Salmonella and campylobacter jejuni

Key facts

• Campylobacter is 1 of 4 key global causes of diarrhoeal diseases. It is considered to be the most common bacterial cause of human gastroenteritis in the world.
• Campylobacter infections are generally mild, but can be fatal among very young children, elderly, and immunosuppressed individuals.
• Campylobacter species can be killed by heat and thoroughly cooking food.
• To prevent Campylobacter infections, make sure to follow basic food hygiene practices when preparing food.

The high incidence of Campylobacter diarrhoea, as well as its duration and possible complications, makes it highly important from a socio-economic perspective. In developing countries, Campylobacter infections in children under the age of 2 years are especially frequent, sometimes resulting in death.

Campylobacter are mainly spiral-shaped, “S”-shaped, or curved, rod-shaped bacteria. Currently, there are 17 species and 6 subspecies assigned to the genus Campylobacter, of which the most frequently reported in human diseases are C. jejuni (subspecies jejuni) and C. coli. Other species such as C. lari and C. upsaliensis have also been isolated from patients with diarrhoeal disease, but are reported less frequently.

The disease

Campylobacteriosis is the disease caused by the infection with Campylobacter:

• The onset of disease symptoms usually occurs 2 to 5 days after infection with the bacteria, but can range from 1 to 10 days.
• The most common clinical symptoms of Campylobacter infections include diarrhoea (frequently bloody), abdominal pain, fever, headache, nausea, and/or vomiting. The symptoms typically last 3 to 6 days.
• Death from campylobacteriosis is rare and is usually confined to very young children or elderly patients, or to those already suffering from another serious disease such as AIDS.
• Complications such as bacteraemia (presence of bacteria in the blood), hepatitis, pancreatitis (infections of liver and pancreas, respectively), and miscarriage have been reported with various degrees of frequency. Post-infection complications may include reactive arthritis (painful inflammation of the joints which can last for several months) and neurological disorders such as Guillain-Barré syndrome, a polio-like form of paralysis that can result in respiratory and severe neurological dysfunction in a small number of cases.

Sources and transmission

Campylobacter species are widely distributed in most warm-blooded animals. They are prevalent in food animals such as poultry, cattle, pigs, sheep and ostriches; and in pets, including cats and dogs. The bacteria have also been found in shellfish.

The main route of transmission is generally believed to be foodborne, via undercooked meat and meat products, as well as raw or contaminated milk. Contaminated water or ice is also a source of infection. A proportion of cases occur following contact with contaminated water during recreational activities.

Campylobacteriosis is a zoonosis, a disease transmitted to humans from animals or animal products. Most often, carcasses or meat are contaminated by Campylobacter from faeces during slaughtering. In animals, Campylobacter seldom causes disease.

The relative contribution of each of the above sources to the overall burden of disease is unclear but consumption of undercooked contaminated poultry is believed to be a major contributor. Since common-source outbreaks account for a rather small proportion of cases, the vast majority of reports refer to sporadic cases, with no easily discernible pattern.

Estimating the importance of all known sources is therefore extremely difficult. In addition, the wide occurrence of Campylobacter also hinders the development of control strategies throughout the food chain. However, in countries where specific strategies have been put in place to reduce the prevalence of Campylobacter in live poultry, a similar reduction in human cases is observed.

Treatment

Treatment is not generally required, except electrolyte replacement and rehydration. Antimicrobial treatment is recommended in invasive cases (when bacteria invade the intestinal mucosa cells and damage the tissues) or to eliminate the carrier state (the condition of people who harbour Campylobacter in their bodies and keep shedding the bacteria while remaining asymptomatic).

