What is campylobacteriosis?
Campylobacteriosis is an infectious disease caused by bacteria of the genus Campylobacter (CDC, 2010). Campylobacter (from the Greek and Latin meaning “curved rod”) are curved, spiral, or S-shaped bacteria, and were first isolated from aborted sheep fetuses in 1909 (Ruiz-Palacios and Amieva, 2008; Allos and Blaser, 2008). Campylobacter are a significant cause of foodborne illness worldwide (Ruiz-Palacios and Amieva, 2008).
Campylobacter jejuni is one of the most common causes of bacterial gastroenteritis in industrialized nations, and affects an estimated 2.4 million people in the United States annually (Pigott, 2008).
Most people who become ill with campylobacteriosis get diarrhea, cramping, abdominal pain, and fever within two to five days after exposure to the organism (CDC, 2010). The diarrhea may be bloody and can be accompanied by nausea and vomiting. The illness typically lasts one week, and some infected persons do not have any symptoms (CDC, 2010). In persons with compromised immune systems, Campylobacteroccasionally spreads to the bloodstream and causes a serious life-threatening infection (CDC, 2010).
How common is Campylobacter?
Campylobacter is one of the most common causes of diarrheal illness in the United States. The vast majority of cases occur as isolated, sporadic events, not as part of recognized outbreaks. Active surveillance through FoodNet indicates that about 13 cases are diagnosed each year for each 100,000 persons in the population (CDC, 2010). Many more cases go undiagnosed or unreported, and campylobacteriosis is estimated to affect over 2.4 million persons every year, or 0.8% of the population (CDC, 2010).
Campylobacteriosis occurs much more frequently in the summer months than in the winter (Allos and Blaser, 2008). The organism is isolated from infants and young adults more frequently than from persons in other age groups and from males more frequently than females (CDC, 2010). Some studies have indicated that campylobacteriosis is most common in children younger than 5 years of age and in males between the ages of 20 and 29 (Craig and Zich, 2010). Although Campylobacter does not commonly cause death, it has been estimated that approximately 124 persons with Campylobacter infections die each year (CDC, 2010).
Fortunately, the incidence of campylobacteriosis has been on the decline in recent years. Between 1996 and 2005, United States Campylobacter infections declined so markedly that Salmonella infections became more frequent than campylobacteriosis (Allos and Blaser, 2008), which had long been considered the leading cause of food-borne illness in the United States.
What sort of germ is Campylobacter?
Campylobacter organisms are spiral-shaped bacteria that can cause disease in humans and animals (CDC, 2010). Campylobacters belong to the family Campylobacteraceae, which includes the genera Campylobacter(to which the campylobacters belong), Acrobacter, and Sulfurospirillum (Ruiz-Palacios and Amieva, 2008). Over 20 species have been recognized within the Campylobacteriaceae family, though only 13 are considered pathogenic (disease-causing) in humans; the genus Campylobacter includes 14 species and 7 subspecies (Ruiz-Palacios and Amieva, 2008).
The majority of human illnesses resulting from Campylobacter are attributable to Campylobacter jejuni (C. jejuni) and Campylobacter coli (C. coli) (Ruiz-Palacios and Amieva, 2008). Infections are less frequently attributable to Campylobacter fetus (C. fetus), Campylobacter upsaliensis (C. upsaliensis), Campylobacter lari(C. lari), Campylobacter hyointestinalis (C. hyointestinalis), Campylobacter cinaedi (C. cinaedi), and Campylobacter fennelliae (C. fennalliae) (Ruiz-Palacios and Amieva, 2008; Giannella, 2010).
Campylobacters range from 0.5 to 8 µm (micrometers; one micrometer is equal to one-millionth (1/1,000,000) of a meter) in width, and can move by darting in corkscrew fashion by propelling itself with a flagellum (a tail-like projection from the end of the cell) (Ruiz-Palacios and Amieva, 2008). Some of the bacteria possess only one flagellum; others have two (Ruiz-Palacios and Amieva, 2008).
