Atypical porcine pestivirus (APPV) belongs to the genus Pestivirus within the family Flaviviridae. Recently, APPV has been identified as the causative agent of congenital tremor (CT) type AII. The disease is a neurological disorder that affects newborn piglets and is characterized by mostly generalized trembling of the animals and often splay legs. CT is well known worldwide, and the virus seems to be highly prevalent in major swine producing areas. However, little is known about the epidemiology of the infection, the transmission and spread of the virus between herds. Here, we show the high prevalence of APPV in processing fluid samples collected from Hungarian pig herds which led us to investigate the cellular targets of the virus in the testicles of newborn piglets affected by CT. By the development of an RNA in situ hybridization assay and the use of immunohistochemistry on consecutive slides, we identified the target cells of APPV in the testicle: interstitial Leydig cells, peritubular myoid cells and endothelial cells of medium-sized arteries. Previous studies have shown that APPV can be found in the semen of sexually mature boars suggesting the role of infected boars and their semen in the transmission of the virus similar to many other members of the Flaviviridae family. As in our case, the virus has not been identified in cells beyond the blood-testis barrier, further studies on infected adult boars’ testicles are needed to analyze the possible changes in the cell tropism that enable the virus to be excreted by the semen.
The SARS-CoV-2 virus was detected for the first time in December 2019 in Wuhan, China. Currently, this virus has spread around the world, and new variants have emerged. This new pandemic virus provoked the rapid development of diagnostic tools, therapies and vaccines to control this new disease called COVID-19. Antibody detection by ELISA has been broadly used to recognize the number of persons infected with this virus or to evaluate the response of vaccinated individuals. As the pandemic spread, new questions arose, such as the prevalence of antibodies after natural infection and the response induced by the different vaccines. In Mexico, as in other countries, mRNA and viral-vectored vaccines have been widely used among the population. In this work, we developed an indirect ELISA test to evaluate S1 antibodies in convalescent and vaccinated individuals. By using this test, we showed that IgG antibodies against the S1 protein of SARS-CoV-2 were detected up to 42 weeks after the onset of the symptoms, in contrast to IgA and IgM, which decreased 14 weeks after the onset of symptoms. The evaluation of the antibody response in individuals vaccinated with Pfizer-BioNTech and CanSinoBio vaccines showed no differences two weeks after vaccination. However, after completing the two doses of Pfizer-BioNTech and the one dose of CanSinoBio, a significantly higher response of IgG antibodies was observed in persons vaccinated with Pfizer-BioNTech than in those vaccinated with CanSinoBio. In conclusion, these results confirm that after natural infection with SARS-CoV-2, it is possible to detect antibodies for up to ten months. Additionally, our results showed that one dose of the CanSinoBio vaccine induces a lower response of IgG antibodies than that induced by the complete scheme of the Pfizer-BioNTech vaccine.
The recent COVID-19 pandemic has demonstrated again the global threat posed by emerging zoonotic coronaviruses. During the past two decades alone, humans have experienced the emergence of several coronaviruses, such as SARS-CoV in 2003, MERS-CoV in 2012, and SARS-CoV-2 in 2019. To date, MERS-CoV has been detected in 27 countries, with a case fatality ratio of approximately 34.5 %. Similar to other coronaviruses, MERS-CoV presumably originated from bats; however, the main reservoir and primary source of human infections are dromedary camels. Other species within the Camelidae family, such as Bactrian camels, alpacas, and llamas, seem to be susceptible to the infection as well, although to a lesser extent. In contrast, susceptibility studies on sheep, goats, cattle, pigs, chickens, and horses obtained divergent results. In the present study, we tested nasal swabs and/or sera from 55 sheep, 45 goats, and 52 cattle, collected at the largest livestock market in the United Arab Emirates, where dromedaries are also traded, for the presence of MERS-CoV nucleic acid by RT-qPCR, and for specific antibodies by immunofluorescence assay (IFA). All sera were negative for MERS-CoV-reactive antibodies, but the nasal swab of one sheep (1.8 %) was positive for MERS-CoV nucleic acid. Next generation sequencing (NGS) of the complete N gene of the sheep-derived MERS-CoV revealed >99 % nucleotide identity to MERS-CoV sequences of five dromedaries in nearby pens and to three reference sequences. The NGS sequence of the sheep-derived MERS-CoV was confirmed by conventional RT-PCR of a part of the N gene and subsequent Sanger sequencing. All MERS-CoV sequences clustered within clade B, lineage 5. In conclusion, our study shows that non-camelid livestock, such as sheep, goats, and cattle do not play a major role in MERS-CoV epidemiology. The one sheep that tested positive most likely reflects an accidental viral spillover event from infected dromedaries in nearby pens.
