Campylobacter infections are among the most common bacterial infections in humans. They produce both diarrheal and systemic illnesses. In industrialized regions, enteric Campylobacter infections produce an inflammatory, sometimes bloody, diarrhea or dysentery syndrome.
Campylobacter jejuni (see image below) is usually the most common cause of community-acquired inflammatory enteritis. In developing regions, the diarrhea may be watery.
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Scanning electron microscope image of Campylobacter jejuni, illustrating its corkscrew appearance and bipolar flagella. Source: Virginia-Maryland Regi....
Infections with Campylobacter-like organisms can produce an enterocolitis/proctocolitis syndrome in homosexual males, who are at increased risk for Helicobacter cinaedi and Helicobacter fennelliae infections.[1] Bacteremia can also occur with H fennelliae.[2] C jejuni infections may also produce serious bacteremic conditions in individuals with AIDS. Most reported bacteremias have been due to Campylobacter fetus fetus infection. Campylobacter lari, which is found in healthy seagulls, has also been reported to produce mild recurrent diarrhea in children. Campylobacter upsaliensis may cause diarrhea or bacteremia, while Campylobacter hyointestinalis, which has biochemical characteristics similar to those of C fetus, causes occasional bacteremia in immunocompromised individuals.
Campylobacter organisms may also be an important cause of traveler's diarrhea, especially in Thailand and surrounding areas of Southeast Asia. In a study of American military personnel deployed in Thailand, more than half of those with diarrhea were found to be infected with Campylobacter species.
The known routes of Campylobacter transmission include fecal-oral, person-to-person sexual contact, unpasteurized raw milk and poultry ingestion, and waterborne (ie, through contaminated water supplies). Exposure to sick pets, especially puppies, has also been associated with Campylobacter outbreaks.
Transmission of Campylobacter organisms to humans usually occurs via infected animals and their food products. Most human infections result from the consumption of improperly cooked or contaminated foodstuffs. Chickens may account for 50-70% of human Campylobacter infections. Most colonized animals develop a lifelong carrier state.
The infectious dose is 1000-10,000 bacteria. Campylobacter infection has occurred after ingestion of 500 organisms by a volunteer; however, a dose of less than 10,000 organisms is not a common cause of illness. Campylobacter species are sensitive to hydrochloric acid in the stomach, and antacid treatment can reduce the amount of inoculum needed to cause disease.
Symptoms of Campylobacter infection begin after an incubation period of up to a week. The sites of tissue injury include the jejunum, the ileum, and can extend to involve the colon and rectum. C jejuni appears to invade and destroy epithelial cells. C jejuni are attracted to mucus and fucose in bile, and the flagella may be important in both chemotaxis and adherence to epithelial cells or mucus. Adherence may also involve lipopolysaccharides or other outer membrane components. Such adherence would promote gut colonization. PEB 1 is a superficial antigen that appears to be a major adhesin and is conserved among C jejuni strains.
Some strains of C jejuni produce a heat-labile, choleralike enterotoxin, which is important in the watery diarrhea observed in infections. Infection with the organism produces diffuse, bloody, edematous, and exudative enteritis. The inflammatory infiltrate consists of neutrophils, mononuclear cells, and eosinophils. Crypt abscesses develop in the epithelial glands, and ulceration of the mucosal epithelium occurs.
Cytotoxin production has been reported in Campylobacter strains from patients with bloody diarrhea. In a small number of cases, the infection is associated with hemolytic-uremic syndrome and thrombotic thrombocytopenic purpura through a poorly understood mechanism. Endothelial cell injury, mediated by endotoxins or immune complexes, is followed by intravascular coagulation and thrombotic microangiopathy in the glomerulus and the gastrointestinal mucosa.
Campylobacter species also produce the bacterial toxin cytolethal distending toxin (CDT), which produces a cell block at the G2 stage preceding mitosis. CDT inhibits cellular and humoral immunity via destruction of immune response cells and necrosis of epithelial-type cells and fibroblasts involved in the repair of lesions. This leads to slow healing and results in disease symptoms.[3]
In patients with HIV infection, Campylobacter infections may be more common, may cause prolonged or recurrent diarrhea, and may be more commonly associated with bacteremia and antibiotic resistance.
