A multi-centre prospective case-control study of campylobacter infection in persons aged 5 years and older in Australia

Burden and Cost of Campylobacter Risk Factors in Australia

Campylobacter is a globally important pathogen with well-studied risk factors, but the burden of risk factors has not been quantified. We quantified the cost of illness attributable to specific domestic risk factors for C. jejuni and C. coli in Australia. We used data from a 2018-2019 case-control study to estimate odds ratios and attributable fractions for risk factors. We used data on national incidence, hospitalization, and premature mortality to quantify burden. We then applied costs related to healthcare utilization, pain and suffering, premature mortality, and lost productivity to each risk factor. In Australia, C. jejuni caused 83.0% of campylobacteriosis infections and chicken consumption resulted in the highest attributable fraction (30.0%), costing approximately US$110 million annually. The excess burden of campylobacteriosis associated with the use of proton-pump inhibitors (PPIs) was US$45 million, with almost half these costs due to disease in adults over 65 years of age. Contact with young dogs (US$30 million) and chicken feces (US$10 million) also contributed to costs and burden. Campylobacteriosis is a significant cost to Australia, particularly because of lost productivity. Effective cross-sectoral interventions to improve chicken meat safety and reduce inappropriate use of PPIs might have substantial economic and human benefits.

Risk factors for campylobacteriosis in Australia: outcomes of a 2018-2019 case-control study

BACKGROUND

We aimed to identify risk factors for sporadic campylobacteriosis in Australia, and to compare these for Campylobacter jejuni and Campylobacter coli infections.

METHODS

In a multi-jurisdictional case-control study, we recruited culture-confirmed cases of campylobacteriosis reported to state and territory health departments from February 2018 through October 2019. We recruited controls from notified influenza cases in the previous 12 months that were frequency matched to cases by age group, sex, and location. Campylobacter isolates were confirmed to species level by public health laboratories using molecular methods. We conducted backward stepwise multivariable logistic regression to identify significant risk factors.

RESULTS

We recruited 571 cases of campylobacteriosis (422 C. jejuni and 84 C. coli) and 586 controls. Important risk factors for campylobacteriosis included eating undercooked chicken (adjusted odds ratio [aOR] 70, 95% CI 13-1296) or cooked chicken (aOR 1.7, 95% CI 1.1-2.8), owning a pet dog aged < 6 months (aOR 6.4, 95% CI 3.4-12), and the regular use of proton-pump inhibitors in the 4 weeks prior to illness (aOR 2.8, 95% CI 1.9-4.3). Risk factors remained similar when analysed specifically for C. jejuni infection. Unique risks for C. coli infection included eating chicken pâté (aOR 6.1, 95% CI 1.5-25) and delicatessen meats (aOR 1.8, 95% CI 1.0-3.3). Eating any chicken carried a high population attributable fraction for campylobacteriosis of 42% (95% CI 13-68), while the attributable fraction for proton-pump inhibitors was 13% (95% CI 8.3-18) and owning a pet dog aged < 6 months was 9.6% (95% CI 6.5-13). The population attributable fractions for these variables were similar when analysed by campylobacter species. Eating delicatessen meats was attributed to 31% (95% CI 0.0-54) of cases for C. coli and eating chicken pâté was attributed to 6.0% (95% CI 0.0-11).

CONCLUSIONS

The main risk factor for campylobacteriosis in Australia is consumption of chicken meat. However, contact with young pet dogs may also be an important source of infection. Proton-pump inhibitors are likely to increase vulnerability to infection.

Recommended Practices to Eliminate Campylobacter from Live Birds and Chicken Meat in Japan

Campylobacter food poisoning is one of the major bacterial foodborne diseases resulting in numerous outbreaks worldwide. Particularly in Japan, one-fourth of the total food poisoning is caused by Campylobacter jejuni/coli. Raw and/or undercooked poultry meat and meat products are known as the main cause of campylobacteriosis. Consequently, effective and immediate actions are needed to eliminate or at least reduce campylobacteriosis. This study aimed at examining the Japanese food regulation system, comparing it with those in the USA and Australia, and making necessary recommendations for a better control of campylobacteriosis in Japan. The study was conducted by a thorough investigation of published literatures, governmental documents, statistical and epidemiological data and public information. The results led to recommendations that the Japanese food regulation authority should consider the following suggestions in order to control campylobacteriosis: 1) assess the Campylobacter safety at the end of processing stage of chicken supply chain based on risk assessment using quantitative/qualitative baseline data collected over Japan, 2) establish a national Campylobacter strategy, including specific campylobacteriosis reduction goals and criteria, and 3) provide the small food business operators with sufficient training and support to implement a Hazard Analysis Critical Control Points (HACCP) as an obligatory food safety requirement. It is acknowledged that it would be difficult to apply foreign regulations directly to Japanese food regulation system due to differences in food culture, regulation, industry structure, and data collection systems. Thus, flexible application is required. Finding and conducting effective Campylobacter control measures can decrease contaminated live birds and chicken meat in Japan, home to a unique food culture of eating raw and/or undercooked chicken meat called Torisashi such as sashimi, tataki and yubiki chicken. Consequently, potentially available research data may be instrumental in finding solutions for reducing campylobacteriosis. Eliminating Campylobacter food poisoning cases in Japan will be a significant achievement in ensuring Japanese and global food safety.

Monitoring the incidence and causes of disease potentially transmitted by food in Australia: Annual report of the OzFoodNet network, 2016

Abstract

In 2016, a total of 44,455 notifications of enteric diseases potentially related to food were received by state and territory health departments in Australia. Consistent with previous years, campylobacteriosis (n = 24,171) and salmonellosis (n = 18,060) were the most frequently-notified infections. Notable increases in incidence were observed for shiga toxin-producing Escherichia coli (n = 343; 166% increase), shigellosis (n = 1,408; 93% increase), campylobacteriosis (33% increase) and salmonellosis (30% increase) when compared with the historical five-year mean. The extent to which the introduction of culture-independent testing as a method of diagnosis has contributed to these increases remains unclear. In total, 188 gastrointestinal outbreaks, including 177 foodborne outbreaks, were reported in 2016. The 11 non-foodborne outbreaks were due to environmental or probable environmental transmission (nine outbreaks) and animal-to-person or probable animal-to-person transmission (two outbreaks). No outbreaks of waterborne or probable waterborne transmission were reported in 2016. Foodborne outbreaks affected 3,639 people, resulting in at least 348 hospital admissions and four deaths. Eggs continue to be a source of Salmonella Typhimurium infection across the country: 35 egg-related outbreaks, affecting approximately 510 people, were reported across six jurisdictions in 2016. Three large multi-jurisdictional Salmonella outbreaks associated with mung bean sprouts (n = 419 cases); bagged salad products (n = 311 cases); and rockmelons (n = 144 cases) were investigated in 2016. These outbreaks highlight the risks associated with fresh raw produce and the ongoing need for producers, retailers and consumers to implement strategies to reduce potential Salmonella contamination.