Worldwide, Mycoplasma gallisepticum (MG) and M. synoviae (MS) are the main agents responsible for chronic respiratory disease in poultry. Therefore, we conducted a systematic review and meta-analysis to estimate their occurrence. We searched electronic databases to find peer-reviewed publications reporting the molecular detection of MG and MS in poultry and used meta-analysis to estimate their pooled occurrence (combined flock and individual), aggregating results at the regional and national levels. We performed a subgroup meta-analysis for subpopulations (broilers, layers, breeders, and diverse poultry including turkeys, ducks, and ostriches) and used meta-regression with categorical modifiers. We retrieved 2,294 publications from six electronic databases and included 85 publications from 33 countries that reported 62 studies with 22,162 samples for MG and 48 studies with 26,413 samples for MS. The pooled occurrence was 38.4% (95% CI: 23.5-54.5) for MS and 27.0% (20.4-34.2) for MG. Among regions, Europe and Central Asia had the lowest occurrence for both pathogens, while MG and MS were highly prevalent in South Asia and sub-Saharan Africa, respectively. MG occurrence was higher in Algeria, Saudi Arabia, and Sudan, whereas China, Egypt, and Ethiopia reported a higher occurrence of MS. MS and MG were more prevalent in the breeders and layers (62.6% and 31.2%, respectively) than in diverse poultry. The year of publication, the sample size, and the level of ambient air pollution (measured indirectly by PM2.5) were associated with the occurrence of both mycoplasmas. Our study revealed a high and heterogeneous occurrence of MG and MS and justifies the need for an early detection and improved control measures to reduce the spread of these pathogens.
The current pandemic caused by a novel coronavirus named as SARS-CoV2 has underlined the importance of emerging diseases of zoonotic importance. Along with human beings, several species of wild and pet animals have been demonstrated to be infected by SARS-CoV2, both naturally and experimentally. Additionally, with constant emergence of new variants, the species susceptibility might further change, warranting intensification of screening efforts. India is a vast and second most populated country, with a habitat of a very diverse range of animal species. In this study we are reporting infection of SARS-CoV2 in captive Asiatic lions. Detailed characterization revealed involvement of delta mutant (Pango lineage B.1.617.2) of SARS-CoV2 at two different locations. Interestingly, no other feline species enclosed in the zoo/park was found infected. The epidemiological and molecular analysis in this study will contribute to the understanding of SARS-CoV2 emerging mutants in wild and domesticated animals.
The exact origin of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) and source of introduction into humans has not been established yet, though it might be originated from animals. Therefore, we conducted a literature review to understand the putative reservoirs, transmission dynamics, and susceptibility patterns of SARS-CoV-2 in animals. Rhinolophu s bats are presumed to be natural progenitors of SARS-CoV-2 related viruses. Initially pangolin was thought to be the source of spillover to human, but they might get infected from human or other animal species. So, the virus spillover pathways to humans remain unknown. Human-to-animal transmission has been testified in pet, farmed, zoo and free-ranging wild animals. Infected animals can transmit the virus to other animals in natural settings like, mink-to-mink, and mink-to-cat transmission. Animal-to-human transmission is not a persistent pathway, while mink-to-human transmission continues to be illuminated. Multiple companion and captive wild animals were infected by emerging alpha variant of concern (B.1.1.7 lineage) whereas Asiatic lions were infected by delta variant, (B.1.617.2). To date, multiple animal species- cat, ferrets, non-human primates, hamsters, and bats, showed high susceptibility to SARS-CoV-2 in experimental condition, while swine, poultry, cattle showed no susceptibility. The founding of SARS-CoV-2 in wild animal reservoirs can confronts the control of the virus in humans and might carry a risk to the welfare and conservation of wildlife as well. We suggest vaccinating pet, and captive animals to stop spillover and spillback events. We recommend sustainable one health surveillance at animal-human-environmental interface to detect and prevent future epidemics and pandemics by Disease X.
The importance of social and spatial structuring of wildlife populations for disease spread, though widely recognized, is still poorly understood in many host-pathogen systems. In particular, system specific kin relationships among hosts can create contact heterogeneities and differential disease transmission rates. Here, we investigate how distance-dependent infection risk is influenced by genetic relatedness in a novel wild boar ( Sus scrofa) - African swine fever (ASF) system. We hypothesized that the infection risk would correlate positively with proximity and relatedness to ASF-infected individuals but expected those relationships to weaken with distance between individuals due to decay in contact rates and genetic similarity. ASF infection risk was shaped by the number of infected animals throughout the zone of potential contact (0-10 km) but not beyond it. This effect was the strongest at close distances (0-2 km) and weakened further on (2-10 km), consistent with decreasing probability of contact. Overall, there was a positive association between genetic relatedness to infectees and infection risk within the contact zone but this effect varied in space. In the high-contact zone (0-2 km), infection risk was not influenced by relatedness when controlled for the number of ASF-positive animals. However, infections were more frequent among close relatives indicating that familial relationships could have played a role in ASF transmission. In the medium-contact zone (2-5 km), infection risk and frequency of paired infections were associated with relatedness. Relatedness did not predict infection risk in low- and no-contact zones (5-10 and >10 km, respectively). Together, our results indicate that the number of nearby infected individuals overrides the effect of relatedness in shaping ASF transmission rates which nevertheless can be higher among close relatives. Highly localized transmission highlights the possibility to control the disease if containment measures are employed quickly and efficiently.