Prevention methods

There are a number of strategies that can be used to prevent disease from Campylobacter:

• Prevention is based on control measures at all stages of the food chain, from agricultural production on a farm, to processing, manufacturing and preparation of foods both commercially and domestically.
• In countries without adequate sewage disposal systems, faeces and articles soiled with faeces may need to be disinfected before disposal.
• Measures to reduce the prevalence of Campylobacter in poultry include enhanced biosecurity to avoid transmission of Campylobacter from the environment to the flock of birds on the farm. This control option is feasible only where birds are kept in closed housing conditions.
• Good hygienic slaughtering practices reduce the contamination of carcasses by faeces, but will not guarantee the absence of Campylobacter from meat and meat products. Training in hygienic food handling for abattoir workers and raw meat producers is essential to keep contamination to a minimum.
• Prevention methods against infection in domestic kitchens are similar to those used against other foodborne bacterial diseases.
• Bactericidal treatment, such as heating (for example, cooking or pasteurization) or irradiation, is the only effective method of eliminating Campylobacter from contaminated foods.

WHO response

In partnership with other stakeholders, WHO is strongly advocating the importance of food safety as an essential element in ensuring access to safe and nutritious diets. WHO is providing policies and recommendations that cover the entire food chain from production to consumption, making use of different types of expertise across different sectors.

WHO is working towards the strengthening of food safety systems in an increasingly globalized world. Setting international food safety standards, enhancing disease surveillance, educating consumers and training food handlers in safe food handling are amongst the most critical interventions in the prevention of foodborne illnesses.

In collaboration with the Food and Agriculture Organization of the United Nations (FAO), the World Organisation for Animal Health (OIE) and the WHO Collaborating Centre at the University of Utrecht, WHO published the report The global view of campylobacteriosis in 2012.

WHO is strengthening the capacities of national and regional laboratories in the surveillance of foodborne pathogens, such as Campylobacter and Salmonella.

WHO is also promoting the integrated surveillance of antimicrobial resistance of pathogens in the food chain, collecting samples from humans, food and animals and analysing data across the sectors.

WHO, jointly with FAO, is assisting Member States by coordinating international efforts for early detection and response to foodborne disease outbreaks through the network of national authorities in Member States.

WHO also provides scientific assessments as basis for international food standards, guidelines and recommendations developed by the FAO/WHO Codex Alimentarius Commission to prevent foodborne diseases.

The following guidance will help people to stay safe while travelling:

• Ensure food is properly cooked and still hot when served.
• Avoid raw milk and products made from raw milk. Drink only pasteurized or boiled milk.
• Avoid ice unless it is made from safe water.
• When the safety of drinking water is questionable, boil it, or if this is not possible, disinfect it with a reliable, slow-release disinfectant agent (usually available at pharmacies).
• Wash hands thoroughly and frequently using soap, in particular after contact with pets or farm animals, or after having been to the toilet.
• Wash fruits and vegetables carefully, particularly if they are eaten raw. If possible, vegetables and fruits should be peeled.

• A guide on safe food for travellers

WHO provides the following guidance for people handling food:

• Both professional and domestic food handlers should be vigilant while preparing food and should observe hygienic rules of food preparation.
• Professional food handlers who suffer from fever, diarrhoea, vomiting, or visible infected skin lesions should report to their employer immediately.
• The WHO Five keys to safer food serve as the basis for educational programmes to train food handlers and educate consumers. They are especially important in preventing food poisoning. The Five keys are:
  • keep clean
  • separate raw and cooked
  • cook thoroughly
  • keep food at safe temperatures
  • use safe water and raw materials.

• Five keys to safer food

Campylobacter, E.Coli and Salmonella

What are Campylobacter, (say ‘cam-pile-oh-bac-ter’) E. coli and Salmonella?

Campylobacter, Escherichia coli (E. coli) and Salmonella are bacteria found in the gut of infected people and animals. They can also be found in water and some foods.

People with these infections usually get diarrhoea (runny poo). Some people, especially young children and older people, can get very ill.

Infected people or animals pass on the bacteria in their faeces (poo). The bacteria can pass into and contaminate (make unsafe) soil, food or water, or surfaces such as toys, bathroom taps or doors, and nappy change tables. You get infected when you swallow the bacteria, for example, by drinking contaminated water or touching your mouth with contaminated hands.

You can get infected by:

• handling raw meat or poultry
• eating contaminated raw or under cooked food
• eating contaminated bought food – for example, takeaways and at restaurants
• drinking contaminated water
• drinking raw milk or raw milk products
• having contact with faeces or faecal matter
• having contact with infected animals
• swimming or playing in contaminated ‘recreational water’, such as rivers and lakes
• travelling overseas.

