Diseases Transmitted by Domestic Livestock: Perils of the Petting Zoo

Bacterial diarrhoea

PURPOSE OF REVIEW

This review describes recent findings about the burden of bacterial diarrhoea and its potential complications, newer diagnostics, the emerging threat of multidrug resistance, and the promise of vaccines in development.

RECENT FINDINGS

Introduction of rotavirus vaccines in over 110 countries has changed the landscape of diarrheal pathogens. In upper middle and high-income countries, the incidence of rotavirus-specific and all-cause gastroenteritis has declined substantially, and norovirus has become the major pathogen in many settings. Bacterial pathogens cause approximately 10-15% of episodes, most often Shigella, nontyphoidal Salmonella (NTS) Campylobacter and Shiga toxin-producing Escherichia coli (STEC). In lower income countries, bacterial pathogens remain a major cause of medically attended diarrhoea with Shigella, Campylobacter and enterotoxigenic Escherichia coli (ETEC) predominating. Multidrug-resistant strains of Shigella, NTS and, Campylobacter have emerged globally requiring judicious use of antibiotics according to current guidance.

SUMMARY

Management of bacterial diarrhoea includes standard fluid and electrolyte therapy, vigilance for potential complications, and use of antibiotics for children who have moderate-severe illness due to pathogens for which efficacy has been demonstrated, or for those at high risk for severe disease. The threat of multiply resistant strains provides impetus for preventive strategies such as development of vaccines.

Using Outbreak Data for Hypothesis Generation: A Vehicle Prediction Tool for Disease Outbreaks Caused by Salmonella and Shiga Toxin-Producing Escherichia coli

Hypothesis generation about potential food and other exposures is a critical step in an enteric disease outbreak investigation, helping to focus investigation efforts and use of limited resources. Historical outbreak data are an important source of information for hypothesis generation, providing data on common food- and animal-pathogen pairs and other epidemiological trends. We developed a model to predict vehicles for Shiga toxin-producing Escherichia coli and Salmonella outbreaks using demographic and outbreak characteristics from outbreaks in the Centers for Disease Control and Prevention's Foodborne Disease Outbreak Surveillance System (1998-2019) and Animal Contact Outbreak Surveillance System (2009-2019). We evaluated six algorithmic methods for prediction based on their ability to predict multiple class probabilities, selecting the random forest prediction model, which performed best with the lowest Brier score (0.0953) and highest accuracy (0.54). The model performed best for outbreaks transmitted by animal contact and foodborne outbreaks associated with eggs, meat, or vegetables. Expanding the criteria to include the two highest predicted vehicles, 83% of egg outbreaks were predicted correctly, followed by meat (82%), vegetables (74%), poultry (67%), and animal contact (62%). The model performed less well for fruit and poultry vehicles, and it did not predict any dairy outbreaks. The final model was translated into a free, publicly available online tool that can be used by investigators to provide data-driven hypotheses about outbreak vehicles as part of ongoing outbreak investigations. Investigators should use the tool for hypothesis generation along-side other sources, such as food-pathogen pairs, descriptive data, and case exposure assessments. The tool should be implemented in the context of individual outbreaks and with an awareness of its limitations, including the heterogeneity of outbreaks and the possibility of novel food vehicles.

A Protocol for the Ethical Assessment of Wild Animal-Visitor Interactions (AVIP) Evaluating Animal Welfare, Education, and Conservation Outcomes

Due to the popularity of wild animal-visitor interactions (AVIs), there is a need for an ethical assessment of their impact on animal welfare, education, and conservation. The protocol presented in this study is designed to evaluate such interactions on an integrated level, using a transparent analysis of all the aspects involved, including all the stakeholders and the potential conflicts of values. The protocol consists of a six-step process encompassing dedicated data acquisition and a specific ethical assessment. When the protocol was applied to assess a "giraffe feeding" interaction, steps devoted to data acquisition found that animal welfare risks were low, and that visitors described giraffes with emotionally linked descriptors more often after the interaction. The net promoter score, which refers to how likely visitors would recommend to a friend to join the animal-visitor interaction, was 74%. The subsequent ethical assessment, which consisted of a comparison of the results of the previous steps with an ethical matrix highlighting the ideal situation for all stakeholders' interests, allowed the overall identification of the ethical concerns entailed by the interaction. A final ethical checklist of the examined AVI had a "yes" in entries regarding animal welfare, emotional, and conservation mindedness outcomes and ethical assessment.

Importance of Wild Species Kept in Captivity as Reservoirs of Salmonella Serotypes for Human in Petting Exhibitions and Zoo in Iran with Focus on Antimicrobial Resistance

Salmonella spp. is the leading cause of zoonotic enteric diseases wich represents a public health concern worldwide. The incidence of zoo-associated salmonellosis is rather high due to the high prevalence and shedding of this bacterium from wild animals specially kept in stressful conditions. To determine the potential public health risk presented by zoo animals in Semnan, we investigated the prevalence of Salmonella serovars Enteritidis and Typhimurium among wild animal species kept in the zoo and pet shops. Totally, 152 fecal samples from species in the zoo and pet shops were collected and Salmonella prevalence and identification was assessed via standard bacteriologic culture methods, serotyping, multiplex-PCR and antimicrobial susceptibility testing. Overall, 21% (32/152) of the samples were confirmed positive for Salmonella and serotyping showed 12.5% (19/32) Salmonella serovar Enteritidis and 8.5% (13/32) serovar Typhimurium, respectively. All the Salmonella isolates were sensitive to Chloramphenicole, Flurefenicole, Meropenem, Ceftizoxime, Imipenem and Ampicillin, while resistance was observed in the case of Nalidixic acid (78%) as the highest resistance, Streptomycin (28%), Oxytetracycline, Neomycin, Furazolidone (each one 15%) and Lincospectin (9.3%). The high occurrence of multidrug resistance Salmonella in zoo and pet animals represents a potential threat to public health and requires strict surveillance and application of hygienic criteria.