.

Fresh Produce and Bottled Water

• Salad Vegetables: Recent studies have identified salad vegetables as a risk factor, likely due to cross-contamination with raw poultry or contaminated water 8.
• Bottled Water: Unexpectedly, some research has found an association between bottled water consumption and Campylobacter infection, though the reasons remain unclear 8.

Animal and Environmental Contact

• Direct Contact: Exposure to animal feces, especially from young pets (puppies, kittens) or livestock, can transmit infection, particularly to children 4 8 11.
• Environmental Sources: Contaminated soil, sewage, and mud can harbor Campylobacter, though their relative contribution to human infection is less well defined 11.

Person-to-Person Transmission

• Although less common, direct fecal-oral transmission can occur, especially in households or child-care settings with poor hand hygiene 4.

Treatment of Campylobacter Infection

Most Campylobacter infections resolve without treatment, but severe cases and certain high-risk groups may require medical intervention. The choice of therapy is increasingly complicated by rising antibiotic resistance.

Treatment Type	Indication/Use	Resistance/Effectiveness	Source
Supportive Care	Hydration, electrolyte replacement	Mainstay for most cases	1 4 13 14
Antibiotics	Severe, prolonged, or high-risk cases	Resistance increasing	1 6 12 13 14 16
Macrolides	Erythromycin, azithromycin preferred	Still effective in most areas	6 12 14
Fluoroquinolones	Ciprofloxacin, formerly first-line	High resistance, less used	6 12 14
Tetracyclines	Alternative, less commonly used	Some resistance present	14
Alternative Therapies	Probiotics, bacteriophage, vaccines (experimental)	Under investigation	15 16

Table 4: Overview of Treatment Options

Supportive Care

• Hydration: The cornerstone of treatment is maintaining fluid and electrolyte balance, especially in children, elderly, or those with significant diarrhea 1 4 13 14.
• Symptom Relief: Antipyretics and antiemetics may be used as needed, but anti-motility agents are generally avoided in bacterial diarrhea 1 4.

Antibiotic Therapy

• Indications: Antibiotics are reserved for severe, prolonged, or systemic illness, and for high-risk groups (immunocompromised, elderly, infants) 1 4 13 14.
• Effectiveness: Meta-analysis shows that antibiotics can reduce the duration of symptoms by about 1.3 days, but overuse is discouraged due to resistance concerns 13 14.
• First-line Agents: Macrolides such as erythromycin (and azithromycin) remain the drugs of choice in most regions 6 12 14.
• Fluoroquinolones (ciprofloxacin, ofloxacin): Once widely used, now often ineffective due to high resistance rates, especially in areas with heavy use in animal agriculture 6 12 14.
• Tetracyclines: Sometimes used as alternatives, but not first-line due to variable resistance 14.

Rising Antibiotic Resistance

• Global Trend: Resistance to fluoroquinolones and, increasingly, macrolides is rising worldwide, largely driven by antibiotic use in animal husbandry 1 6 12 14.
• Implications: Resistance reduces treatment options and emphasizes the need for prudent antibiotic use and ongoing surveillance 6 12 14 16.

Alternative and Emerging Therapies

• Probiotics: Under investigation for their ability to restore gut flora and reduce symptom duration.
• Bacteriophage Therapy: Experimental use of viruses that target Campylobacter in the gut or in poultry flocks.
• Vaccines: Research is ongoing, especially targeting capsular polysaccharides, but no human vaccine is currently available 15 16.
• Novel Compounds: Anti-Campylobacter bacteriocins and other approaches are being tested in animal and laboratory settings 15 16.

Prevention as Treatment

• Strict food hygiene, proper cooking, safe water, and handwashing are critical to prevent infection and reduce the need for medical treatment 1 4 9 15.

Conclusion

Campylobacter infection is a leading cause of bacterial gastroenteritis, with most cases resulting from contaminated food, water, or direct animal contact. While often self-limiting, the infection can cause severe symptoms and rare but serious complications. Diagnosis relies on clinical suspicion and laboratory testing, and while antibiotics can shorten illness duration in select cases, rising resistance is a growing concern. Prevention through food safety and hygiene remains the foundation of control.

Key Points:

• Symptoms include diarrhea (sometimes bloody), abdominal pain, fever, and malaise; complications can occur in rare cases 1 3 4 5.
• Types: Most infections are caused by C. jejuni, followed by C. coli, with emerging species increasingly recognized 1 6 7 10.
• Causes: The main sources are undercooked poultry, contaminated water, unpasteurized milk, and direct animal contact; emerging risks include salad vegetables and bottled water 1 4 8 9 14 15.
• Treatment focuses on supportive care; antibiotics are reserved for severe cases, with macrolides preferred, but resistance is rising. Alternative therapies are under active investigation 6 12 13 14 15 16.

By understanding the symptoms, types, causes, and treatments of Campylobacter infection, both individuals and healthcare providers can play a role in reducing the burden of this common yet preventable disease.