These infections cause similar symptoms. You need to see a doctor to find out which infection you have.

You may have some or all of the following:

• diarrhoea, which may have blood in it
• stomach pain or cramps, which may be severe
• flu-like symptoms, including headache, muscle pains, fever and fatigue (feeling very tired)
• nausea
• vomiting.

Some people, especially young children and older people, can get very ill and may need hospital treatment.

Campylobacter symptoms usually appear 1 to 10 days after becoming infected. Symptoms can last for up to 10 days but most people will usually get better within 10 days.

E. coli symptoms usually appear 2 to 10 days after being infected. Most people get better within 10 days. Although most types of E. coli are harmless, some types, such as Shiga toxin-producing E. coli (STEC, also called verocytotoxigenic E. coli or VTEC), can cause serious illness.

Salmonella symptoms usually appear 6 to 72 hours after becoming infected. The symptoms usually last between 1 and 7 days but in more severe cases they can last up to 10 days.

If you have symptoms and think you’re infected, this is what you should do.

• Go to your doctor. They may ask to test a specimen (small amount) of your faeces. Your doctor will give you advice on how to collect the specimen and what to do with it.
• Take medicines if your doctor prescribes them.
• Drink plenty of water while you have diarrhoea or vomiting.
• Go back to your doctor if you have a child that is ill and is not able to drink.
• Stay away from school, early childhood centres or work until at least 48 hours (2 days) after the symptoms have gone. However, you should also follow the advice of your doctor or local Public Health Service.

Campylobacter, E. coli or Salmonella are notifiable diseases – meaning that your doctor will inform the Medical Officer of Health of your local Public Health Service (PHS). The PHS may contact you to find out how you were infected. This helps to prevent more cases of the infection.

Here’s what you can do to prevent getting Campylobacter, E. coli or Salmonella – or passing them on.

Wash your hands thoroughly by using plenty of soap and hot water, cleaning between fingers and under fingernails, rinsing well and drying on a clean dry towel or paper towel:

• before and after preparing food
• after going to the toilet or changing a baby’s nappy
• after caring for people who are ill
• after playing or working with animals.

Clean areas and surfaces (including toys) that may have become contaminated with a suitable cleaning solution.

• Thaw meat in the fridge and not at room temperature.
• Keep raw meat covered and separate from other foods, and store at the bottom of the fridge.
• Use separate chopping boards when preparing raw foods and cooked foods, or wash the board in hot soapy water between preparing raw and cooked foods.
• Cook chicken thoroughly until the juices are clear.
• Cook all minced meat patties and sausages thoroughly.
• Avoid drinking raw milk and raw milk products.
• Avoid eating shellfish which has been gathered from contaminated waters.
• Wash fruit and vegetables before use.

If you have one of these infections, avoid preparing food for other people. If you must do so, wash and dry your hands well first.

Don’t go swimming in a pool if you have diarrhoea. You need to wait at least 2 weeks after the symptoms have gone.

If you or a child are unwell then do not share bathwater, as this can easily transmit infection.

For more information, speak to your doctor or nurse, or contact the Public Health Service (look in the phone book or search the internet for contact details). You can also call Healthline on 0800 611 116.

When people worry about eating undercooked chicken, they usually focus on getting sick from salmonella bacteria. But another common type of bacteria called campylobacter can also make you ill if you eat poultry that isn’t fully cooked.

Like a salmonella infection, campylobacteriosis can cause diarrhea and sometimes other serious complications.

Infants and children have a greater chance than adults for campylobacter infection, but it can strike anyone at any age. Males are also more likely than females to become infected. It’s more common in summer than winter.

About 1.3 million people are infected in the United States every year, and that doesn’t include the many people who never report their symptoms or become officially diagnosed.

Causes

Campylobacter bacteria can get into your system if you eat undercooked poultry or you eat food that has touched raw or undercooked poultry.

