B.S. Bharath Kumar1* and Vyankat Gangadhar Jadhav2
1 Veterinary Officer, Veterinary Dispensary, Katgal, Kumta, Uttara Kannada, Department of Animal Husbandry and Veterinary Services, Government of Karnataka-581362
2 Livesstock Development Officer, Taluka Mini Veterinary Polyclinic, Degloor, Nanded, Maharashtra-431717
Campylobacter is the most common cause of bacterial gastroenteritis around the globe. WHO estimated that the incidence of Campylobacteriosis is 1 in 4 causes of gastrointestinal disease in both developed and developing world. Poultry is considered as one of the most important reservoirs of Campylobacter species and represents a very significant vehicle for the transmission to humans. Nonetheless, Campylobacteriosis risk management system is in place at national and international level, so far it has not been possible to cater Campylobacter free poultry to the consumer. Numerous studies have been reported that the incident of food-borne illnesses linked to food handlers. According to the EFSA Scientific Opinion published in 2010, the risk of human campylobacteriosis linked to poultry handling, preparation and consumption accounts for 20 to 30% of human cases of campylobacteriosis. Fig. 1 presents a summary of an overview of human Campylobacteriosis. It is important to educate consumers regarding the severity ofCampylobacteriosis and impart knowledge of food safety practices.
Campylobacter spp is a gram-negative microorganism, non-spore-forming, which colonizes the mucosal surfaces of the intestinal tracts, oral cavities, or urogenital tracts of most warm-blooded animals. The species can grow in pH between 6.5 and 7.5 and in temperatures between 37°C and 42°C. Thus, they are considered thermophile and birds have been widely regarded as natural hosts of these organisms. Campylobacter species, particularly Campylobacter jejuni and Campylobacter coli are the most common to cause gastroenteritis in humans. The genus Campylobacter is commonly found in nature and can contaminate drinking water. Among sporadic human cases, contact with live poultry, consumption of poultry meat, drinking water from untreated water sources, and contact with pets and other animals have been identified as the important sources of infections.
Virulence and survival feature
The onset and infection of Campylobacter require several virulence factors including motility, chemotaxis, adherence, and invasion of the host cell, toxin production, structures of the cell envelope, iron uptake system, multidrug and bile resistance, and mechanisms of responses to stress. Additionally, it can also form a biofilm, a polymeric matrix synthesized by aggregates of microbial cells from the same or different microorganisms that are attached to various types of surfaces. These biofilms protect the bacteria from a hostile environment which allows the pathogen to survive. Besides several virulence factors, previous studies reveal that Campylobacter spp are also increasing antimicrobial resistance particularly strains isolated from food. Furthermore, it has not been possible to control the Campylobacter at farm level because it is resistant to various veterinary antibiotics. Thus, it has not been able to provide Campylobacter free poultry to the consumers.
Prevalence of Campylobacter in poultry
Campylobacter spp. have been found in many avian species, both domesticated and wild. Among domesticated birds, a high prevalence of C. jejuni and C. coli is often found in broiler chickens, breeder flocks and egg-laying hens. Thus, poultry is recognised as the major reservoir of Campylobacter infection for humans. The prevalence of Campylobacter in poultry can lead to a greater exposure risk when consumers mishandle raw poultry in the domestic kitchen. Infection in poultry is predominantly through the oral-faecal route or through vertical transmission from parent flocks. The cross-contamination normally passes on to generation to the next from same farm animal and it is very unusual that cross contaminated from environment to the animal.
The chicken meat in retail is tainted with C. jejuni up to 98% of cases in the US and from 60% to 80% of cases in Europe.The highest occurrence of Campylobacter (36.7%) in broiler meat was detected in 2016 reported by Europe. In 2011 nationwide survey on raw chicken on retail sales in the Republic of Ireland (ROI) revealed Campylobacter was detected in 50.2% of samples using a quantitative method, with bacteria counts ranging from of 10 CFU/g, to of 61,000 CFU/g. These high levels of bacteria spreads easily in the environment, especially in a domestic setting with mishandling, thus allowing the contamination further.
