Stray Dogs as Reservoirs of the Zoonotic AgentsLeptospira interrogans,Trypanosoma cruzi, andAspergillusspp. in an Urban Area of Chiapas in Southern Mexico

The Relationship Between the Spatial Occurrence of Leptospira Exposed Animals and the Characteristics of the Peridomiciles They Inhabit in a Locality of Southeastern Mexico

The occurrence of Leptospira in mammals is an indicator for assessing potential health risks, particularly in tropical regions. Understanding their hosts' habitat characteristics and spatial occurrence is essential to surveil them. This study aimed to determine the characteristics of the peridomiciles associated with the spatial occurrence of Leptospira hosts. We inventoried the characteristics of the peridomiciles. Blood serum was gathered from dogs, opossums, and rodents for a microagglutination essay to detect exposure to several serogroups of Leptospira. A generalized linear model with binomial distribution helped estimate risk ratios and 95% confidence intervals between a seropositive animal's occurrence and the peridomiciles' characteristics. For estimates with the occurrence of one or more seropositive animals, a multinomial model was fitted. The seroprevalence in rodents was 81.8%; in opossums 31.2%; and 56.5% for dogs. The most frequent serogroup in dogs and rodents was Canicola. In opossums, the seroreaction was against Tarassovi, Ballum, Sejroe, and Cynopteri. The results showed that the peridomicile area (m2), the geographic polygon, and the accumulation of plastic containers (PET) were characteristics related to the occurrence of seropositive animals. The results revealed that the peridomicile's characteristics and spatial distribution in the locality help explain the occurrence of Leptospira hosts.

Domestic Dog Infection with Trypanosoma cruzi from Northern and Southern Regions of Mexico

Background: Chagas disease or American trypanosomiasis, caused by Trypanosoma cruzi and vectored by triatomines, affects millions of people worldwide. In endemic countries including Mexico, infections in domestic animals, such as dogs, may affect the risk of human disease when they serve as a source of infection to vectors that subsequently infect humans. Materials and Methods: We conducted a cross-sectional study of 296 dogs from two cities near the northern and southern borders of Mexico: Reynosa, Tamaulipas, and Tuxtla Gutierrez, Chiapas. Infection was measured based on testing of blood using T. cruzi quantitative PCR (qPCR) and up to three antibody detection assays. The StatPak immunochromatographic assay was used to screen samples and the indirect fluorescent antibody (IFA) and multiplex microsphere immunoassay (MIA) tests were used as secondary tests on all samples that screened positive and a subset of negatives. Serologic positivity was defined based on reactivity on at least two independent tests. Results: Of the 280 samples tested for parasite DNA, two (0.7%) were positive, one of which (0.4%) was confirmed as T. cruzi discrete typing unit TcIV. Overall, 72 (24.3%) samples were reactive for T. cruzi antibodies via StatPak of which 8 were also positive using MIA and 2 were also positive using IFA (including one of the PCR-positive dogs). Overall, nine dogs (3.4%) met study criteria of positivity based on either/both serology or PCR tests. Positive dogs were found in both regions of Mexico; five (2.7%) from Reynosa and four (3.6%) from Tuxtla Gutierrez. We found no association between infection status and state of origin, sex, age group, breed group, neighborhood, and whether other pets lived in the home. Conclusion: Our results re-emphasize dogs' utility as sentinels for T. cruzi in Mexico and underscore the need for improved veterinary diagnostic tests and parasite surveillance at the household level in endemic countries.

Review of leptospirosis in dogs from Mexico: Epidemiology, diagnosis, prevention, and treatment

Leptospirosis, classified by the World Health Organization as an emerging and neglected disease, is caused by the zoonotic pathogen Leptospira interrogans. This review aims to outline the Mexican epidemic of L. interrogans in dogs, including diagnosis and prevention methods. This review article searched articles from the publishers Wiley, Springer, PubMed, Redalyc, SciElo, and Elsevier. Among the 200 Mexican articles concerning Leptospira epidemiology, diagnosis, treatment, and vaccination, those that failed to meet the set inclusion criteria were excluded. The worldwide study of L. interrogans has focused on this bacterium. In Mexico, up-to-date information on canine prevalence, diagnosis, and vaccine use is scarce. Flow cytometrically detected Salmonella serovars differ from those in current vaccines, emphasizing the importance of broadening vaccine serovar coverage.

Merging socioecological variables to predict risk of Chagas disease

How far are we from predicting the occurrence of zoonotic diseases? In this paper we have made use of both socioecological and ecological variables to predict Chagas disease occurrence. Chagas disease involves, Trypanosoma cruzi, a complex life-cycle parasite which requires two hosts: blood-feeding triatomine insects and vertebrate hosts including humans. We have used a common risk assessment method combined with datasets that imply critical environmental and socioeconomic drivers of Chagas dynamics to predict the occurrence of this disease. We also carried out a network analysis to assess the interactions among triatomines and mammal host species given their human contact via whether hunted, domesticated or associated with anthropogenic landscapes in Mexico. We found that social backwardness variation, lack of health services and altitude had the largest relative influence Chagas events. Triatoma pallidipennis made use of the largest host diversity. Host species shared by the highest number of different triatomines were a woodrat, the highly appreciated bushmeat, and racoon. These results indicate both the predominance of socio-economic factors over ecological ones, and how close we are from predicting zoonotic diseases.

