Understanding leptospirosis eco-epidemiology by environmental DNA metabarcoding of irrigation water from two agro-ecological regions of Sri Lanka

Background

Leptospirosis is one of the most significant zoonoses across the world not only because of its impact on human and animal health but also because of the economic and social impact on agrarian communities. Leptospirosis is endemic in Sri Lanka where paddy farming activities, the use of draught animals in agriculture, and peridomestic animals in urban and rural areas play important roles in maintaining the infection cycle of pathogenic Leptospira, especially concerning animals as a potential reservoir. In this study, an environmental DNA (eDNA) metabarcoding methodology was applied in two different agro-ecological regions of Sri Lanka to understand the eco-epidemiology of leptospirosis.

Methodology/Principal findings

Irrigation water samples were collected in Kandy District (wet zone mid-country region 2) and Girandurukotte, Badulla District (intermediate zone low-country region 2); and analysed for the presence of pathogenic Leptospira, associated microbiome and the potential reservoir animals. Briefly, we generated PCR products for high-throughput sequencing of multiple amplicons through next-generation sequencing. The analysis of eDNA showed different environmental microbiomes in both regions and a higher diversity of Leptospira species circulating in Kandy than in Girandurukotte. Moreover, the number of sequence reads of pathogenic Leptospira species associated with clinical cases such as L. interrogans was higher in Kandy than in Girandurukotte. Kandy also showed more animal species associated with pathogenic bacterial species than Girandurukotte. Finally, several pathogenic bacterial species including Arcobacter cryaerophilus, responsible for abortion in animals, was shown to be associated with pathogenic Leptospira.

Conclusions/Significance

Leptospirosis has been considered to be endemic in wet regions, consistently, leptospiral sequences were detected strongly in Kandy. The great Leptospira species diversity in Kandy observed in this study shows that the etiological agents of leptospirosis in Sri Lanka might be underestimated. Furthermore, our eDNA metabarcoding can be used to discriminate bacterial and animal species diversity in different regions and to explore environmental microbiomes to identify other associated bacterial pathogens in the environment.

Leptospirosis is a widespread bacterial zoonosis with increasing importance due to its vast range of reservoir hosts. Early symptoms are shared by other infectious diseases common in tropical and sub-tropical regions, where the real burden and risk factors need to be known. In Sri Lanka, leptospirosis is mostly an occupational disease associated with freshwater or animal exposure in agriculture communities. Thus, there is a need for understanding the epidemiology of leptospirosis in agrarian regions of the country for developing better prevention and intervention strategies. In this study, we applied an environmental DNA metabarcoding methodology to understand the environmental microbiome, potential reservoir animals and the Leptospira species circulating in two different agro-ecological regions of Sri Lanka: Kandy (wet region mid-country region 2) and Girandurukotte (intermediate region low-country region 2). It is known that pathogenic Leptospira are excreted through the urine of reservoir animals in the environment, where they can persist in humid conditions. Congruently, this study showed a higher detection of pathogenic Leptospira in the environment of Kandy where the environmental microbiome showed a higher diversity than Girandurukotte. Potential animal reservoirs were also detected in samples positive for pathogenic Leptospira, suggesting that environmental DNA metabarcoding can provide important information for management and intervention strategies to control leptospirosis.

Survival time of Leptospira kirschneri serovar Grippotyphosa under different environmental conditions

Leptospirosis is a re-emerging zoonotic disease of high medical importance that affects humans worldwide. Humans or animals acquire an infection with pathogenic leptospires either by direct contact with infected animals or by indirect contact to contaminated environment. Survival of Leptospira spp. in the environment after having been shed via animal urine is thus a key factor to estimate the risk of infection, but not much is known about the tenacity of pathogenic leptospires. Here, the survival time of both a laboratory strain and a field strain of L. kirschneri serovar Grippotyphosa in animal urine and their tenacity while drying was investigated and compared at different temperatures (15°C-37°C). Leptospira spp. are also often found in rivers and ponds. As the infection risk for humans and animals also depends on the spreading and survival of Leptospira spp. in these environments, the survival of L. kirschneri serovar Grippotyphosa was investigated using a 50-meter-long hose system simulating a water stream. Both strains did not survive in undiluted cattle or dog urine. Comparing different temperatures and dilution media, the laboratory strain survived the longest in diluted cattle urine with a slightly alkaline pH value (3 days), whilst the field strain survived in diluted dog urine with a slightly acid pH value up to a maximum of 24 h. Both strains did not survive drying on a solid surface. In a water stream, leptospires were able to move faster or slower than the average velocity of the water due to their intrinsic mobility but were not able to survive the mechanical damage caused by running water in the hose system. From our results we conclude, that once excreted via animal urine, the leptospires immediately need moisture or a water body to survive and stay infectious.

Northern and southern blacklegged (deer) ticks are genetically distinct with different histories and Lyme spirochete infection rates

Lyme borreliosis (LB) is the archetypal emerging zoonosis and is dependent on transmission by ticks in the genus Ixodes. Understanding the origin, maintenance, and spread of these ticks contributes much to our understanding of the spread of LB and other disease agents borne by these ticks. We collected 1232 Ixodes scapularis ticks from 17 east coast sites ranging from New Hampshire to Florida and used mtDNA, three nuclear genetic loci, and incorporated Bayesian analyses to resolve geographically distinct tick populations and compare their demographic histories. A sparse, stable, and genetically diverse population of ticks in the Southeastern US, that is rarely infected with the agent of LB is genetically distinct from an abundant, expanding, and comparatively uniform population in the Northeast, where epidemic LB now constitutes the most important vector borne disease in the United States. The contrasting geography and demography of tick populations, interpreted in the context of the geological history of the region, suggests that during the last glacial period such ticks occupied distinct refugia, with only the northern-most site of refuge giving rise to those ticks and pathogens now fueling the epidemic.

Potent, specific MEPicides for treatment of zoonotic staphylococci

Coagulase-positive staphylococci, which frequently colonize the mucosal surfaces of animals, also cause a spectrum of opportunistic infections including skin and soft tissue infections, urinary tract infections, pneumonia, and bacteremia. However, recent advances in bacterial identification have revealed that these common veterinary pathogens are in fact zoonoses that cause serious infections in human patients. The global spread of multidrug-resistant zoonotic staphylococci, in particular the emergence of methicillin-resistant organisms, is now a serious threat to both animal and human welfare. Accordingly, new therapeutic targets that can be exploited to combat staphylococcal infections are urgently needed. Enzymes of the methylerythritol phosphate pathway (MEP) of isoprenoid biosynthesis represent potential targets for treating zoonotic staphylococci. Here we demonstrate that fosmidomycin (FSM) inhibits the first step of the isoprenoid biosynthetic pathway catalyzed by deoxyxylulose phosphate reductoisomerase (DXR) in staphylococci. In addition, we have both enzymatically and structurally determined the mechanism by which FSM elicits its effect. Using a forward genetic screen, the glycerol-3-phosphate transporter GlpT that facilitates FSM uptake was identified in two zoonotic staphylococci, Staphylococcus schleiferi and Staphylococcus pseudintermedius. A series of lipophilic ester prodrugs (termed MEPicides) structurally related to FSM were synthesized, and data indicate that the presence of the prodrug moiety not only substantially increased potency of the inhibitors against staphylococci but also bypassed the need for GlpT-mediated cellular transport. Collectively, our data indicate that the prodrug MEPicides selectively and robustly inhibit DXR in zoonotic staphylococci, and further, that DXR represents a promising, druggable target for future development.

Brucellosis in the Middle East: Current situation and a pathway forward

Brucellosis is a bacterial endemic zoonotic disease of global significance with detrimental impacts on public health and food animal production. It is caused by Brucella spp., an expanding group of pathogens able to infect various host species. Bovines and small ruminants, which excrete the bacteria in milk and in reproductive discharges, are major sources of infection for humans and other animals. Contact with contaminated animals and consumption of unpasteurized dairy products are the main routes for human infection. In spite of the considerable progress of knowledge gained and success achieved in brucellosis control in the developed world, this disease continues to be an important burden in the Middle East (ME). Common risk factors implicated in the difficulty and complexity of brucellosis control within the region include (1) social and political instabilities; (2) insufficient resources and infrastructure for appropriate diagnosis, reporting, and implementation of control measures; (3) variation of livestock husbandry systems and their commingling with other livestock and wildlife; and (4) traditional cultural practices, including consumption of unpasteurized dairy products. Development of core interdisciplinary competencies is required for a true One Health–based endeavor against the disease. National awareness and educational programs addressing all population sectors from consumers to decision-makers seem to be the next logical, sustainable, and economically viable approach toward improving disease status in this region. In the present review, we describe the current situation of brucellosis in the ME, focusing on the major limitations and shortcomings regarding disease control. We propose a regional approach toward public awareness of brucellosis as the first step in mitigating the disease and discuss the potential benefits, and components of such a strategy, which can further be used as a model for other endemic zoonotic diseases.