A meta-analysis of case-control studies examining sporadic campylobacteriosis in Australia and New Zealand from 1990 to 2016

OBJECTIVE

We conducted a meta-analysis of case-control studies to identify locally relevant risk factors for sporadic campylobacteriosis in Australia and New Zealand.

METHODS

We searched Medline, Web of Science, ProQuest and Google Scholar using PRISMA guidelines. Reference lists and grey literature were hand-searched. Meta-analyses were conducted in the R package 'metafor' using published odds ratios and 95% confidence intervals.

RESULTS

We identified 325 articles, from which we included 10 that described case-control studies. Four risk factors were statistically significant in the meta-analysis: eating undercooked poultry (OR=4.28, 95%CI 3.09-5.93); eating poultry cooked outside the home (OR=2.13, 95%CI 1.66-2.72); having pet chickens (OR=3.29, 95%CI 2.12-5.10); and overseas travel (OR=5.55, 95%CI 3.20-9.63). Among children, having pet dogs showed elevated but not significant risk (OR=1.57, 95%CI 0.99-2.49).

CONCLUSIONS

We identified consumption of chicken meat and contact with domestic chickens as important risk factors for campylobacteriosis in Australia and New Zealand. Implications for public health: While consumption of chicken meat is a well-known risk factor for campylobacteriosis, zoonotic transmission is often overlooked. This research indicates a greater need for public health awareness surrounding zoonotic campylobacteriosis, especially for young children.

External contamination of broilers by Campylobacter spp. increases from the farm to the slaughterhouse

1. In this study, classical and molecular microbiological methods for detection and quantification of Campylobacter spp. were used to estimate their prevalence in faecal samples and skin swabs collected from 31 broiler flocks (20 farms) in Portugal, and measure the impact of transport-related factors on the expected rising excretion rates from the farm to the slaughterhouse. 2. Data on husbandry practices and transport conditions were gathered, including time in transit, distance travelled or ante-mortem plant-holding time. 3. A generalised linear mixed model was used to evaluate the significance of a potential post-transport rise in Campylobacter spp. counts and to assess risk determinants. 4. At least one flock tested positive for Campylobacter spp. in 80% of the sampled farms. At the slaughterhouse, Campylobacter spp. were detected in all faecal samples, C. jejuni being the most commonly isolated. 5. A post-transport rise of Campylobacter spp. counts from skin swabs was observed using classical microbiological methods (from a mean of 1.43 to 2.40 log₁₀ CFU/cm²) and molecular techniques (from a mean of 2.64 to 3.31 log₁₀ genome copies/cm²). 6. None of the husbandry practices or transport-related factors were found to be associated with Campylobacter spp. counts. 7. This study highlights the need for more research to better understand the multi-factorial nature of Campylobacter spp., a public health threat that was found to be highly prevalent in a sample of Portuguese poultry farms.

Characteristics of Campylobacter Gastroenteritis Outbreaks in Australia, 2001 to 2016

Campylobacter spp. are a globally important cause of bacterial gastroenteritis, with Australia experiencing higher rates of illness than many comparable high-income countries. Despite the high disease incidence, outbreaks of campylobacteriosis in Australia are infrequently detected and reported. We examined the epidemiology of Campylobacter outbreaks in Australia, with particular emphasis on assessing transmission routes and evidence as reported during public health investigations. A national register of enteric and foodborne disease outbreaks was used to summarize data on all Campylobacter outbreaks reported in Australia between 2001 and 2016. Outbreak data were reviewed and analyzed for trends over time. Additional information was sought from state and territory epidemiologists, to validate transmission routes. A total of 84 Campylobacter outbreaks were reported, with 51 (61%) being classified as foodborne. Specific food vehicles were identified for 33 (65%) outbreaks, with 28 (85%) implicating chicken or chicken-containing dishes. Although no increase in the proportion of foodborne Campylobacter outbreaks was observed, examination of specific food vehicles demonstrated a significant increase in outbreaks because of poultry-liver containing foods (p = 0.04). One quarter of all 1042 outbreak-associated cases occurred in aged-care facilities (ACFs), including 17 associated hospitalizations and three deaths. After review of evidence data, 23 outbreaks (27%) were determined to have an unknown route of transmission, including 10 (43%) outbreaks occurring in ACFs. Campylobacter spp. remain a less commonly reported cause of gastroenteritis outbreaks in Australia. Although many reported outbreaks can be linked to foodborne transmission, over a quarter were unable to identify either a food vehicle or transmission source, particularly for outbreaks occurring in aged care. Increased efforts to improve evidence collection and understanding of transmission dynamics for outbreaks of campylobacteriosis, particularly in aged care, are required.

An outbreak of hepatitis A in Canada: The use of a control bank to conduct a case-control study

An outbreak of 18 cases of hepatitis A virus infection across five Canadian provinces was investigated. Case onsets occurred between October 2017 and May 2018. A retrospective matched case-control study was conducted to identify the likely source of the outbreak. Three matched controls were recruited for each case using a previously established control bank, supplemented by landline and cell phone call lists. Univariate and multivariate matched analyses were conducted to identify a potential outbreak source. Seventy-two per cent of controls were recruited through the control bank, and required on average 25.5 calls per recruited control; 20% of controls were recruited through a landline sample and 8% of controls were recruited through a cell phone sample, requiring an average of 847.3 and 331.7 calls per recruited control, respectively. Results of the analysis pointed to shrimp/prawns (odds ratio (OR) 15.75, p = 0.01) and blackberries (OR 7.21, p = 0.02) as foods of interest, however, an outbreak source could not be confirmed. The control bank proved to be a more efficient method for control recruitment than random call lists. Expanding the control bank size and using alternative methods, such as online surveys, may prove beneficial for increasing the timeliness of a case-control study during an outbreak investigation.

Characteristics of Campylobacter and Salmonella Infections and Acute Gastroenteritis in Older Adults in Australia, Canada, and the United States

BACKGROUND

The early detection of enteric infections in older adults is challenging because typical signs and symptoms of disease may be less common, absent, or overlooked. Understanding illness characteristics of enteric infections among older adults could improve the timeliness and accuracy of clinical diagnoses, thereby improving patient outcomes and increasing cases reported to surveillance.

METHODS

Here, we describe illness characteristics (percentage reporting bloody diarrhea, fever, vomiting, abdominal pain; percentage hospitalized; duration of hospitalization; and duration of illness) among older adults (≥65 years) with acute gastroenteritis and culture-confirmed Campylobacter and nontyphoidal Salmonella infections in Australia, Canada, and the United States and compare these characteristics with those among younger people (<5 years, 5-24 years, and 25-64 years).