Advanced approaches for the diagnosis and chemoprevention of canine vector-borne pathogens and parasites-Implications for the Asia-Pacific region and beyond

Vector-borne pathogens (VBPs) of canines are a diverse range of infectious agents, including viruses, bacteria, protozoa and multicellular parasites, that are pernicious and potentially lethal to their hosts. Dogs across the globe are afflicted by canine VBPs, but the range of different ectoparasites and the VBPs that they transmit predominate in tropical regions. Countries within the Asia-Pacific have had limited prior research dedicated to exploring the epidemiology of canine VBPs, whilst the few studies that have been conducted show VBP prevalence to be high, with significant impacts on dog health. Moreover, such impacts are not restricted to dogs, as some canine VBPs are zoonotic. We reviewed the status of canine VBPs in the Asia-Pacific, with particular focus on nations in the tropics, whilst also investigating the history of VBP diagnosis and examining recent progress in the field, including advanced molecular methods, such as next-generation sequencing (NGS). These tools are rapidly changing the way parasites are detected and discovered, demonstrating a sensitivity equal to, or exceeding that of, conventional molecular diagnostics. We also provide a background to the armoury of chemopreventive products available for protecting dogs from VBP. Here, field-based research within high VBP pressure environments has underscored the importance of ectoparasiticide mode of action on their overall efficacy. The future of canine VBP diagnosis and prevention at a global level is also explored, highlighting how evolving portable sequencing technologies may permit diagnosis at point-of-care, whilst further research into chemopreventives will be essential if VBP transmission is to be effectively controlled.

Immune Monitoring of Paediatric Patients Infected with Rickettsia rickettsii, Ehrlichia canis and Coinfected

In 2021, 273 Rocky Mountain spotted fever cases were reported nationwide in Mexico. In Chihuahua City, fourteen samples were obtained from children suspected of rickettsial infection. The analysis of samples (January to December 2021) showed prevalence rates of 28.5%, 43%, and 28.5% for Rickettsia rickettsii, Ehrlichia canis, and both pathogens in coinfection, respectively. The analysis of clinical haematological and biochemistry analytes showed alterations; 100% of the children had elevated liver enzymes and coagulation times, 64% showed leukocytosis due to neutrophilia, 55% had thrombocytopenia, lymphopenia, and hypoalbuminemia, and 45% showed normocytic normochromic anaemia. Statistically significant differences were observed in the expression of the chemokines IL-8, RANTES, CXCL9/MIG, and CXCL10/IP-10 across the coinfected and control groups, and the difference in IP-10 expression was significant for patients infected by R. rickettsii compared to the control group. Additionally, significant differences were observed for expression levels of IL-1β, IL-6, IL-17, IFNγ, and TNFα among the R. rickettsii-positive group compared to the control group. On the other hand, the coinfected group exhibited modified levels of IL-6, IL-8, and IL-10 compared with the control group. Finally, significant differences were observed for CD8+ T lymphocyte subpopulations between individuals positive for R. rickettsii and those positive for E. canis.

Investigating the free-roaming dog population and gastrointestinal parasite diversity in Tulúm, México

Free-roaming domestic dogs (Canis lupus familiaris) pose major conservation and public health risks worldwide. To better understand the threat of domestic dogs to wildlife and people and add to the growing literature on free-roaming dog ecology, a study was conducted to estimate the dog population in Tulúm, México. A modified mark-recapture technique and program MARK were used to obtain dog population estimates along six different transects dividing the city. Population estimates ranged from 19.75 dogs in one transect to 101.841 dogs in another, with 150 total dogs identified throughout the study and an estimated minimum population density of 48.57 dogs/km2. Fecal samples were also opportunistically collected for parasite identification through fecal flotation analysis using the McMaster technique. Out of 25 samples collected, 19 tested positive for gastrointestinal parasites with the most common species found being Ancylostoma caninum, followed by Toxocara canis, Dipylidium caninum, and Cystoisospora spp. Parasite loads ranged from 50 to 10,700 ova per gram of feces. The large population of free-roaming dogs and the prevalence of three zoonotic parasites highlight the importance of understanding free-roaming dog ecology and educating the public on the health risks free-roaming dogs pose. Los perros callejeros (Canis lupus familiaris) representan un gran riesgo para la conservación de animales y la salud pública mundialmente. Para comprender mejor la amenaza que significan los perros domésticos para la fauna silvestre y los humanos y aportar a la creciente bibliografía sobre la ecología de los perros callejeros, se realizó una investigación para estimar la población de los perros en Tulúm, México. Se utilizó una técnica modificada de marcado y recaptura junto con el programa MARK para estimar la población canina en seis transectos de la ciudad. Los estimados varían desde 19.75 perros en un transecto hasta 101,841 en otro, con un total de 150 perros identificados en el transcurso de la investigación y una densidad mínima estimada de 48,57 perros/km2. Además, se hizo una recolección oportunista de muestras de heces para la identificación de parásitos por medio del análisis de flotacíon fecal, con el método McMaster. De las 25 muestras recolectadas, 19 resultaron positivas para parásitos gastrointestinales, de las cuales las especies más comunes fueron Ancylostomoa caninum, seguida por Toxocara canis, Dipylidium caninum, y Cystoisospora spp. Las cargas parasitarias variaron desde 50 hasta 10.700 óvulos por gramo de heces. La alta población de perros callejeros y la prevalencia de tres enfermedades zoonóticas resaltan la importancia de entender la ecología de los perros callejeros y educar al público sobre los riesgos que significan los perros callejeros para la salud.

Canine leptospirosis in stray and sheltered dogs: a systematic review

The aim of this systematic review was to investigate the prevalence of leptospirosis among stray and sheltered dogs worldwide. Six databases were searched, which resulted in the retrieval of 476 articles. Sixty articles were selected for analysis according to 10 quality criteria. Among the selected papers, 26 papers [43.4% (26/60)] met five of the 10 quality criteria established, 10 papers [16.7% (10/60)] met three criteria, nine papers [15.0% (9/60)] met four criteria, six papers [10.0% (6/60)] met six criteria, four papers [6.7% (4/60)] met eight criteria, and three papers [5.0% (3/60)] met nine of the 10 criteria, whereas two papers [1.7% (1/60)] met two and seven [1.7% (1/60)] criteria. Publications originated mainly from the Americas [45.0% (27/60)] and in the last 16 years (2003-2019) [81.7% (49/60)], and most of the sampled dogs were stray dogs [65.0% (39/60)]. The most commonly used diagnostic test for leptospirosis was the microscopic agglutination test [78.4% (47/60)] followed by polymerase chain reaction [21.7% (13/60)], and the most common serovars were Canicola [71.4% (35/49)], Icterohaemorrhagiae [65.3% (32/49)], Grippotyphosa [40.8% (20/49)], and Pomona [40.8% (20/49)]. In conclusion, our results showed that Leptospira spp. are present in unowned dogs worldwide; however, the low-methodological quality of the recovered cross-sectional studies precluded a meta-analysis.