Systematic Review and Meta-Analysis of the Occurrence of ESKAPE Bacteria Group in Dogs, and the Related Zoonotic Risk in Animal-Assisted Therapy, and in Animal-Assisted Activity in the Health Context

Animal-assisted interventions are widely implemented in different contexts worldwide. Particularly, animal-assisted therapies and animal-assisted activities are often implemented in hospitals, rehabilitation centers, and other health facilities. These interventions bring several benefits to patients but can also expose them to the risk of infection with potentially zoonotic agents. The dog is the main animal species involved used in these interventions. Therefore, we aimed at collecting data regarding the occurrence of the pathogens ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter spp.) in dogs, in order to draft guidelines concerning the possible monitoring of dogs involved in animal-assisted therapies and animal-assisted activities in healthcare facilities. We performed a literature search using the PRISMA guidelines to examine three databases: PubMed, Web of Science, and Scopus. Out of 2604 records found, 52 papers were identified as eligible for inclusion in the review/meta-analysis. Sixteen papers reported data on E. faecium; 16 on S. aureus; nine on K. pneumoniae; four on A. baumannii; eight on P. aeruginosa; and six on Enterobacter spp. This work will contribute to increased awareness to the potential zoonotic risks posed by the involvement of dogs in animal-assisted therapies, and animal-assisted activities in healthcare facilities.

Dual oxidase Duox and Toll-like receptor 3 TLR3 in the Toll pathway suppress zoonotic pathogens through regulating the intestinal bacterial community homeostasis in Hermetia illucens L

Black soldier fly (BSF; Hermetia illucens L.) larvae can convert fresh pig manure into protein and fat-rich biomass, which can then be used as aquafeed for select species. Currently, BSF is the only approved insect for such purposes in Canada, USA, and the European Union. Pig manure could serve as a feed substrate for BSF; however, it is contaminated with zoonotic pathogens (e.g., Staphylococcus aureus and Salmonella spp.). Fortunately, BSF larvae inhibit many of these zoonotic pathogens; however, the mechanisms employed are unclear. We employed RNAi, qRT-PCR, and Illumina MiSeq 16S rDNA high-throughput sequencing to examine the interaction between two immune genes (Duox in Duox-reactive oxygen species [ROS] immune system and TLR3 in the Toll signaling pathway) and select pathogens common in pig manure to decipher the mechanisms resulting in pathogen suppression. Results indicate Bsf Duox-TLR3 RNAi increased bacterial load but decreased relative abundance of Providencia and Dysgonomonas, which are thought to be commensals in the BSF larval gut. Bsf Duox-TLR3 RNAi also inactivated the NF-κB signaling pathway, downregulated the expression of antimicrobial peptides, and diminished inhibitory effects on zoonotic pathogen. The resulting dysbiosis stimulated an immune response by activating BsfDuox and promoting ROS, which regulated the composition and structure of the gut bacterial community. Thus, BsfDuox and BsfTLR3 are important factors in regulating these key gut microbes, while inhibiting target zoonotic pathogens.

Epidemiological serosurvey of vector-borne and zoonotic pathogens among homeless people living in shelters in Marseille: cross-sectional one-day surveys (2005-2015)

Homeless people are often exposed to unhygienic environments as well as to animals carrying arthropods which both transmit zoonotic infections and human louse-borne pathogens. We attempted to determine the prevalence of antibodies against several vector-borne and zoonotic pathogens among homeless adults living in Marseille. During the 2005-2015 period, we collected sera samples from 821 homeless adults living in shelters. Antibodies against Bartonella quintana, Bartonella henselae, Borrelia recurrentis, Coxiella burnetii, Francisella tularensis (with a cut-off of 1:100), Rickettsia akari, Rickettsia conorii, Rickettsia felis, Rickettsia prowazekii, and Rickettsia typhi (with a cut-off of 1:64) were searched by microimmunofluorescence (MIF). MIF-positive serum samples were confirmed by cross-adsorption to characterise cross-reacting antigens and immunoblotting. Positive sera by Western blot were further tested using qPCR. We evidenced a prevalence of 4.9% seroreactivity to at least one pathogen including phase II C. burnetii (2.1%), B. quintana (1.7%), R. conorii (0.4%), R. prowazekii (0.4%), R. typhi (0.1%), B. recurrentis (0.1%), and F. tularensis (0.1%). No DNA from any pathogens was detected. A comparison with studies conducted prior to the 2000-2003 period showed a decrease in the overall seroprevalence of several vector-borne and zoonotic infections.

Cat-to-Human Transmission of Mycobacterium bovis, United Kingdom

Human infection with Mycobacterium bovis is reported infrequently in the United Kingdom. Most cases involve previous consumption of unpasteurized milk. We report a rare occurrence of 2 incidents of cat-to-human transmission of M. bovis during a cluster of infection in cats.

Use of meat juice and blood serum with a miniaturised protein microarray assay to develop a multi-parameter IgG screening test with high sample throughput potential for slaughtering pigs

BACKGROUND

Serological screening of pig herds at the abattoir is considered a potential tool to improve meat inspection procedures and herd health management. Therefore, we previously reported the feasibility of a miniaturised protein microarray as a new serological IgG screening test for zoonotic agents and production diseases in pigs. The present study investigates whether the protein microarray-based assay is applicable for high sample throughput using either blood serum or meat juice.

MATERIAL AND METHODS

Microarrays with 12 different antigens were produced by Abbott (formerly Alere Technologies GmbH) Jena, Germany in a previously offered 'ArrayTube' platform and in an 'ArrayStrip' platform for large-scale use. A test protocol for the use of meat juice on both microarray platforms was developed. Agreement between serum and meat juice was analysed with 88 paired samples from three German abattoirs. Serum was diluted 1:50 and meat juice 1:2. ELISA results for all tested antigens from a preceding study were used as reference test to perform Receiver Operating Characteristic analysis for both test specimens on both microarray platforms.

RESULTS

High area under curve values (AUC > 0.7) were calculated for the analysis of T. gondii (0.87), Y. enterocolitica (0.97), Mycoplasma hyopneumoniae (0.84) and Actinobacillus pleuropneumoniae (0.71) with serum as the test specimen and for T. gondii (0.99), Y. enterocolitica (0.94), PRRSV (0.88), A. pleuropneumoniae (0.78) and Salmonella spp. (0.72) with meat juice as the test specimen on the ArrayStrip platform. Cohens kappa values of 0.92 for T. gondii and 0.82 for Y. enterocolitica were obtained for the comparison between serum and meat juice. When applying the new method in two further laboratories, kappa values between 0.63 and 0.94 were achieved between the laboratories for these two pathogens.

CONCLUSION

Further development of a miniaturised pig-specific IgG protein microarray assay showed that meat juice can be used on microarray platforms. Two out of twelve tested antigens (T. gondii, Y. enterocolitica) showed high test accuracy on the ArrayTube and the ArrayStrip platform with both sample materials.

Prevalence of Mycobacterium leprae in armadillos in Brazil: A systematic review and meta-analysis

Understanding the prevalence of M. leprae infection in armadillos is important because of evidence from Brazil and other countries of an association between contact with armadillos and the development of Hansen’s Disease (leprosy). Our aim was to characterize studies which have investigated natural M. leprae infection in wild armadillos in Brazil, and to quantify and explore variability in the reported prevalence of infection. We conducted a systematic review (PROSPERO CRD42019155277) of publications in MEDLINE, EMBASE, Global Health, Scopus, LILACS, Biblioteca Digital Brasileira de Teses e Dissertações, Catálogo de Teses e Dissertações de CAPES, and Biblioteca Virtual em Saúde up to 10/2019 using Mesh and text search terms (in English, Portuguese, Spanish, and French). The 10 included studies represented a total sample of 302 armadillos comprising 207 (69%) Dasypus novemcinctus, 67 (22%) Euphractus sexcinctus, 16 (5%) Priodontes maximus, 10 (3%) Cabassous unicinctus, and 2 (1%) Cabassous tatouay from 7 different states. Methods used included histopathology (4 studies), PGL-1 and LID-1 antigen detection (4 studies) and examination for clinical signs of disease (4 studies). Eight studies used PCR of which 7 targeted the RLEP repetitive element and 3 tested for inhibitory substances. M. leprae prevalence by PCR ranged from 0% (in 3 studies) to 100% in one study, with a summary estimate of 9.4% (95% CI 0.4% to 73.1%) and a predictive interval of 0–100%. The average prevalence is equivalent to 1 in 10 armadillos in Brazil being infected with M. leprae, but wide variation in sample estimates means that the prevalence in any similar study would be entirely unpredictable. We propose instead that future studies aim to investigate transmission and persistence of M. leprae within and between armadillo populations, meanwhile adopting the precautionary principle to protect human health and an endangered species in Brazil.

The risk to human health of contact with armadillos infected with Mycobacterium leprae, a bacterium that causes Hansen’s Disease (leprosy), is uncertain, but evidence from Brazil and other countries appears to show a link between contact with armadillos and increased risk of Hansen’s Disease in people. How much of Hansen’s Disease in the human population is caused by contact with armadillos will depend on the size of the risk, the type and frequency of contact and how common it is in the population, and the role of other (human-to-human) transmission routes for Mycobacterium leprae. Our review has shown that one other key factor, the proportion of wild armadillos infected with Mycobacterium leprae, cannot be predicted with any certainty based on data from studies conducted to date. We suggest that much bigger and longer-term studies are needed, perhaps in partnership with animal conservation and ecology groups, to map Mycobacterium leprae infection in armadillos across Brazil and correlate this with proximity to human habitats. At the same time, data must be gathered in studies focused on populations of armadillos to characterize Mycobacterium leprae transmission and persistence within groups of animals, for example, using trackers and repeated sampling over the animals’ lifespans. In the meantime, the precautionary principle should prevail, and public health and educational efforts should be directed to improving community knowledge and changing behaviour to protect people and armadillos.

