Frequency and factors associated of potential zoonotic pathogens (Borrelia spp., Rickettsia spp., Leishmania spp., and Anaplasma phagocytophilum) in equids in the state of Bahia, Brazil

Serosurvey of Leishmania infantum in equids in different European countries

Leishmaniosis is a vector-borne and zoonotic disease with major sanitary implications at global scale. In Europe, Leishmania infantum is the only endemic etiologic agent, which has been previously reported in a wide range of mammal. However, the information about the role of equids in the L. infantum epidemiology is limited. We aimed to assess the seroprevalence and identify potential risk factors associated with L. infantum seropositivity in equine populations across several European countries. A total of 1364 equids, including 1005 horses, 240 donkeys and 119 mules/hinnies from Spain, Italy, United Kingdom and Ireland were sampled between 2011 and 2023. The overall seroprevalence of L. infantum was 9.8 % using indirect immunofluorescence test. A significant higher prevalence of anti-L. infantum antibodies was found in donkeys (27.9 %) and mules/hinnies (21.1 %) compared to horses (4.0 %). By country, significantly higher seropositivity was detected in equids from Italy (17.7 %; 70/395) compared to Spain (11.2 %; 63/561), while no positivity was found in animals from Ireland and UK. Our results indicate a moderate and heterogeneous spatial circulation of L. infantum in equids from southern Europe. The variable 'species' (donkeys and mules/hinnies) was identified as risk factor associated with L. infantum seropositivity. This survey constitutes the largest seroepidemiological study evaluating the circulation of L. infantum in equids at global scale. Additionally, we report for the first time L. infantum exposure in mules/hinnies in Europe. Our findings suggest the potential role of equids in the L. infantum epidemiological cycle in southern Europe and the need to implement specific surveillance programs in these species.

Lyme borreliosis in Brazil: a critical review on the Baggio-Yoshinari syndrome (Brazilian Lyme-like disease)

SUMMARYLyme borreliosis or Lyme disease is the most frequently reported tick-borne disease in the Northern Hemisphere. In countries of the Southern Hemisphere, such as Brazil, since the early 1990s, some researchers have argued for the existence of an autochthonous Lyme-like borreliosis, known locally as the Baggio-Yoshinari syndrome (BYS), an alleged "Brazilian borreliosis" supposedly caused by a different strain of Borrelia burgdorferi and transmitted by hard ticks. Currently, the existence of BYS in Brazil is still accepted by a large part of the human health care workers, scientists, medical societies, and patients. In fact, this alleged "Brazilian borreliosis" has been the tick-borne zoonotic disease with the greatest number of reported cases and published studies in Brazil during this century, second only to Brazilian spotted fever. In this manuscript, we reviewed all manuscripts directly related to BYS that have been published in Brazil during the last 35 years. This analysis included 199 individual human cases that have been reported in Brazil since 1989, plus multiple studies on ticks, domestic, and wild animals. Our revision aimed to provide a critical opinion on whether the current published works allow healthcare workers, public health agencies, and patients to accept the existence of Lyme disease, BYS, or other Lyme borreliosis-related disease in Brazil. For this purpose, we evaluated the strengths and weaknesses of each published study, considering the diagnostic methods used, such as serological, microbiological, and molecular analyses. Based on these evaluations, we conclude that there is not enough evidence to support the occurrence of Lyme borreliosis in Brazil or that BYS (Brazilian Lyme-like disease) is caused by a bacterium of the genus Borrelia. This assumption is based on the inaccuracy, unreliability, and misinterpretation of the different diagnostic methods that have been used in Brazil. Recognizing the lack of technical evidence for the occurrence of Lyme borreliosis in Brazil has highly relevant implications. For example, it becomes imperative to raise awareness among the country's medical profession, as they have adopted unnecessary and extreme therapies recommended for patients with a supposed borrelial infection, including BYS, in Brazil. Finally, the technical analyses carried out in this study could be applied to other countries in the Southern Hemisphere (e.g., Argentina, South Africa, Australia), where cases classified and alleged as Lyme disease have been reported.

Evidence of Horse Exposure to Anaplasma phagocytophilum, Borrelia burgdorferi, and Leishmania infantum in Greece through the Detection of IgG Antibodies in Serum and in an Alternative Diagnostic Sample-The Saliva