The bacteria usually live in the digestive systems of animals, including poultry and cattle. Unpasteurized milk can also have campylobacter bacteria.

Campylobacteriosis usually develops in isolated cases. Sometimes, though, there can be an outbreak when several people have the same infection.

In developing countries, the bacteria can be found in water and sewage systems.

Symptoms

The infection usually lasts about a week. If you’ve been infected, symptoms start within a couple of days of consuming the bacteria.

The most common symptom is diarrhea. The stool may have blood in it. You may also be sick to your stomach and vomit.

Other signs of infection include:

Some people never get any symptoms. When you have a weakened immune system, the bacteria can cause a very serious infection of your bloodstream.

When to Call a Doctor

If you have a weakened immune system, see your doctor soon after diarrhea and other symptoms appear. Your immune system can be weakened by an infection, such as HIV, or by medications to treat cancer, for example.

If you’re generally in good health and you get a bout of diarrhea, you may wait a couple of days. Treat it as you would any illness that causes diarrhea.

If you feel very sick, which can happen in serious cases, then see your doctor sooner. Some of the symptoms to watch for include:

• Diarrhea for more than 2 days
• Signs of dehydration (dark pee, dry mouth and skin, dizziness)
• Severe pain in your gut or rectum
• Fever of 102 F or more

Tests and Diagnosis

Diarrhea and vomiting are common campylobacteriosis symptoms, but they can also be symptoms of many other illnesses. This is true for bloody stools, too.

To make an official diagnosis, your doctor may ask for a stool sample, which will be sent to a lab.

Someone at your doctor’s office will give you a special container in which to collect the sample. It can take several days to get the results.

In rare cases, a doctor may order a blood test, but these results take even longer -- up to 2 weeks.

Treatment

Most people get over the infection without medicine or special treatments. You should drink lots of fluids while you have diarrhea.

Unless your doctor tells you otherwise, don’t take anything to prevent vomiting and diarrhea. That’s your body’s way of getting rid of the infection.

If your immune system is weak, your doctor might prescribe medicine to fight the infection.

Doctors will often first try levofloxacin (Levaquin). If you can’t take it for some other reasons, they may prescribe one of these common antibiotics that are used to treat several types of infections:

Possible Complications

Usually, the infection clears up within 2 to 10 days. If left untreated, campylobacteriosis may lead to serious consequences for a very small number of people.

Some problems can happen early on. One example is a gallbladder infection (cholecystitis).

There can also be complications from the later stages of the infection, too, though serious long-term problems are unusual.

The infection is associated with arthritis in rare cases. It may also lead to Guillain-Barre syndrome. It’s a disorder in which your immune system attacks nerves in your body. You can be partially paralyzed and be in the hospital for weeks.

Prevention

The most effective way to avoid campylobacteriosis is to cook poultry to at least 165 F. The meat should be white, not pink. You should never eat chicken that looks undercooked.

Heating foods and pasteurizing dairy products are the only ways of knocking out the bacteria in foods that have been contaminated.

Here are some other tips:

• Wash your hands before cooking and after touching raw poultry or meat.
• Keep uncooked meat and poultry away from other foods, such as vegetables, by using separate cutting boards, utensils, and cooking surfaces.
• Wash your hands after touching a pet or pet feces.
• Make sure your child or anyone with diarrhea washes his or her hands well.

What About Work or School?

To help reduce the spread of campylobacteriosis, try to avoid school or work or any public places until your stool is firm.

If you still have diarrhea, stay home and try to stay hydrated if possible. A relapse is possible, but not likely.

Centers for Disease Control and Prevention: “What is campylobacteriosis?”

World Health Organization: “Campylobacter.”

Wisconsin Division of Public Health: “Campylobacteriosis.”

Vermont Department of Health, “Campylobacter”

Antimicrobe.org: “Camylobacter species.”

SA Health (Government of South Australia): “Campylobacter infection.”