The seroprevalence of brucellosis and molecular characterization of Brucella species circulating in the beef cattle herds in Albania

Background

Brucellosis is a ubiquitous zoonotic disease globally. It is endemic among bovines, sheep, and goats in Albania. The national control and eradication programs for brucellosis has been applied on sheep and goat farms as well as large dairy cattle farms, i.e., those with more than ten milking cows. The current study aims at estimating the herd and average individual animal prevalence of brucellosis in the national beef cattle herds, the missing information that was essential to propose the most appropriate control measures for this sub-population. Rose Bengal Test (RBT), Fluorescence Polarization Assay (FPA), and Enzyme-Linked Immunosorbent Assay (ELISA) were used as serological tests and classical bacteriology for isolation. Results were also used to investigate the difference in sensitivity between the assays used.

Methodology

In total, 655 animals from 38 beef cattle herds from six southern districts of Albania were sampled. Sera were tested using RBT, FPA, and ELISA. Fifteen positive cows and a bull from eight high-prevalence positive herds were slaughtered, and particular tissue samples were collected for bacteriology.

Results

The overall herd seroprevalence in the tested beef cattle population was 55%, while the overall average within-herd prevalence (including only positive herds) was 38.3%, 42.7%, and 45.6% determined by the RBT, ELISA, and FPA, respectively. FPA was used for the first time in the diagnosis of bovine brucellosis in Albania, and its sensitivity was higher than RBT and ELISA. Three B. abortus strains were identified, two from the supra-mammary lymph node of two cows and one from the epididymis of a seropositive bull.

Conclusion

Brucellosis was highly prevalent in beef cattle in the southern part of Albania, and B. abortus was isolated from this subpopulation. To the best of our knowledge, this is the first statistically based survey of bovine brucellosis in beef herds in Albania. Using the FPA in parallel with other serological tests improved overall diagnostic sensitivity. Test and slaughter policy is not a rational approach for the control of brucellosis in beef cattle in Albania, and vaccination is only applicable, including strict control of the movement of animals.

Four European Salmonella Typhimurium datasets collected to develop WGS-based source attribution methods

Zoonotic Salmonella causes millions of human salmonellosis infections worldwide each year. Information about the source of the bacteria guides risk managers on control and preventive strategies. Source attribution is the effort to quantify the number of sporadic human cases of a specific illness to specific sources and animal reservoirs. Source attribution methods for Salmonella have so far been based on traditional wet-lab typing methods. With the change to whole genome sequencing there is a need to develop new methods for source attribution based on sequencing data. Four European datasets collected in Denmark (DK), Germany (DE), the United Kingdom (UK) and France (FR) are presented in this descriptor. The datasets contain sequenced samples of Salmonella Typhimurium and its monophasic variants isolated from human, food, animal and the environment. The objective of the datasets was either to attribute the human salmonellosis cases to animal reservoirs or to investigate contamination of the environment by attributing the environmental isolates to different animal reservoirs.

Leptospirosis: a six-case report from west black sea, Turkey

Leptospirosis is a ubiquitous acute bacterial zoonosis. This report describes six cases presenting to our hospital with symptoms such as fever and muscle pain and diagnosed as leptospirosis. All cases presented with fever, muscle pain, and lethargy and were engaged in activities such as farming, hunting, and fishing. Thrombocytopenia and impaired liver function tests were found in all patients, increased creatine-kinase in five, and increased creatinine in four. Leptospirosis was diagnosed using polymerase chain reaction (PCR). The course of the disease resulted in cure in three cases, chronic kidney disease sequelae in one, and death in two. In conclusion, the possibility of leptospirosis should be considered in patients presenting with non-specific symptoms such as fever and muscle pain and developing thrombocytopenia, and liver and kidney function disorder. Risk factors should also be investigated when taking histories. Early diagnosis and antibiotic therapy being started as quickly as possible are important in terms of the course of the disease.

Molecular Epidemiology of Infectious Zoonotic and Livestock Diseases

Zoonotic and livestock diseases are very important globally both in terms of direct impact on human and animal health and in terms of their relationship to the livelihood of farming communities, as they affect income generation and food security and have other, indirect consequences on human lives. More than two-thirds of emerging infectious diseases in humans today are known to be of animal origin. Bacterial, viral, and parasitic infections that originate from animals, including hypervirulent and multidrug-resistant (MDR) bacterial pathogens, such as livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA), invasive nontyphoidal Salmonella of animal origin, hyperviruent Clostridium difficile, and others, are of major significance to public health. Understanding the origin, risk factors, transmission, prevention, and control of such strains has been a challenge for various reasons, particularly due to the transdisciplinary partnership between and among human, environment, and animal health sectors. MDR bacteria greatly complicate the clinical management of human infections. Food animal farms, pets in communities, and veterinary hospital environments are major sources of such infections. However, attributing such infections and pinpointing sources requires highly discriminatory molecular methods as outlined in other parts of this curated series. Genotyping methods, such as multilocus sequence typing, pulsed-field gel electrophoresis, restriction fragment length polymorphism, and several others, have been used to decipher sources of foodborne and other zoonotic infectious diseases. In recent years, whole-genome-sequence-based approaches have been increasingly used for molecular epidemiology of diseases at the interface of humans, animals, and the environment. This part of the series highlights the major zoonotic and foodborne disease issues. *This article is part of a curated collection.

Malassezia Yeasts in Veterinary Dermatology: An Updated Overview

Lipophilic yeasts of the genus Malassezia are important skin commensals and opportunistic skin pathogens in a variety of animals. The species M. pachydermatis was first isolated from the skin of a captive Indian rhinoceros with an exfoliative dermatitis in 1925, recognized as an important otic pathogen of dogs in the 1950's, and finally accepted, after several years of controversy, as a common cause of canine dermatitis in the 1990's. Since then, there has been considerable research into the biology of Malassezia yeasts and their interaction with their animal hosts. In dogs and cats, M. pachydermatis is associated with ceruminous otitis externa and a "seborrhoeic" dermatitis, wherein pruritic, erythematous skin lesions, often with brown/black greasy, malodourous material matting hairs, preferentially develop in intertriginous areas. Skin disease is favored by folds, underlying hypersensitivity disorders, endocrinopathies, defects of cornification, and in cats, various visceral paraneoplastic syndromes. Diagnosis is based on detecting the yeast in compatible skin lesions, usually by cytology, and observing a clinical and mycological response to therapy. Treatment normally comprises topical or systemic azole therapy, often with miconazole-chlorhexidine shampoos or oral itraconazole or ketoconazole. Management of concurrent diseases is important to minimize relapses. Historically, wild-type Malassezia isolates from dogs and cats were typically susceptible to azoles, with the exception of fluconazole, but emerging azole resistance in field strains has recently been associated with either mutations or quadruplication of the ERG11 gene. These observations have prompted increased interest in alternative topical antifungal drugs, such as chlorhexidine, and various essential oils. Further clinical trials are awaited with interest.

A first insight into the genomic diversity of Leptospira strains isolated from patients in Cuba

Leptospirosis is a neglected disease causing severe infections in humans and animals. Due in part to misdiagnosis, this infectious disease results in nearly 60,000 deaths per year around the globe. This study represents the first effort to describe the diversity of pathogenic Leptospira in Cuba based on whole-genome sequencing. We have collected nineteen whole-blood samples from patients that were diagnosed as having leptospirosis between 2008 and 2012 in Cuba. In addition, we have enhanced our sample set by three historical strains that were used for the development of a human vaccine in 1990s. The Leptospira strains were grown and serotyped by the microscopic agglutination test, and the draft genomes were generated by NGS (Illumina). Subsequently, the core genomes were analyzed and compared to the genetic data available from other Caribbean islands and countries in Central America. Core genome Multi-locus Sequence Typing (cgMLST) revealed four different core genome clonal groups (cgCGs), with the highest number of samples belonging to L. interrogans, followed by L. borgpetersenii and L. kirschneri. All cgCGs that were found in Cuba have been also identified from multiple origins across the globe, except in neighbor countries and Central America. Serotyping divided the samples into the serogroups Canicola, Ballum and Pomona. The most frequent cgCGs, cgCG28, associated with serogroup Canicola, and cgCG15, associated with serogroup Ballum, have also been identified from samples isolated from dogs, rodents, and pigs; suggesting that these hosts represent the major source of human infection in Cuba. The vaccine strains did not significantly differ from the recent patient isolates. However, the increasing prevalence of samples belonging to the serogroup Ballum combined with the fact that the available vaccine in Cuba represents inactivated Leptospira belonging to serogroups other than Ballum, should be a valuable information for the National and Regional Leptospirosis Control Programs.

Who is at risk of occupational Q fever: new insights from a multi-profession cross-sectional study

OBJECTIVES

Q fever is a zoonosis caused by the bacterium Coxiella burnetii. It is recognised as an occupational hazard for individuals who are in regular contact with animal birth products. Data from the literature are not comparable because different serological assays perform very differently in detecting past infections. It is therefore essential to choose the right assay for obtaining reliable data of seroprevalence. Obstetricians are another profession potentially at risk of Q fever. They can be infected from birth products of women with Q fever during pregnancy. There is little data, however, for Q fever in this occupational group. Our study therefore had two purposes. The first was to obtain reliable seroprevalence data for occupational groups in regular contact with animal birth products by using an assay with proven excellent sensitivity and specificity for detecting past infections. The second purpose was to obtain primary data for obstetricians.

DESIGN

We carried out a cross-sectional study.

SETTING

The study included shepherds, cattle farmers, veterinarians and obstetricians from Thuringia.

PARTICIPANTS

77 shepherds, 74 veterinarians, 14 cattle farmers, 17 office employees and 68 obstetricians participated. The control group consisted of 92 blood donors.

PRIMARY OUTCOME MEASURE

The primary outcome measure was C. burnetii phase II specific IgG. The assay used was evaluated for this purpose in a previous study.