Detection of Trypanosoma cruzi infection by PCR in Canis lupus familiaris and their ectoparasites in Chile

Chronic Chagas disease affects humans and animals, involving rural and urban inhabitants. Dogs participate in the maintenance and transmission of Trypanosoma cruzi. The objective of this study was to evaluate the presence of T. cruzi in dogs and their ticks and fleas, in a rural area of Central Chile. Trypanosoma cruzi was detected by PCR both in dogs and ectoparasites. From the blood samples obtained, 57% were infected by T. cruzi, 5.4% of the ticks detected were positive, and all fleas were negative. Additionally, we performed electrocardiograms and found supraventricular arrhythmia in 44% of T. cruzi-positive dogs. Nevertheless, their risk for supraventricular arrhythmias was not higher in infected versus noninfected dogs. Considering the detected infection levels, dogs act as T. cruzi hosts in Central Chile, and ticks could be used as an indicator of infection when blood samples are not available. However, at this point, there is no indication that these ticks could pass on the parasite to another host. Periodic ectoparasitic treatment of pets should reduce the chance of vectorial transmission of T. cruzi and improve canine health; however, this is an uncommon practice among rural communities, so governmental programs are encouraged to tackle this problem.

Combined use of real-time PCR and serological techniques for improved surveillance of chronic and acute American trypanosomiasis in dogs and their owners from an endemic rural area of Neotropical Mexico

In this study, the prevalence of T. cruzi infection was estimated in dogs and their owners from a rural community in Mexico using serological techniques for chronic infection cases, qPCR for acute phase cases, and a combination of both techniques to detect chronic and acute infections. Eighty-nine blood samples were collected from owners and their dogs for obtaining serum and parasite DNA. Prevalence was calculated using (i) positive cases detected in a serological test (ELISA and Western blot), (ii) positive cases detected in a qPCR test, and (iii) positive cases detected by both techniques. Sensitivity, specificity, and predictive values were determined individually for serology, qPCR and for both techniques used simultaneously. The prevalence observed varied: for serology, 25.8% of the dogs and 7.9% of the owners were seropositive, while for qPCR 29.2% of the dogs and 10.1% of the owners were identified as positive. Combination of serological and molecular techniques resulted in a prevalence of 38.2% for dogs and 12.4% for their owners. The sensitivity, specificity and predictive values calculated for both techniques improved when both techniques were used simultaneously (sensitivity of 92.4% and specificity of 100% for infected dogs and sensitivity of 93.4% and specificity of 100% for infected owners). Combined use of serological tests and qPCR allowed identifying a greater number of positive cases in dogs and their owners. This strategy may help implement adequate and timely epidemiological surveillance of American trypanosomiasis in order to prevent the appearance of new cases of Trypanosoma cruzi infections in endemic zones.

Mini-exon gene reveals circulation of TcI Trypanosoma cruzi (Chagas, 1909) (Kinetoplastida, Trypanosomatidae) in bats and small mammals in an ecological reserve in southeastern Mexico

A wide variety of mammals are involved in the sylvatic cycle of Trypanosomacruzi, the causative agent of Chagas disease. In many areas in Latin America where T.cruzi is endemic, this cycle is poorly known, and its main reservoirs have not been identified. In this study we analyzed T.cruzi infection in bats and other small mammals from an Ecological Reserve in southeastern Mexico. From January through March 2021, we captured wild individuals to extract cardiac and peripheral blood, and infection was detected by PCR of the mini-exon gene. In bats, the prevalence of infection was 16.36%, while in small mammals the prevalence was 28.57%. All of the samples that were positive for T.cruzi were identified as the TCI genotype. Our findings suggest that this zone, situated at the periphery of urban zones might have epidemiological relevance in the sylvatic cycle of T.cruzi and needs to be monitored. The infection of bats in this area is particularly concerning since the flight pattern of this populations overlaps with human settlements. Despite being subject to conservation protections, there continue to be anthropogenic actions that disturb the study area, which could exacerbate risks to public health.

An Observational Study of Human Leptospirosis in Seychelles

A 1-year population-based prospective study was launched in Seychelles, a country with one of the highest human incidence of leptospirosis worldwide, to describe the characteristic features of the epidemiology of the disease and highlight the most prominent risk factors. Diagnosis was based on the IgM enzyme-linked immunosorbent assay, microscopic agglutination test, and real-time PCR. A standardized questionnaire was administered to 219 patients aged ≥ 13 years consulting for acute febrile illness. The high incidence of leptospirosis in Seychelles was confirmed. The disease was particularly severe, as the case fatality rate was 11.8%. Leptospirosis was positively associated in univariate analysis with socio-professional and clinical variables including gardening/farming, oliguria, jaundice, conjunctivitis, history of hepatitis C virus infection, anemia, thrombocytopenia, and/or biological renal failure. Epidemiological analyses of the questionnaires highlighted a link of the disease with living in houses (versus apartment), the presence of animals around and in houses, gardening, and misuse of personal protective equipment. Multivariate analyses indicated that being a farmer/landscaper and having cattle and cats around the home are the most significant drivers of leptospirosis. Biological features most associated with leptospirosis were thrombocytopenia, leukocytosis, high values for renal function tests, and elevated total bilirubin. We report changes in behavior and exposure compared with data collected on leptospirosis 25 years ago, with indication that healthcare development has lowered case fatality. Continuous health education campaigns are recommended as well as further studies to clarify the epidemiology of human leptospirosis, especially the role of domestic animals.