RESULTS

A significant negative correlation was found between all symptoms and increasing age group, except for bloody diarrhea in cases of acute gastroenteritis. Adults aged ≥85 years reported bloody diarrhea in only 9% of nontyphoidal Salmonella and 4% of Campylobacter infections compared with 59% and 55% among children aged <5 years. Conversely, a greater percentage of older adults (≥65) than younger persons (<5, 5-24, 25-64) reported being hospitalized, with an increasing linear relationship in age groups 65 years and older.

CONCLUSIONS

Although older adults are more likely to have severe illness and be hospitalized, we found that the proportion of persons reporting symptoms typically associated with enteric infections decreases with age. These findings have implications for clinical recognition and treatment of gastrointestinal illness, as well as for public health research.

Use of a case-control study and control bank to investigate an outbreak of locally acquired cyclosporiasis in Canada, 2016

BACKGROUND

Cyclospora is an intestinal parasite that is not endemic in Canada. However, national outbreaks of locally acquired cases have been reported since 2013. These outbreaks were suspected to be associated with consumption of produce imported from countries where Cyclospora is endemic. Identification of the source can be challenging because of reporting delays and limited traceability of produce.

OBJECTIVE

To report on a national outbreak of locally acquired cyclosporiasis, highlight the challenges of investigating these outbreaks and document the first time use of a control bank to recruit controls for a national outbreak case-control study in Canada.

METHODS

Cases of cyclosporiasis were identified through provincial laboratory testing and reported through provinces to the national level. Cases were interviewed about food exposures using a questionnaire and food exposures reported by cases were compared to Foodbook reference values. To narrow down the food items of interest, a matched case-control study was conducted. Controls for the study were recruited primarily from a control bank, that is, a list of individuals who had previously agreed to participate in public health-related surveys.

RESULTS

In total, 87 cases of locally acquired cyclosporiasis with onset or report dates between May 19, 2016 and August 10, 2016 were reported by four provinces. Comparing case exposures to Foodbook reference values identified several food items of interest, including blackberries, other berries, herbs and leafy greens. The case-control study identified only blackberries and mesclun greens as significantly more frequently consumed by cases than controls. Due to lack of product details for blackberries and mesclun greens, the source of the outbreak was not conclusively identified.

CONCLUSION

Blackberries were the primary food item of interest, but could not be identified as the conclusive source due to lack of traceability. The control bank was found to be a useful tool for control recruitment.

Veal Liver as Food Vehicle for Human Campylobacter Infections

A matched case-control study in Quebec, Canada, evaluated consumption of veal liver as a risk factor for campylobacteriosis. Campylobacter was identified in 28 of 97 veal livers collected concurrently from slaughterhouses and retailers. Veal liver was associated with human Campylobacter infection, particularly when consumed undercooked.

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

INTRODUCTION

The 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 study. Case isolates and contemporaneous isolates from food and animal sources will be sequenced to conduct source attribution modelling, and findings will be combined with the case-control study in a source-assigned analysis.

METHODS AND ANALYSIS

The case-control study will include 1200 participants (600 cases and 600 controls) across three regions in Australia. Cases will be recruited from campylobacteriosis notifications to health departments. Only those with a pure and viable Campylobacter isolate will be eligible for selection to allow for whole genome sequencing of isolates. Controls will be recruited from notified cases of influenza, frequency matched by sex, age group and geographical area of residence. All participants will be interviewed by trained telephone interviewers using a piloted questionnaire.We will collect Campylobacter isolates from retail meats and companion animals (specifically dogs), and all food, animal and human isolates will undergo whole genome sequencing. We will use sequence data to estimate the proportion of human infections that can be attributed to animal and food reservoirs (source attribution modelling), and to identify spatial clusters and temporal trends. Source-assigned analysis of the case-control study data will also be conducted where cases are grouped according to attributed sources.

ETHICS AND DISSEMINATION

Human and animal ethics have been approved. Genomic data will be published in online archives accompanied by basic metadata. We anticipate several publications to come from this study.

Determinants of sporadic Campylobacter infections in Denmark: a nationwide case-control study among children and young adults

BACKGROUND

Each year more than 4,000 cases of campylobacteriosis are reported in Denmark, making it the most common bacterial gastrointestinal infection. Here we describe a case-control study to identify sources of infection with a focus on environmental factors.

METHODS

From January to December 2016, we conducted a prospective case-control study among Danish persons aged 1-30 years. Participants were invited by letter to complete an online questionnaire. Crude and adjusted ORs were calculated and final parsimonious multivariate models developed using logistic regression.

RESULTS

The study recruited 1366 cases and 4,418 controls, of whom 65% and 66%, respectively, completed the questionnaire. A multivariate model for domestically acquired cases showed, among others, increased risk of infection with bathing in fresh water (OR=5.1), contact to beach sand (OR=1.8), owning a pet dog with diarrhea (OR=4.6), and eating minced beef (OR=2.6) or chicken (OR=2.5). The model for children highlighted similar risk factors but also included bathing in a paddling pool (OR=13.6) and eating fresh strawberries (OR=5.3). A separate analysis for persons reporting foreign travel showed increased infection risk when traveling to Asia, Africa, or Turkey and that eating from street kitchens and having contact to water during traveling were also risk factors.

CONCLUSION

Environmental factors and animal contact account for a sizeable proportion of domestic Campylobacter infections in the age group studied. The study also re-confirmed handling/consumption of chicken as an important risk factor while highlighting minced beef as a potential new risk factor. Overall, these results contribute to a better understanding of the transmission dynamics of Campylobacter and will be used to improve national guidelines for prevention of infection.

The campylobacteriosis conundrum - examining the incidence of infection with Campylobacter sp. in Australia, 1998-2013

Campylobacter sp. are a globally significant cause of gastroenteritis. Although rates of infection in Australia are among the highest in the industrialized world, studies describing campylobacteriosis incidence in Australia are lacking. Using national disease notification data between 1998 and 2013 we examined Campylobacter infections by gender, age group, season and state and territory. Negative binomial regression was used to estimate incidence rate ratios (IRRs), including trends by age group over time, with post-estimation commands used to obtain adjusted incidence rates. The incidence rate for males was significantly higher than for females [IRR 1·20, 95% confidence interval (CI) 1·18-1·21], while a distinct seasonality was demonstrated with higher rates in both spring (IRR 1·18, 95% CI 1·16-1·20) and summer (IRR 1·17, 95% CI 1·16-1·19). Examination of trends in age-specific incidence over time showed declines in incidence in those aged <40 years combined with contemporaneous increases in older age groups, notably those aged 70-79 years (IRR 1998-2013: 1·75, 95% CI 1·63-1·88). While crude rates continue to be highest in children, our findings suggest the age structure for campylobacteriosis in Australia is changing, carrying significant public health implications for older Australians.

Non food-related risk factors of campylobacteriosis in Canada: a matched case-control study

BACKGROUND

Campylobacteriosis is a prominent bacterial gastrointestinal infection worldwide with several transmission pathways. Its non-foodborne routes have been less documented and quantified. The study aimed to quantitatively explore the role of potential risk factors not directly associated with food for sporadic cases of C. jejuni infection in Canada.