RESULTS

Of the 250 blood samples we analysed, the very highest seroprevalences (64%-77%) occurred in individuals with frequent animal contact. There were no significant differences between shepherds, cattle farmers and veterinarians. The seroprevalence in people working in administration was lower but still significantly greater than the control. No obstetricians or midwives tested positive.

CONCLUSIONS

Shepherds, cattle farmers and veterinarians have a high risk of C. burnetii infection. However, our study clearly proves that there was no increased risk for people working in an obstetric department.

Costs and Benefits of Alternative Strategies to Control the Spread of Livestock-Acquired Methicillin-Resistant Staphylococcus Aureus From Pig Production

BACKGROUND

Livestock-acquired methicillin-resistant Staphylococcus aureus (LA-MRSA) is a concern in healthcare and a political priority in some countries.

OBJECTIVE

This study investigates the net societal costs of 2 alternative strategies for controlling LA-MRSA in Denmark: (1) eradicating LA-MRSA in all pig housing units, and (2) containing LA-MRSA within the units.

METHODS

Benefits and costs are considered for affected economic sectors: healthcare, pig production, pig-related industries, and public administration.

RESULTS

The cost to society of eradication is estimated at €2.3 to €2.5 billion (present value). Containment will cost €55 to €93 million. For both strategies, the main cost lies in primary pig production-for containment this is mainly due to establishing and operating anterooms and shower rooms, and for eradication it is due to production losses, loss of genetic resources, and costs of cleaning and disinfection.

CONCLUSION

Compared with these costs, health economic benefits are moderate for both strategies. Containment is superior to eradication when measured by a benefit-cost ratio.

Food-to-Humans Bacterial Transmission

Microorganisms vehiculated by food might benefit health, cause minimal change within the equilibrium of the host microbial community or be associated with foodborne diseases. In this chapter we will focus on human pathogenic bacteria for which food is conclusively demonstrated as their transmission mode to human. We will describe the impact of foodborne diseases in public health, the reservoirs of foodborne pathogens (the environment, human and animals), the main bacterial pathogens and food vehicles causing human diseases, and the drivers for the transmission of foodborne diseases related to the food-chain, host or bacteria features. The implication of food-chain (foodborne pathogens and commensals) in the transmission of resistance to antibiotics relevant to the treatment of human infections is also evidenced. The multiplicity and interplay of drivers related to intensification, diversification and globalization of food production, consumer health status, preferences, lifestyles or behaviors, and bacteria adaptation to different challenges (stress tolerance and antimicrobial resistance) from farm to human, make the prevention of bacteria-food-human transmission a modern and continuous challenge. A global One Health approach is mandatory to better understand and minimize the transmission pathways of human pathogens, including multidrug-resistant pathogens and commensals, through food-chain.

Public Health Risk Associated with Botulism as Foodborne Zoonoses

Botulism is a rare but severe neurological disease in man and animals that is caused by botulinum neurotoxins (BoNTs) produced by Clostridium botulinum and atypical strains from other Clostridium and non-Clostridium species. BoNTs are divided into more than seven toxinotypes based on neutralization with specific corresponding antisera, and each toxinotype is subdivided into subtypes according to amino acid sequence variations. Animal species show variable sensitivity to the different BoNT toxinotypes. Thereby, naturally acquired animal botulism is mainly due to BoNT/C, D and the mosaic variants CD and DC, BoNT/CD being more prevalent in birds and BoNT/DC in cattle, whereas human botulism is more frequently in the types A, B and E, and to a lower extent, F. Botulism is not a contagious disease, since there is no direct transmission from diseased animals or man to a healthy subject. Botulism occurs via the environment, notably from food contaminated with C. botulinum spores and preserved in conditions favorable for C. botulinum growth and toxin production. The high prevalence of botulism types C, D and variants DC and CD in farmed and wild birds, and to a lower extent in cattle, raises the risk of transmission to human beings. However, human botulism is much rarer than animal botulism, and botulism types C and D are exceptional in humans. Only 15 cases or suspected cases of botulism type C and one outbreak of botulism type D have been reported in humans to date. In contrast, animal healthy carriers of C. botulinum group II, such as C. botulinum type E in fish of the northern hemisphere, and C. botulinum B4 in pigs, represent a more prevalent risk of botulism transmission to human subjects. Less common botulism types in animals but at risk of transmission to humans, can sporadically be observed, such as botulism type E in farmed chickens in France (1998-2002), botulism type B in cattle in The Netherlands (1977-1979), botulism types A and B in horses, or botulism type A in dairy cows (Egypt, 1976). In most cases, human and animal botulisms have distinct origins, and cross transmissions between animals and human beings are rather rare, accidental events. But, due to the severity of this disease, human and animal botulism requires a careful surveillance.

Cats as a reservoir of Bartonella henselae for dogs

Bartonellosis is a disease affecting a variety of animals. Many Bartonella infections are zoonotic, including cat scratch disease. Within the genus Bartonella are 45 species, of which more than 10 can infect cats and dogs. Companion animals serve as reservoirs for several zoonotic species of Bartonella, and may also serve as sentinels for zoonotic Bartonella species harbored by wildlife. The aim of this study was to determine the frequency of the occurrence of Bartonella spp. DNA in dogs from households where cats with clinical bartonellosis were kept. The presence of DNA with 99-100% compliance of the nucleotide sequence with the sequence of the Bartonella DNA isolated from cats was demonstrated in the body of 10% of tested dogs. The results indicate that cats serve as a Bartonella reservoir for dogs, and the dogs can play the same role with regard to humans.

Evidence of fish and human pathogens associated with doctor fish (Garra rufa, Heckel, 1843) used for cosmetic treatment

Doctor fish (Garra rufa, Heckel, 1843) are increasingly used for cosmetic treatment raising particular concerns regarding the potential transmission of infections to clients. Investigations of microbial causes undertaken in two outbreaks of mortality among G. rufa used for cosmetic treatment revealed the presence of multiple bacteria, including both fish and human pathogens such as Aeromonas veronii, A. hydrophila, Vibrio cholerae, Shewanella putrefaciens, Mycobacterium marinum and M. goodii. This range of bacteria indicates an intense microbial proliferation involving multiple pathogens, most likely induced by the poor health condition of the fish. Most of the detected pathogens are well-known agents of zoonosis. Indeed, M. goodii is an emerging nosocomial human pathogen that has never been detected in fish to date, nor in other animals. This first detection of M. goodii associated with fish infection points out a new zoonotic potential for this pathogen. These findings point out that handling, poor environmental conditions and the presence of fish pathogens, that can compromise the immune system of fish, can result in a mixed microbial proliferation and increase the spread of waterborne bacteria, including zoonosis agents. Accordingly, the microbiological surveillance of fish used for cosmetic treatment is extremely important, particularly in association with mortality outbreaks.

Recent Research on Occupational Animal Exposures and Health Risks: A Narrative Review

PURPOSE OF REVIEW

In the last year, an increasing number of studies have reported on methicillin-resistant Staphylococcus aureus (MRSA) transmission in Africa and Asia and in migrant workers. We reviewed original research on occupational health and safety of animal workers published from January 1, 2018, through June 30, 2019, with a targeted focus on infectious disease studies published in these populations.

RECENT FINDINGS

Studies focused on occupational exposures to infectious agents, dust and allergens, pesticides, and occupational injury. Research on zoonotic MRSA used whole genome-sequencing technologies to evaluate transmission in Africa and Asia. Swine worker exposure to porcine coronavirus and emerging influenza A viruses was documented in China. 16s RNA amplicon sequencing identified distinct microbiota compositions in households with active animal farmers. Multiple bioaerosol exposures were assessed for industrial dairy workers. Occupational injury studies highlighted the struggles of Latino animal workers in the USA. These studies highlighted the global expansion of zoonotic antibiotic resistance and identified novel occupational zoonoses of concern. The integration of microbiome assessment and compound mixtures into the evaluation of dust and endotoxin exposures for animal workers marks a new direction for this work.

Identification of Bartonella rochalimae in Guinea Pigs (Cavia porcellus) and Fleas Collected from Rural Peruvian Households

In the present study, we tested 391 fleas collected from guinea pigs (Cavia porcellus) (241 Pulex species, 110 Ctenocephalides felis, and 40 Tiamastus cavicola) and 194 fleas collected from human bedding and clothing (142 Pulex species, 43 C. felis, five T. cavicola, and four Ctenocephalides canis) for the presence of Bartonella DNA. We also tested 83 blood spots collected on Flinders Technology Associates (FTA) cards from guinea pigs inhabiting 338 Peruvian households. Bartonella DNA was detected in 81 (20.7%) of 391 guinea pig fleas, in five (2.6%) of 194 human fleas, and in 16 (19.3%) of 83 guinea pig blood spots. Among identified Bartonella species, B. rochalimae was the most prevalent in fleas (89.5%) and the only species found in the blood spots from guinea pigs. Other Bartonella species detected in fleas included B. henselae (3.5%), B. clarridgeiae (2.3%), and an undescribed Bartonella species (4.7%). Our results demonstrated a high prevalence of zoonotic B. rochalimae in households in rural areas where the research was conducted and suggested a potential role of guinea pigs as a reservoir of this bacterium.

Distribution and Ecological Drivers of Spotted Fever Group Rickettsia in Asia

Spotted fever group and related rickettsia (SFGR) are a neglected group of pathogens that belong to the genus Rickettsia. SFGR are zoonotic and are transmitted by arthropod vectors, primarily ticks, fleas and mites to accidental hosts. These emerging and re-emerging infections are widely distributed throughout the world. Land-use change and increasing human-wildlife conflict compound the risk of SFGR infection to local people in endemic areas and travelers to these regions. In this article, we discuss the rickettsial organisms causing spotted fever and related diseases, their arthropod vectors in Asia and the impact of land-use change on their spread.