C fetus is covered with a surface S-layer protein that functions like a capsule and disrupts c3b binding to the organisms, resulting in both serum and phagocytosis resistance.
C jejuni infections also show recurrence in children and adults with immunoglobulin deficiencies. Acute C jejuni infection confers short-term immunity. Patients develop specific immunoglobulin G (IgG), immunoglobulin M (IgM), and immunoglobulin A (IgA) antibodies in serum; IgA antibodies also develop in intestinal secretions. The severity and persistence of C jejuni infections in individuals with AIDS and hypogammaglobulinemia indicates that both cell-mediated and humoral immunity are important in preventing and terminating infection.
The oral cavity contains numerous Campylobacter species, such as Campylobacter concisus, that have been associated with a subtype of inflammatory bowel disease.[4, 5]
An estimated 0.8 million cases of campylobacteriosis occur annually in the United States.[6]
International
C jejuni infections are extremely common worldwide, although exact figures are not available, particularly in low- and middle-income countries. In high-income countries, the incidence has been estimated to be 4.4-9.3 per 1000 population.[7] New Zealand reported the highest national campylobacteriosis rate, which peaked in May 2006 at 400 per 100,000 population.[8] After implementation of a national strategy to reduce foodborne Campylobacter infections, the rates subsequently fell in 2006-2008.[9]
Mortality/Morbidity
Campylobacter infections are usually self-limited and rarely cause mortality. Exact figures are unavailable, but occasional deaths have been attributed to Campylobacter infections, typically in elderly or immunocompromised persons and secondary to volume depletion in young, previously healthy individuals.
Race
Campylobacter infections have no clear racial predilection.
Sex
Campylobacter organisms are isolated more frequently from males than females. Homosexual men appear to be at increased risk for infection with atypical Campylobacter species such as Helicobacter cinaedi and H fennelliae.
Age
Campylobacter infections can occur in all age groups.
Studies show a peak incidence in children younger than 1 year and in persons aged 15-29 years. The age-specific attack rate is highest in young children. In the United States, the highest incidence of Campylobacter infection in 2010 was in children younger than 5 years and was 24.4 cases per 100,000 population,[10] However, the rate of fecal cultures positive for Campylobacter species is greatest in adults and older children.
Asymptomatic Campylobacter infection is uncommon in adults.
In developing countries, Campylobacter infection is very common in the first 5 years of life. Asymptomatic infection is also more common. In Bangladesh, up to 39% of all children younger than 2 years have asymptomatic infection.
For additional information on pediatric Campylobacter infections, see Campylobacter Infections.
Campylobacter infections can range from asymptomatic to, rarely, severe life-threatening colitis with toxic megacolon.[11]
All Campylobacter species associated with enteric illnesses cause identical clinical manifestations.
Gastroenteritis
The symptoms and severity of the gastroenteritis produced can vary.
Patients may have a history of ingestion of inadequately cooked poultry, unpasteurized milk, or untreated water. The incubation period is 1-7 days and is probably related to the dose of organisms ingested.
A brief prodrome of fever, headache, and myalgias lasting up to 24 hours is followed by crampy abdominal pain, fever as high as 40°C, and as many as 10 watery, frequently bloody, bowel movements per day. Fever, which develops in more than 90% of patients, may be low or high grade and can persist for a week.
Patients with C jejuni infection who report vomiting, bloody diarrhea, or both tend to have a longer illness and require hospital admission.[12]
Abdominal pain and tenderness may be localized. Pain in the right lower quadrant may mimic acute appendicitis (pseudoappendicitis).
Tenesmus occurs in approximately 25% of patients.
In some cases, acute abdominal pain is the only symptom, with pain typically in the right lower quadrant. Among the symptoms, abdominal pain is more likely to result from Campylobacter infection than from Salmonella or Shigella infections.