METHODS

This retrospective matched case-control study was built on an enhanced campylobacteriosis surveillance system and on a survey of healthy people and their behaviour with regards to potential risk factors for gastrointestinal infections that occurred in the same area in Canada. Eighty-five cases were individually matched by age and season to 170 controls.

RESULTS

Through conditional logistic regression, risk factors were found only among water-related factors (drinking untreated water, using tap filter, drinking water from well and swimming in natural water), whereas drinking bottled water was protective. Among the 32 non-water related factors explored, 12 were surprisingly 'protective' factors without relevant explanation for that effect (for example gardening, attending a barbecue, eating food from a fast-food restaurant), suggesting that human infection by Campylobacter may be more frequently acquired at home than outside the home.

CONCLUSIONS

This study confirms and quantifies the importance of the waterborne transmission of campylobacteriosis. People are encouraged to drink only treated water and to avoid the ingestion of natural water as much as possible while swimming or playing in water. Globally, general hygiene and proper food handling and cooking practices at home should continue to be encouraged.

Human Campylobacteriosis in Luxembourg, 2010-2013: A Case-Control Study Combined with Multilocus Sequence Typing for Source Attribution and Risk Factor Analysis

Campylobacteriosis has increased markedly in Luxembourg during recent years. We sought to determine which Campylobacter genotypes infect humans, where they may originate from, and how they may infect humans. Multilocus sequence typing was performed on 1153 Campylobacter jejuni and 136 C. coli human strains to be attributed to three putative animal reservoirs (poultry, ruminants, pigs) and to environmental water using the asymmetric island model. A nationwide case-control study (2010-2013) for domestic campylobacteriosis was also conducted, including 367 C. jejuni and 48 C. coli cases, and 624 controls. Risk factors were investigated by Campylobacter species, and for strains attributed to different sources using a combined case-control and source attribution analysis. 282 sequence types (STs) were identified: ST-21, ST-48, ST-572, ST-50 and ST-257 were prevailing. Most cases were attributed to poultry (61.2%) and ruminants (33.3%). Consuming chicken outside the home was the dominant risk factor for both Campylobacter species. Newly identified risk factors included contact with garden soil for either species, and consuming beef specifically for C. coli. Poultry-associated campylobacteriosis was linked to poultry consumption in wintertime, and ruminant-associated campylobacteriosis to tap-water provider type. Besides confirming chicken as campylobacteriosis primary source, additional evidence was found for other reservoirs and transmission routes.

Spatial variation in attributable risks

The attributable risk (AR) measures the contribution of a particular risk factor to a disease, and allows estimation of disease rates specific to that risk. While previous studies consider variability in ARs over demographic categories, this paper considers the extent of spatial variability in ARs estimated from multilevel data with confounders both at individual and geographic levels. A case study considers the AR for diabetes in relation to elevated BMI, and area rates for diabetes attributable to excess weight. Contextual adjustment includes known area variables, and unobserved spatially clustered influences, while spatial heterogeneity (effect modification) is considered in terms of varying effects of elevated BMI by neighbourhood deprivation category. The application is to patient register data in London, with clear evidence of spatial variation in ARs, and in small area diabetes rates attributable to excess weight.

Prevalence, Antimicrobial Resistance and Risk Factors for Thermophilic Campylobacter Infections in Symptomatic and Asymptomatic Humans in Tanzania

The genus Campylobacter comprises members known to be a leading cause of foodborne gastrointestinal illness worldwide. A study was conducted to determine the epidemiology and antimicrobial resistance of Campylobacter in humans in Morogoro, Eastern Tanzania. Isolation of Campylobacter from stool specimens adopted the Cape Town protocol. Campylobacter isolates were preliminarily identified by conventional phenotypic tests and subsequently confirmed by matrix-assisted laser desorption/ionization-time-of-flight (MALDI-TOF) mass spectrometry and polymerase chain reaction. Antimicrobial resistance testing employed the disc diffusion method. A small proportion of the test isolates was also subjected to agar dilution method. Risk factors for human illness were determined in an unmatched case-control study. Thermophilic Campylobacter were isolated from 11.4% of the screened individuals (n = 1195). The agreement between PCR and MALDI-TOF was perfect (κ = 1.0). Symptomatics and young individuals were infected with higher numbers than asymptomatic and adults, respectively. The majority (84.6%) of the isolates were C. jejuni and the remaining were C. coli. Isolates had highest resistance (95.6%) for colistin sulphate and lowest for ciprofloxacin (22.1%). The rates of resistance for other antibiotics (azithromycin, erythromycin, tetracycline, cephalothin, gentamycin, nalidixic acid, ampicillin, amoxycillin, norfloxacin, chloramphenicol) ranged from 44.1% to 89%. Comparison between disc diffusion and agar dilution methods indicated a good correlation, and the tests were in agreement to each other (κ ≥ 0.75). Human illness was found to be associated with young age and consumption of chicken meat and pre-prepared salad. Our data indicate the presence of antibiotic-resistant thermophilic Campylobacter in humans in the study area. There is a need for routine investigation of the presence of the organisms in gastroenteritis aetiology, including determination of their antibiotic susceptibilities.

An assessment of risk posed by a Campylobacter-positive puppy living in an Australian residential aged-care facility

INTRODUCTION

In April and June 2012, two outbreaks of Campylobacter gastroenteritis were investigated in an Australian aged-care facility (ACF); a Campylobacter-positive puppy was identified as a potential source of infection.

METHODS

An expert panel was convened to assess transmission risk from the puppy to elderly residents and to guide further public health action. Criteria considered as part of the panel's assessment included the puppy's infectivity, the bacterium's transmissibility, puppy-resident contact, infection control and cleaning practices and animal management at the facility. A literature review was used to assist the panel, with a final risk being determined using a likelihood and consequence matrix.

RESULTS

The panel determined that the setting and low infective dose made transmission likely despite varying degrees of contact between the puppy and cases. While infection control practices were generally appropriate, the facility's animal policy did not adequately address potential zoonotic risk.

CONCLUSION

In summary, puppies should not be considered as companion animals in ACFs due to high rates of Campylobacter carriage and the underlying susceptibility of the elderly. Infection control and animal policies in ACFs should reflect an awareness of zoonotic disease potential.