Expanding beyond zoonoses: the benefits of a national One Health coordination mechanism to address antimicrobial resistance and other shared health threats at the human-animal-environment interface in Kenya

In order to manage global and transnational health threats at the human- animal-environment interface, a multisectoral One Health approach is required. Threats of this nature that require a One Health approach include, but are not limited to, emerging, endemic and re-emerging zoonotic diseases, food safety, antimicrobial resistance (AMR), vector-borne and neglected infectious diseases, toxicosis and pesticides. Relevant Kenyan authorities formally institutionalised One Health in 2011 through the establishment of the Zoonotic Disease Unit (ZDU) and its advisory group, the Zoonoses Technical Group. At that time, the One Health agenda focused on zoonotic diseases. As the issue of AMR began to gain traction globally, a One Health approach to its management was advocated in Kenya in 2015. This paper summarises a series of interviews (with respondents and key informants) that describe how AMR institutionalisation evolved in Kenya. It also examines how responses to other health threats at the human-animal- environment interface were coordinated and used to identify gaps and make recommendations to improve One Health coordination at the national level in Kenya. Results showed that the road to the institutionalisation of AMR through the National Action Plan on Prevention and Containment of Antimicrobial Resistance, 2017-2022 and a formally launched One Health coordination mechanism, the National Antimicrobial Stewardship Interagency Committee (NASIC), took ten years. Moreover, supplementary actions are still needed to further strengthen AMR coordination. In addition to the ZDU and NASIC, Kenya has established two other formal multisectoral and multidisciplinary coordination structures, one for aflatoxicosis and the other for health threats associated with pesticide use. The country has four distinct and separate One Health coordination mechanisms: for zoonoses, for AMR, for aflatoxicosis and for the health threats associated with pesticide use. The main gap lies in the lack of overall coordination between these topic-specific structures. An overall coordination mechanism for all One Health issues is therefore needed to improve synergy and complementarity. None of the topic-specific mechanisms plays a critical role in the policy development process, institutionalisation or implementation of activities related to the other topic areas. The authors recommend renaming the ZDU as the One Health Office, and expanding it to include AMR and food safety teams, and their associated technical working groups. Through this restructuring, the One Health Office would become an umbrella organisation dealing with all four issues mentioned above. Based on Kenya's experience, the authors recommend that other countries also consider expanding the scope of multisectoral One Health coordination mechanisms to include other shared health threats.

Human as a potential vector of bovine tuberculosis in cattle

INTRODUCTION AND OBJECTIVE

Bovine tuberculosis (bTB, bovine TB) is caused by mycobacteria which are grouped within the MTBC. TB in animals is a highly infectious and progressive disease which can be transmitted to humans. Since 2009, Poland has gained official bTB-free status. Despite the official fact of bTB-free status, a dozen bTB outbreaks are still noted each year. Since 2000 in Poland, every year 1/5 of the national herd is subject to intradermal skin TB testing to control the bTB outbreaks in the cattle population. Application, with 5-year intervals between each government-funded skin test, undoubtedly resulted in financial savings. However it also seems to have caused several adverse and worrying events, e.g. an increase in the number of reactors detected and removed from a single tested herd. The objective of this study was the examination of 898 cattle imputed with bTB infection in Poland between 2008-2012.

MATERIAL AND METHODS

The study concerned a potential epidemic outbreak with suspected bTB transmission. 20 cows came from 3 herds in the same county located in the same province in southern Poland.

RESULTS

134 MTBC strains were identified. In MIRU-VNTR, all isolates showed the same genetic pattern 322532243421232. Based on molecular investigation, the characteristics of M. bovis strains isolated from cattle from 3 different herds confirmed the common source of this zoonotic disease.

CONCLUSIONS

Although not bacteriologically proven, everything points to the fact that humans were the vector of bovine tuberculosis transmission between herds. This finding confirms transmission between 3 cattle herds in the Małopolskie Province in southern Poland (Podhale). The outbreak of tuberculosis in animals finally compromised public health.

Prevalence of Orientia tsutsugamushi, Anaplasma phagocytophilum and Leptospira interrogans in striped field mice in Gwangju, Republic of Korea

This study investigated the prevalence of Orientia tsutsugamushi, Anaplasma phagocytophilum, and Leptospira interrogans in wild rodents through molecular detection using organ samples and through serological assay using blood samples of mice collected from two distinct sites in Gwangju Metropolitan City, Republic of Korea (ROK). A total of 47 wild rodents, identified as Apodemus agrarius (A. agrarius), were captured from June to August 2016. The seroprevalence of antibodies against bacterial pathogens in A. agrarius sera was analyzed; 17.4% (8/46) were identified as O. tsutsugamushi through indirect immunofluorescence assay and 2.2% (1/46) were identified as Leptospira species through passive hemagglutination assay. Using polymerase chain reaction, the spleen, kidney and blood samples were investigated for the presence of O. tsutsugamushi, A. phagocytophilum, and L. interrogans. Out of the 47 A. agrarius, 19.1% (9/47) were positive for A. phagocytophilum and 6.4% (3/47) were positive for L. interrogans, while none were positive for O. tsutsugamushi. Four out of 46 (8.7%) blood samples, six out of 45 (13.3%) spleen samples, and one out of 47 (2.1%) kidney samples were positive for A. phagocytophilum. Three out of 47 (6.4%) kidney samples were positive for L. interrogans. The sequencing results of PCR positive samples demonstrated > 99% similarity with A. phagocytophilum and L. interrogans sequences. A. phagocytophilum was mostly detected in the spleen, whereas L. interrogans was mostly detected in the kidneys. Notably, A. phagocytophilum and L. interrogans were detected in A. agrarius living in close proximity to humans in the metropolitan suburban areas. The results of this study indicate that rodent-borne bacteria may be present in wild rodents in the metropolitan suburban areas of ROK.

Genotypic and phenotypic profiles of virulence factors and antimicrobial resistance of Proteus mirabilis isolated from chicken carcasses: potential zoonotic risk

Proteus mirabilis is an opportunistic pathogen often associated with a variety of human infections acquired both in the community and in hospitals. In this context, the present work aimed to evaluate the genotypic and phenotypic characteristics of the virulence factors and antimicrobial resistance determinants of 32 P. mirabilis strains isolated from chicken carcasses in a poultry slaughterhouse in the north of the state of Paraná, Brazil, in order to assess a potential zoonotic risk. The isolates presented a variety of virulence genes that contribute to the development of infection in humans. The mrpA, pmfA, atfA (fimbriae), ireA (siderophores receptor), zapA, ptA (Proteases), and hpmA (hemolysin) genes were found in 32 (100%) isolates and ucaA (fimbriae) in 16 (50%). All isolates showed aggregative adherence in HEp-2 cells and formed biofilms. Of all strains, 27 (84.38%) showed cytotoxic effects in Vero cells. Antimicrobial susceptibility was tested using 20 antimicrobials, in which 25 (78.13%) strains were considered multidrug-resistant. The presence of blaESBL and blaampC genes conferring resistance to β-lactams and qnr to quinolones were also detected in the isolates after presumption in the phenotypic test, in which 7 (21.88%) isolates contained the CTX-M-2 group, 11 (34.38%) contained CIT group and 19 (59.38%) contained qnrD. Therefore, chicken carcasses contaminated with P. mirabilis may pose a health risk to the consumer, as these isolates have a variety of virulence and antimicrobial resistance characteristics that can be found in P. mirabilis strains isolated from human infections.

Whole genome sequencing to characterize shiga toxin-producing Escherichia coli O26 in a public health setting

BACKGROUND

Shiga-toxin producing Escherichia coli (STEC) O26:H11 is the second most common cause of severe diarrhea and hemolytic uremic syndrome worldwide. The implementation of whole genome sequencing (WGS) enhances the detection and in-depth characterization of these non-O157 STEC strains. The aim of this study was to compare WGS to phenotypic serotyping and pulse field gel electrophoresis (PFGE) for characterization of STECO26 strains following a zoonotic outbreak from cattle to humans.

METHODS AND RESULTS

This study evaluated seven E. coli strains; two strains isolated from two children with gastrointestinal symptoms and five strains from five calves suspected as the source of infection. Six of these isolates were serotyped phenotypically and by WGS as E. coli O26:H11 while one bovine isolate could be serotyped only by WGS as E. coli O182:H25. Stx1 was detected in two human- and two bovine-isolates using PCR and WGS. Using WGS, all four STECO26 isolates belong to sequence type (ST) 21 while the two stx1 negative E. coli O26 were ST29. All four STECO26 isolates were indistinguishable by PFGE. However, the data generated by WGS linked the two human STECO26 isolates to only one bovine STECO26 strain by having identical high-quality single nucleotide polymorphisms (hqSNPs) and identical virulence factor profiles while the remaining bovine STECO26 isolate differed by 7 hqSNPs and lacked virulence factor toxB.

CONCLUSIONS

These data demonstrated that WGS provided significant information beyond traditional epidemiological tools allowing for comprehensive characterization of the STEC. Using this approach, WGS was able to identify the specific source of infection in this study.

Impact of way of life and environment on the prevalence of Chlamydia felis in cats as potentional sources of infection for humans

INTRODUCTION AND OBJECTIVES

Chlamydia (C.) felis can cause infection which may be associated with conjunctivitis and/or respiratory tract disease, particularly in kittens, but could also be the cause of the disease in adult cats. Infection is more common in multi-cat environments. The zoonotic potential of C. felis appears low, but exposure to this microorganism is possible by handling the affected cats, by contact with their aerosol, and also via fomites.