Differences based on Campylobacter species
In contrast to C jejuni infection, C fetus infection causes diarrheal illness less frequently and is the most commonly identified species in bacteremia. However, C fetus infection that produces diarrheal illness results in clinical manifestations that are similar to those of C jejuni infection. C fetus is an opportunistic agent in debilitated hosts, but healthy hosts may also be affected.[13]
Campylobacter bacteremia is common, and C fetus fetus is frequently isolated from the bloodstream, possibly because it resists the bactericidal activity of serum, while the more common C jejuni does not. Persons who develop Campylobacter bacteremia are usually older and are more likely to have cellulitis, endovascular infection, or a device-related infection.[14]
Systemic illness with a predilection for vascular sites is characteristic. Meningitis,[15] vascular infections, thrombophlebitis, peritonitis and cellulitis can occur.[16]
C fetus infection may cause intermittent diarrhea or nonspecific abdominal pain. It should also be considered in individuals with nonspecific fever who are either immunocompromised or have had exposure to cattle and sheep.[17]
Campylobacter organisms are curved or spiral, motile, non–spore-forming, gram-negative rods. Organisms from young cultures have a vibriolike appearance, but, after 48 hours of incubation, organisms appear coccoid. Campylobacter organisms are motile by means of unipolar or bipolar flagellae. They are both oxidase- and catalase-positive and microaerophilic, requiring reduced oxygen (5-10%) and increased carbon dioxide (3-10%). The organisms grow slowly, with 3-4 days required for primary isolation from stool samples, and even longer from blood.
Clinical diagnosis of enteric Campylobacter infection is established by demonstrating the organism via direct examination of feces or by isolation of the organisms.
Campylobacter organisms multiply more slowly than other enteric bacteria; thus, unusual techniques are used for isolation from fecal specimens.
These include growth at 42°C, use of antibiotic-containing media, and micropore filtration to keep larger bacilli from contaminating the culture.
Specific types of selective media are blood-based, antibiotic-containing media such as Skirrow, Butzler, and Campy-BAP.
Micropore filtration is based on filters with pores small enough to prevent the passage of microbes but large enough to allow passage of organism-free fluid. Filters with a pore diameter of 25 nm to 0.45 µm are usually used in this procedure, which can also be used to remove microorganisms from water and air for microbiological testing.
Multiple media types can be used to cultivate C jejuni, although Mueller-Hinton broth and agar best support C jejuni growth. The optimum atmosphere for C jejuni growth is 85% N2, 10% CO2, and 5% O2.[18]
Campylobacter organisms are oxidase positive with C jejuni hydrolysing hippurate.[19]
Results of stool cultures usually do not remain positive beyond 2 weeks.
Darkfield or phase-contrast microscopy of fecal specimens can also be used to assess for characteristic darting motility within 2 hours of passage.
A Gram stain of stool samples for characteristic curved rods is specific, with a sensitivity of 50-75%.
Fecal leukocytes and erythrocytes are present in 75% of patients with Campylobacter enteritis and can be detected with direct light microscopic examination using methylene blue or Gram stain.
Peripheral blood leukocytosis may be present.
Dehydration may be clinically evident in patients who are moderately to severely ill.
If infection with C fetus or another atypical species is suspected, incubation at 37°C and use of media without cephalosporins are required.
Serodiagnosis of C jejuni infections can be improved by using highly specific recombinant antigens in an enzyme-linked immunoassay (ELISA) technique.[20]
Real-time polymerase chain reaction (PCR) can be used to quickly and accurately detect C jejuni directly in diarrheal stool.[21]
The newer methods such as molecular biology techniques (PCR) and immunoenzymatic methods[22] are more sensitive than traditional culture methods.[23, 24]
Culture-independent tests, such as rapid tests for detection of antigens in stool specimens, are available.[25, 26, 27] However, their use as standalone tests has been questioned.[28]
Up to 80% of patients with Campylobacter infection demonstrate evidence of proctocolitis on sigmoidoscopy. However, findings may be identical to those observed in pseudomembranous colitis or inflammatory bowel disease. Sigmoidoscopic abnormalities range from focal mucosal edema and hyperemia with patchy petechiae to diffuse or aphthoid ulceration.
Replacement of fluids and electrolytes is the mainstay of therapy in patients with Campylobacter infections. Promote rehydration with oral glucose-electrolyte solutions. Failure to achieve hydration with oral intake may require intravenous fluids.