Campylobacters are commensal organisms that live in many birds and animals (Ruiz-Palacios and Amieva, 2008). The fact that they have a commensal relationship means that the bacteria benefit from living in the animals, but do not cause a serious disadvantage to the animals by being present. Thus, in animal hosts, Campylobacter colonization is generally asymptomatic (Ruiz-Palacios and Amieva, 2008). Other than birds, the bacteria are also found in dogs, cattle, horses, goats, pigs, cats, and sheep (Adachi et al., 2007).
These bacteria are fairly fragile, cannot tolerate drying, and can be killed by oxygen (CDC, 2010). They grow only in places with less oxygen than the amount in the atmosphere, and they grow best in environments containing only 5-10% oxygen (CDC, 2010; Ruiz-Palacios and Amieva, 2008).
Freezing reduces the number of Campylobacter bacteria on raw meat (CDC, 2010).
C. jejuni is the species of Campylobacter most commonly isolated from patients with diarrhea (Ruiz-Palaciosand Amieva, 2008). These bacteria grow best at the body temperature of a bird (CDC, 2010). The bacteria seem well-adapted to birds, which carry it without becoming ill (CDC, 2010). C. jejuni cannot, however, withstand freezing temperatures or drying, and these characteristics help prevent more extensive transmission of the bacteria (Allos and Blaser, 2008).
The serotypic diversity of C. jejuni is extensive: more than 90 serotypes based on O antigens and 50 serotypesbased on somatic antigens have been isolated (Allos and Blaser, 2008).
The incidence of C. jejuni infections fell by more than 30% in the United States between 1998 and 2003; in 1998, 21.7 cases were reported per 100,000 population, and by 2003, the rate was down to 12.9 cases per 100,000 people (Allos and Blaser, 2008). However, the burden of Campylobacter infections is likely much higher than reported, as even active surveillance systems substantially underreport the actual incidence of infection (Allos and Blaser, 2008).
What are the symptoms of campylobacteriosis?
Symptoms of Campylobacter infection include diarrhea, cramps, abdominal pain, nausea, headache, fever, vomiting, and bloody diarrhea (Adachi et al., 2010). Tenesmus (the feeling of incomplete evacuation) occurs, but is uncommon (Adachi et al., 2010). The clinical features of infection – in particular, severe abdominalcramping and pain – can mimic acute appendicitis (Craig and Zich, 2010).
Initially, infected individuals tend to experience general malaise and fever, followed by abdominal cramps and pain (Adachi et al., 2007). Diarrhea tends to begin 24 to 48 hours after the onset of fever and abdominal pain (Craig and Zich, 2010). In most cases, the diarrheal stools are initially loose and bile-colored, but in approximately 40% of cases the stools progress to become watery, grossly bloody (blood visible to the naked eye), or melanotic (Craig and Zich, 2010). At the height of the infection, patients pass between 8 and 10 stools per day; in some patients, the number is higher than 10 (Craig and Zich, 2010).
Illness lasting longer than one week occurs in between 10 and 20% of cases in which the patient seeks out medical attention (Allos and Blaser, 2008). Additionally, up to 20% of victims may experience a clinicalrelapse; however, the relapse is typically less severe than the original symptoms (Adachi et al., 2007).
How is the infection diagnosed?
Many different kinds of infections can cause diarrhea and bloody diarrhea (CDC, 2010). Campylobacterinfection is diagnosed when a culture of a stool specimen yields the organism (CDC, 2010).
How can campylobacteriosis be treated?
Almost all persons infected with Campylobacter recover without any specific treatment (CDC, 2010). Rehydration and correction of electrolyte abnormalities are the mainstays of treatment for individuals infected with Campylobacter bacteria (Ruiz-Palacios and Amieva, 2008). Thus, patients should drink extra fluids as long as the diarrhea lasts (CDC, 2010).
Antimotility agents (such as Immodium) have been associated in some studies with prolonging symptoms, as well as with fatalities (Ruiz-Palacios and Amieva, 2008). Thus, those studies advise against using such drugs to treat Campylobacter infection (Ruiz-Palacios and Amieva, 2008).
In more severe cases, antibiotics such as erythromycin or a fluoroquinolone can be used, and can shorten the duration of symptoms if given early in the illness (CDC, 2010). Some studies indicate that antimicrobialtherapy should be considered by health care providers for cases that involve bloody diarrhea, fever, worsening of symptoms, a large number of stools, or in patients who are immunosuppressed (Ruiz-Palacios and Amieva, 2008). However, your doctor will decide whether antibiotics are necessary.