A tradition and an epidemic: determinants of the campylobacteriosis winter peak in Switzerland

Campylobacteriosis is the most frequently reported food borne infection in Switzerland. We investigated determinants of infections and illness experience in wintertime. A case-control study was conducted in Switzerland between December 2012 and February 2013. Cases were recruited among laboratory-confirmed campylobacteriosis patients. Population-based controls were matched according to age group, sex and canton of residence. We determined risk factors associated with campylobacteriosis, and help seeking behaviour and illness perception. The multivariable analysis identified two factors associated with an increased risk for campylobacteriosis: consumption of meat fondue (matched odds ratio [mOR] 4.0, 95% confidence interval [CI] 2.3-7.1) and travelling abroad (mOR 2.7, 95% CI 1.1-6.4). Univariable analysis among meat fondue consumers revealed chicken as the type of meat with the highest risk of disease (mOR 3.8, 95% CI 1.1-13.5). Most frequently reported signs and symptoms among patients were diarrhoea (98%), abdominal pain (81%), fever (66%), nausea (44%) and vomiting (34%). The median perceived disease severity was 8 on a 1-to-10 rating scale. Patients reported a median duration of illness of 7 days and 14% were hospitalised. Meat fondues, mostly "Fondue chinoise", traditionally consumed during the festive season in Switzerland, are the major driver of the epidemic campylobacteriosis peak in wintertime. At these meals, individual handling and consumption of chicken meat may play an important role in disease transmission. Laboratory-confirmed patients are severely ill and hospitalisation rate is considerable. Public health measures such as decontamination of chicken meat and improved food handling behaviour at the individual level are urgently needed.

Detection and molecular analysis of Campylobacter ureolyticus in domestic animals

Previous studies showed the presence of Campylobacter ureolyticus in a large proportion of diarrhoeal samples from patients in Ireland. This emerging gastrointestinal pathogen was the second most common Campylobacter species detected in patients presenting with gastroenteritis, surpassed only by C. jejuni. However, the source of C. ureolyticus infections in humans remains unknown. The aim of this study was to investigate the presence of C. ureolyticus in a range of domestic animals. Over a period of 6 months, 164 samples collected from various domestic animals were tested using molecular method based on detection of the C. ureolyticus specific hsp60 gene. These included canine faeces (n = 44), feline faeces (n = 31) and porcine faeces (n = 89). C. ureolyticus was detected in 32% (10/31) of feline faeces, 9% (4/44) of canine faeces and 18% (16/89) of porcine faeces. Random Amplified Polymorphic DNA (RAPD) analysis of C. ureolyticus isolates showed that an isolate from a cat is genetically similar to a strain isolated from a patient presenting with gastroenteritis.

This study reports the first detection and isolation of this organism in domestic animals in Ireland, with a potential source for human infection. Together with the previously reported detection of C. ureolyticus in bovine samples, it is likely that this emerging pathogen has a zoonotic potential.

Pathogen exclusion properties of canine probiotics are influenced by the growth media and physical treatments simulating industrial processes

AIMS

Manufacturing process used in preparation of probiotic products may alter beneficial properties of probiotics. The effect of different growth media and inactivation methods on the protective properties of canine-originated probiotic bacteria against adhesion of canine enteropathogens was investigated.

METHODS AND RESULTS

Three established dog probiotics, Lactobacillus fermentum VET9A, Lactobacillus plantarum VET14A and Lactobacillus rhamnosus VET16A, and their mixture were assessed using the dog mucus pathogen exclusion model. The pathogens used were Enterococcus canis, Salmonella enterica serovar Typhimurium and Clostridium perfringens. The effect of growth media, one reflecting laboratory and the other manufacture conditions, and viability (viable and heat inactivated, 80°C per 30 min) on the pathogen exclusion properties of probiotics were characterized. Greater pathogen exclusion percentages were noted for probiotics growing in conditions reflecting manufacture when compared to laboratory (P < 0·05). Inactivation of probiotics by heat (80°C per 30 min) increased pathogen exclusion compared with their viable forms (P < 0·05).

CONCLUSIONS

Manufacturing process conditions such as growth media, incubation temperature and pretreatment methods may significantly affect the protective properties of the tested strains.

SIGNIFICANCE AND IMPACT OF THE STUDY

Growing conditions and pretreatment methods should be carefully considered when designing new probiotics to reduce the risk of common infections in dogs. The studied probiotics are promising potential feed additives for dogs.

Case-control studies of sporadic enteric infections: a review and discussion of studies conducted internationally from 1990 to 2009

Epidemiologists have used case-control studies to investigate enteric disease outbreaks for many decades. Increasingly, case-control studies are also used to investigate risk factors for sporadic (not outbreak-associated) disease. While the same basic approach is used, there are important differences between outbreak and sporadic disease settings that need to be considered in the design and implementation of the case-control study for sporadic disease. Through the International Collaboration on Enteric Disease "Burden of Illness" Studies (the International Collaboration), we reviewed 79 case-control studies of sporadic enteric infections caused by nine pathogens that were conducted in 22 countries and published from 1990 through to 2009. We highlight important methodological and study design issues (including case definition, control selection, and exposure assessment) and discuss how approaches to the study of sporadic enteric disease have changed over the last 20 years (e.g., making use of more sensitive case definitions, databases of controls, and computer-assisted interviewing). As our understanding of sporadic enteric infections grows, methods and topics for case-control studies are expected to continue to evolve; for example, advances in understanding of the role of immunity can be used to improve control selection, the apparent protective effects of certain foods can be further explored, and case-control studies can be used to provide population-based measures of the burden of disease.

Antimicrobial resistance in campylobacter: susceptibility testing methods and resistance trends

Most Campylobacter infections are self-limiting but antimicrobial treatment (e.g., macrolides, fluoroquinolones) is necessary in severe or prolonged cases. Susceptibility testing continues to play a critical role in guiding therapy and epidemiological monitoring of resistance. The methods of choice for Campylobacter recommended by the Clinical and Laboratory Standards Institute (CLSI) are agar dilution and broth microdilution, while a disk diffusion method was recently standardized by the European Committee on Antimicrobial Susceptibility Testing (EUCAST). Macrolides, quinolones, and tetracyclines are among the common antimicrobials recommended for testing. Molecular determination of Campylobacter resistance via DNA sequencing or PCR-based methods has been performed. High levels of resistance to tetracycline and ciprofloxacin are frequently reported by many national surveillance programs, but resistance to erythromycin and gentamicin in Campylobacter jejuni remains low. Nonetheless, variations in susceptibility observed over time underscore the need for continued public health monitoring of Campylobacter resistance from humans, animals, and food.

Risk factors for campylobacteriosis of chicken, ruminant, and environmental origin: a combined case-control and source attribution analysis

BACKGROUND

Campylobacteriosis contributes strongly to the disease burden of food-borne pathogens. Case-control studies are limited in attributing human infections to the different reservoirs because they can only trace back to the points of exposure, which may not point to the original reservoirs because of cross-contamination. Human Campylobacter infections can be attributed to specific reservoirs by estimating the extent of subtype sharing between strains from humans and reservoirs using multilocus sequence typing (MLST).