Seropositivity for Trypanosoma cruzi and Leishmania mexicana in dogs from a metropolitan region of Central Mexico

Trypanosoma cruzi and Leishmania mexicana are parasites of humans and other mammals, causing American Trypanosomiasis and Cutaneous Leishmaniasis, respectively. Domestic dogs are considered key hosts for these parasites in the domicile and peridomicile cycles of transmission, due to their abundance and contact with human population. In Mexico, there are few studies that involve the study of infection with these parasites in dogs, and have only been carried out mainly in the endemic areas for these diseases. In the state of Querétaro (Mexico), infections with both parasites have been reported for dogs only from rural areas, with no records for the metropolitan zone. We analyzed the seropositivity to T. cruzi and L. mexicana in dogs from localities within of the metropolitan zone of Querétaro City in order to determine if these animals are exposed to these parasites and thus, could be an important part of the transmission cycle of these trypanosomatids in a densely populated urban region within the state of Querétaro, Mexico. Serum samples were collected from 303 dogs housed in the Animal Control centers of the municipalities of Querétaro and El Marques, analyzed by indirect ELISA and Western Blot using as an antigen the Iron Superoxide Dismutase (FeSODe) of the parasites. From the total serum samples, we detected 10.2% of seropositivity for T. cruzi and 2.9% for L. mexicana. Our results represent the first evidence of infection with T. cruzi in domestic dogs from the Metropolitan Zone of Querétaro, and the first record for L. mexicana in Central Mexico. Ongoing investigations seek to confirm the circulation of these parasites in the area to evaluate the risk associated to the human population.

Understanding the oral transmission of Trypanosoma cruzi as a veterinary and medical foodborne zoonosis

Chagas disease is a neglected tropical disease transmitted by the protozoan Trypanosoma cruzi that lately has been highlighted because several outbreaks attributed to oral transmission of the parasite have occurred. These outbreaks are characterized by high mortality rates and massive infections that cannot be related to other types of transmission such as the vectorial route. Oral transmission of Chagas disease has been reported in Brazil, Colombia, Venezuela, Bolivia, Ecuador, Argentina and French Guiana, most of them are massive oral outbreaks caused by the ingestion of beverages and food contaminated with triatomine feces or parasites' reservoirs secretions and considered since 2012 as a foodborne disease. In this review, we present the current status and all available data regarding oral transmission of Chagas disease, highlighting its relevance as a veterinary and medical foodborne zoonosis.

Trypanosoma cruzi infections and associated pathology in urban-dwelling Virginia opossums (Didelphis virginiana)

Trypanosoma cruzi, a zoonotic protozoan parasite, infects a wide range of mammals. The southern United States has endemic sylvatic transmission cycles maintained by several species of wildlife and domestic dogs. We hypothesized that urban-dwelling opossums (Didelphis virginiana) in South Texas are infected with T. cruzi, and that tissue pathology would be associated with infection. In 2017, we collected blood, heart tissue and anal gland secretions from 100 wild opossums across three seasons that were trapped by animal control in South Texas. In addition, anal gland tissue and intercostal muscle were collected from 43 of the 100 opossums for which time allowed the extra tissue collection. All blood, tissue, and secretion samples were screened for T. cruzi DNA using qPCR with confirmation of positive status achieved through one or more additional PCR assays, including a qPCR to determine the parasite discrete typing unit (DTU). T. cruzi DNA was detected in at least one tissue of 15% of the opossums sampled: blood clot (9%), heart tissue (10%), anal gland secretions (12%), intercostal muscle (16.3%), and anal gland tissue (11.6%). Infection was detected in two or more different tissue types in nine of the opossums. The 35 tissues for which parasite DTU was determined were exclusively 'Tcl'- a DTU previously associated with locally-acquired human disease in the United States. T. cruzi-positive opossums were nearly 14 times more likely to exhibit significant heart lesions on histopathology (lympoplasmacytic inflammation±fibrosis) when compared to negative opossums (OR = 13.56, CI = 1.23-751.28, p-value = 0.03). Three triatomines were opportunistically collected from the study site, of which two were infected (66.7%), and bloodmeal analysis revealed canine, opossum, and human bloodmeals. Given the presence of parasite in opossum blood, unique potential for shedding of parasite in anal glad secretions, and evidence of vectors feeding on opossums, it is likely that opossums serve as wild reservoirs around urban dwellings in South Texas.

Leptospira spp. and Toxoplasma gondii in stranded representatives of wild cetaceans in the Philippines

Background

The stranding events of cetaceans in the Philippines provide opportunities for gathering biological information and specimens, especially from the pelagic forms. As part of an effort to monitor the health of wild cetaceans, this study detected Leptospira spp. and Toxoplasma gondii, causative agents of the emerging zoonotic diseases leptospirosis and toxoplasmosis respectively, in their stranded representatives. From October 2016–August 2018, 40 cetaceans (representing 14 species) that stranded nationwide were sampled for brain, cardiac muscle, skeletal muscle, kidney, and blood tissues, urine, and sera. These were subjected to molecular, serological, culture, and histopathological analyses to detect the target pathogens.

Results

T. gondii was detected in 20 (71%) of the 28 cetaceans with biological samples subjected to either molecular detection through RE gene amplification or IgG antibodies detection through agglutination-based serological assay. On the other hand, Leptospira was detected in 18 (64%) of 28 cetaceans with biological samples subjected to bacterial culture, molecular detection through 16S rDNA amplification, or IgM antibodies detection through ELISA-based serological assay.

