Toxoplasma gondii is a paradigmatic zoonotic parasite from the One Health perspective, since it is broadly distributed and virtually infects all warm-blooded species. A wide variety of serological techniques have been developed to detect T. gondii infection in humans and animals. Our aim was to describe and compare the main characteristics of these serological tests and validation processes and to critically analyze whether these tests meet the standards required to ensure an accurate serological diagnosis. The current systematic review and meta-analysis included 134 studies that were published from 2013 to 2023. QUADAS 2 tool was used to evaluate the quality of the included studies. A total of 52 variables related to the characteristics of the techniques and analytical and diagnostic validation parameters were studied. A wider panel of tests was developed for humans, including techniques exclusively developed for humans that involve costly equipment and the measurement of different Ig isotypes that are considered biomarkers of congenital toxoplasmosis. Studies conducted in humans frequently employed commercial techniques as reference tests, measured different immunoglobulin isotypes with a predominance for IgG (>50%) and discriminated between acute and chronic infections. In animals, the most commonly used reference techniques were in-house tests, which almost exclusively detected IgG. Common limitations identified in a large number of studies were some misunderstandings of the terms "gold standard" and "reference test" and the absence of information about the negative and positive control sera used or the exact cutoff employed, which were independent of the quality of the study. There is a lack of analytical validation, with few evaluations of cross-reactivity with other pathogens. Diagnostic odds ratio values showed that indirect ELISA based on native or chimeric antigens performed better than other tests. The reproducibility of serological test results in both humans and animals is not guaranteed due to a lack of relevant information and analytical validation. Thus, several key issues should be considered in the future, including interlaboratory ring trials.

Background: Emerging viral diseases are spreading to new geographic locations, influenced by human activities and climate change. Morbillivirus canis (also known as canine distemper virus, CDV), the etiological agent of CD, is distributed worldwide and shared between wild and domestic animals. Methods: A systematic review using MeSH terms was carried out from 1985 to 2024, focusing the search on studies (PubMed and WOS) that would detect CDV and sequence it in a known genotype in Carnivora hosts. Articles were reviewed by four researchers, and after quality assessment, we selected 160 published papers for data extraction, analysis, and spatial meta‐analysis. Considering species studied, geographical location, and classified genotypes we identify 457 different individual studies (records) from which 332 records CDV was sequenced into a classifiable 17 main genotypes. Spatial meta‐analysis was performed using QGIS, revealing distributions of animals in which a CDV lineage has been isolated; geographical lineages overlapping on different hosts have been measured as a density function. Results: CDV host species belonged to the suborder Caniformia (93.7%) into families such as Canidae (75.2%), Mustelidae (9.7%), and Procyonidae (7.6%). Suborder Feliformia (6.1%) showed wild Felidae (5.1%) as the most represented family. Samples used were brain (13.74%), lung (12.4%), blood (10.8%), and nasal‐eye discharges (8.9%; 8.1%). Reverse transcription‐PCR (RT‐PCR) (60.34%) and real‐time‐quantitative PCR (RT‐qPCR) (26.57%) detecting H gene (62%) were most used to detect viral ARN. On genotypes, Europe/South America‐1 (27.4%), Europe‐3/Artic (15.5%), Asia‐1 (14.5%), America‐1 (11.2%), Europe‐2/European Wildlife and Africa (Africa‐1 and Africa‐2) (7.6%) were the most represented worldwide, being America‐1 and Europe/South America‐1 the most widely distributed around the world. Conclusions: The analysis showed the wide multihost capacity and diversity of CDV, with dog ( Canis lupus familiaris ) as the most frequent (40%) and red fox ( Vulpes vulpes ) (30.2%) as the main wild host. Most of the detected lineages can be detected in several wild host families, in addition to the dog, suggesting constant spillover phenomena in shared habitats at the domestic–wild interface. The most cosmopolitan lineages mirror the distribution routes of their hosts, showing that it is difficult to establish a CDV‐fixed picture in an interconnected world.

The aim of this study was to estimate the seroprevalence and risk factors associated with Toxoplasma gondii exposure in dogs and cats from Bangkok, Thailand. Blood samples from 318 dogs and 321 cats were tested for T. gondii antibodies by modified agglutination test (cut-off 1:25). Additionally, 18 dogs and 20 cats were longitudinally sampled for T. gondii antibodies during the same study period, between June and July 2019. The overall seroprevalence in dogs and cats was 7.9% (25/318; 95% CI 4.9–10.8%) and 18.7% (95% CI 14.4–23.0%), respectively. For dogs, risk factors identified were being a mixed-breed animal and living totally outdoors, while increasing age was shown to be a risk factor for cats. Seroconversion was not detected and titres from positive animals remained constant over longitudinal study. The present study indicates that there is a prominent presence of T. gondii in urban and peri-urban areas of Bangkok, suggesting that outdoor dogs and cats should be considered as a possible risk factor for humans.