METHODOLOGY/PRINCIPAL FINDINGS

We investigated risk factors for human campylobacteriosis caused by Campylobacter strains attributed to different reservoirs. Sequence types (STs) were determined for 696 C. jejuni and 41 C. coli strains from endemic human cases included in a case-control study. The asymmetric island model, a population genetics approach for modeling Campylobacter evolution and transmission, attributed these cases to four putative animal reservoirs (chicken, cattle, sheep, pig) and to the environment (water, sand, wild birds) considered as a proxy for other unidentified reservoirs. Most cases were attributed to chicken (66%) and cattle (21%), identified as the main reservoirs in The Netherlands. Consuming chicken was a risk factor for campylobacteriosis caused by chicken-associated STs, whereas consuming beef and pork were protective. Risk factors for campylobacteriosis caused by ruminant-associated STs were contact with animals, barbecuing in non-urban areas, consumption of tripe, and never/seldom chicken consumption. Consuming game and swimming in a domestic swimming pool during springtime were risk factors for campylobacteriosis caused by environment-associated STs. Infections with chicken- and ruminant-associated STs were only partially explained by food-borne transmission; direct contact and environmental pathways were also important.

CONCLUSION/SIGNIFICANCE

This is the first case-control study in which risk factors for campylobacteriosis are investigated in relation to the attributed reservoirs based on MLST profiles. Combining epidemiological and source attribution data improved campylobacteriosis risk factor identification and characterization, generated hypotheses, and showed that genotype-based source attribution is epidemiologically sensible.

Foodborne and waterborne infections in elderly community and long-term care facility residents,Victoria, Australia

We calculated rates of foodborne and waterborne infections reported to the health department in Victoria, Australia, during 2000-2009 for elderly residents of long-term care facilities (LTCFs) and the community. We used negative binomial regression to estimate incidence rate ratios, adjusting for age, sex, and reporting period. We analyzed 8,277 infections in elderly persons. Rates of campylobacteriosis, legionellosis, listeriosis, toxigenic Escherichia coli infections, and shigellosis were higher in community residents, and rates of Salmonella infection were higher in LTCF residents. Each year, 61.7 Campylobacter infections were reported per 100,000 LTCF residents, compared with 97.6 per 100,000 community residents. LTCF residents were at higher risk for S. enterica serotype Typhimurium associated with outbreaks. Rates of foodborne infections (except salmonellosis) were similar to or lower for LTCF residents than for community residents. These findings may indicate that food preparation practices in LTCFs are safer than those used by elderly persons in the community.

Investigation of prevalence and risk factors forCampylobacterin broiler flocks at slaughter: results from a UK survey

During 2007–2009 a UK-wide, 3-year stratified randomized survey of UK chicken broiler flocks was conducted to estimate the prevalence ofCampylobacter-infected batches of birds at slaughter. Thirty-seven abattoirs, processing 88·3% of the total UK slaughter throughput, were recruited at the beginning of the survey. Of the 1174 slaughter batches sampled, 79·2% were found to be colonized withCampylobacter, the majority of isolates beingC. jejuni. Previous partial depopulation of the flock [odds ratio (OR) 5·21], slaughter in the summer months (categorized as June, July and August; OR 14·27) or autumn months (categorized as September, October and November; OR 1·70) increasing bird age (40–41 days, OR 3·18; 42–45 days, OR 3·56; ⩾46 days, OR 13·43) and higher recent mortality level in the flock (1·00–1·49% mortality, OR 1·57; ⩾1·49% mortality, OR 2·74) were all identified as significant risk factors forCampylobactercolonization of the birds at slaughter. Time in transit to the slaughterhouse of more than 2·5 h was identified as a protective factor (OR 0·52).

Gastroenteritis in older people living in the community: results of two Australian surveys

We analysed two large national surveys conducted in 2001 and 2008 to examine incidence and outcomes of gastroenteritis in older Australians. A case was someone reporting ≥3 loose stools or ≥1 episode of vomiting in 24 h, excluding non-infectious causes. We compared cases arising in the elderly (≥65 years) and in other adults (20-64 years). Elderly people experienced 0·33 [95% confidence interval (CI) 0·24-0·42] episodes of gastroenteritis/person per year, compared to 0·95 (95% CI 0·74-1·15) in other adults. Elderly cases reported less stomach cramps, fever and myalgia than younger cases, and were more likely to be hospitalized, although this was not statistically significant. In multivariable analysis, gastroenteritis in elderly people was associated with travelling within the state (odds ratio 1·35, 95% CI 1·07-1·71). Elderly people were less concerned about food safety than other adults. Older Australians were less likely to report gastroenteritis and experienced different symptoms and outcomes from other adults.

Source attribution of human campylobacteriosis using a meta-analysis of case-control studies of sporadic infections

Campylobacter spp. is a widespread and important cause of human illness worldwide. Disease is frequently associated with foodborne transmission, but other routes of exposure, such as direct contact with live animals and person-to-person transmission, are also recognized. Identifying the most important sources of human disease is essential for prioritizing food safety interventions and setting public health goals. Numerous case-control studies of sporadic infections of campylobacteriosis have been published. These studies investigated a variety of potential risk factors for disease, often using different methodologies and settings. Systematic reviews (SRs) consist of a formal process for literature review focused on a specific research question, and include the identification of relevant literature, quality assessment of relevant studies, summarization or statistical analysis of data, and conclusions. With the objective of identifying the most important risk factors for human sporadic campylobacteriosis, we performed a SR of case-control studies of human sporadic cases and a meta-analysis of the obtained results. A combined SR focusing on Salmonella and Campylobacter studies was performed and the results analysed separately. From 1295 identified references, 131 passed the relevance screening, 73 passed the quality assessment stage, and data was extracted from 72 studies. Of these, 38 focused on campylobacteriosis. Information on exposures of cases and controls, and estimated odds ratios for investigated risk factors were collected and analysed. In the meta-analysis, heterogeneity between the studies and possible sources of bias were investigated, and pooled odds ratios for identified risk factors were estimated. Results suggest that travelling abroad, eating undercooked chicken, environmental sources, and direct contact with farm animals were significant risk factors for campylobacteriosis. Sub-analyses by geographical region, age group, and study period were performed, and differences were discussed.

The importance of a One Health approach to public health and food security in Australia – a perspective from the Chief Medical Officer

I have had the privilege of being Australia?s Chief Medical Officer for the past 18 months, which has given me a unique perspective on a range of health-related matters. My role is to provide advice to the Minister and the Department of Health and Ageing (DoHA) including input to the development and administration of major health reforms for all Australians and ensuring the development of evidence-based public health policy. I am responsible for the DoHA?s Office of Health Protection and I chair the Australian Health Protection Principal Committee which advises and makes recommendation to the Australian Health Ministers? Advisory Council on national approaches to public health emergencies, communicable disease threats and environmental threats to public health.

