One health approach of campylobacteriosis in Egypt: An emerging zoonotic disease

World Health Organization (WHO) defined zoonotic diseases as diseases transmitted from animals to humans and vice versa with or without vector, where more than 75% of the human’s diseases have been transmitted from animals or their products. Nevertheless, campylobacteriosis is still one of the most important food borne zoonotic diseases that is likely to challenge global public health all over the world. In Egypt, campylobacteriosis causes severe losses in comparison with other food borne pathogens like Salmonella or Escherichia coli. The potential sources of Campylobacter transmission are poultry backyards and meat, cattle meat, raw milk and water. The main clinical manifestations of human’s campylobacteriosis are gastroenteritis and later on nervous signs. Prevention and control strategic plans of campylobacteriosis are very crucial.


Introduction
Campylobacteriosis has long been recognized as serious food borne zoonotic disease of worldwide public health threat.Campylobacteriosis caused by Campylobacter jejuni (C.jejuni) or Campylobacter coli (C.coli) is responsible for gastroenteritis in human [1].Recently, infection with Campylobacter organisms is likely to challenge global public health either in developing or developed industrial countries.Different international strategies were planned to reduce the risk of Campylobacter transmission [2].Despite public health burden associated with campylobacteriosis, the disease situation remains difficult to be exactly estimated in developing countries as a result of lacking of a national surveillance system [3].Therefore, implementation of periodical national evaluation of the foodborne campylobacteriosis is very critical issue.
So, this review will discuss campylobacteriosis epidemiological situation in Egypt, reservoirs and transmission methods, the organism pathogenesis, clinical disease manifestations, isolation and identification of Campylobacters and then emphasis on the different control and prevention interventions.Finally some suggestions will be offered from the standpoint of One Health approach.
In 2005, military personnel with diarrhea were participated in a military exercise in the northwestern Egyptian desert and the pathogens causing diarrhea were identified in 53.6% of 129 enrolled cases.C. jejuni with other enteropathogenic bacteria, virus and protozoa were identified [8].Similar study was conducted in 2011, on 72 personnel with travelers' diarrhea in Multinational Force and Observers camp in the Southern Sinai, Egypt and the bacteriological examination of their stool revealed isolation of C. jejuni from 7 (10%) [9].
Later on, Campylobacter spp.were identified from patients with gastroenteritis in Cairo, Egypt using conventional and polymerase chain reaction (PCR) methods in 6.6% of human stool samples [10,11].Recently, the epidemiology of Campylobacter among an Egyptian pediatric population was described and the results pointed out to the variability in Campylobacter spp.and C. jejuni capsular polysaccharide (CPS) diversity in this population; furthermore, the high prevalence of type-6 secretion system (T6SS) among C. jejuni isolates as there was no significant associations between clinical illness and Campylobacter spp., C. jejuni CPS types, or suspected virulence factors [12].

Reservoirs and transmission methods
Poultry is recognized as a primary source for Campylobacter spp.transmission to humans as strain of C. jejuni can survive in chicken droppings for up to 6 days after excretion [13].Comprehensive studies conducted in different Egyptian governorates proved that chickens reared in farms or houses is the main source of Campylobacter infections for contact persons [14][15][16][17].Phylogenetic tree analysis emphasized genetic relatedness among Campylobacter isolates from chickens and those from humans [18].
Processed chickens plays an important role for human foodborne campylobacteriosis in Egypt.Different types of Campylobacter spp.(C.jejuni and C. coli) were isolated from retail fresh or frozen chicken carcasses skin and meat [15,19,20,] as well as from barbequed and products of chickens [21,22].Campylobacter strains isolated from chicken carcasses showed identical molecular characterization with those in handler's employees and consumers which signifying the high possibilities of zoonotic hazards [15,20,21].
Cattle and beef meat products considered as reservoir for Campylobacter spp., highlighting the importance of non-poultry farms as possible sources of human infection [23].The population genetics approach revealed that the vast majority (97%) of Campylobacter diseases could be attributed to farmed animals and poultry as principal sources of human disease, while wild animals and environmental sources are responsible for just (3%) of the disease [24].
Water is considered as another vital source for Campylobacter public health hazard in Egypt [28].C. jejuni contamination of drinking water municipal plants in three locations at Giza governorate, Egypt were proved and the organisms were isolated from diarrheic patients at the surveyed locations assuredly due to drinking water from these plants [30].However C. jejuni isolates were also detected in ground water samples and stool specimens from the inhabitants of the villages in Giza, Egypt [31].

Pathogenesis
Intestinal colonization and adhesion are the first and crucial stages of Campylobacter pathogenesis.Colonization is secondary to chemotaxis process by the intestinal mucus (mucins and glycoproteins) [32].Bacterial adhesion to the host's intestinal epithelial surface is mediated by many proteins adhesins like CapA that located on the bacterium surface [33].The resulting cell death is related to the production of several cytotoxins like Cytolethal Distending Toxin (CDT) [34].This toxin has desoxy-ribonuclease activity and determines the cell cycle block and fragmentation of the nucleus causing cell damage.