Conclusions

There is the plausibility of toxoplasmosis and leptospirosis in cetacean populations found in the Philippines, however, acute or chronic phases of infections in sampled stranded individuals cannot be confirmed in the absence of supporting pathological observations and corroborating detection tests. Further studies should look for more evidences of pathogenicity, and explore the specific mechanisms by which pelagic cetacean species become infected by Leptospira spp. and T. gondii. As there is growing evidence on the role of cetaceans as sentinels of land-sea movement of emerging pathogens and the diseases they cause, any opportunity, such as their stranding events, should be maximized to investigate the health of their populations. Moreover, the role of leptospirosis or toxoplasmosis in these stranding events must be considered.

Risk Factors and Prediction of Leptospiral Seropositivity Among Dogs and Dog Handlers in Malaysia

This study determined the potential risk factors that may contribute to seropositivity among dogs and dog handlers from working dog and dog shelter institutions. Data was collected from dogs (n = 266) and dog handlers (n = 161) using a standardised guided questionnaire. Serum obtained from the dogs and dog handlers was tested using the microscopic agglutination test (MAT). A logistic regression analysis was used to predict leptospiral seropositivity of dogs and dog handlers based on potential risk factors. A total of 22.2% of dogs and 21.7% of dog handlers were seropositive. The significant predictors for the dogs' seropositivity were presence of rats (OR = 4.61 (95% CI: 1.05, 20.33), p = 0.043) and shared common area (OR = 5.12 (95% CI: 1.94, 13.46), p = 0.001) within the organisation. Significant predictor for dog handler seropositivity was contact time with the dogs of more than six hours/day (OR = 3.28 (95% CI: 1.28, 8.40), p = 0.013) after controlling for the effect of other risk factors such as small mammal contact, rat infestation at home, flooding at housing area (within three months) and urban locality. The exposure to various disease sources identified poses risk to dogs and dog handlers. Risk could be reduced with adequate application of protection at work while handling dogs and thus limiting contact with these sources and reducing exposure to infection.

A review on the occurrence of companion vector-borne diseases in pet animals in Latin America

Companion vector-borne diseases (CVBDs) are an important threat for pet life, but may also have an impact on human health, due to their often zoonotic character. The importance and awareness of CVBDs continuously increased during the last years. However, information on their occurrence is often limited in several parts of the world, which are often especially affected. Latin America (LATAM), a region with large biodiversity, is one of these regions, where information on CVBDs for pet owners, veterinarians, medical doctors and health workers is often obsolete, limited or non-existent. In the present review, a comprehensive literature search for CVBDs in companion animals (dogs and cats) was performed for several countries in Central America (Belize, Caribbean Islands, Costa Rica, Cuba, Dominican Republic, El Salvador, Guatemala, Honduras, Mexico, Nicaragua, Panama, Puerto Rico) as well as in South America (Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, French Guiana, Guyana (British Guyana), Paraguay, Peru, Suriname, Uruguay, Venezuela) regarding the occurrence of the following parasitic and bacterial diseases: babesiosis, heartworm disease, subcutaneous dirofilariosis, hepatozoonosis, leishmaniosis, trypanosomosis, anaplasmosis, bartonellosis, borreliosis, ehrlichiosis, mycoplasmosis and rickettsiosis. An overview on the specific diseases, followed by a short summary on their occurrence per country is given. Additionally, a tabular listing on positive or non-reported occurrence is presented. None of the countries is completely free from CVBDs. The data presented in the review confirm a wide distribution of the CVBDs in focus in LATAM. This wide occurrence and the fact that most of the CVBDs can have a quite severe clinical outcome and their diagnostic as well as therapeutic options in the region are often difficult to access and to afford, demands a strong call for the prevention of pathogen transmission by the use of ectoparasiticidal and anti-feeding products as well as by performing behavioural changes.

Seropositivity for Trypanosoma cruzi in domestic dogs from Sonora, Mexico

BACKGROUND

Chagas disease is an important health problem in Latin America due to its incapacitating effects and associated mortality. Studies on seropositivity for Trypanosoma cruzi in Mexican dogs have demonstrated a direct correlation between seropositivity in humans and dogs, which can act as sentinels for the disease in this region. The objective of this study was to determine the seropositivity for T.cruzi infection in dogs from Sonora, a northern borderstate of Mexico.

METHODS

Responsible pet owners were selected at random from an urban area of Empalme municipality, Sonora, Mexico, and from there, 180 dog samples were collected. Anti-T. cruzi antibodies were determined using the enzyme-linked immunosorbent assay (ELISA) method. Reactive ELISA sera were processed by indirect immunofluorescence to confirm the presence of anti-T. cruzi antibodies. For the statistical analysis, chi-square tests were conducted.

RESULTS

Dogs' sera showed a seropositivity rate of 4.44%. The rate of seropositivity was not associated with the dogs' age, sex, or socioeconomics pertaining to the geographical area. One sample (1/180, 0.55%) showed the acute state of the disease.

CONCLUSIONS

The study found a presence of anti-T. cruzi antibodies in dogs in this area, which suggests vector transmission. There is a need for active surveillance programs throughout the state of Sonora and vector control strategies should also be implemented in endemic regions.

Allergic bronchopulmonary aspergillosis is associated with pet ownership in cystic fibrosis

BACKGROUND

Late diagnosis of allergic bronchopulmonary aspergillosis (ABPA) is associated with significant lung function decline and morbidity in cystic fibrosis (CF). The association of ABPA and domestic pet ownership in patients with CF has not been elucidated yet. Our objective was to determine the association of ABPA with pet ownership in patients with CF.

METHODS

Clinical and microbiological data from certified local patient registry were analyzed for 109 patients with CF aged 1-64 years: 55 pet owner and 54 non-pet owners. The primary outcome of the retrospective observational study was the occurrence of ABPA in pet owners and non-pet owners with CF. The free statistical software R was utilized to investigate logistic regression models for association factors.

RESULTS

Of the 109 patients included in the study, 61 (56%) were female. The mean age of the total group was 25.4 ± 13.2 years. Adjusted analysis revealed that ABPA (OR 5.0227, 95% CI: 1.182-21.340, p = 0.029) was associated with pet ownership in patients with CF. Furthermore, ABPA in pet owners with CF was associated with an increased number of exacerbations (OR 6.446, 95% CI: 1.057-39.328, p = 0.043). Other outcomes did not significantly differ.