MATERIAL AND METHODS

In the study, 140 cats of various breeds from Košice region in Slovakia were studied. Conjunctival samples were obtained from 71 clinically healthy cats (50.7%) and 69 cats with clinical signs of conjunctivitis and upper respiratory tract impairment (49.3%). Cats were divided into 4 groups according to breed and type of environment in which they lived. In the 1^st group were cats kept inside only (n=33), in the 2^nd group, free-roaming cats (n=50), the 3^rd group comprised stray cats, taken from the streets (n=28), and the 4^th group included cats kept in shelters or deposit devices (n=29). Molecular method PCR and DNA sequencing was used as the diagnostic method.

RESULTS

Overall positivity was 17.1%. Of the 24 positive cats, the highest positivity was detected in the population of stray cats (35.7%) and shelter cats (31%). In the group of free-roaming cats, 10% had positivity. No positive animals were detected in the group of cats kept inside only. It was also found that the risk of C. felis in cats with clinical signs of disease was more than 7-fold higher than in cats without clinical signs of conjunctivitis and respiratory tract.

CONCLUSIONS

The obtained results show that cats, especially stray and shelter cats, can be important sources of feline chlamydiosis, and due to their close contact with people they can present a risk for transmission.

A Review of Zoonotic Pathogens of Dromedary Camels

Dromedary, or one-humped, camels Camelus dromedarius are an almost exclusively domesticated species that are common in arid areas as both beasts of burden and production animals for meat and milk. Currently, there are approximately 30 million dromedary camels, with highest numbers in Africa and the Middle East. The hardiness of camels in arid regions has made humans more dependent on them, especially as a stable protein source. Camels also carry and may transmit disease-causing agents to humans and other animals. The ability for camels to act as a point source or vector for disease is a concern due to increasing human demands for meat, lack of biosafety and biosecurity protocols in many regions, and a growth in the interface with wildlife as camel herds become sympatric with non-domestic species. We conducted a literature review of camel-borne zoonotic diseases and found that the majority of publications (65%) focused on Middle East respiratory syndrome (MERS), brucellosis, Echinococcus granulosus, and Rift Valley fever. The high fatality from MERS outbreaks during 2012-2016 elicited an immediate response from the research community as demonstrated by a surge of MERS-related publications. However, we contend that other camel-borne diseases such as Yersinia pestis, Coxiella burnetii, and Crimean-Congo hemorrhagic fever are just as important to include in surveillance efforts. Camel populations, particularly in sub-Saharan Africa, are increasing exponentially in response to prolonged droughts, and thus, the risk of zoonoses increases as well. In this review, we provide an overview of the major zoonotic diseases present in dromedary camels, their risk to humans, and recommendations to minimize spillover events.

Risk factors for human leptospirosis following flooding: A meta-analysis of observational studies

Leptospirosis is probably the most widespread zoonotic disease in the world especially in tropical countries. There has been an increase in individual studies, which assessed the frequency of leptospirosis in flood conditions. Some studies showed contact with floods was significantly associated with the occurrence of leptospirosis while other studies reported differently. The objective of this meta-analysis was to synthesize the evidence on the risk factors which are associated with human leptospirosis following flooding. We set up the inclusion criteria and searched for the original studies, addressing leptospirosis in human with related to flood in health-related electronic databases including PubMed, Embase, Ovid Medline, google scholar and Scopus sources. We used the terms ‘leptospirosis’, ‘flood’, ‘risk factor’ and terms from the categories were connected with “OR” within each category and by “AND” between categories. The initial search yielded 557 citations. After the title and abstract screening, 49 full-text papers were reviewed and a final of 18 observational studies met the pre-specified inclusion criteria. Overall, the pooled estimates of 14 studies showed that the contact with flooding was a significant factor for the occurrence of leptospirosis (pooled OR: 2.19, 95%CI: 1.48–3.24, I²:86%). On stratification, the strength of association was greater in the case-control studies (pooled OR: 4.01, 95%CI: 1.26–12.72, I²:82%) than other designs (pooled OR:1.77,95%CI:1.18–2.65, I²:87%). Three factors such as ‘being male’(pooled OR:2.06, 95%CI:1.29–2.83), the exposure to livestock animals (pooled OR: 1.95, 95%CI:1.26–2.64), the lacerated wound (pooled OR:4.35, 95%CI:3.07–5.64) were the risk factors significantly associated with the incidence of leptospirosis following flooding in the absence of within-study heterogeneity (I²: 0%). We acknowledge study limitations such as publication bias and type 2 statistical errors. We recommended flood control and other environmental modifications that are expected to reduce the risk of leptospiral infection, and a multi-sectoral effort to this aspect would have long-term benefits.

Predicting badger visits to farm yards and making predictions available to farmers

The use of agricultural resources or environments by wildlife may result in opportunities for transmission of infections amongst wild animals, livestock and humans. Targeted use of biosecurity measures may therefore reduce disease risks, although this requires practical knowledge of where such measures would be most effective, and effective means of communicating risks so that stakeholders can make informed decisions about such investment. In parts of Europe, the European badger Meles meles may act as a wildlife reservoir for Mycobacterium bovis, the causative agent of bovine tuberculosis, and badger visits to farmyards may provide potential opportunities for transmission of M. bovis to cattle. Biosecurity measures are effective in reducing badger activity in farmyards, although it is unclear which farms should be targeted with such measures. We used cameras to monitor badger activity in 155 farmyards in south west England and Wales, and related variations in the presence and frequency of badger visits to farm characteristics. Badgers were recorded on camera in 40% of farmyards monitored. However, the frequency of visits was highly variable, with badgers recorded on >50% of nights in only 10% of farms. The presence of badgers in farmyards was positively associated with the density of badger setts, the number of feed stores and the number of cattle sheds, and negatively associated with the distance to the nearest active badger sett, the presence of a house/dwelling and the number of cattle housed on the farm. The frequency of visits was negatively associated with the distance to the nearest active badger sett and the number of cattle housed. Models predicted the presence/absence of badgers in farmyards with 73% accuracy (62% sensitivity, 81% specificity, using a cut off value of 0.265). Models could not distinguish between farms with low/high frequency of visits, although farms predicted as having badgers present typically had a higher frequency of visits than those that were not. We developed and present an interactive web based application: the Badger Farm Assessment Tool (BFAT), to allow users to enter the characteristics of a farm and generate a relative risk score describing the likelihood of badger visits.

Complex bacterial flora of imported pet tortoises deceased during quarantine: Another zoonotic threat?

Turtoises are a great puzzle when it comes to their bacterial flora, the composition and structure of which are still unknown in details. Its component which has been best described so far is Salmonella spp., presumably due to the threat of reptile-associated salmonellosis in humans. This investigation tried to assess and characterize intestinal bacterial flora of imported tortoises found dead during quarantine. Most of the animals carried various serovars of Salmonella showing no antimicrobial resistance. Presence of multiresistant Escherichia coli was possibly a result of industrial breeding and high usage of antimicrobials. Thirteen bacterial species or genera like Citrobacter spp., Morganella spp., Pseudomonas spp. were identified. Their commensal character is assumed, although pathogenic potential might be verified. The results indicate global tortoise trade as a source of common and exotic bacteria or antimicrobial resistance mechanisms in new geographical areas. These dangers indicate the need for a systematic survey of exotic pets and establishment of legal requirements for reptile health conditions on breeding, trade premises and in households with such pets.

Endoparasites and vector-borne pathogens in dogs from Greek islands: Pathogen distribution and zoonotic implications

The present study investigated the presence of endo- and ecto-parasites, and vector-borne pathogens, in dogs from four islands of Greece. A total of 200 (123 owned and 77 sheltered) dogs were examined with different microscopic, serological and molecular methods.

Of the examined dogs, 130 (65%) were positive for one or more parasites and/or vector-borne pathogens. The most common zoonotic intestinal helminths recorded were Ancylostomatidae (12.5%) and Toxocara canis (3.5%). Ninety-three dogs (46.5%) seroreacted to Rickettsia conorii. Twenty-two (11%) of them were also PCR positive and 7 (3.5%) showed corpuscles suggestive of Rickettsia spp. on the blood smears. Nineteen dogs (9.5%) were seropositive for Ehrlichia canis, three of them being also PCR positive. Dogs positive for Anaplasma phagocytophilum-Anaplasma platys (1%), Dirofilaria immitis (0.5%) and Babesia canis (0.5%) were also found. Fleas and ticks were recorded in 53 (26.5%) and 50 (25%) dogs, respectively, and all specimens were identified as Ctenocephalides felis felis and Rhipicephalus sanguineus sensu lato. Binary multiple univariate Generalized Linear Models were used to investigate factors and clinical signs related to the recorded positivity, while the association of specific signs with the pathogens was evaluated using tests of independence. Knowledge of occurrence and impact of zoonotic parasites and vector-borne pathogens in dog populations is crucial to prevent the infection in animals and people, and to control the risk of spreading of these pathogens in endemic and non-endemic areas.

Both owned and sheltered dogs can harbor a variety of intestinal and extra-intestinal endoparasites, as well as vector-borne pathogens and ectoparasites, of zoonotic concern. Dog shelters and stray dogs are present in several touristic areas of Greece, including Sporades and Cyclades islands, where tourists often bring their pets with them, likely travelling from non-endemic to endemic areas. The present study has been carried out with the aim to evaluate the occurrence of the aforementioned pathogens. Data obtained showed that they are present in canine populations of Greece, with possibilities of infection for travelling dogs, which can also contribute to the spreading of zoonotic vector-borne diseases, introducing new pathogens in previously non-endemic areas. For these reasons, a constant monitoring of the epidemiological situation, improving control measures and correct diagnostic approaches are of primary importance for the prevention of canine and human infections, decreasing the spreading of potentially deadly pathogens.