Clinical manifestations
Campylobacter in poultry induces only diarrhea or sub-clinical infection.However in human, Campylobacter incubation period ranges from 2-7 days.The average organism shedding is 1-3 weeks after incubation period.Symptoms of campylobacteriosis include gastroenteritis, diarrhoea, vomiting, stomach pain and fever [35].The illness is usually self-limiting and symptoms could subside within one week; nevertheless complications like dehydration, hepatitis and neurological disorders may be noticed [3].Campylobacter infections sequelae are Guillain-Barré Syndrome (GBS), reactive arthritis, irritable bowel syndrome and Miller Fisher Syndrome.Campylobacter isolation rates and diarrhea histories in Egyptian patients suggested that Campylobacter associated diseases are common, as well as the widespread exposure to Campylobacter infections is associated with production of antiganglioside antibodies that prompted paralysis and GBS [36].Deaths were recorded especially in young, elderly as well as immunosuppressed persons.

Isolation and identification
Isolation and identification of Campylobacter spp.are usually done as Quinn et al. [37].Temperature tolerance test is important to demonstrate the ability of isolates to grow under microaerophilic conditions (25°C, 37°C and 42°C) after 72 hrs incubation.For Campylobacter isolation, samples are inoculated in thioglycolate broth and incubated under microaerophilic conditions (5% O 2 , 10% CO 2 and 85% N 2 ) at 37-42˚C for 48-72 hrs.After enrichment, positive broth should be plated onto selective media containing blood and selective antibiotics (compete intestinal flora) like Butzler, Blaser and Skirrow media.Microscopic examination under phase contrast microscope is used for detection of characteristic Campylobacter darting motility.Films stained with Gram's to demonstrate the characteristic features of Campylobacter organisms.Biochemical and other tests that are used for identification of Campylobacter isolates include: catalase and oxidase production, nitrate reduction, H 2 S production, citrate utilization, urea hydrolysis, glycine tolerance, NaCl tolerance, hippurate hydrolysis tests and sensitivity to nalidixic acid and cephalothin.The 16S rRNA gene, the Internal Transcribed Spacer (ITS) region and 23S rRNA genes have been used for differentiate between Campylobacter spp.and strains [38].

Control and prevention interventions
Earlier, ciprofloxacin (member of fluoroquinolones) was used successfully for the treatment of Egyptian Campylobacter travellers' diarrhea cases without resistance [39].The emergence of resistance to quinolones in Campylobacter may be a threatening trend that has not been previously reported in Egypt [7].The antimicrobial susceptibility among C. jejuni and C. coli recovered from rural Egyptian children from 1995-2000 revealed decreasing in ciprofloxacin susceptibility in C. jejuni and C. coli, but there was no resistance to macrolide (erythromycin or azithromycin) [40].Lately, resistance of C. jejuni and C. coli strains isolated from Egyptian diarrheic children to fluoroquinolones was confirmed [41].Human Campylobacter strains showed resistance 87.5% to ampicillin, 75% to streptomycin and tetracycline, 62.5% to erythromycin and 50% to chloramphenicol [14].
However, gentamicin, amikacin and chloramphenicol were the most effective antibiotics for the in vitro treatment of C. jejuni and C. coli isolates from Egyptian children suffering from gastroenteritis [11].
The risk of Campylobacter diarrhea decreases in presence of barriers to keep birds and animals out of the eating area, absence of garbage and feces on the floor of bathing facilities, stressing on mass-media public health awareness programs for changing hygiene-promoting behaviors and practices, strengthening on recent diagnostic facilities, setting up national surveillance programs as well as providing incentives from funding organizations for collaborations in Campylobacter research as other emerging disease in developing countries [42,43].Public health awareness regarding the correct use of municipal and ground water for drinking or cooking only after treatment by filtration and/or boiling is important [31].
Efficient control measures at the farm contributes to reducing the risk of human infection [23].There is a trial for preparation of Campylobacter bactericins in Egyptian chickens as it proved efficacy in prevention of Campylobacter colonization in layer flocks [44].In human, currently there is still no approved vaccines against diarrhea associated with Campylobacter due to incomplete understanding of the pathogenic mechanisms of the disease.Probiotics are living bacteria have been shown promising results for prevention and control of C. jejuni colonization among Egyptian chicken farms [45,46].

Conclusion
Despite campylobacteriosis is a disease of zoonotic importance in Egypt, there is a gap of knowledge about the diseases epidemiology in different localities which hinders accurate assessment of the human health burden.There is an urgent need for collaborative surveillance and intervention national plans for the control of such infection.
From the standpoint of One Health approach, a complete health surveillance program of Campylobacter infections must be done nationally to provide data about the disease occurrence and common routes of transmission.Notifications of the disease in all suffering regions should be happen rapidly, as well, it is very important to collect, analyze, and interpret data to create relationship between Campylobacter isolates of human and those of animal's origin.Increasing of the public health awareness, education and training of the target populations (Veterinarians, farm, abattoir and restaurant workers, household, nurses, doctors in hospitals, etc…) is very crucial.Biosecurity measures, vaccination or using natural competitive exclusion compounds (probiotics and acids) are very critical to reduce the risk of infection in the farm and consequently reduce the level of transmission to human.