Campylobacter, the bacteria responsible for most food-borne diseases

“Campylobacter, the discreet bacterium” is the title of the new book published by Betelgeux, in which seven experts specialised in different areas tackle the most relevant issues related to food safety and controlling Campylobacter spp.

Campylobacter was first described in 1886 by the German paediatrician and bacteriologist Theodore Escherich as curved or spiral bacteria present in the colon of children who died from what he called “infantile cholera”.

The mircoorganisms of the Campylobacter genus are microaerophillic gram-negative bacillus, between 0.5-5 µm long and 0.2-0.8 wide, shaped as a comma or as a curved spiral, which can move by means of unipolar or bipolar flagella. The thermophilic Campylobacter spp. species­, including C. jejuni, C. coli, C. lari, C. upsaliensis and C. helveticus, achieve optimum development at temperatures between 42-43ºC, and they are the most frequent cause of gastroenteritis in humans. A significant majority of human infections are due to Campylobacter jejuni (80%) and, to a lesser extent, to Campylobacter coli (10%) (AESAN 2012).

The World Health Organisation (WHO 2011) considers that, globally, Campylobacter is one of the main causes of food-borne diarrhoeal diseases. Campylobacteriosis is the common name used to describe the infectious diseases caused by species of Campylobacter ssp. Most cases of campylobacteriosis are associated to consumption of contaminated food, particularly poultry; thus, this bacterium is considered a food safety issue of primary importance. In fact, campylobacteriosis is currently considered a zoonosis, that is, a disease or infection that can be transmitted naturally between animals and humans.

According to reports by the European Food Safety Authority (EFSA 2011) and the Spanish Agency for Food Safety and Nutrition (AESAN 2012), Campylobacter spp. is the food-borne pathogen responsible for the largest number of cases of diseases related to food consumption since 2005, as shown in Figure 1, which indicates the zoonoses cases reported and confirmed in the European Union during 2011 (EFSA 2013). This figure shows how campylobacteriosis is the cause of a much higher number of cases than any of the other zoonoses in humans, with well over 220,000 events reported, more than twice those of salmonellosis, the second most relevant zoonosis.

Figure 1. Number of zoonoses cases in humans reported and confirmed in the European Union in 2011 (EFSA 2013).

In 2010, a total of 6,340 cases of campylobacteriosis were reported in Spain, which represents an incidence ratio of 15.14 cases per 100,000 population. Unlike other pathogenic microorganisms related to food consumption, such as Salmonella, Campylobacter is not well known by the general public of and it does not appear regularly in the media, despite it having a significant presence in epidemiological counts and being a bacteria responsible for the largest number of food-borne infections, as mentioned before.

Although Campylobacter spp. does not cause a severe illness in most cases, the extent of the health issues it creates affects a total of 400-500 million people globally (Ganan et al. 2012) so it has a considerable impact on the world health and healthcare costs. Additionally, developing countries show an incidence of Campylobacter infections among under 2-year olds that can be deadly and particularly frequent.

Estimating the costs related to campylobacteriosis is very complex, as this type of assessment must be based on assumptions about the real incidence of the diseases and, as seen before, these involve a high degree of uncertainty. Taking as a reference an economic study completed in the United Kingdom, which considered direct costs for diagnostic, treatment and admission to hospital, as well as indirect costs, such as work absenteeism, the annual cost for campylobacteriosis was estimated at approximately 300 euros per patient. From these figures, Hernández calculated that the annual cost of campylobacteriosis in Spain would amount to 120 million euros (Hernandez 2007).

Campylobacteriosis in humans is caused, as mentioned, by thermotolerant Campylobacter spp. species, which are widely distributed in nature and are mainly found in the digestive tract of birds and mammals. Birds are the most common carrier of Campylobacter spp., probably due to their higher body temperature.

Although animals rarely develop the disease, bacteria can easily reach and contaminate the different food products obtained from them, such as meat, raw milk and dairy products, and less frequently, fish and fish products, mussels and fresh vegetables. The main routes causing the Campylobacter spp. infection in humans include the following: ingesting the microorganism when consuming food, particularly raw or rare meat, non-pasteurised milk or contaminated water and ice; cross-contamination when preparing food in household kitchens or catering environments; contact with infected animals or direct transmission.

This clearly explains that, from a food safety perspective, food contamination by Campylobacter is an important concern for health authorities and several strategies have been proposed to control it. These strategies apply to primary production (mainly livestock), food industry, distribution, catering and restaurant industry, as well as the final consumer, and they also include measures to improve systems for detecting, isolating, reporting and confirming infection cases as they occur. As indicated by the World Health Organisation (WHO 2011), these measures include improving biosafety in agricultural and livestock operations to prevent the bacteria from being transmitted from the environment to the birds in the farms; training workers in slaughterhouses, raw meat producers and food handlers on food safety and hygienic handling; and the correct and hygienic handling of raw poultry and correct food preparation in domestic and catering environments.

Currently, there is no single action or technique proven to effectively prevent the presence of Campylobacter in food. The adequate control of this pathogen requires combining control strategies at different stages of the food chain.

All these issues are addressed in more depth in “Campylobacter, the discreet bacteria”, a new book published in December 2015. The authors approached this book from a theoretical and practical perspective in order to help understanding the causes for Campylobacter ssp. contamination and identifying the specific aspects that will allow designing solutions to the problems derived from contamination by this pathogen. As an advance of the book publication, Betelgeux offers on its website an exclusive preview of the first chapter: “Campylobacter: an emerging pathogen”.

 References

• AESAN (2012). Informe del Comité Científico de la Agencia Española de Seguridad Alimentaria y Nutrición (AESAN) con relación a las medidas de control para reducir la presencia de Campylobacter spp. en carne fresca de aves (pollo). Scientifc Committee Journal, issue no. 16: 21-55.
• EFSA (2011). Scientific Opinion on Campylobacter in broiler meat production: control options and performance objectives and/or targets at different stages of the food chain. The EFSA Journal, 9(4): 2105.
• EFSA (2012). European Food Safety Authority. Scientific report of EFSA and ECDC. The European Union Summary Report on Trends and Sources of Zoonoses, Zoonotic Agents and Food-borne Outbreaks in 2010. The EFSA Journal, 10 (3): 2.597, p: 1-442.
• EFSA (2013). The European Union Summary Report on Trends and Sources of Zoonoses, Zoonotic Agents and Food-borne Outbreaks in 2011
• Ganan M., Silván J.M., Carrascosa A.V., Martínez-Rodríguez A.J. (2012) Alternative strategies to use antibiotics or chemicals products for controlling Campylobacter in the food chain. Food Control, 24, pp: 6-14.
• Hernández J. (2007). Campylobacter: líder en patología intestinal infecciosa Admission Speech as Member of the Royal Academy of Medicine of the Valencia Community: www.ramcv.com/Discursos/Dr.%20Hernandez%20Haba.pdf‎
• OMS (2011) Campylobacter. Descriptive note number 255. Octoer 2011.

Article published in October’s edition of Limpiezas magazine written by Dr. Enrique J. Orihuel Iranzo – CEO of Betelgeux-, Ramón Bertó Navarro – Operations Director of Betelgeux-  and Dr. Fernando Lorenzo Cartón -Research and Technical Department Manager of Betelgeux-. Issue 118 of the Limpiezas magazine can be checked: here.