Living with plague: Lessons from the Soviet Union's antiplague system

Zoonoses, such as plague, are primarily animal diseases that spill over into human populations. While the goal of eradicating such diseases is enticing, historical experience validates abandoning eradication in favor of ecologically based control strategies (which reduce morbidity and mortality to a locally accepted risk level). During the 20th century, one of the most extensive plague-eradication efforts in recorded history was undertaken to enable large-scale changes in land use in the former Soviet Union (including vast areas of central Asia). Despite expending tremendous resources in its attempt to eradicate plague, the Soviet antiplague response gradually abandoned the goal of eradication in favor of plague control linked with developing basic knowledge of plague ecology. Drawing from this experience, we combine new gray-literature sources, historical and recent research, and fieldwork to outline best practices for the control of spillover from zoonoses while minimally disrupting wildlife ecosystems, and we briefly compare the Soviet case with that of endemic plague in the western United States. We argue for the allocation of sufficient resources to maintain ongoing local surveillance, education, and targeted control measures; to incorporate novel technologies selectively; and to use ecological research to inform developing landscape-based models for transmission interruption. We conclude that living with emergent and reemergent zoonotic diseases-switching to control-opens wider possibilities for interrupting spillover while preserving natural ecosystems, encouraging adaptation to local conditions, and using technological tools judiciously and in a cost-effective way.

Tuberculosis at the animal-human interface in the Ugandan cattle corridor using a third-generation sequencing platform: a cross-sectional analysis study

INTRODUCTION

Mycobacterial diseases are a significant source of disease burden, with Mycobacterium tuberculosis being the most common infectious cause of death worldwide. Given this, the emergence of antibiotic resistance in these species is of particular interest. By examining the epidemiology of mycobacteria in humans and cattle in an area of intense human-animal contact (the Ugandan cattle corridor [UCC]) and using a novel whole-genome sequencing technique to analyse organism diversity, this study will explore the role bidirectional transmission of mycobacteria plays in the local ecology, as well the significance of zoonotic Mycobacterium bovis in the human population.

METHODS AND ANALYSIS

This ongoing study includes both a cross-sectional analysis of the UCC mycobacteria-positive population and novel laboratory-based research focused on differentiating the species causing M. tuberculosis complex-linked disease. We will use a third-generation sequencing platform (the MinION sequencer from Oxford Nanopore Technology), comparing data from a sample subset to the Illumina platform as a means of measuring viability of the MinION platform in this specific setting. Our full sample set will be sequenced on Illumina and the data will be used to perform epidemiological and phylogenetic analyses.

ETHICS AND DISSEMINATION

Ethical approval was obtained from both the University of Minnesota IRB committee and the Ugandan National Council for Science and Technology-Research Ethics Committee. Samples were obtained after patients signed an informed consent indicating samples could be retained and used for research purposes. All samples are deidentified, with only basic demographic and geographic information being retained per national tuberculosis (TB) recording guidelines. Significant drug resistance results will be referred back to the local TB control officer to inform patient care. Final results of the study will be submitted to infectious disease-specific journals and will be submitted to the annual Infectious Diseases Society of America (IDSA) meeting.

Intracellular invasion and survival of Brucella neotomae, another possible zoonotic Brucella species

In 1967, Brucella neotomae was first isolated from Neotoma lepida, the dessert wood rat, in Utah. With little infection data since its discovery, the zoonotic potential of this Brucella species is largely unknown. Recent reports of isolation from human cerebrospinal fluid, along with current literature suggest that B. neotomae has the ability to infect various hosts and cell types. In this report we extend the knowledge of B. neotomae ATCC 23459’s intracellular invasion and survival abilities to a variety of cell lines through gentamicin protection assays. Some of the phagocytic and epithelial cell lines from various mammalian species represent characteristics of some cell types that could be encountered by Brucella in potential hosts. It was found that B. neotomae ATCC 23459 exhibits generally lower intracellular bacterial CFUs compared to the mouse-passaged strain of B. neotomae ATCC 23459, B. suis 1330, and B. abortus 2308. Ultimately, these observations provide a small piece of the puzzle in the investigation of the breadth of B. neotomae’s pathogenic potential.

Human Pasteurella multocida Infection with Likely Zoonotic Transmission from a Pet Dog, Spain

We report a case of urinary tract infection caused by an unusual genotype (sequence type 211) of Pasteurella multocida associated with human infection. Molecular genetic analysis of P. multocida isolates obtained from the human patient and his pet strongly suggests a zoonotic transmission of this bacterium.

Distribution of Brucella field strains isolated from livestock, wildlife populations, and humans in Italy from 2007 to 2015

Brucellosis is a major public health problem still prevalent as a neglected endemic zoonosis requiring proactive attention in many communities worldwide. The present study involved analysis of Brucella field strains submitted for typing to the Italian National Reference Laboratory for Brucellosis from 2007 to 2015. Strains were identified at the species and biovar levels by classic and molecular techniques according to the World Organisation for Animal Health Manual. In total, 5,784 strains were typed: 3,089 Brucella abortus (53.4%), 2,497 B. melitensis (43.2%), 10 B. ovis (0.2%), 181 B. suis (3.1%), and 7 B. ceti (0.1%). The 2,981 strains from cattle were typed as B. abortus biovars 1, 3, and 6 (90.1%) and B. melitensis biovar 3 (9.9%). The 318 strains from water buffalo were typed as B. abortus biovars 1, 3 (95.9%) and B. melitensis biovar 3 (4.1%). The 2,279 strains from sheep and goats were typed as B. abortus biovars 1 and 3 (4.3%); B. melitensis biovars 1, 3, (95.3%); and B. ovis (0.4%). The 173 strains from wild boar were typed as B. suis biovar 2 (98.3%) and B. melitensis biovar 3 (1.7%). The 11 strains from pigs were typed as B. suis biovar 2. The 13 strains from humans were typed as B. melitensis biovar 3. The two strains from horses were typed as B. abortus biovar 1, while the seven strains from dolphins were typed as B. ceti. This additional knowledge on the epidemiology of brucellosis in Italy may be useful to formulate policies and strategies for the control and eradication of the disease in animal populations. The animal species affected, biovars typed, geographical origins, and spatial distributions of isolates are herein analyzed and discussed.

Genetic structure, antimicrobial resistance and frequency of human associated Escherichia coli sequence types among faecal isolates from healthy dogs and cats living in Canberra, Australia

Extraintestinal pathogenic Escherichia coli (ExPEC) cause clinical infections in humans. Understanding the evolution and dissemination of ExPEC strains via potential reservoirs is important due to associated morbidity, health care costs and mortality. To further understanding this survey has examined isolates recovered from the faeces of 221 healthy dogs and 427 healthy cats. The distribution of phylogroups varied with host species, and depended on whether the animal was living in a shelter or a home. The human associated STs 69, 73, 95, 131 and 127 were prevalent, with 30.5% of cat isolates and 10.3% of dog isolates representing these ExPEC sequence types. Resistance to the antibiotics ampicillin and tetracycline was common, but resistance to other antimicrobials was negligible.

SNP-IT Tool for Identifying Subspecies and Associated Lineages of Mycobacterium tuberculosis Complex

The clinical phenotype of zoonotic tuberculosis and its contribution to the global burden of disease are poorly understood and probably underestimated. This shortcoming is partly because of the inability of currently available laboratory and in silico tools to accurately identify all subspecies of the Mycobacterium tuberculosis complex (MTBC). We present SNPs to Identify TB (SNP-IT), a single-nucleotide polymorphism-based tool to identify all members of MTBC, including animal clades. By applying SNP-IT to a collection of clinical genomes from a UK reference laboratory, we detected an unexpectedly high number of M. orygis isolates. M. orygis is seen at a similar rate to M. bovis, yet M. orygis cases have not been previously described in the United Kingdom. From an international perspective, it is possible that M. orygis is an underestimated zoonosis. Accurate identification will enable study of the clinical phenotype, host range, and transmission mechanisms of all subspecies of MTBC in greater detail.

Do humans spread zoonotic enteric bacteria in Antarctica?

Reports of enteric bacteria in Antarctic wildlife have suggested its spread from people to seabirds and seals, but evidence is scarce and fragmentary. We investigated the occurrence of zoonotic enteric bacteria in seabirds across the Antarctic and subantarctic region; for comparison purposes, in addition to seabirds, poultry in a subantarctic island was also sampled. Three findings suggest reverse zoonosis from humans to seabirds: the detection of a zoonotic Salmonella serovar (ser. Enteritidis) and Campylobacter species (e.g. C. jejuni), typical of human infections; the resistance of C. lari isolates to ciprofloxacin and enrofloxacin, antibiotics commonly used in human and veterinary medicine; and most importantly, the presence of C. jejuni genotypes mostly found in humans and domestic animals but rarely or never found in wild birds so far. We also show further spread of zoonotic agents among Antarctic wildlife is facilitated by substantial connectivity among populations of opportunistic seabirds, notably skuas (Stercorarius). Our results highlight the need for even stricter biosecurity measures to limit human impacts in Antarctica.