Background: Acute and chronic besnoitiosis in extensive natural-service herds can have relevant effects in the health of bulls and negative consequences in their productive performance. Recent progress has been made in order to elucidate the pathogenesis of this disease. In this context, the study of biomarkers of inflammation in serum would contribute to gaining knowledge about the physiopathology of bovine besnoitiosis. Serological biomarkers could help in early diagnosis and prognosis, as seropositive bulls may have mild or severe testicular lesions. Methods: Herein, we have investigated the diagnostic and/or prognostic value of a panel of serum (serological) biomarkers related to inflammation, including total protein, globulin and albumin, haptoglobin (Hp), adenosine deaminase (ADA) paraoxonase-1 (PON-1) and acetylcholinesterase (AChE) in naturally and experimentally B. besnoiti-infected males classified according to different clinical phases of the disease (acute, chronic and subclinical besnoitiosis). Results: Results showed a similar response pattern in these biomarkers for naturally and experimentally infected cattle, with a few relevant variations. Most significant changes occurred during the acute phase of infection, although significant changes in a few biomarkers were also observed during the chronic infection. Haptoglobin, albumin, PON-1 and ADA were identified as the biomarkers that showed changes of higher magnitude in the acute phase of the infection, whereas high total protein and globulin values were found in chronically infected cattle. We have described the changes of a panel of inflammatory biomarkers of acute and chronic bovine besnoitiosis. Conclusions: In summary, several biomarkers with promising diagnostic value have been identified. The biomarkers associated with acute infection are related to previously reported molecular biomarkers in testicular parenchyma of infected bulls and could help in the diagnosis of early infections and complement results from specific immunoglobulin M (IgM) detection. Graphical

Canine morbillivirus (CDV), the cause of canine distemper, is a pathogen affecting many hosts. While modified live virus (MLV) vaccines are crucial for controlling the disease in dogs, cases of vaccine-related infections have been found in both domestic and wild animals. Specifically, the America-1 and Rockborn-like vaccine genotypes are concerning due to their spread and ability to transmit between different species. This study conducted a review and analysis of molecular detections of these strains in various carnivores (domestic, captive, synanthropic, and wild species). This study used a conceptual model considering host ecology and the domestic–wild interface to evaluate plausible transmission connections over time using Linear Directional Mean (LDM) and Weighted Mean Centre (WMC) methods. Statistical analyses examined the relationship between how likely a strain is to spread and factors like host type and vaccination status. The findings showed that the America-1 genotype spread in a more organised way, with domestic dogs being the main source and recipient, bridging different environments. Synanthropic mesocarnivores also played this same role, with less intensity. America-1 was most concentrated in the North Atlantic and Western Europe. In contrast, the Rockborn-like strain showed a more unpredictable and restricted spread, residual circulation from past use rather than ongoing spread. Species involved in vaccine-related infections often share characteristics like generalist behaviour, social living, and a preference for areas where domestic animals and wildlife interact. We did not find a general link between a host vaccination status and the likelihood of the strain spreading. The study emphasised the ongoing risk of vaccine-derived strains moving from domestic and synanthropic animals to vulnerable wild species, supporting the need for improved vaccination approaches. Mapping these plausible transmission routes can serve as a basis for targeted surveillance, not only of vaccine-derived strains, but of any other circulating genotype.

Sewer-associated rodents inhabiting urban and peri-urban areas constitute a potential infection source for many zoonotic pathogens at a global scale. However, there is a lack of scientific information about the implications of these micromammals in regions with fragile sanitary services, low economic resources and weak educational systems. Consequently, this study aimed to review the scientific knowledge about rodent-borne zoonoses in sewer-related environments from countries with lower Human Development Index (HDI). Our results revealed a low number of publications (n = 13) evaluating the epidemiology of sewer-associated rodents in countries with lower HDI, which were distributed across Central/South America (69.2 %; 9/13), Africa (23.1 %; 3/13) and Asia (7.7 %; 1/13). The most evaluated rodents were Rattus norvegicus -brown rat- (present in 10/13 articles), followed by Rattus rattus -black rat- (6/13) and Mus musculus -house mouse- (5/13). Fourteen zoonotic pathogens were assessed, specifically bacteria (n = 6 publications) and parasites (n = 7), with the highest prevalence described for Bartonella spp. (85.0 %), Calodium hepaticum (83.8 %), Rickettsia spp. (75.0 %), Leptospira spp. (68.0 %) and Hymenolepis nana (60.0 %). Most reviewed publications described the use of molecular methods and direct examination of samples to identify the pathogens studied (46.2 %; 6/13 each), followed by the MALDI-TOF technique (15.4 %; 2/13). The four clusters building the semantic network reinforced the pivotal role of sewer-associated rodents as reservoirs of both vector-borne pathogens and directly transmitted zoonoses. Our findings evidence a severe gap of knowledge in lower-resource areas about the role of sewer-associated rodents in the epidemiology of zoonotic diseases, which could impact on the sanitary system of not only the evaluated countries, but also in other developed and non-developed regions worldwide.