Abstract

Infection with Campylobacter jejuni is one of the most common causes of gastroenteritis worldwide; it occurs more frequently than do infections caused by Salmonella species, Shigella species, or Escherichia coli O157:H7. In developed countries, the incidence of Campylobacter jejuni infections peaks during infancy and again during early adulthood. Most infections are acquired by the consumption and handling of poultry. A typical case is characterized by diarrhea, fever, and abdominal cramps. Obtaining cultures of the organism from stool samples remains the best way to diagnose this infection. An alarming recent trend is the rapid emergence of antimicrobial agent-resistant Campylobacter strains all over the world. Use of antibiotics in animals used for food has accelerated this trend. It is fortunate that complications of C. jejuni infections are rare, and most patients do not require antibiotics. Guillain-Barré syndrome is now recognized as a post-infectious complication of C. jejuni infection, but its incidence is

Campylobacter jejuni infection is one of the most commonly identified bacterial causes of acute gastroenteritis worldwide. In developing countries, Campylobacter species are an important cause of childhood morbidity caused by diarrheal illness. They are among the most common causes of diarrhea in travelers from developed nations. Remarkably, in many studies in the United States and other industrialized countries, Campylobacter infections were found to cause diarrheal disease >2–7 times as frequently as infections with Salmonella species, Shigella species, or Escherichia coli O157:H7 [1, 2]. Although 14 species of Campylobacter have been identified, in the United States >99% of reported infections with Campylobacter are with C. jejuni [3]. Therefore, this paper will be limited to a discussion of C. jejuni.

History

Despite their widespread occurrence, Campylobacter species were not understood as a cause of diarrhea in humans until 1957 [4], and their impact in terms of sheer numbers of human infections emerged only in the past 20 years. The first recognized Campylobacter infections were reported in the early part of the 20th century and occurred in farm animals. The infections were attributed to Vibrio fetus (now known to be Campylobacter fetus) and were realized by veterinarians to be a cause of septic abortions in sheep and cattle. In 1947, V. fetus was reported to be the cause of septic abortion in a woman, and during the next 3 decades, the organism was believed to be a rare, opportunistic, invasive pathogen that occurred principally in debilitated hosts.

In 1973, the new genus Campylobacter was proposed [5]. Finally, the development and increasingly widespread use of selective media for isolation of Campylobacter from stool samples in the 1970s led to the recognition in the early 1980s of the importance of these infections as a cause of human gastrointestinal illness. By the mid-to-late 1980s, it had been determined that Campylobacter species are one of the most common bacterial causes of diarrhea worldwide.

Microbiology

Campylobacter species are gram-negative bacilli that have a curved or spiral shape (hence their initial classification as vibrios). Recently, the complete genome sequence of C. jejuni was characterized. Of note was the finding of hypervariable regions that might be important in the survival of the organism [6]. Campylobacter species are motile by means of unipolar or bipolar flagellae. The organisms grow quite slowly; 72–96 h are required for primary isolation from stool samples, and isolation from blood can take even longer. They grow best at 42°C. Because most Campylobacter species are resistant to cephalothin (an agent to which most other stool flora are susceptible), the usual method for isolation from stool samples is use of a medium that contains cephalothin. Because some Campylobacter species, especially non-jejuni Campylobacter species, are susceptible to cephalothin, the filter method and antibiotic-free media should be used if initial results of cultures are negative and the suspicion of Campylobacter infection is high. This method involves first filtering the stool onto an antibiotic-free medium through 0.45–0.65-μm filters; the filters will block the passage of most stool flora but will permit the passage of smaller bacteria such as Campylobacter species [7].

Clinical Characteristics of Campylobacter Gastroenteritis

Most typically, infection with C. jejuni results in an acute, self-limited gastrointestinal illness characterized by diarrhea, fever, and abdominal cramps. Clinically, Campylobacter infection is indistinguishable from acute gastrointestinal infections produced by other bacterial pathogens, such as Salmonella, Shigella, and Yersinia species. In most patients, the diarrhea is either loose and watery or grossly bloody; 8–10 bowel movements per day occur at the peak of illness [2]. In some patients, the diarrhea is minimal and abdominal cramps and pain are the predominant features; this can lead to a mistaken diagnosis of acute abdomen and unnecessary laparotomy. Fever is reported by >90% of patients and can be low-grade or >40°C and persist for up to 1 week. By that time, the illness has usually resolved, even in the absence of specific antibiotic treatment. Occasionally, however, patients can develop a longer, relapsing diarrheal illness that lasts several weeks [8]. Although Campylobacter is rarely identified in the stools of healthy persons, depending upon the population studied, as many as 50% of persons who are infected during outbreaks are asymptomatic [9].