The use of antibiotics to treat uncomplicated Campylobacter infections is controversial, with studies showing that erythromycin rapidly eliminated Campylobacter organisms from the stool without affecting the duration of illness. Studies in children with C jejuni dysentery have shown benefit from early treatment with erythromycin. Antibiotics may be indicated if any of the following occur:
High fever
Bloody diarrhea
Excessive bowel movements (ie, >8 stools per day)
Worsening symptoms
Failure of symptoms to improve
Persistence of symptoms for longer than 1 week
Pregnancy
HIV infection and other immunocompromised states
Avoid antimotility agents because they prolong the duration of symptoms and have been associated with fatalities.
Individuals with hypogammaglobulinemia who have recurrent C jejuni bacteremia may require fresh frozen plasma with antibiotics.
Patients with severe dysentery or a relapsing course may require hospitalization.
Patients with endovascular C fetus infections require at least 4 weeks of treatment; gentamicin is believed to be the agent of choice. Treatment with ampicillin or third-generation cephalosporins is an alternative.
C fetus CNS infections are rare and should be treated in a prolonged manner with a carbapenem such as meropenem.[15]
Azithromycin therapy would be a primary antibiotic choice for Campylobacter infections, when indicated (see Medical Care),[30] with a typical regimen of 500 mg/d for 3 days. If the patient is bacteremic, treatment can be extended to two weeks.[31] However, erythromycin is the classic antibiotic of choice. Its resistance remains low,[32] and it can be used in pregnant women and children.
The use of fluoroquinolones in food animals has resulted in fluoroquinolone-resistant Campylobacter strains worldwide.[33, 34] Quinolone resistance of C jejuni and Campylobacter coli is conferred by the mutation gyrA C-257-T, which can be identified with methods such as multiplex PCR.[35] A 2008 study from the United Kingdom found fluoroquinolone-resistant Campylobacter species in 22% of poultry and 75% of pig farms.[36] High levels of ciprofloxacin resistance have also been reported in developing countries, with resistance ranging from 30% to greater than 70%.[37, 38] Some evidence has shown that multidrug resistance in pediatric patients in developing countries may be related to the food chain.[39] Consequently, their use as empiric therapy should be avoided.
Infections involving macrolide resistance could be treated with amoxicillin-clavulanate.[40]
Specific antibiotic doses to treat Campylobacter infections have not been fully defined for tetracycline, therefore, the doses below are empirical. Tetracyclines should be avoided in pregnancy and children.
Antibiotic treatment does not prolong carriage of C jejuni.[41]
CNS infections can be treated with meropenem.[42, 43] Life-threatening infections can be treated with carbapenems and aminoglycosides.
Clinical Context:
Acts by binding to 50S ribosomal subunit of susceptible microorganisms and blocks dissociation of peptidyl tRNA from ribosomes, causing RNA-dependent protein synthesis to arrest. Nucleic acid synthesis is not affected.
Concentrates in phagocytes and fibroblasts as demonstrated by in vitro incubation techniques. In vivo studies suggest that concentration in phagocytes may contribute to drug distribution to inflamed tissues.
Treats mild-to-moderate microbial infections.
Plasma concentrations are very low, but tissue concentrations are much higher, giving it value in treating intracellular organisms. Has a long tissue half-life.
Effective against a wide range of organisms, including the most common gram-positive and gram-negative organisms. Has additional coverage of so-called atypical infections such as Chlamydia, Mycoplasma, and Legionella species.
Indicated for treatment of patients with mild-to-moderate infections, including acute bronchitic infections that may be observed with bronchiectasis.
Clinical Context:
DOC for Campylobacter infections. Macrolide antibiotic that inhibits bacterial growth by blocking dissociation of peptidyl t-RNA from ribosomes, causing RNA-dependent protein synthesis to arrest. For C jejuni (not C fetus) infections.
Clinical Context:
Inhibits protein synthesis and thus bacterial growth by binding to 30S and possibly 50S ribosomal subunits of susceptible bacteria. For C jejuni (not C fetus) infections.
