Risk Factors For Campylobacter Infection Research Articles

Prevalence of and Risk Factors for Campylobacter spp. Colonization of Broiler Chicken Flocks in Greece.

The prevalence and risk factors for Campylobacter spp. colonization of broiler flocks and broiler carcass contamination in Greek slaughterhouses were investigated. Over a 14-month period, a pool of 10 ceca and 5 neck skin samples from chicken carcasses were collected from each of 142 batches of broiler flocks slaughtered in 3 different slaughterhouses. Information on potential risk factors for Campylobacter infection in broilers was collected by an on-farm interview and linked according to the Campylobacter contamination status of broiler flocks and differences in farm characteristics and management practices identified from questionnaires. Campylobacter spp. was isolated from 73.94% and 70.42% of ceca (95% CI 65.92-80.94) and carcasses (95% CI 62.19-77.78), respectively. A significant correlation (p < 0.001) between the presence of Campylobacter spp. in broiler ceca and contamination of carcasses was found, suggesting the spread of the microorganism on the skin of carcasses during the slaughtering procedure. A multiple logistic regression showed the disinfection of the poultry house being conducted by unskilled personnel (odds ratio [OR] ¼ = 3.983) as a significant risk factor (p < 0.05) and the use of straw litter as bedding material (OR ¼ = 0.170) and closure of windows during the intervals of production cycles (OR ¼ = 0.396) as significant protective factors (p < 0.05) for broiler flock contamination. These results are important and help further the understanding of the epidemiology of Campylobacter spp. derived from poultry in Greece.

Investigating locally relevant risk factors for Campylobacter infection in Australia: protocol for a case–control study and genomic analysis

IntroductionThe CampySource project aims to identify risk factors for human Campylobacter infection in Australia. We will investigate locally relevant risk factors and those significant in international studies in a case–control...

Prevalence and risk factors for Campylobacter infection of chicken in peri-urban areas of Nairobi, Kenya

Prevalence and risk factors for Campylobacter infection of chicken in peri-urban areas of Nairobi, Kenya

Broiler health status has a major negative impact on broiler flock contamination with Campylobacter spp. in Lithuania

Abstract The objective of this study was to determine risk factors for Campylobacter infection in broiler flocks in Lithuania. Each broiler flock was tested for the contamination with Campylobacter spp., and various broiler farm, flock and abattoir as well as the weather-associated characteristics were analysed using the statistical package SPSS. Study revealed that 59.3% of the examined broiler flocks were contaminated with Campylobacter spp. Statistical analysis revealed that broiler flock contamination with Campylobacter was abattoir- and farm-dependent. Among a number of risk factors (e.g. the number of broiler houses at the farm, the type of ventilation system, the presence of the anteroom and boot security, etc.) identified, two broiler health-associated characteristics: (i) broiler age and (ii) the average weight per bird at abattoir had the highest impact on the increased prevalence of Campylobacter spp. in broilers. According to our results broiler health status has a major negative effect on broiler flock contamination with Campylobacter. Thus, it needs to be considered when improving control of Campylobacter spp. in broilers.

A combined case-control and molecular source attribution study of human Campylobacter infections in Germany, 2011\u20132014

Campylobacter infection is the most commonly notified bacterial enteritis in Germany. We performed a large combined case-control and source attribution study (Nov 2011-Feb 2014) to identify risk factors for sporadic intestinal Campylobacter infections and to determine the relative importance of various animal sources for human infections in Germany. We conducted multivariable logistic regression analysis to identify risk factors. Source attribution analysis was performed using the asymmetric island model based on MLST data of human and animal/food isolates. As animal sources we considered chicken, pig, pet dog or cat, cattle, and poultry other than chicken. Consumption of chicken meat and eating out were the most important risk factors for Campylobacter infections. Additional risk factors were preparation of poultry meat in the household; preparation of uncooked food and raw meat at the same time; contact with poultry animals; and the use of gastric acid inhibitors. The mean probability of human C. jejuni isolates to originate from chickens was highest (74%), whereas pigs were a negligible source for C. jejuni infections. Human C. coli isolates were likely to originate from chickens (56%) or from pigs (32%). Efforts need to be intensified along the food chain to reduce Campylobacter load, especially on chicken meat.