CONCLUSION

Owning a pet was associated with ABPA in patients with CF. Future prospective multicenter longitudinal studies are needed to investigate chronological causality between pet ownership, ABPA development, and pulmonary exacerbations and to determine whether these estimates are generalizable for ABPA susceptible patients beyond CF (asthma, bronchiectasis).

Risk factors associated with leptospirosis in dogs from Northern California: 2001-2010

The present study was performed to identify risk factors for canine leptospirosis at a tertiary referral institution in northern California from 2001 through 2010 and to describe case characteristics. In this retrospective case-control study, 67 dogs with leptospirosis and 271 controls were evaluated at the William R. Pritchard Veterinary Medical Teaching Hospital (Davis, CA) from March, 2001 , through November, 2010. Medical records of cases and controls were analyzed to identify signalment, exposure history, and clinical signs that increased the risk for a diagnosis of leptospirosis. Among cases, most were vomiting and lethargic and had leukocytosis and azotemia. Total white cell count, neutrophil count, and monocyte count were higher in dogs with leptospirosis, whereas the platelet count was lower. Serum concentrations of urea nitrogen, creatinine, and bilirubin were elevated in dogs with leptospirosis as well. On average, case dogs were hospitalized for 11 days and had hospital bills exceeding $5000. Mortality was 13% of case dogs, with the predominant serovar being Pomona. Dogs with leptospirosis were more likely to reside in the central or south coast (odds ratio [OR]=7.33), Sierra Nevada foothills (OR=4.50), San Francisco Bay area (OR=4.2), and north coast (OR=2.85) of California when compared with controls. Dogs 5-10 years old (OR=3.22) or over 10 years old (OR=2.76) and herding (OR=3.1) or hound breed (OR=4.6) dogs were more likely to have leptospirosis than the control group. Leptospirosis was associated with acute renal failure in older, undervaccinated dogs. The regional distribution, large breed predisposition, and finding of predominantly Pomona serovar suggest wildlife or other contacts as an important route of exposure. Knowledge of risk factors, vaccination history, and clinical signs can increase an index of suspicion for leptospirosis and contribute to improved strategies for prevention of leptospirosis in dogs, understanding of the ecology of the disease for all species, and protection of human health.

European consensus statement on leptospirosis in dogs and cats

Leptospirosis is a zoonotic disease with a worldwide distribution affecting most mammalian species. Clinical leptospirosis is common in dogs but appears to be rare in cats. Both dogs and cats, however, can shed leptospires in the urine. This is problematic as it can lead to exposure of humans. The control of leptospirosis, therefore, is important not only from an animal but also from a public health perspective. The aim of this consensus statement is to raise awareness of leptospirosis and to outline the current knowledge on the epidemiology, clinical features, diagnostic tools, prevention and treatment measures relevant to canine and feline leptospirosis in Europe.

American trypanosomiasis and associated risk factors in owned dogs from the major city of Yucatan, Mexico

Background

The American trypanosomiasis is a zoonosis caused by the protozoa Trypanosoma cruzi (T. cruzi). The disease is widely distributed throughout the American continent, affecting a wide range of hosts, including dogs. It is present in the canine population in the State of Yucatan, Mexico. However, no significant studies in owned dogs have been performed in the metropolitan area of Merida. A transversal study was conducted in 370 owned dogs from Merida, Yucatan, Mexico.

Methods

A cross-sectional study including 370 dogs was performed in a major city of Yucatan, Mexico, to detect IgG antibodies against T. cruzi. A commercial ELISA test kit was used and a chi-square test used to evaluate associated risk factors; odds ratio (OR) and 95 % confidence interval (CI) were also estimated.

Results

The indirect ELISA and western blot (WB) tests were used to detect specific immunoglobulin G antibodies against T. cruzi in serum samples. A prevalence of 12.2 % was found; age and area of residence were statistically associated with seropositivity in dogs (p <0.05).

Conclusions

Results from the present study suggests the presence and abundance of the vector in urban conditions where a high number of seropositive cases of T. cruzi cases were found.

Prevalence and Transmission of Trypanosoma cruzi in People of Rural Communities of the High Jungle of Northern Peru

Background

Vector-borne transmission of Trypanosoma cruzi is seen exclusively in the Americas where an estimated 8 million people are infected with the parasite. Significant research in southern Peru has been conducted to understand T. cruzi infection and vector control, however, much less is known about the burden of infection and epidemiology in northern Peru.

Methodology

A cross-sectional study was conducted to estimate the seroprevalence of T. cruzi infection in humans (n=611) and domestic animals [dogs (n=106) and guinea pigs (n=206)] in communities of Cutervo Province, Peru. Sampling and diagnostic strategies differed according to species. An entomological household study (n=208) was conducted to identify the triatomine burden and species composition, as well as the prevalence of T. cruzi in vectors. Electrocardiograms (EKG) were performed on a subset of participants (n=90 T. cruzi infected participants and 170 age and sex-matched controls). The seroprevalence of T. cruzi among humans, dogs, and guinea pigs was 14.9% (95% CI: 12.2 – 18.0%), 19.8% (95% CI: 12.7- 28.7%) and 3.3% (95% CI: 1.4 – 6.9%) respectively. In one community, the prevalence of T. cruzi infection was 17.2% (95% CI: 9.6 - 24.7%) among participants < 15 years, suggesting recent transmission. Increasing age, positive triatomines in a participant's house, and ownership of a T. cruzi positive guinea pig were independent correlates of T. cruzi infection. Only one species of triatomine was found, Panstrongylus lignarius, formerly P. herreri. Approximately forty percent (39.9%, 95% CI: 33.2 - 46.9%) of surveyed households were infested with this vector and 14.9% (95% CI: 10.4 - 20.5%) had at least one triatomine positive for T. cruzi. The cardiac abnormality of right bundle branch block was rare, but only identified in seropositive individuals.