Clinical Context:
For treatment of multiple organism infections in which other agents do not have wide-spectrum coverage or are contraindicated because of potential for toxicity. For C fetus (not C jejuni) infection.
Clinical Context:
Aminoglycoside antibiotic. May be needed in severe infections. Dosing regimens are numerous; adjust dose based on CrCl and changes in volume of distribution. Can be used for C fetus infections. May be administered IV/IM.
Clinical Context:
Inhibits cell-wall synthesis by binding to penicillin-binding proteins; resistant to most beta-lactamases. Can be used for C fetus meningitis.
Clinical Context:
Broad-spectrum penicillin; interferes with bacterial cell wall synthesis during active replication, causing bactericidal activity against susceptible organisms; alternative to amoxicillin when unable to take medication orally.
Clinical Context:
Synthetic, broad-spectrum antibacterial compounds. Novel mechanism of action, targeting bacterial topoisomerases II and IV, leads to a sudden cessation of DNA replication. Oral bioavailability is nearly 100%. For C jejuni (not C fetus) infections.
Clinical Context:
For pseudomonal infections and infections due to multidrug resistant gram-negative organisms. For C jejuni (not for C fetus) infections.
In some cases, systemic Campylobacter infections are diagnosed retrospectively following empirical antibiotic therapy with clinical resolution. In such cases, follow-up blood cultures should be obtained, and treatment can be stopped if they are negative.
Oral erythromycin may not be adequate for systemic C jejuni or C fetus endovascular infections.
Pasteurization of milk and chlorination of drinking water destroy Campylobacter organisms.
Unpasteurized milk and untreated surface water should not be consumed.
Raw milk may not be safe, even if it conforms to routine testing by somatic cell and coliform counts.[44]
Treatment with antibiotics can reduce fecal excretion.
Health care workers with Campylobacter infections should not provide direct patient care or prepare food while they have diarrhea or are shedding Campylobacter organisms in the stool. However, person-to-person transmission is unusual.
After diarrhea resolves, infective organisms may be present in the stool for up to 3 weeks.
Separate cutting boards should be used for foods of animal origin and other foods. After preparing raw food of animal origin, all cutting boards and countertops should be carefully cleaned with soap and hot water.[45, 46]
Chicken should be adequately cooked.
When outbreaks occur, community education can be directed at proper food-handling techniques, including thorough cooking of poultry.
As noted above, handling and consumption of poultry meat is a significant source of illness. One control strategy that has been suggested is to keep colonized and noncolonized flocks separate.[47]
Fresh chicken can be the dominant source of Campylobacter infection, and replacing this with frozen chicken can reduce Campylobacter levels.[8]
Eating raw animal products such as beef and cattle liver should be avoided.[48]
Cross-contamination of food items not normally associated with Campylobacter infections should be considered and prevented.[49]
Potential complications of Campylobacter infections include the following:
Toxic megacolon
Pseudomembranous colitis
Gastrointestinal hemorrhage
Hemolytic-uremic syndrome
Thrombotic thrombocytopenic purpura
Immunoproliferative small intestinal disease (This is a type of lymphoma that involves mucosa-associated lymphoid tissue [MALT]. It has been found to be associated with C jejuni infection.[50] )
Reactive arthritis
[51, 52]
Bacteremia
Endocarditis
Cholecystitis
Urinary tract infection
Pancreatitis
Stillbirths, septic abortions (C fetus)
Intrauterine growth restriction[53]
Guillain-Barré syndrome (GBS) (GBS may develop secondary to cross-immunoreactivity between human gangliosides GM1 and GD1a and C jejuni lipopolysaccharides. In one study, up to 25% of patients with GBS had stool cultures positive for C jejuni. However, because of shortcomings of standard serological methods, the role of C jejuni may have been underestimated.[54, 55] In a study using a highly specific ELISA based on recombinant antigens, 80% of 36 patients with acute GBS were found to have serological evidence of preceding C jejuni infection, compared with 3.5% of controls.[56] In a 2012 study from New Zealand, investigators reported a marked reduction in GBS incidence 3 years after initiation of an intensive program to prevent food borne campylobacteriosis.[57] Of the over 8,000 C jejuni multilocus sequence typing sequence types (STs) described, ST-22 has been associated with Guillain-Barré syndrome.[58] )