Among the various zoonotic pathogens that infect horses, Anaplasma phagocytophilum, Borrelia spp. and Leishmania spp. have gained scientific interest, and relevant molecular and serological studies in horses have been conducted worldwide. Moreover, human and veterinary medicine have extensively applied alternatives to serum diagnostic samples-such as saliva-for detecting pathogens or antibodies. In this study, we investigated the exposure of horses in Greece to A. phagocytophilum, B. burgdorferi, and L. infantum, and we assessed the diagnostic accuracy of saliva compared to serum in detecting IgG antibodies against the abovementioned pathogens. Paired saliva and serum samples were collected from 317 horses from different regions in Greece. The paired samples were examined using the indirect fluorescent antibody test (IFAT) for detecting IgG antibodies against A. phagocytophilum, B. burgdorferi, and L. infantum. Sensitivity, specificity, positive likelihood ratio (PLR), and negative likelihood ratio (NLR) were determined to assess the validity of saliva as an alternative to serum. The receiver operating characteristic (ROC) curve revealed that the optimal cut-off value for detecting antibodies against all the examined pathogens in saliva was 1/10. Higher seropositivity rates were found for B. burgdorferi (15.14%) and A. phagocytophilum (14.19%) compared to L. infantum (1.26%). The detection of IgG antibodies using IFAT in saliva samples had a good test performance compared to serum. The two sample types had a substantial to almost perfect agreement. Although the sensitivity was moderate (70.83-75.56%) in all cases, the specificity was almost perfect to perfect (99.63-100%). This study provides the first evidence that horses in Greece are exposed to A. phagocytophilum and B. burgdorferi and confirms that the seroprevalence of L. infantum in horses in Greece remains low. Our findings suggest that saliva sampling coupled with IFAT could be successfully applied for detecting IgG antibodies against these important zoonotic pathogens in large-scale epidemiological studies in horses, at the population level, as an alternative to serum.

Clinical evolution of equine leishmaniasis with self-limiting cutaneous disease caused by Leishmania infantum in northeastern Brazil: A case report

Leishmania infantum infections have long been described in humans and dogs worldwide, but characterization of equine cases remains scarce. We describe the clinical evolution of a natural L. infantum infection to contribute to the diagnostic knowledge and epidemiology of equine leishmaniasis (EL). An auction-acquired four-year-old Mangalarga Marchador mare from Pernambuco state, presented a few subcutaneous nodules on the head and neck upon arrival at the purchaser's stud at Bahia state, in November of 2019. They progressed to multiple ulcerated and non-ulcerated nodules and spread to both right limbs in seven weeks. Hematology revealed anemia, lymphocytosis, monocytosis, and elevated plasma fibrinogen. Histopathology of the biopsied nodules identified a granulomatous dermatitis with macrophages containing Leishmania amastigotes. PCR detected Leishmania in skin lesions, but not in blood or spleen aspirate samples; ITS1 PCR-RFLP and DNA sequencing confirmed L. infantum species. A topical antiseptic and insect-repellent therapy and a monthly follow-up were established. All lesions improved progressively, without specific anti-Leishmania treatment, and 14 months later there was a consistent resolution. This first description of EL by L. infantum in an endemic area is relevant to emphasize the need for epidemiological studies, and to enhance clinicians' awareness for differential diagnosis.

Prevalence of zoonotic and non-zoonotic Rickettsia in horses: A systematic review and meta-analysis

In a broad sense, Rickettsiae are a group of microorganisms that can be transmitted mechanically or biologically to animals and humans. Rickettsioses are associated with hematic manifestations. Its prevalence in humans, dogs and other animals has been widely explored, but not in equine species. To determine the prevalence of Rickettsia infection in horses. A systematic review of the literature was carried out in five databases for the proportion of horses infected with Rickettsia, defined by molecular and immunological techniques. A meta-analysis was performed using a random-effects model to calculate the pooled prevalence and 95% confidence intervals (CI). The Cochran's Q test and the I² statistic were used to assess the between-study-heterogeneity. The pooled prevalence of Rickettsia in equines was 37.0% (95% CI: 26.0%-47.0%), with significant heterogeneity among studies (I² = 98.12%). In the subgroup analysis, the prevalence of Rickettsia in horses was found to be 24.0% (95%CI: 10.0%-41.0%) for IFI, 47.0% (95%CI: 30.0%-64.0%) for IFA, 14.0% (95%CI: 11.0%-17.0%) for IFAT and 39.0% (95%CI: 0.0%-95.0%) for PCR. There was a high prevalence of Rickettsia among horses, with some of the species being zoonotic, with their corresponding implications for humans, which increasingly are in close contact with equines, particularly horses and their ticks, posing a risk for spillover and transmission.

Participatory appraisal for healthcare and welfare management strategies of donkeys (Equus ascinus) in Balochistan, Pakistan

In spite of the significant importance of the donkeys (Equus ascinus) as draft animal in resource-poor countries like Pakistan, they are equines not receiving the appropriate care. They face challenges including injuries, diseases, lack of basic environment and mismanagement by their owners. The present study aims to provide a brief update on the current status of management of healthcare and the welfare of domestic donkeys using participatory epidemiological tools. These tools can help to provide better strategies for improving their productivity and inclusion in human society. This study was mainly focused only on donkeys and horses, mules and ponies were excluded from the study. We carried out a systematic review of the relevant available published literature and shortlisted 50 articles reporting on the different health related characteristics of donkeys. A comprehensive questionnaire was completed by 191 donkey owners, including nine farriers (all men, average age = 38.24 ± 12.43) over a time span from October 2021 to March 2022. Multivariate Odds Ratios (MORs) and 95% confidence intervals were used to assess the predictions of health management and welfare measures for the surveyed donkeys. The most common observed medical problems in donkey health were hyperlipaemia (28.06%), lameness (16.33%) and dental (20.41%) problems. One-third (34.31%) of the donkeys were underweight. The dull donkey with poor appetite needs a clinical emergency owing to a high risk of developing hyperlipemia, which may be life-threatening. These findings are quite useful for the improvement of healthcare management and the welfare of donkeys.