title: Reassessment of the Enteropathogenicity of MesophilicAeromonasSpecies.
abstract: Cases ofAeromonasdiarrhea have been described all over the world. The genusAeromonasincludes ca. 30 species, of which 10 have been isolated in association with gastroenteritis. The dominating species that account for ca. 96% of the identified strains areAeromonas caviae, A. veronii,A. dhakensis, andA. hydrophila. However, the role ofAeromonasas a true enteropathogen has been questioned on the basis of the lack of outbreaks, the non-fulfillment of Koch's postulates and the low numbers of acute illnesses in the only existing human challenge study. In the present study we reassess the enteropathogenicity ofAeromonasusing dose response models for microbial infection and acute illness. The analysis uses the data from the human challenge study and additional data from selected outbreak investigations where the numbers exposed and the dose were reported, allowing their inclusion as "natural experiments". In the challenge study several cases of asymptomatic shedding were found (26.3%, 15/57), however, only 3.5% (2/57) of those challenged withAeromonasdeveloped acute enteric symptoms (i.e., diarrhea). The "natural experiments" showed a much higher risk of illness associated with exposure toAeromonas, even at moderate to low doses. The median dose required for 1% illness risk, was ~1.4 × 104times higher in the challenge study (1.24 × 104cfu) compared to natural exposure events (0.9 cfu). The dose response assessment presented in this study shows that the combined challenge and outbreak data are consistent with high infectivity ofAeromonas, and a wide range of susceptibility to acute enteric illness. To illustrate the outcomes, we simulate the risk associated with concentrations ofAeromonasfound in different water and food matrices, indicating the disease burden potentially associated with these bacteria. In conclusion this study showed thatAeromonasis highly infectious, and that human susceptibility to illness may be high, similar to undisputed enteropathogens likeCampylobacterorSalmonella.
authors.affiliation: Centre for Zoonoses and Environmental Microbiology, Centre for Infectious Disease Control, National Institute for Public Health and the Environment, BilthovenNetherlands; Center for Global Safe WASH, Hubert Department of Global Health, Rollins School of Public Health, Emory University, Atlanta, GAUSA.
authors.forename: Peter
authors.initials: P
authors.lastname: Teunis
authors.affiliation: Unitat de Microbiologia, Departament de Ciènces Médiques Bàsiques, Facultat de Medicina i Ciències de la Salut, Pere Virgili Institute for Health Research, Universitat Rovira i Virgili, Reus Spain.
authors.forename: Maria J
authors.initials: MJ
authors.lastname: Figueras
keywords: Aeromonas; challenge study; food; infective dose; outbreaks; risk of illness; risk of infection; water