Extreme precipitation events and increased risk of campylobacteriosis in Maryland, U.S.A

Consumption of contaminated poultry, raw milk and water are significant risk factors for Campylobacter infection. Previous studies also have investigated the association between weather (temperature and precipitation) and increased risk of campylobacteriosis, but limited information exists regarding the impacts of extreme heat and precipitation events on campylobacteriosis risk, and how such risk may differentially impact coastal communities. We obtained Campylobacter case data 2002–2012; n=4804) from the Maryland Foodborne Diseases Active Surveillance Network (FoodNet). We identified extreme heat and extreme precipitation events during this time (2002–2012) using location and calendar day specific thresholds (95th percentile for extreme heat and 90th percentile for extreme precipitation) that were computed based on a 30-year baseline (1960–1989). We linked these datasets using GIS and used negative binomial generalized estimating equations adjusted for demographic confounders to calculate the association between exposure to extreme events and risk of campylobacteriosis in Maryland. We observed that a one-day increase in exposure to extreme precipitation events was associated with a 3% increase in risk of campylobacteriosis in coastal areas of Maryland (Incidence Rate Ratio (IRR): 1.03, 95% confidence interval (CI): 1.01, 1.05), but such an association was not observed in noncoastal areas. Furthermore, the risk associated with extreme precipitation events was considerably higher during La Niña periods (IRR: 1.09, 95% CI: 1.05, 1.13), while there was no evidence of elevated risk during El Niño or ENSO Neutral periods. Exposure to extreme heat events was not associated with an increased risk of campylobacteriosis, except during La Niña periods (IRR: 1.04, 95% CI: 1.01, 1.08). Extreme precipitation events could result in flooding within coastal areas that may bring water contaminated with bacterial pathogens (originating from sources such as septic systems, municipal wastewater treatment plants and concentrated animal feeding operations) into close proximity with individuals, where frequency of contact may be higher.

Survey of Campylobacter spp. in owned and unowned dogs and cats in Northern Italy

Campylobacteriosis is among the most common bacterial causes of human gastroenteritis worldwide and pet ownership has been identified as a risk factor for Campylobacter infection in humans. Since canine and feline prevalence data are scarce in Italy, the present study was carried out to assess the prevalence, species distribution and risk factors for Campylobacter infection in dogs and cats under different husbandry conditions. Rectal swabs were collected from 171 dogs (household pets, n = 100; shelter-housed dogs, n = 50; dogs from breeding kennels, n = 21) and 102 cats (household pets, n = 52; shelter-housed cats, n = 21; free-roaming cats n = 29) in Northern Italy.Campylobacter was isolated from 17% (n = 29) of dogs and 14.7% (n = 15) of cats. C. jejuni was the most common isolate in both species (Campylobacter spp.-positive dogs, 55.2%; Campylobacter spp.-positive cats, 53.3%), followed by C. upsaliensis (Campylobacter spp.-positive dogs, 27.6%; Campylobacter spp.-positive cats, 40%). Other Campylobacter species were rarely detected, but included C. hyointestinalis subsp. hyointestinalis, C. lari and C. coli in dogs and C. coli and C. helveticus in cats. Among considered variables (sex, age, origin, diarrhoea, season of sampling), origin was identified as a risk factor for dogs, with shelter-housed dogs at higher risk than household dogs (odds ratio, 2.84; 95% CI 1.17, 6.92; P = 0.021).The results of this study, particularly the high prevalence of C. jejuni in Campylobacter-positive animals, demonstrated that household and stray dogs and cats in Northern Italy might pose a zoonotic risk for humans. Moreover, biosecurity measures should be improved in dog shelters.

Prevalence and risk factors of Campylobacter infection in broiler flocks from southern Spain

An extensive epidemiological study was performed to determine the prevalence and risk factors of Campylobacter infection in broiler farms in Andalusia (southern Spain). A total of 2221 cloacal swabs and 747 environmental swabs from 291 broiler flocks were screened between April 2010 and May 2012. The prevalence of Campylobacter in individual animals was 38.1%, and the flock prevalence was 62.9%. Flocks were predominantly infected by C. jejuni and C. coli but were also infected by untyped Campylobacter spp., and mixed-species infection could be found. Risk factors for Campylobacter infection were assessed from direct interview of the farmers. The number of positive samples by flock was modelled assuming a binomial distribution. Analysis indicated five factors associated with increased intra-flock prevalence: presence of dogs or cats on the farm, older age of the broiler flock, the application of thinning of flocks, the presence of windows with canvas blinds, and the presence of rodents in the poultry house. Two factors were associated with decreased intra-flock prevalence: the treatment of drinking water and having an entrance room for access into the poultry house. This is the first study performed on broilers farms from Spain reporting the risk factors of Campylobacter infection and is the largest study on the prevalence of Campylobacter infection.