Association of rodent-borne Leptospira spp. with urban environments in Malaysian Borneo

Although leptospirosis is traditionally considered a disease of rural, agricultural and flooded environments, Leptospira spp. are found in a range of habitats and infect numerous host species, with rodents among the most significant reservoirs and vectors. To explore the local ecology of Leptospira spp. in a city experiencing rapid urbanization, we assessed Leptospira prevalence in rodents from three locations in Malaysian Borneo with differing levels of anthropogenic influence: 1) high but stable influence (urban); 2) moderate yet increasing (developing); and 3) low (rural). A total of 116 urban, 122 developing and 78 rural rodents were sampled, with the majority of individuals assigned to either the Rattus rattus lineage R3 (n = 165) or Sundamys muelleri (n = 100). Leptospira spp. DNA was detected in 31.6% of all rodents, with more urban rodents positive (44.8%), than developing (32.0%) or rural rodents (28.1%), and these differences were statistically significant. The majority of positive samples were identified by sequence comparison to belong to known human pathogens L. interrogans (n = 57) and L. borgpetersenii (n = 38). Statistical analyses revealed that both Leptospira species occurred more commonly at sites with higher anthropogenic influence, particularly those with a combination of commercial and residential activity, while L. interrogans infection was also associated with low forest cover, and L. borgpetersenii was more likely to be identified at sites without natural bodies of water. This study suggests that some features associated with urbanization may promote the circulation of Leptospira spp., resulting in a potential public health risk in cities that may be substantially underestimated.

Leptospirosis is a significant zoonotic disease that is found in a range of environments worldwide, most notably tropical regions prone to flooding. The bacterial agents of this disease, Leptospira spp., are most often associated with rodents, including species frequently found in urban areas. In cities, rodent populations are often larger and denser than those found in natural environments, which can lead to higher rates of contact with people and impact human disease risk. To investigate the impacts of urbanization on Leptospira spp., we sampled rodents at locations with differing levels of human influence, from highly urbanized to rural, surrounding a city in Malaysian Borneo. We found that 31.6% of all rodents were positive for Leptospira spp. DNA, and that two primary species were present, L. interrogans and L. borgpetersenii, both of which are known human pathogens. Statistical analyses revealed that infected animals were more common in areas with higher levels of human influence, and were more likely to occur at sites with limited forest cover, and mixed commercial and residential activity. Our study adds to a growing body of evidence suggesting that there is a significant yet underappreciated risk of leptospirosis for people living in urban environments.

Discovery of Leptospira spp. seroreactive peptides using ORFeome phage display

Background

Leptospirosis is the most common zoonotic disease worldwide. The diagnostic performance of a serological test for human leptospirosis is mainly influenced by the antigen used in the test assay. An ideal serological test should cover all serovars of pathogenic leptospires with high sensitivity and specificity and use reagents that are relatively inexpensive to produce and can be used in tropical climates. Peptide-based tests fulfil at least the latter two requirements, and ORFeome phage display has been successfully used to identify immunogenic peptides from other pathogens.

Methodology/Principal findings

Two ORFeome phage display libraries of the entire Leptospira spp. genomes from five local strains isolated in Malaysia and seven WHO reference strains were constructed. Subsequently, 18 unique Leptospira peptides were identified in a screen using a pool of sera from patients with acute leptospirosis. Five of these were validated by titration ELISA using different pools of patient or control sera. The diagnostic performance of these five peptides was then assessed against 16 individual sera from patients with acute leptospirosis and 16 healthy donors and was compared to that of two recombinant reference proteins from L. interrogans. This analysis revealed two peptides (SIR16-D1 and SIR16-H1) from the local isolates with good accuracy for the detection of acute leptospirosis (area under the ROC curve: 0.86 and 0.78, respectively; sensitivity: 0.88 and 0.94; specificity: 0.81 and 0.69), which was close to that of the reference proteins LipL32 and Loa22 (area under the ROC curve: 0.91 and 0.80; sensitivity: 0.94 and 0.81; specificity: 0.75 and 0.75).

Conclusions/Significance

This analysis lends further support for using ORFeome phage display to identify pathogen-associated immunogenic peptides, and it suggests that this technique holds promise for the development of peptide-based diagnostics for leptospirosis and, possibly, of vaccines against this pathogen.

Leptospirosis is an infectious disease that is transmitted from animals to humans. It is associated with a broad range of clinical presentations, and diagnostic tests with high diagnostic accuracy are required in order to enable accurate diagnosis. Leptospirosis is diagnosed by detecting DNA of the pathogen or antibodies against it in patients’ blood; the latter are preferred in resource limited regions, and diagnostics based on peptides (small fragments of proteins) are advantageous because they are inexpensive to produce and more stable in hot climates than full-length proteins. We used a technique called open reading frame phage display to identify peptides from Leptospira spp. that could be used to detect antibodies against them in human blood. In this method, the pathogen’s genome is fragmented, the corresponding peptides displayed on the surfaces of phages (viruses that infect bacteria), and the peptides that bind most strongly to the patients’ antibodies are then selected by screening. Using this method, we identified 2 leptospiral peptides that accurately identified antibodies against Leptospira spp. in sera from patients with leptospirosis. These results are encouraging because they demonstrate that ORFeome phage display may be a powerful tool to develop better diagnostics for leptospirosis for use in less developed areas.

Molecular typing of Streptococcus suis strains isolated from diseased and healthy pigs between 1996-2016

Streptococcus suis is an economically important pathogen of pigs as well as a zoonotic cause of human disease. Serotyping is used for further characterization of isolates; some serotypes seem to be more virulent and more widely spread than others. This study characterizes a collection of German field isolates of Streptococcus suis from pigs dating from 1996 to 2016 with respect to capsular genes (cps) specific for individual serotypes and pathotype by multiplex PCR and relates results to the clinical background of these isolates. The most prominent finding was the reduction in prevalence of serotype-2/serotype-1/2 among invasive isolates during this sampling period, which might be attributed to widely implemented autogenous vaccination programs in swine against serotype 2 in Germany. In diseased pigs (systemically ill; respiratory disease) isolates of serotype-1/serotype-14, serotype-2/serotype-1/2, serotype 3 to 5 and 7 to 9 were most frequent while in carrier isolates a greater variety of cps types was found. Serotype-1/serotype-14 seemed to be preferentially located in joints, serotype 4 and serotype 3 in the central nervous system, respectively. The virulence associated extracellular protein factor was almost exclusively associated with invasive serotype-1/serotype-14 and serotype-2/serotype-1/2 isolates. In contrast, lung isolates of serotype-2/serotype-1/2 mainly harbored the gene for muramidase-released protein. Serotype 4 and serotype 9 isolates from clinically diseased pigs most frequently carried the muramidase-released protein gene and the suilysin gene. When examined by transmission electron microscopy all but one of the isolates which were non-typable by molecular and serological methods showed various amounts of capsular material indicating potentially new serotypes among these isolates. Given the variety of cps types/serotypes detected in pigs, not only veterinarians but also medical doctors should consider other serotypes than just serotype 2 when investigating potential human cases of Streptococcus suis infection.

Zoonotic approach to Shiga toxin-producing Escherichia coli: integrated analysis of virulence and antimicrobial resistance in ruminants and humans

In 2014-2016, we conducted a cross-sectional survey in 115 sheep, 104 beef and 82 dairy cattle herds to estimate Shiga toxin-producing Escherichia coli (STEC) prevalence, and collected data on human clinical cases of infection. Isolates were characterised (stx1, stx2, eae, ehxA) and serogroups O157 and O111 identified by PCR, and their antimicrobial resistance (AMR) profiles were determined by broth microdilution. STEC were more frequently isolated from beef cattle herds (63.5%) and sheep flocks (56.5%) than from dairy cattle herds (30.5%) (P < 0.001). A similar but non-significant trend was observed for O157:H7 STEC. In humans, mean annual incidence rate was 1.7 cases/100 000 inhabitants for O157 STEC and 4.7 for non-O157 STEC, but cases concentrated among younger patients. Distribution of virulence genes in STEC strains from ruminants differed from those from human clinical cases. Thus, stx2 was significantly associated with animal STEC isolates (O157 and non-O157), ehxA to ruminant O157 STEC (P = 0.004) and eae to human non-O157 STEC isolates (P < 0.001). Resistance was detected in 21.9% of human and 5.2% of animal O157 STEC isolates, whereas all non-O157 isolates were fully susceptible. In conclusion, STEC were widespread in ruminants, but only some carried virulence genes associated with severe disease in humans; AMR in ruminants was low but profiles were similar to those found in human isolates.

Tularemia as a waterborne disease: a review

Francisella tularensis is a Gram-negative, intracellular bacterium causing the zoonosis tularemia. This highly infectious microorganism is considered a potential biological threat agent. Humans are usually infected through direct contact with the animal reservoir and tick bites. However, tularemia cases also occur after contact with a contaminated hydro-telluric environment. Water-borne tularemia outbreaks and sporadic cases have occurred worldwide in the last decades, with specific clinical and epidemiological traits. These infections represent a major public health and military challenge. Human contaminations have occurred through consumption or use of F. tularensis-contaminated water, and various aquatic activities such as swimming, canyoning and fishing. In addition, in Sweden and Finland, mosquitoes are primary vectors of tularemia due to infection of mosquito larvae in contaminated aquatic environments. The mechanisms of F. tularensis survival in water may include the formation of biofilms, interactions with free-living amoebae, and the transition to a 'viable but nonculturable' state, but the relative contribution of these possible mechanisms remains unknown. Many new aquatic species of Francisella have been characterized in recent years. F. tularensis likely shares with these species an ability of long-term survival in the aquatic environment, which has to be considered in terms of tularemia surveillance and control.