Marked campylobacteriosis decline after interventions aimed at poultry, New Zealand

Beginning in the 1980s, New Zealand experienced rising annual rates of campylobacteriosis that peaked in 2006. We analyzed notification, hospitalization, and other data to explore the 2007-2008 drop in campylobacteriosis incidence. Source attribution techniques based on genotyping of Campylobacter jejuni isolates from patients and environmental sources were also used to examine the decline. In 2008, the annual campylobacteriosis notification rate was 161.5/100,000 population, representing a 54% decline compared with the average annual rate of 353.8/100,000 for 2002-2006. A similar decline was seen for hospitalizations. Source attribution findings demonstrated a 74% (95% credible interval 49%-94%) reduction in the number of cases attributed to poultry. These reductions coincided with the introduction of a range of voluntary and regulatory interventions to reduce Campylobacter spp. contamination of poultry. The apparent success of these interventions may inform approaches other countries could consider to help control foodborne campylobacteriosis.

Enteropathogenic bacteria in dogs and cats: diagnosis, epidemiology, treatment, and control

This report offers a consensus opinion on the diagnosis, epidemiology, treatment, and control of the primary enteropathogenic bacteria in dogs and cats, with an emphasis on Clostridium difficile, Clostridium perfringens, Campylobacter spp., Salmonella spp., and Escherichia coli associated with granulomatous colitis in Boxers. Veterinarians are challenged when attempting to diagnose animals with suspected bacterial-associated diarrhea because well-scrutinized practice guidelines that provide objective recommendations for implementing fecal testing are lacking. This problem is compounded by similar isolation rates for putative bacterial enteropathogens in animals with and without diarrhea, and by the lack of consensus among veterinary diagnostic laboratories as to which diagnostic assays should be utilized. Most bacterial enteropathogens are associated with self-limiting diarrhea, and injudicious administration of antimicrobials could be more harmful than beneficial. Salmonella and Campylobacter are well-documented zoonoses, but antimicrobial administration is not routinely advocated in uncomplicated cases and supportive therapy is recommended. Basic practices of isolation, use of appropriate protective equipment, and proper cleaning and disinfection are the mainstays of control. Handwashing with soap and water is preferred over use of alcohol-based hand sanitizers because spores of C. difficile and C. perfringens are alcohol-resistant, but susceptible to bleach (1:10 to 1:20 dilution of regular household bleach) and accelerated hydrogen peroxide. The implementation of practice guidelines in combination with the integration of validated molecular-based testing and conventional testing is pivotal if we are to optimize the identification and management of enteropathogenic bacteria in dogs and cats.

Marked campylobacteriosis decline after interventions aimed at poultry, New Zealand

Beginning in the 1980s, New Zealand experienced rising annual rates of campylobacteriosis that peaked in 2006. We analyzed notification, hospitalization, and other data to explore the 2007-2008 drop in campylobacteriosis incidence. Source attribution techniques based on genotyping of Campylobacter jejuni isolates from patients and environmental sources were also used to examine the decline. In 2008, the annual campylobacteriosis notification rate was 161.5/100,000 population, representing a 54% decline compared with the average annual rate of 353.8/100,000 for 2002-2006. A similar decline was seen for hospitalizations. Source attribution findings demonstrated a 74% (95% credible interval 49%-94%) reduction in the number of cases attributed to poultry. These reductions coincided with the introduction of a range of voluntary and regulatory interventions to reduce Campylobacter spp. contamination of poultry. The apparent success of these interventions may inform approaches other countries could consider to help control foodborne campylobacteriosis.

Screening of Australian plants for antimicrobial activity against Campylobacter jejuni

Campylobacter jejuni is the most common cause of acute enteritis in humans, with symptoms such as diarrhoea, fever and abdominal cramps. In this study, 115 extracts from 109 Australian plant species were investigated for their antimicrobial activities against two C. jejuni strains using an in vitro broth microdilution assay. Among the plants tested, 107 (93%) extracts showed activity at a concentration between 32 and 1024 µg/mL against at least one C. jejuni strain. Seventeen plant extracts were selected for further testing against another six C. jejuni strains, as well as Campylobacter coli, Escherichia coli, Salmonella typhimurium, Bacillus cereus, Proteus mirabilis and Enterococcus faecalis. The extract from Eucalyptus occidentalis demonstrated the highest antimicrobial activity, with an inhibitory concentration of 32 µg/mL against C. jejuni and B. cereus. This study has shown that extracts of selected Australian plants possess antimicrobial activity against C. jejuni and thus may have application in the control of this organism in live poultry and retail poultry products.

Potential sources of Campylobacter infection on chicken farms: contamination and control of broiler-harvesting equipment, vehicles and personnel

AIMS

To test the efficacy of enhanced biosecurity measures on poultry farms for reducing environmental contamination with Campylobacter during partial depopulation of broiler flocks prior to normal slaughter age. The study has also evaluated the risk of infection from live-bird transport crates that are routinely cleaned at the slaughterhouse, but may remain contaminated.

METHODS AND RESULTS

On-farm sampling and Campylobacter isolation was undertaken to compare the prevalence of contamination on vehicles, equipment and catching personnel during farm visits that took place under normal or enhanced biosecurity. Campylobacters were found in almost all types of sample examined and enhanced biosecurity reduced the prevalence. However, the additional measures failed to prevent colonisation of the flocks. For transport crates, challenge trials involved exposure of broilers to commercially cleaned crates and genotyping of any campylobacters isolated. The birds were rapidly colonised with the same genotypes as those isolated from the cleaned crates.

CONCLUSIONS

The enhanced biosecurity measures were insufficient to prevent flock colonisation, and the problem was exacerbated by inadequate cleaning of transport crates at the slaughterhouse.

SIGNIFICANCE AND IMPACT OF THE STUDY

Current commercial practices in the United Kingdom facilitate the spread of campylobacters among broiler chicken flocks. Prevention of flock infection appears to require more stringent biosecurity than that studied here.

Epidemiology of Campylobacter jejuni outbreak in a middle school in Incheon, Korea

On July 6, 2009, an outbreak of gastroenteritis occurred among middle school students in Incheon. An investigation to identify the source and describe the extent of the outbreak was conducted. A retrospective cohort study among students, teachers, and food handlers exposed to canteen food in the middle school was performed. Using self-administered questionnaires, information was collected concerning on symptoms, days that canteen food was consumed, and food items consumed. Stool samples were collected from 66 patients and 11 food handlers. The catering kitchen was inspected and food samples were taken. Of the 791 people who ate canteen food, 92 cases became ill, representing an attack rate of 11.6%. Thirty-one (40.3%) of the 77 stool specimens were positive for Campylobacter jejuni. Interviews with kitchen staff indicated the likelihood that undercooked chicken was provided. This is the first recognized major C. jejuni outbreak associated with contaminated chicken documented in Korea.