Conclusions

Our research documents a substantial prevalence of T. cruzi infection in Cutervo and highlights a need for greater attention and vector control efforts in northern Peru.

Chagas disease causes significant morbidity and mortality throughout Central and South America. The epidemiology and control of this disease is subject to unique regional particularities, including the behavior and ecology of the local insect vector species. Significant resources have been allocated towards research and control efforts in southern Peru, yet very little is known about the prevalence and epidemiology of Trypanosoma cruzi in northern Peru. Our study highlights significant T. cruzi infection in northern Peru and is one of the first to document substantial transmission by the insect Panstrongylus lignarius. Our results illustrate major gaps in knowledge and the need for public health interventions targeted at Chagas disease in the region of Cutervo Province of northern Peru.

Characteristics of rural leptospirosis patients admitted to referral hospitals during the 2008 leptospirosis outbreak in Sri Lanka: implications for developing public health control measures

To determine the exposure risk factors of highly endemic rural leptospirosis in tropical setting, we conducted a prospective, hospital-based case control study in Sri Lanka. A conceptual hierarchy of variables was used to analyze the data. Case patients included 38 (34%) females and 73 (66%) males with a mean age of 36 yr (SD 12.7 yr). Using piped, chlorinated water for drinking/general purposes (odds ratio [OR] 0.33, 95% confidence interval [CI] 0.16-0.67), paddy fields in the vicinity of home (OR 1.77, 95% CI 1.06-2.97), sighting dogs at home yard/dog ownership (OR 1.79, 95% CI 1.11-2.91), sighting cattle at home yard/cattle ownership (OR 1.69, 95% CI 1.00-2.84), and work in a paddy field (OR 3.02, 95% CI 1.68, 5.41) were the main predictors of leptospirosis among febrile patients. In high endemic tropical settings with rural leptospirosis, risk factors in residential environments, rather than individual exposures, seemed to play a major role in leptospirosis disease transmission.

Seroprevalence and major antigens recognized by sera from Trypanosoma cruzi-infected dogs from Jalisco, México

Chagas disease is a major endemic disease caused by the protozoan parasite Trypanosoma cruzi. This parasitic disease is widely distributed throughout Latin America, affecting 10 million people. There are also reports of canine infection in the southern part of the United States. Dogs are considered the predominant domestic reservoir for T. cruzi in many areas of endemicity. In México, dog infection by this parasite has been poorly studied. In this work 209 dogs from six villages in Jalisco, México, were assessed to detect anti-T. cruzi antibodies by ELISA and Western blot. Seventeen (17) seropositive dogs (8.1 %) were detected by both tests, representing a seropositive value similar to that found in some southern states of México where the infection is present. No statistical differences were observed concerning the age and sex of infected and non-infected dogs. The major antigens recognized by positive sera were 26, 32, 66 and 80kDa. These proteins are candidates to develop a specific diagnostic method for canine Chagas. No antibodies against HSP16 protein were found in T. cruzi seropositive sera. This is the first report of canine serology of Chagas disease in this central part of México. This report will contribute to the knowledge of the infection status of domestic reservoirs in the state of Jalisco, México.

Sperm morphological features associated with chronic Chagas disease in the semen of experimentally infected dogs

The presence of trypanosomatids in the reproductive systems of different mammals (causing genital lesions in the acute stage of the disease) may predispose the animals to low semen quality. However, there are no studies examining the alterations in the sperm morphological features in the chronic stage of Trypanosoma cruzi infection. Knowledge of these aspects is important to understand the other ways of transmission of the Chagas disease. Progressive motility, mass motility, concentration, and sperm morphology of 84 ejaculates of dogs that were chronically infected with T. cruzi were evaluated. Most of the findings were consistent with the reference values and with those obtained from healthy control dogs. The scrotal circumference was not correlated with spermatozoa concentration in the infected animals. In conclusion, the T. cruzi Ninoa (MHOM/MX/1994/Ninoa) strain does not cause significant alterations in the semen quality of dogs experiencing chronic Chagas disease (at concentrations of 5 × 10(4) to 1 × 10(6) parasites per animal).

Health impact evaluation of alternative management systems in vicuña (Vicugna vicugna mensalis) populations in Peru

To determine the impact of farming over vicuña population in Peru, serum samples were collected from 207 vicuñas (126 captive vicuñas and 81 free-ranging vicuñas) and 614 domestic South American camelids (571 alpacas and 43 llamas), in ten Andean communities at the Salinas y Aguada Blanca reserve, province of Arequipa, southern Peru. Samples were tested for the presence of leptospirosis, foot and mouth disease (FMD), bovine viral diarrhea (BVD), bovine herpesvirus type 1 (BHV-1), brucellosis, bluetongue disease (BT), paratuberculosis, and neosporosis. Serological results showed that 1.9% (4/207) of vicuñas, 18.6% (106/571) of alpacas, and 23.3% (10/43) of llamas were positive to one or more Leptospira serovars. One percent of vicuñas (2/207) and 2.4% of domestic camelids (15/614) had Neospora caninum antibodies tested by ELISA, but only two vicuñas and two alpacas were confirmed by Western blot. Epidemiological evaluation found an association of leptospirosis to sex and age (p < 0.001), with female subjects older than 2.5 years at higher risk of infection. Interestingly, antibodies against Leptospira serovars were only found in captive vicuñas. This is the first study where health status of free-ranging and captive vicuñas has been compared. Results indicate minimal to nil presence of FMD, BVD, BHV-1, brucellosis, BT, paratuberculosis, and neosporosis allied to health disorders in our sample. The detection of seropositive animals against Leptospira, however, unveils the likely significance of leptospirosis in wild and domestic South American camelids, the impact of mixed husbandry over vicuña population and the risk to human health.