Classical swine fever (CSF) is caused by classical swine fever virus (CSFV) and has led to huge ecnomic losses for the pig industry worldwide. Although vaccination and other control measures have been carried out, it is essential to establish a rapid and valid method for CSF vaccination monitoring and clinical diagnosis. CSFV E2 protein has been well-known as a major antigen for antibody detection. It is significant to improve affinity between E2 protein and CSFV antibody for a better performance of detection method. In this study, a recombinant E2 extracellular protein (aa 1-331), which has a native homodimer conformation and has a high affinity with anti-CSFV-E2 monoclonal antibody WH303, was expressed using Bac-to-Bac baculovirus expression system. A novel immunochromatographic test strip based on the recombinant CSFV E2 protein was developed for CSFV antibody detection. The sensitivity of this strip for detecting CSFV standard positive serum was 1:102400, 4 times higher than that of the previously developed CnC2 test strip. No cross reaction with antibodies of other swine viruses was observed. The detection of clinical swine serum samples (n=138) demonstrated that the agreements of this E2 test strip with three commercial ELISA kits were 88.40% (122/138), 86.23% (119/138), and 96.38% (133/138), respectively. Our data indicated that a novel E2 test strip with higher sensitivity has been developed and can be applied for clinical sample detections, providing a new powerful and simple approach for CSFV antibody monitoring.
Leptospirosis is a zoonotic neglected disease of worldwide public health concern. Leptospira species can infect a wide range of wild and domestic mammals and can lead to a spectrum of disease, including severe and fatal forms. Herein, we report for the first time a fatal Leptospira interrogans infection in a free-ranging nonhuman primate (NHP), a black-tufted marmoset. Icterus, pulmonary hemorrhage, interstitial nephritis and hepatocellular dissociation were the main findings raising the suspicion of leptospirosis. Diagnostic confirmation was based on specific immunohistochemical and PCR assays for Leptospira species. Immunolocalization of leptospiral antigens and identification of pathogenic species ( L. interrogans species) were important for better understanding the pathogenesis of disease. One Health related implications of free-ranging NHPs in anthropized areas and transmission dynamics of human and animal leptospirosis are discussed.
Mongolia and Eastern Siberia, Russia are border regions in Asia with high incidence of tuberculosis (TB). In this study, we aimed to investigate MDR -TB transborder transmission with a focus on endemic and epidemic Mycobacterium tuberculosis clones and drug resistance patterns. M. tuberculosis strains (291 from Mongolia and 754 from Russia) were collected within cross-sectional population-based surveys in 2010-2016. DNA was genotyped in 24 MIRU-VNTR loci and by PCR testing of the key SNP markers to discriminate within Beijing genotype. In total, 1045 isolates were divided into 435 MIRU-types that were assigned to Lineage 2 (Beijing isolates) and Lineage 4 (Ural, Haarlem, Latin-American-Mediterranean [LAM], S, and unclassified isolates). Beijing genotype was dominant in both countries, but most of Russian and all Mongolian Beijing strains belonged to different subtypes of the modern Beijing sublineage with only negligible overlap between the two countries. In particular, the Beijing types #342-32, #3819-32, #1773-32 (Asian African 2 group) were found only in Mongolia. LAM was the most common non-Beijing genotype (11.0% in Mongolia and 14.7% in Russia) and its isolates mostly belonged to LAM-RUS branch. MDR rate was higher in Russia compared to Mongolia among newly diagnosed patients: 29.4% versus 4.2% (p < 0.001) but similar and high in the retreatment subgroups (65.8% and 67.4%, respectively). In Russian collection, a higher MDR rate was observed in (i) Beijing compared to non-Beijing (47.5% versus 38.8%, p = 0.03), (ii) Beijing B0/W148 subtype compared to Beijing Central Asian/Russian subtype (64.5% versus 39.3%, p <0.001). In Mongolia, MDR rate was similar in Beijing (29.7%) and non-Beijing (27.5%) genotypes. In conclusion, population structures of the Beijing genotype in Mongolia and Russian borderline regions differ significantly including specific patterns of drug resistance. In contrast, largely overlapping LAM subtypes may correlate with historical endemic circulation of the LAM-RUS branch in Northern Eurasia.