Riding in shopping carts and exposure to raw meat and poultry products: prevalence of, and factors associated with, this risk factor for salmonella and campylobacter infection in children younger than 3 years

Riding in a shopping cart next to raw meat or poultry is a risk factor for Salmonella and Campylobacter infections in infants. To describe the frequency of, and factors associated with, this behavior, we surveyed parents of children aged younger than 3 years in Foodborne Disease Active Surveillance Network sites. We defined exposure as answering yes to one of a series of questions asking if packages of raw meat or poultry were near a child in a shopping cart, or if a child was in the cart basket at the same time as was raw meat or poultry. Among 1,273 respondents, 767 (60%) reported that their children visited a grocery store in the past week and rode in shopping carts. Among these children, 103 (13%) were exposed to raw products. Children who rode in the baskets were more likely to be exposed than were those who rode only in the seats (odds ratio [OR], 17.8; 95% confidence interval [CI], 11.0 to 28.9). In a multivariate model, riding in the basket (OR, 15.5; 95% CI, 9.2 to 26.1), income less than $55,000 (OR, 1.8; 95% CI, 1.0 to 3.1), and Hispanic ethnicity (OR, 2.3; 95% CI, 1.2 to 4.5) were associated with exposure. Our study shows that children can be exposed to raw meat and poultry products while riding in shopping carts. Parents should separate children from raw products and place children in the seats rather than in the baskets of the cart. Retailer use of leak-proof packaging, customer placement of product in a plastic bag and on the rack underneath the cart, use of hand sanitizers and wipes, and consumer education may also be helpful.

Risk factors for indigenousCampylobacter jejuniandCampylobacter coliinfections in The Netherlands: a case-control study

A case-control study comprising 1315Campylobacter jejunicases, 121Campylobacter colicases and 3409 frequency-matched controls was conducted in The Netherlands in 2002–2003. Risk factors for bothC. jejuniandC. colienteritis were consumption of undercooked meat and barbecued meat, ownership of cats and use of proton pump inhibitors. Consumption of chicken was a predominant risk factor forC. jejunienteritis, but many additional risk factors were identified. Unique risk factors forC. coliinfections were consumption of game and tripe, and swimming. Contact with farm animals and persons with gastroenteritis were predominant risk factors forC. jejunienteritis in young children (0–4 years). Important risk factors for the elderly (⩾60 years) were eating in a restaurant, use of proton pump inhibitors and having a chronic intestinal illness. Consumption of chicken in spring, steak tartare in autumn and winter and barbecued meat in rural areas showed strong associations withC. jejuniinfections. This study illustrates that important differences in risk factors exist for differentCampylobacterspp. and these may differ dependent on age, season or degree of urbanization.

Outbreaks of campylobacteriosis in Australia, 2001 to 2006

The objective of this study was to examine the frequency of Campylobacter outbreaks in Australia and determine common transmission routes and vehicles. Summary and unit data on Campylobacter outbreaks that occurred between January 2001 and December 2006 were systematically collected and analyzed. Data from Campylobacter mandatory notifications for the same period were used for comparison. During the study period there were 33 Campylobacter outbreaks reported, affecting 457 persons. Of these, 147 (32%) had laboratory-confirmed infections, constituting 0.1% of notified Campylobacter cases. Campylobacter outbreaks most commonly occurred during the Australian Spring (September to November; n = 14, 45%), when notifications generally peaked. Transmission was predominantly foodborne or suspected foodborne (n = 27, 82%), commercial settings (n = 15, 55%) being most commonly involved. There were eight foodborne outbreaks (30%) attributed to food prepared or eaten at institutions; four (15%) at aged care facilities and three (11%) at school camps. A vehicle or suspected vehicle was determined for 16 (59%) foodborne outbreaks; poultry (chicken or duck) was associated with 11 (41%) of these, unpasteurized milk and salad were associated with two outbreaks each. Three potential waterborne outbreaks were detected, and one was due to person-to-person transmission. Campylobacter outbreaks were more commonly detected during this study period compared to a previous 6-year period (n = 9) when prospective recording of information was not undertaken. However, outbreak cases continue to constitute a very small proportion of notifications. Improved recognition through subtyping is required to enhance outbreak detection and investigation so as to aid policy formulation for prevention of infection. In addition to detection of chicken as a common source of outbreaks, these data highlight the importance of directing policy at commercial premises, aged care facilities, and school camps to reduce Campylobacter disease burden.

Case-control study of risk factors for sporadic Campylobacter infections in northeastern Spain

BACKGROUND

An age-matched case-control study was conducted in northeastern Spain to identify major risk factors for sporadic Campylobacter infections and their relative importance.

METHODS

Cases were aged >6 months, residents of Sector Sanitario Huesca with diarrhea and confirmed culture of Campylobacter not related to outbreak. For each case <15 years of age, the patient closest in age to the case was selected from the medical records of the case's pediatrician to serve as a control. If the case was >or=15 years of age, the control was nominated by the case.

RESULTS

Eighty one cases (median age 2.3 years, 79% <15 years) and 81 controls were enrolled. Three exposures, in the 7 days prior to symptom onset, were independent predictors for illness after multivariate conditional logistic regression analysis: consuming three or more times chicken [odds ratio (OR)(adjusted) = 6.1; confidence interval (CI): 2.0-18.5; population attributable fraction (PAF) = 36.1%], consuming sliced deli meat unhygienically handled at retail stores (OR(adjusted) = 4.1; CI: 1.2-13.2; PAF = 24.5%) and contact with animals (OR(adjusted) = 2.8; CI: 1.1-7.3; PAF = 19. 0%). Among cases <15 years of age, only consuming chicken >or=3 times (OR(adjusted) = 7.8; CI: 2.2-26.7; PAF = 43.6%) and contact with animals (OR(adjusted) = 3.7; CI: 1.2-11.0; PAF = 25.1%) were independent predictors for disease. Consuming sliced deli meat unhygienically handled at retail stores was significantly more frequent among <15-year age group (56.3% versus 26.6.0%, P = 0.04).

CONCLUSION

A control programme for Campylobacter in the food chain and targeted food-safety education to prevent cross-contamination seem warranted to decrease the opportunity of human exposure to the pathogen in northeastern Spain.

Estimate of the number of Campylobacter infections in the Hunter region, NSW, 2004-2007

OBJECTIVES

Campylobacteriosis is not notifiable in NSW and the number of cases of Campylobacter disease is thus not well described.

METHODS

De-identified campylobacteriosis records for 2004-2007 were requested from laboratories in the Hunter region of NSW. Based on notifying laboratory, a Salmonella notification weighting was applied to laboratory-confirmed campylobacteriosis cases to provide an overall estimate of Campylobacter disease in the area.

RESULTS

The estimated median of the annual number of laboratory-confirmed campylobacteriosis cases was 788 (range 700-1022). The ratio of estimated Campylobacter cases to Salmonella notifications was 5.5 : 1.

CONCLUSION

Campylobacter infection causes considerable disease in the Hunter, and likely in NSW. Regular review of Campylobacter laboratory results may be valuable.