Foodborne campylobacteriosis in Australia

Thermophilic Campylobacter are an important cause of human illness worldwide. Campylobacter reservoirs include a wide variety of wild birds, poultry, farm animals, domestic pets and natural water systems. In Australia, infection is mainly associated with foodborne transmission, though other routes of exposure including waterborne and direct zoonotic transmission are not uncommon. Most cases of infection appear to be sporadic in nature, with outbreaks rarely reported. Epidemiological and microbiological evidence suggests chicken meat is the principal source of infection among cases. A recent study estimated there are more than 50,000 cases of Campylobacter infection attributed to chicken meat each year in Australia. When outbreaks are detected, they are most often associated with the consumption of poultry, contaminated water and occasionally unpasteurised milk. The lack of recognised foodborne outbreaks of campylobacteriosis could be due to organism-related factors such as the inability of thermophilic Campylobacter to multiply on food left at room temperature, their microaerophilic nature and their susceptibility to drying. However, it is likely that outbreaks of Campylobacter infection are also under-reported in developed countries due to the current lack of a suitable phenotypic or genotypic typing method for routine surveillance and outbreak detection. The future development of improved typing methods for detecting outbreaks should enable further sources and risk factors for Campylobacter infection to be determined.

Risk factors for Campylobacter infection in Danish broiler chickens

Data from the Quality Assurance System in Danish Broiler Production (KIK system) were analyzed to identify within farm biosecurity- and management-related risk factors for Campylobacter infection in Danish broiler flocks. In the study, data from 2,835 flocks originating from 187 farms in the time period of December 2009 to November 2010 were included. The PCR test results of fecal samples collected on socks revealed that 14% of the Danish broiler flocks were positive to Campylobacter during the study period. Of the positive flocks, 55% were positive during summer time and the positive flocks during summer time were related to areas where clustering of infected farms was identified in previous conducted studies. The median number of people working in or entering broiler houses was 2 (from 1 to 7). The median slaughter age of Danish broiler flocks was 35 d (from 31-61 d). A multivariable logistic regression model with a random effect of farm was performed. The analysis revealed that flocks had a higher risk of acquiring positive infection status during summer time: odds ratio = 12.59 (95% CI: 6.79-23.36) and when more than one person entered the broiler house: odds ratio = 2.03 (95% CI: 1.19-3.84). Furthermore, there was a higher risk of a positive infection status if the test result of the farm for the previous flock was positive: odds ratio = 1.80 (95% CI: 1.22-2.63), if the broiler houses were built before and during 1990: odds ratio = 1.60 (95% CI: 1.17-2.18), and if the average slaughter age of the birds was more than 35 d: odds ratio = 1.33 (95% CI: 1.02-1.76).

The effect of presence of infected neighbouring farms for the Campylobacter infection status in Danish broiler farms

Neighbourhood risk factors for Campylobacter infection in Danish broilers were evaluated. Campylobacter infection status of a flock was identified by PCR analysis of cloacal swab samples collected as a part of national surveillance program. Included into the study were, in total, 10,876 broiler flocks sent by 226 farms to processing plants from 2007 to 2009. A multivariable logistic regression model with autocorrelation structure was used to model the effect of exposure variables on the probability of being tested positive to Campylobacter. Results showed a significant protective effect with the absence of infected neighbours within a distance of 2km. The analysis was adjusted for potential confounding factors. Seasonal cyclic patterns of the Campylobacter infection was accounted for by using sine and cosine function. Predicted probability maps showed a heterogeneous spatial and temporal risk of Campylobacter infection in Danish broiler.

Risk factors associated with the presence of Campylobacter-positive broiler flocks in Sweden

Approximately 40% of Swedish broiler producers deliver Campylobacter-negative broilers in 90–100% of their flocks, showing that it is possible to produce Campylobacter-free broilers in Sweden. This study investigated risk factors associated with the presence of Campylobacter-positive flocks at Swedish broiler producers. A total of 37 producers, with 90 broiler houses including 144 compartments, participated in the study. An on-farm interview was performed to collect information on potential risk factors for Campylobacter infection in broilers, with questions about farmcharacteristics such as the environment around the farm and broiler houses, design of the broiler houses and on-farm management practices. Negative binomial regression models were used to assess the statistical significance of risk factors associated with the within-farm number of Campylobacter-positive flocks (the outcome). Campylobacter is transmitted in broiler flocks due to multiple factors and several potential sources, illustrating the complexity of Campylobacter epidemiology in broilers. Factors significantly associated with increased proportion of Campylobacter-positive flocks were the presence of other livestock on the farm, or the presence of cattle, swine, poultry or fur animals within 1 km of the farm. Poor or average general tidiness were associated with increased proportion of Campylobacter-positive flocks, but decreased if split slaughter was seldom or never applied or if farm workers changed footwear twice or three times instead of once before entering the broiler house.