Campylobacter species are often associated with antibiotic resistance, and have been developing resistance to an increasing number of antibiotics in recent years (Ruiz-Palacios and Amieva, 2008). The bacteria are often resistant to ampicillin, penicillin, and cephalosporins, and have been increasingly associated with resistance to fluoroquinolone in most countries over the past 10 years (Ruiz-Palacios and Amieva, 2008). Studies have shown a correlation between the increased resistance to fluoroquinolones and the license of those antibiotics for use in poultry and in general veterinary medicine, which led some researchers to hypothesize that the introduction of those antibiotics in those contexts led to an increased reservoir of resistant Campylobacter(Ruiz-Palacios and Amieva, 2008).
When antimicrobial therapy is begun within the first 4 days of illness, studies have shown a substantialreduction in the length of time that Campylobacter bacteria is shed in the stool, as well as a shorter symptomatic period (Ruiz-Palacios and Amieva, 2008). In immunocompromised individuals not treated withantimicrobials, shedding of the organism can continue for a period of time from 2 weeks to 3 months after the initial infection (Ruiz-Palacios and Amieva, 2008).
Are there long-term consequences to Campylobacter infection?
Most people who get campylobacteriosis recover completely within two to five days, although sometimes recovery can take up to 10 days (CDC, 2010).
Rarely, Campylobacter infection results in long-term consequences. Some people develop a condition called reactive arthritis, also known as Reiter’s Syndrome (CDC, 2010). Others may develop a rare disease called Guillain-Barré syndrome that affects the nerves of the body beginning several weeks after the diarrheal illness (Ruiz-Palacios and Amieva, 2008).
Guillain-Barré syndrome occurs when a person’s immune system is “triggered” to attack the body’s own nerves resulting in paralysis that lasts several weeks and usually requires intensive care (CDC, 2010). The syndrome is rare in children, and persons older than 59 years of age are at the highest risk for developing the complication (Ruiz-Palacios and Amieva, 2008).
It is estimated that approximately one in every 1,000 reported Campylobacter illnesses leads to Guillain-Barrésyndrome, and that as many as 40% of Guillain-Barré syndrome cases in this country may be triggered by campylobacteriosis (CDC, 2010). In fact, studies have suggested that Campylobacter is the single most common cause of Guillain-Barré syndrome (Ruiz-Palacios and Amieva, 2008).
Additionally, Campylobacter infection can spread to the bloodstream, a condition which is called bacteremia. The majority of Campylobacter infections in human bloodstreams result from infection with C. fetus, not the more common C. jejuni (Lima and Guerrant, 2010). Campylobacter bacteremia is uncommon, and most cases occur in malnourished children and patients with chronic debilitating illnesses or immunodeficiency (Ruiz-Palacios and Amieva, 2008). Bacteremia has been estimated to occur in 1.5 per every 1000 cases of enteritis (Ruiz-Palacios and Amieva, 2008).
How do people become infected with this germ?
Campylobacteriosis usually occurs in single, sporadic cases, but it can also occur in outbreaks, when a number of people become ill at one time (CDC, 2010). Most cases of campylobacteriosis are associated with eating raw or undercooked poultry meat or from cross-contamination of other foods by these items (CDC, 2010). Between 50 and 70% of Campylobacter infections are caused by consumption of contaminated poultry (Giannella, 2010). Outbreaks of Campylobacter are usually associated with unpasteurized milk or contaminated water (CDC, 2010).
Direct contact between humans and infected animals has led to infection (Allos and Blaser, XXX; CDC, 2010). Household pets – particularly young dogs and cats with diarrhea – have been implicated as the source of human cases of campylobacteriosis (Allos and Blaser, 2008).
The organism is not usually spread from one person to another, but this can happen if the infected person is producing a large volume of diarrhea (CDC, 2010). Additionally, infants may get the infection by contact with poultry packages in shopping carts (CDC, 2010).
A very small number of Campylobacter organisms (fewer than 500) can cause illness in humans (CDC, 2010). Even one drop of juice from raw chicken meat can infect a person.
