Disease burden of selected gastrointestinal pathogens in Australia, 2010

The biofilm matrix of Campylobacter jejuni determined by fluorescence lectin-binding analysis

Campylobacter jejuni is responsible for the most common bacterial foodborne gastroenteritis. Despite its fastidious growth, it can survive harsh conditions through biofilm formation. In this work, fluorescence lectin-binding analysis was used to determine the glycoconjugates present in the biofilm matrix of two well-described strains. Screening of 72 lectins revealed strain-specific patterns with six lectins interacting with the biofilm matrix of both strains. The most common sugar moiety contained galactose and N-acetylgalactosamine. Several lectins interacted with N-acetylglucosamine and sialic acid, probably originated from the capsular polysaccharides, lipooligosaccharides and N-glycans of C. jejuni. In addition, glycoconjugates containing mannose and fucose were detected within the biofilm, which have not previously been found in the C. jejuni envelope. Detection of thioflavin T and curcumin highlighted the presence of amyloids in the cell envelope without association with specific cell appendages. The lectins ECA, GS-I, HMA and LEA constitute a reliable cocktail to detect the biofilm matrix of C. jejuni.

High incidence of hospitalisation due to infectious gastroenteritis in older people associated with poor self-rated health

OBJECTIVES

To estimate the incidence and risk factors for gastroenteritis-related hospitalisations in older adults.

DESIGN

Longitudinal cohort study.

PARTICIPANTS

The 45 and Up Study is a large-scale Australian prospective study of adults aged ≥ 45 years (mean 62.7 years) at recruitment in 2006-2009. Self-reported demographic, health and dietary information at recruitment from 265,440 participants were linked to infectious gastroenteritis hospitalisation data.

OUTCOME MEASURES

We estimated the incidence of hospitalisation for infectious gastroenteritis, and calculated HRs using Cox regression, adjusting for sociodemographic, health and behavioural variables, with age as the underlying time variable.

RESULTS

There were 6077 incident infectious gastroenteritis admissions over 1,111,000 person-years. Incidence increased exponentially with increasing age; from 2.4 per 1000 (95% CI 2.2 to 2.5) in individuals aged 45-54 years to 9.5 per 1000 (95% CI 9.2 to 9.8) in those aged 65+ years. After adjustment, hospitalisation due to infectious gastroenteritis was significantly more common in those reporting use of proton pump inhibitors (HR 1.6, 95% CI 1.5 to 1.7), and those with poorer self-rated health (HR 4.2, 95% CI 3.6 to 4.9).

CONCLUSIONS

Infectious gastroenteritis results in hospitalisation of approximately 1% of people ≥ 65 years old each year. Early recognition and supportive treatment of diarrhoea in older patients with poorer self-rated health may prevent subsequent hospitalisation.

Campylobacteriosis: the role of poultry meat

The incidence of human infections caused by Campylobacter jejuni and Campylobacter coli, the main bacterial agents of gastrointestinal disease, has been increasing worldwide. Here, we review the role of poultry as a source and reservoir for Campylobacter. Contamination and subsequent colonization of broiler flocks at the farm level often lead to transmission of Campylobacter along the poultry production chain and contamination of poultry meat at retail. Yet Campylobacter prevalence in poultry, as well as the contamination level of poultry products, vary greatly between different countries so there are differences in the intervention strategies that need to be applied. Temporal patterns in poultry do not always coincide with those found in human infections. Studies in rural and urban areas have revealed differences in Campylobacter infections attributed to poultry, as poultry seems to be the predominant reservoir in urban, but not necessarily in rural, settings. Furthermore, foreign travel is considered a major risk factor in acquiring the disease, especially for individuals living in the northern European countries. Intervention strategies aimed at reducing Campylobacter colonization in poultry and focused at the farm level have been successful in reducing the number of Campylobacter cases in several countries. Increasing farm biosecurity and education of consumers are likely to limit the risk of infection. Overall, poultry is an important reservoir and source of human campylobacteriosis, although the contribution of other sources, reservoirs and transmission warrants more research.

Adoption of a microbial health-based target for Australian drinking water regulation

The health-based targets of 1 in 10,000 for infection and 10(-6) disability adjusted life years (DALYs) per person per year are increasingly being considered, or have already been adopted, to define microbial safety targets for water. The aim of this paper is to convey information about how these two targets compare by converting each of the target values to a common metric. The metric chosen for viral (rotavirus and norovirus) and protozoan (Cryptosporidium) reference pathogens is the estimated maximum number of annual drinking water-associated cases of acute diarrhoeal disease tolerated. For the reference bacterial pathogen Campylobacter, sequelae to acute diarrhoeal illness have also been considered in estimating the tolerable number of cases for the DALY target. Also investigated is whether non-compliance with targets would be detected as a waterborne disease outbreak by the health surveillance system in an extreme hypothetical situation whereby all tolerable cases per annum occurred as a single event. The paper highlights that verification of compliance with targets cannot be demonstrated by the absence of reported drinking water-associated outbreaks alone and concludes that introduction of a quantitative health-based outcome for drinking water in Australia would help improve water quality management by providing a common goal directly linked to health outcomes.

Global Epidemiology of Campylobacter Infection

Campylobacter jejuni infection is one of the most widespread infectious diseases of the last century. The incidence and prevalence of campylobacteriosis have increased in both developed and developing countries over the last 10 years. The dramatic increase in North America, Europe, and Australia is alarming, and data from parts of Africa, Asia, and the Middle East indicate that campylobacteriosis is endemic in these areas, especially in children. In addition to C. jejuni, there is increasing recognition of the clinical importance of emerging Campylobacter species, including Campylobacter concisus and Campylobacter ureolyticus. Poultry is a major reservoir and source of transmission of campylobacteriosis to humans. Other risk factors include consumption of animal products and water, contact with animals, and international travel. Strategic implementation of multifaceted biocontrol measures to reduce the transmission of this group of pathogens is paramount for public health. Overall, campylobacteriosis is still one of the most important infectious diseases that is likely to challenge global health in the years to come. This review provides a comprehensive overview of the global epidemiology, transmission, and clinical relevance of Campylobacter infection.

Evolution of regulatory targets for drinking water quality

The last century has been marked by major advances in the understanding of microbial disease risks from water supplies and significant changes in expectations of drinking water safety. The focus of drinking water quality regulation has moved progressively from simple prevention of detectable waterborne outbreaks towards adoption of health-based targets that aim to reduce infection and disease to a level well below detection limits at the community level. This review outlines the changes in understanding of community disease and waterborne risks that prompted development of these targets, and also describes their underlying assumptions and current context. Issues regarding the appropriateness of selected target values, and how continuing changes in knowledge and practice may influence their evolution, are also discussed.