Population-Attributable Risk Estimates for Risk Factors Associated withCampylobacterInfection, Australia

In 2001-2002, a multicenter, prospective case-control study involving 1,714 participants > or =5 years of age was conducted in Australia to identify risk factors for Campylobacter infection. Adjusted population-attributable risks (PARs) were derived for each independent risk factor contained within the final multivariable logistic regression model. Estimated PARs were combined with adjusted (for the > or =5 years of age eligibility criterion) notifiable disease surveillance data to estimate annual Australian Campylobacter case numbers attributable to each risk factor. Simulated distributions of "credible values" were then generated to model the uncertainty associated with each case number estimate. Among foodborne risk factors, an estimated 50,500 (95% credible interval 10,000-105,500) cases of Campylobacter infection in persons > or =5 years of age could be directly attributed each year to consumption of chicken in Australia. Our statistical technique could be applied more widely to other communicable diseases that are subject to routine surveillance.

Campylobacter spp. in conventional broiler flocks in Northern Ireland: Epidemiology and risk factors

Risk factors for Campylobacter infection in conventional broiler flocks in the time period up to the first removal of birds to slaughter were investigated over a maximum of five consecutive production cycles in a cohort of 88 broiler farms in Northern Ireland. Samples for Campylobacter culture, which consisted of 14 cloacal swabs per flock, were collected from one house on each farm prior to the first depopulation of birds. In total 388 flocks were sampled, of which 163 tested positive for Campylobacter spp. (42.0%; 95% CI 35.1–48.9%). Data on farm and flock variables were obtained from questionnaires and random-effects logistic regression modelling used to investigate the association between these and the Campylobacter status of flocks. Six variables, all of which were significant at p < 0.05, were included in the final multivariable model. These included a combined variable on the presence of rodents on farms, which showed an increased odds of infection in flocks where the farmer reported having observed rodents during the production cycle (OR = 2.1) and/or where rodent droppings were observed at the sampling visit (OR = 2.9). Other variables that were significantly associated with an increased odds of infection included the age of the birds at sampling (odds ratio for its linear effect = 1.16 for each day of increase in age), season (summer versus other seasons OR = 2.0), farms with three or more broiler houses (OR = 2.9 compared to those with one house), the frequency of footbath disinfectant changes (OR = 2.5 for once weekly and OR = 4.0 for less than once weekly compared to twice weekly changes) and a categorical variable on the standard of tidiness and cleanliness of the broiler house ante-room (OR = 2.0 and OR = 4.9 for flocks from houses with poorer standards). There was no significant evidence of direct carry-over of infection from one production cycle to the next, neither was there evidence of other farm species acting as a source of infection.

Survival of Campylobacter jejuni in mineral bottled water according to difference in mineral content: Application of the Weibull model

The aim of the study was to examine the hypothesis proposed by Evans et al. [2003. Hazards of healthy living: bottled water and salad vegetables as risk factors for Campylobacter infection. Emerg. Infect. Dis. 9(10), 1219–1225] that mineral bottled water accidentally contaminated by Campylobacter jejuni would represent a risk factor for C ampylobacter infection. Culturability of C. jejuni cells inoculated in low- and high-mineral bottled water during storage at 4 °C in the dark was performed by surface plating and modelled using the Weibull model. The loss of C. jejuni culturability observed in all conditions tested was shown to be dependent on strain, preculture condition and water composition. Following inoculation of C. jejuni, the rapid loss of culturability was not correlated to complete cell death as the passage into embryonated eggs enabled recovery of cells from the viable but non-culturable state. In conclusion, the sanitary risk associated with contaminated bottled water cannot be excluded although it is presumably low. Culture conditions, strain and water type must be taken into account in the evaluation of the risk factors as they influence significantly Campylobacter survival in water.