Campylobacteriosis incident occurs in all age groups with the highest rate of notification reported in the 0–5 year and the percentage of people hospitalised and died was highest among persons aged ≥ 65 years. Common symptoms include mildness such as diarrhoea, abdominal pain, malaise, fever, nausea and vomiting. The illness is self-limiting, the duration of illness lasting from 3 to 6 days to up 10 days. The incubation period is between 2–5 days but may vary from 1 to 11 days. Although diarrhoea is the most common clinical symptom of Campylobacter spp infection, a broad clinical spectrum is associated with this infection, from asymptomatic carriage to systemic illness and bacteraemia to localised infection and association with many more complications. Recently, the researchers identified that a small proportion of Campylobacteriosis patient developed reactive arthritis shortly after gastroenteritis.
Guillain-Barre Syndrome (GBS)
Uncommon cases of complication can occur at post campylobacteriosis infection, for instance, an acute immune-mediated inflammation of the peripheral nerves known as GBS often resulting in neuromuscular paralysis. In general, most of the GBS patients can fully recover within a few weeks/ months, and do not have any further problems. However, in some cases, it may take longer to recover, and there is a possibility of permanent nerve damage. The incidents of GBS in relation to peripheral nervous system destruction caused by campylobateriosis have been studied globally. Approximately, 40% of GBS cases are associated with post Campylobacteriosis infection.
Campylobacteriosis control relevant to poultry
The control of Campylobacter in the food chain is a tremendous challenge for every stakeholder. It is both the pervasive and the low infective dose required for illness. It is often difficult to detect the origin of exposure to Campylobacter, because of its sporadic nature of the infection and the important role of cross-contamination. Indeed, there is no single control measure approach that can completely eliminate Campylobacter from the food chain, or even reduce to the safe level, without affecting product attributes. Consumers’ acceptability of the decontamination method of the poultry meats varies from country to country.In EU, recently amended EU Regulation 2073/2005 has included the maximum permitted level of 1000 CFU/g at the slaughter for the broiler (Commission Regulation (EU) 2017/1495). Although recently amended EU Regulation 2073/2005 has included the maximum permitted level of 1000 CFU/g at the slaughter for the broiler (Commission Regulation (EU) 2017/1495), the infective dose is as low as 500 cells.
Food safety training
Despite, the fact that food safety and nutrition is part of the curriculum of primary and secondary school in the most developed countries.In Ireland ‘Social, Personal and Health Education’ (SPHE) programme is the curriculum in all Irish primary schools since 2002. In United States, food safety program is in the curriculum as well as additional educational strategies have been employed to improve food safety in elementary and middle school students such as electronic game, Kitchen Ninja to the Rescue. However, the current foodborne illness reports indicate that food handlers’ knowledge remained low. In most cases, the knowledge was not always translated into practice. This leads us to suggest that only risk perception and perceived behavioural control are the only make differences in food safety practices.Food businesses across the globe are legally required to have a food safety management system based on the principles of Hazard Analysis & Critical Control Point (HACCP) and have trained the food handlers since 1998. HACCP trainings are mandatory and improved food handler’s knowledge and hygiene practices . The training alone is not elixir, the food handlers’ knowledge, attitude and practices are required to monitored by Environmental Health Officer (EHO) on their routine inspection of the food businesses . Refresher training is also required to provide upon the EHO’s recommendation and or periodically otherwise food safety knowledge of the trained food handlers decline significantly.
Future perspective and conclusion
In conclusion, poultry is the main contributor to human campylobacteriosis and is still one of the most pandemic infectious diseases that is a foreseeable threat to consumers in the years ahead. Countless studies demonstrated that an absolute elimination of Campylobacter in the poultry production chain is not feasible. The Campylobacter tainted poultry remain cross-contaminate from farm to fork. While all the food businesses require legitimately to implement HACCP to mitigate the incidents, it is almost impossible to control particularly in the domestic setting. Which lead to suggest that the integrated effort from all stakeholders in terms of biosecurity at the farm level, effective HACCP at processing along with distribution and ultimately inform the consumer about the risk associated with it. Accordingly, the incident of campylobacteriosis perhaps lowered in human’s population. This review provides well-grounded and updated useful information for food industries, health services and public food safety authorities with regards to stepping up the risk communication effort to consumer and advice appropriate mitigation measures. It is noticeable that in order to lower the Campylobacteriosis incident, the development of the strategy to combat is necessary. Such a strategy will establish the appropriate measure to control the Campylobacter from farm to fork. Further research is needed to identify the most efficient channel in risk communication to the consumer.