Endemicity of leptospirosis in domestic and wild animal species from Reunion Island (Indian Ocean)

Leptospirosis is the major infectious disease on Reunion Island but little is known about the animal reservoir. We conducted a wide-ranging survey that included samples from 574 animals belonging to 12 species. The seroprevalence and prevalence of renal carriage varied greatly depending on the species, with the highest seroprevalence (79·5%) found in Norway rats, and the lowest (13·2%) in tenrecs. The renal carriage rate ranged from 84·6% in mice to 0% in tenrecs. Our results suggest that rodents are the most important reservoirs of leptospirosis on Reunion Island. The epidemiological role that animals play in human infection is discussed. For the first time, we quantified the renal concentration of leptospires in ten naturally infected mammals. The history of Reunion Island colonization probably explains why the circulating Leptospira serogroups were similar to those found in Europe. Our study provides evidence that will help implement preventive measures against this zoonosis.

High-resolution melting (HRM) of the cytochrome B gene: a powerful approach to identify blood-meal sources in Chagas disease Vectors

Methods to determine blood-meal sources of hematophagous Triatominae bugs (Chagas disease vectors) are serological or based on PCR employing species-specific primers or heteroduplex analysis, but these are expensive, inaccurate, or problematic when the insect has fed on more than one species. To solve those problems, we developed a technique based on HRM analysis of the mitochondrial gene cytochrome B (Cyt b). This technique recognized 14 species involved in several ecoepidemiological cycles of the transmission of Trypanosoma cruzi and it was suitable with DNA extracted from intestinal content and feces 30 days after feeding, revealing a resolution power that can display mixed feedings. Field samples were analyzed showing blood meal sources corresponding to domestic, peridomiciliary and sylvatic cycles. The technique only requires a single pair of primers that amplify the Cyt b gene in vertebrates and no other standardization, making it quick, easy, relatively inexpensive, and highly accurate.

Chagas disease is one of the most important tropical diseases in America. This disease is caused by the parasite Trypanosoma cruzi and transmitted through the feces of blood-sucking insects known as triatomines. Different species of insects have different habits and food sources that confer variable degrees of epidemiological importance. In this paper, we propose the use of High Resolution Melting (HRM) analysis of cytochrome b (cyt b) gene PCR products to identify blood-food sources in triatomines. This tool can effectively differentiate blood-meal sources of insects collected from the field. Such data allows for targeted investigations of insect species that are likely to be involved in the transmission of the parasite to humans in different regions. This knowledge is very important because it allows establishing and designing vector control and surveillance strategies according to each geographical area and to stop the transmission of the parasite to human populations by insects.

Protecting animal and human health and the nation's food supply through veterinary diagnostic laboratory testing

The current detection system for animal diseases requires coordination between veterinarians; veterinary medical laboratories; and state, federal, and international agencies, as well as associated private sector industries. Veterinary clinical pathologists in clinical and governmental laboratories often have responsibilities and expertise in one or more laboratory disciplines involved in diagnosing zoonotic and/or emerging diseases and diseases exotic to the United States that are important to animal and human health and the nation's food supply. The knowledge and roles of all veterinary laboratory professionals are vital to detect, monitor, and confirm diseases and conditions that affect animal and human health and the nation's animal food supply.

2010 ACVIM small animal consensus statement on leptospirosis: diagnosis, epidemiology, treatment, and prevention

This report offers a consensus opinion on the diagnosis, epidemiology, treatment, and prevention of leptospirosis in dogs, an important zoonosis. Clinical signs of leptospirosis in dogs relate to development of renal disease, hepatic disease, uveitis, and pulmonary hemorrhage. Disease may follow periods of high rainfall, and can occur in dogs roaming in proximity to water sources, farm animals, or wildlife, or dogs residing in suburban environments. Diagnosis is based on acute and convalescent phase antibody titers by the microscopic agglutination test (MAT), with or without use of polymerase chain reaction assays. There is considerable interlaboratory variation in MAT results, and the MAT does not accurately predict the infecting serogroup. The recommended treatment for optimal clearance of the organism from renal tubules is doxycycline, 5 mg/kg PO q12h, for 14 days. Annual vaccination can prevent leptospirosis caused by serovars included in the vaccine and is recommended for dogs at risk of infection.

Invasive mould infections of the naso-orbital region of cats: a case involving Aspergillus fumigatus and an aetiological review

CASE AND CONTEXT: This report describes a cat diagnosed with sinonasal-orbital Aspergillus fumigatus infection using advanced imaging, histopathology and culture. Aetiology, clinical aspects and treatment of this rare and devastating infection are discussed with reference to a literature review of invasive mould (ie, filamentous fungal) infections involving tissues of the naso-orbital region of cats.

PRESENTATIONS

Invasive fungal infections can present with different localisations (nasal passages, sinuses, orbits, subcutaneous space, palate, etc) depending on the species involved and its means of introduction into the tissues. Localised subcutaneous lesions (swellings, ulcerations, masses, nodules, etc), without concomitant signs of nasal/orbital disease, generally result from traumatic injuries and subsequent inoculation of fungal spores into the subcutaneous space. In contrast, naso-ocular involvement and concurrent signs of nasal disease (nasal discharge, sneezing, masses protruding from the nostrils) generally result from inhalation of spores, with subsequent spread of infection into the nasal planum or penetration of overlying bone and invasion of the subcutaneous space. Aspergillus species typically show such an invasion mechanism and frequently affect orbital tissues. Dematiaceous fungi (ie, filamentous fungi with brown/black hyphae) are reported to cause solitary, less invasive, slowly developing lesions, probably as a result of traumatic injuries with inoculation of fungal propagules. Accordingly, the subcutaneous space is more frequently primarily involved.

TREATMENT AND OUTCOME

Whatever the mould species, reported treatment options include surgery and a series of antifungal drugs. The outcome is frequently poor, especially for Aspergillus infections, although various measures can be taken to maximise the chances of success, as discussed in this report.