Incidence trend and risk factors for campylobacterinfections in humans in Norway

BackgroundThe objectives of the study were to evaluate whether the increase in incidence of campylobacteriosis observed in humans in Norway from 1995 to 2001 was statistically significant and whether different biologically plausible risk factors were associated with the incidence of campylobacteriosis in the different counties in Norway.MethodsTo model the incidence of domestically acquired campylobacteriosis from 1995 to 2001, a population average random effect poisson model was applied (the trend model). To case data and assumed risk-factor/protective data such as sale of chicken, receiving treated drinking water, density of dogs and grazing animals, occupation of people in the municipalities and climatic factors from 2000 and 2001, an equivalent model accounting for geographical clustering was applied (the ecological model).ResultsThe increase in incidence of campylobacteriosis in humans in Norway from 1995 to 2001 was statistically significant from 1998. Treated water was a protective factor against Campylobacter infections in humans with an IRR of 0.78 per percentage increase in people supplied. The two-level modelling technique showed no evidence of clustering of campylobacteriosis in any particular county. Aggregation of data on municipality level makes interpretation of the results at the individual level difficult.ConclusionThe increase in incidence of Campylobacter infections in humans from 1995 to 2001 was statistically significant from 1998. Treated water was a protective factor against Campylobacter infections in humans with an IRR of 0.78 per percentage increase in people supplied. Campylobacter infections did not appear to be clustered in any particular county in Norway.

Strain and host characteristics of Campylobacter jejuni infections in Finland

The relative importance of different risk-factors for Campylobacter infections and the role of bacterial strain and host characteristics are uncertain. Swimming in natural sources of water was recently described as a novel independent risk-factor for domestically-acquired Campylobacter infections. The present study investigated exposure factors and demographical characteristics (collected in a questionnaire), and determined whether Campylobacter jejuni serotypes could be linked to each other or to the severity of the disease in domestically-acquired sporadic C. jejuni infections during a seasonal peak in Finland. Swimming was associated positively with an age of <or= 5 years, and C. jejuni serotype Pen 6,7 was found significantly more frequently among patients who reported swimming. The geographical distribution among serotypes differed, in that 54% of the isolates belonging to the Pen 4 complex serotype were identified in the Helsinki area, and 74% of the Pen 21 isolates were from the Kuopio area. Pen 57 was associated with a disease of shorter duration, but no serotype could be linked to hospitalisation or antimicrobial therapy. However, advanced age was associated with hospitalisation and a longer period of hospitalisation. Risk-factors and sources of infection for C. jejuni infection may not be identical for all individuals. This study supports the concept that individuals belonging to different age groups and living in different geographical areas may acquire C. jejuni infections from different sources.

HUMAN CAMPYLOBACTER-ASSOCIATED ENTERITIS ON THE CARIBBEAN ISLAND OF BARBADOS

A longitudinal study of the incidence of Campylobacter enteritis in Barbados was undertaken from January 2000 to August 2003. Diarrheal stools received by the central public health laboratory were cultured for Campylobacter. The number of reported Campylobacter cases exceeded those of Shigella but were less than those of Salmonella, and increased steadily with each year. Isolates from stools were mainly C. jejuni (63.6%) and C. coli (31.8%). The highest isolation rate was found in children 1-4 years of age (40.8%), followed by infants less than 1 year of age (16.9%) and those 5-9 years of age (11.3%). The number of reported cases was higher in March, from June to August, and in November and December. There was no correlation between incidence and either rainfall, temperature, or humidity. Further epidemiologic investigation of this disease is needed to evaluate risk factors for Campylobacter infection and determine routes of transmission in Barbados.

Swimming andCampylobacterInfections1

A matched case-control study was conducted to study risk factors for domestically acquired sporadic Campylobacter infections in Finland. Swimming in natural sources of water was a novel risk factor. Eating undercooked meat and drinking dug-well water were also independent risk factors for Campylobacter infection.

Risk factors for Campylobacter spp. infection in Senegalese broiler-chicken flocks

Our objective was to identify the risk factors for Campylobacter infection in Senegalese broiler flocks. Seventy broiler farms were studied around Dakar from January 2000 to December 2001 around Dakar. A questionnaire was administered to the farmers, and samples of fresh droppings were taken to assess the flocks’ Campylobacter status. About 63% of the flocks were infected by Campylobacter spp.; Campylobacter jejuni was the most-prevalent species ( P<0.05). An elevated risk of Campylobacter infection was associated with other animals (mainly laying hens, cattle and sheep) being bred in the farm, the farm staff not wearing their work clothing exclusively in the poultry houses, uncemented poultry-house floors and the use of cartons that transport chicks from the hatchery to the farm as feed plates (rather than specifically designed feed plates). Alternatively, thorough cleaning and disinfection of poultry-house surroundings and manure disposal outside the farm were associated with decreased flock risk.