Historically in developed countries, reported hepatitis E cases were typically travellers returning from countries where hepatitis E virus (HEV) is endemic, but now there are increasing numbers of non-travel-related ("autochthonous") cases being reported. Data for HEV in New Zealand remain limited and the transmission routes unproven. We critically reviewed the scientific evidence supporting HEV transmission routes in other developed countries to inform how people in New Zealand may be exposed to this virus. A substantial body of indirect evidence shows domesticated pigs are a source of zoonotic human HEV infection, but there is an information bias towards this established reservoir. The increasing range of animals in which HEV has been detected makes it important to consider other possible animal reservoirs of HEV genotypes that can or could infect humans. Foodborne transmission of HEV from swine and deer products has been proven, and a large body of indirect evidence (e.g. food surveys, epidemiological studies and phylogenetic analyses) support pig products as vehicles of HEV infection. Scarce data from other foods suggest we are neglecting other potential sources of foodborne HEV infection. Moreover, other transmission routes are scarcely investigated in developed countries; the role of infected food handlers, person-to-person transmission via the faecal-oral route, and waterborne transmission from recreational contact or drinking untreated or inadequately treated water. People have become symptomatic after receiving transfusions of HEV-contaminated blood, but it is unclear how important this is in the overall hepatitis E disease burden. There is need for broader research efforts to support establishing risk-based controls.

This research investigates the presence of a naturalized clade of Escherichia coli in wetland and stream biofilms. Escherichia coli is used as a faecal indicator in water quality monitoring programmes worldwide, with the assumption that this bacterium is exclusively a commensal of the vertebrate gut. However, recent findings indicate growth and multiplication of E. coli in water and soils. This study seeks to clarify the relationships between environmental and commensal E. coli strains retrieved from New Zealand streams by evaluating fundamental genetic differences using the multilocus sequence typing (MLST) method. Environmental and commensal strains showed a high diversity of MLST profiles. Genetic analyses of linkage disequilibrium, index of association and rates of synonymous and nonsynonymous substitutions were used to investigate sequence variability and nature of change. Phylogenetic trees based on the concatenated sequences of the seven MLST housekeeping genes displayed distinct clustering of environmental strains. Comparison of the New Zealand sequences with worldwide E. coli strains retrieved from the Shigatox MLST database online did not allow the identification of a clear environmental genotype. However, some New Zealand aquatic E. coli isolates showed close relationships with strains from human and bovine origins, suggesting that environmental isolates were originally derived from subpopulations of commensal E. coli from these sources.

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