What are Campylobacter infections?What are the signs and symptoms of Campylobacter infections?How are Campylobacter infections transmitted?What is the infectious dose of Campylobacter?What is the pathogenesis of Campylobacter infections?What is the pathophysiology of diarrhea in Campylobacter infections?What are the characteristics of Campylobacter infections in patients with HIV infection?What is the pathophysiology of C fetus Campylobacter infections?What is the pathophysiology of C jejuni Campylobacter infections?What is the incidence of Campylobacter infections in the US?What is the global incidence of Campylobacter infections?What are the risk factors for Campylobacter infection caused mortality?What are the racial predilections for Campylobacter infections?How does the incidence of Campylobacter infections vary by sex?Which age groups are at greatest risk for Campylobacter infections?What is the typical history in patients with Campylobacter infections?What are the signs and symptoms of Campylobacter infections?How do the clinical histories vary among different Campylobacter species?What are the physical findings characteristic of Campylobacter infections?How are Campylobacter organisms characterized?What are the differential diagnoses for Campylobacter Infections?How are Campylobacter infections diagnosed?What is the role of sigmoidoscopy in the diagnosis of Campylobacter infections?What is the initial therapy for Campylobacter infections?What is the role of antibiotics in the treatment of Campylobacter infections?What is the role of surgery in the treatment of Campylobacter infections?When should specialists be consulted in the treatment of Campylobacter infections?What activity restrictions are needed during the treatment of Campylobacter infections?Which antibiotics are used in the treatment of Campylobacter infections?Which medications in the drug class Antibiotics are used in the treatment of Campylobacter Infections?What are the limitations of oral erythromycin in the treatment of Campylobacter infections?How are Campylobacter infections prevented?What are potential complications of Campylobacter infections?What is the prognosis of Campylobacter infections?What is included in patient education for Campylobacter infections?
Mahmud H Javid, MBBS, Consultant in Infectious Diseases, Shifa International Hospital, Pakistan
Disclosure: Nothing to disclose.
Coauthor(s)
Shadab Hussain Ahmed, MD, AAHIVS, FACP, FIDSA, Professor of Clinical Medicine, The School of Medicine at Stony Brook University Medical Center; Adjunct Clinical Associate Professor, Department of Medicine, New York College of Osteopathic Medicine of New York Institute of Technology; Attending Physician, Department of Medicine, Division of Infectious Diseases, Director of HIV Prevention Services, Administrative HIV Designee, Nassau University Medical Center
Disclosure: Nothing to disclose.
Specialty Editors
Francisco Talavera, PharmD, PhD, Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference
Disclosure: Received salary from Medscape for employment. for: Medscape.
Michael Stuart Bronze, MD, David Ross Boyd Professor and Chairman, Department of Medicine, Stewart G Wolf Endowed Chair in Internal Medicine, Department of Medicine, University of Oklahoma Health Science Center; Master of the American College of Physicians; Fellow, Infectious Diseases Society of America; Fellow of the Royal College of Physicians, London
Disclosure: Nothing to disclose.
Chief Editor
Michael Stuart Bronze, MD, David Ross Boyd Professor and Chairman, Department of Medicine, Stewart G Wolf Endowed Chair in Internal Medicine, Department of Medicine, University of Oklahoma Health Science Center; Master of the American College of Physicians; Fellow, Infectious Diseases Society of America; Fellow of the Royal College of Physicians, London
Baker MG, Kvalsvig A, Zhang J, Lake R, Sears A, Wilson N. Declining Guillain-Barré syndrome after campylobacteriosis control, New Zealand, 1988–2010. Emerg Infect Dis. Feb 2012.
Scanning electron microscope image of Campylobacter jejuni, illustrating its corkscrew appearance and bipolar flagella. Source: Virginia-Maryland Regional College of Veterinary Medicine, Blacksburg, Virginia.
Scanning electron microscope image of Campylobacter jejuni, illustrating its corkscrew appearance and bipolar flagella. Source: Virginia-Maryland Regional College of Veterinary Medicine, Blacksburg, Virginia.