Fecal leukocytes and RBCs are detected in the stools of 75% of infected persons [10]. The peripheral WBC count may be mildly elevated. Other laboratory studies, including liver function, electrolytes, and hematocrit levels, are normal. Because diffuse colonic inflammation may be seen on sigmoidoscopic examination, Campylobacter enteritis may be confused with early inflammatory bowel disease. Diagnosis of Campylobacter enteritis is confirmed by obtaining cultures of the organism from stool samples. Some laboratories have begun performing PCR analysis on stool samples for Campylobacter, but this is not yet a standard practice. Species-specific assays, such as PCR-enzyme-linked immunosorbent assays to detect Campylobacter antigens in stool samples, have been developed and also may become useful in the diagnosis of Campylobacter infections [11].

Complications of Campylobacter Infections

Local complications of Campylobacter infections occur as a result of direct spread from the gastrointestinal tract and can include cholecystitis, pancreatitis, peritonitis, and massive gastrointestinal hemorrhage. Extraintestinal manifestations of Campylobacter infection are quite rare and may include meningitis, endocarditis, septic arthritis, osteomyelitis, and neonatal sepsis. Bacteremia is detected in 6 ingested organisms are needed to produce illness in 10%–50% of persons) [28], person-to-person transmission is unusual. Outbreaks of Campylobacter infection in day care centers or mental institutions are almost unheard of. Although the reported incidence of Campylobacter infection among homosexual men is almost 40 times greater than in the general population [29], recent analysis shows the rate is not higher than among heterosexual men of a similar age [3].

Campylobacter in developing countries. The epidemiology of Campylobacter infections is quite different in developing countries than in the industrialized world. In tropical developing countries, Campylobacter infections are hyperendemic among young children, especially those aged 1 week), pregnancy, infection with HIV, and other immunocompromised states.

The decision to use antibiotics should be made judiciously. In the United States, the most common cause of bloody diarrhea is not Campylobacter but E. coli O157:H7 infection [1]. Recent studies suggest that administration of antibiotics to children with E. coli O157:H7 infection actually increases the risk of the hemolytic uremic syndrome (HUS) [30], a recognized sequela of this infection. Therefore, young children with bloody diarrhea (and others who might be at risk of infection with E. coli O157:H7 and HUS) should not be treated with antibiotics unless it is absolutely necessary or until this infection is ruled out.

Until a few years ago, if antimicrobial therapy was indicated for Campylobacter infection, fluoroquinolones were considered the drugs of choice. This approach was the simplest for physicians and patients alike because the symptoms of Campylobacter enteritis (fever, abdominal cramps, and diarrhea) are clinically indistinguishable from those of bacterial gastroenteritis caused by other organisms, such as Salmonella or Shigella species. Because these other pathogens were also generally susceptible to fluoroquinolones, empirical treatment with these drugs could be used without waiting for the results of stool cultures. Fluoroquinolones were especially apt to be used for the treatment of traveler's diarrhea.

However, in the past few years, a rapidly increasing proportion of Campylobacter strains all over the world have been found to be fluoroquinolone-resistant (table 2). Primary resistance to quinolone therapy in humans was first noted in the early 1990s in Asia and in European countries such as Sweden, The Netherlands, Finland, and Spain. Not surprisingly, this coincided with initiation of the administration of the fluoroquinolone, enrofloxacin, to food animals in those countries [31]. A similar increase in rates of resistance to fluoroquinolones in Campylobacter isolates from humans was observed in the United Kingdom after the approval of the use of fluoroquinolones in veterinary animals there as well [32].

Percentage of Campylobacter isolates (from humans) with primary resistance to fluoroquinolones.