How does food or water become contaminated with Campylobacter?
Many chicken flocks are infected with Campylobacter but show no signs of illness. Campylobacter can be easily spread from bird to bird through a common water source or through contact with infected feces (CDC, 2010). When an infected bird is slaughtered, Campylobacter organisms can be transferred from the intestines to the meat (CDC, 2010). In 2005, Campylobacter was present on 47% of raw chicken breasts tested through the FDA-NARMS Retail Food program (CDC, 2010). Campylobacter is also present in the giblets, especially the liver (CDC, 2010).
Unpasteurized milk can become contaminated if the cow has an infection with Campylobacter in her udder or the milk is contaminated with manure (CDC, 2010). Surface water and mountain streams can become contaminated from infected feces from cows or wild birds (CDC, 2010). This infection is common in the developing world, and travelers to foreign countries are also at risk for becoming infected with Campylobacter(CDC, 2010).
What can be done to prevent Campylobacter infection?
Some simple food handling practices can help prevent Campylobacter infections.
References (in order of appearance)
Centers for Disease Control and Prevention. “Campylobacter: General Information” Centers for Disease Control and Prevention: Your Online Source for Credible Health Information. Centers for Disease Control and Prevention, 20 Jul. 2010. Web. 14 July 2011. <http://www.cdc.gov/nczved/divisions/dfbmd/diseases/campylobacter/>.
Centers for Disease Control and Prevention. “Campylobacter: Technical Information” Centers for Disease Control and Prevention: Your Online Source for Credible Health Information. Centers for Disease Control and Prevention, 20 Jul. 2010. Web. 14 July 2011. <http://www.cdc.gov/nczved/divisions/dfbmd/diseases/campylobacter/technical.html>.
Ruiz-Palacios, Guillermo M. and Manuel R. Amieva “Campylobacter jejuni and Campylobacter coli.” Principles and Practice of Pediatric Infectious Diseases. Ed. Sarah S. Long, Larry K. Pickering, and Charles G. Prober. 3rd ed. Philadelphia: Churchill Livingstone Elsevier, 2008. 867-872.
Ruiz-Palacios, Guillermo M. and Manuel R. Amieva “Other Campylobacter Species.” Principles and Practice of Pediatric Infectious Diseases. Ed. Sarah S. Long, Larry K. Pickering, and Charles G. Prober. 3rd ed. Philadelphia: Churchill Livingstone Elsevier, 2008. 872-874.
Allos, Ban Mishu and Martin J. Blaser “Campylobacter Infections.” Cecil Medicine. Ed. Lee Goldman and Dennis Ausiello. 23rd ed. Philadelphia: Saunders Elsevier, 2008. 2230-2233.
Pigott, David C. “Foodborne Illness.” Emergency Medicine Clinics of North America 26.2 (2008): 475-497.
Craig, Sandy A., and David K. Zich. “Gastoenteritis.” Rosen’s Emergency Medicine: Concepts and ClinicalPractice. Ed. John A.Marx, et al. 7th ed. Vol. 1. Philadelphia: Saunders Elsevier, 2010. 1200-1226. 2 vols.
Adachi, Javier A., et al. “Infectious Diarrhea from Wilderness and Foreign Travel.” Wilderness Medicine. Ed. Paul S. Auerbach. 5th ed. Philadelphia: Mosby Elsevier, 2007. 1418-1444.
Lima, Aldo A. M., and Richard L. Guerrant. “Inflammatory Enteritides.” Mandell, Douglas, and Bennett’s Principles and Practice of Infectious Diseases. Ed. Gerald M. Mandell, John E. Bennett, and Ralph Dolin. 7th ed. Vol. 1. Philadelphia: Churchill Livingstone Elsevier, 2010. 1389-1398. 2 vols.
Giannella, Ralph A. “Infectious Enteritis and Proctocolitis and Bacterial Food Poisoning.” Sleisenger and Fordtran’s Gastrointestinal and Liver Disease. Ed. Mark Feldman, Lawrence S. Friedman, and Lawrence J. Brandt. 9th ed. Philadelphia: Saunders Elsevier, 2010. 1843-1887.