H6H6 subtype avian influenza virus (AIV) is currently prevalent in wild birds and poultry. Its host range has gradually expanded to the mammals, such as swine. Some strains of H6N6 AIV have even acquired the ability to bind to human-like receptors SA-α2, 6Gal, thus increasing the risk of animal-human transmission. To investigate whether H6N6 AIV can cross interspecies barriers from poultry to mammals and even humans, we assessed the molecular characteristics, receptor-binding preference, replication in mice, and the human lung of three chicken-originated H6N6 strains. Among the three chicken-originated H6N6 strains, A/CK/ZZ/346/2014 (ZZ346) virus with P186T, H156R, S263G mutation of hemagglutinin (HA) showed the ability to bind to avian-like SAα-2,3Gal and human-like SAα-2,6Gal receptors. Moreover, H6N6 viruses, especially the ZZ346 strain, could replicate and infect mice and human lungs. Our study detected the H6N6 virus favorable to bind to both avian-like SAα-2,3Gal and human-like SAα-2,6Gal receptors, verified its ability to cross the species barrier to infect mice, and verified to infect human lungs without prior adaptation. This study emphasizes the importance of continuous and intense monitoring of the evolution of the H6N6 virus in the terrestrial bird.
Rabbit Haemorrhagic Disease (RHD) is a significant viral disease affecting lagomorphs. The first documented cases of RHD in Singapore occurred in adult pet European rabbits in September 2020. Singapore subsequently declared the outbreak resolved in December 2020. Epidemiological investigations ruled out introductions via importation of infected rabbits and contaminated feed. The source could not be definitively determined. However, the findings suggest that the incident involved both inter- and intra-household transmission and veterinary clinic-household transmission. This incident demonstrated the importance of sustained application of biosecurity measures, epidemiological investigations, and control, including active case finding, expedient vaccine dissemination, and risk communications. It shows that Singapore, an urbanised city-state, without a significant lagomorph population, could still encounter emerging diseases such as rabbit haemorrhagic disease. Given its social impact on rabbit owners, the National Parks Board Singapore and the private veterinarians worked together to communicate and urge the adoption of biosecurity measures and assuage the concerns of rabbit owners.
Bacteriophage is considered an alternative to antibiotics and environmentally friendly approach to tackle antimicrobial resistance (AMR) in aquaculture. Here, we reported isolation, morphology and genomic characterizations of a newly isolated lytic bacteriophage, designated pAh6.2TG. Host range and stability of pAh6.2TG in different environmental conditions, and protective efficacy against a pathogenic multidrug-resistant (MDR) Aeromonas hydrophila in Nile tilapia were subsequently evaluated. The results showed that pAh6.2TG is a member of the family Myoviridae which has genome size of 51,780 bp, encoding 65 putative open reading frames (ORFs), and is most closely related to Aeromonas phage PVN02 (99.33% nucleotide identity). The pAh6.2TG was highly specific to A. hydrophila and infected 83.3% tested strains of MDR A. hydrophila (10 out of 12) with relative stability at pH 7 9, temperature 0 40 °C and salinity 0 40 ppt. In experimental challenge, pAh6.2TG treatments significantly improved survivability of Nile tilapia exposed to a lethal dose of the pathogenic MDR A. hydrophila, with relative percent survival (RPS) of 73.3% and 50% for phage multiplicity of infection (MOI) 1.0 and 0.1, respectively. Significant reduction of bacterial counts in rearing water at 3 h (6.7 ± 0.5 to 18.1 ± 6.98 folds) and in fish liver at 48 h post-treatment (2.7 ± 0.24 to 34.08 ± 26.4 folds) was observed in phage treatment groups while opposite pattern for bacterial counts was observed in untreated control. Interestingly, the surviving fish provoked specific antibody (IgM) against the challenged A. hydrophila. These results might explain the higher survival in phage treatment groups. In summary, the findings suggested that the lytic bacteriophage pAh6.2TG is an effective alternative to antibiotics to control MDR A. hydrophila in tilapia and possibly other freshwater fish.
Introduction: The Coronavirus Disease 2019 (COVID-19) pandemic has had a variable worldwide impact, likely related to country-level characteristics. In this ecological study, we explored the association of COVID-19 case rates (per 100,000 people) and death rates (per 100,000 people) with country-level population health characteristics, economic and human development indicators, and habitat-related variables. Methods: To calculate country-level COVID-19 case and death rates, the number of cases and deaths were extracted from the Johns Hopkins Coronavirus Resource Center for 2020. Country-level population health characteristics, economic and human development indicators, and habitat-related variables were extracted from several publicly available online sources of international organizations. Results were tabulated according to world zones and country economies. Univariate and multivariable linear regression analyses were performed to examine determinants of COVID-19 case rates and death rates. Results: A total of 187 countries and territories were analyzed, with an aggregate COVID-19 case rate of 779 per 100,000 people, a death rate of 19 per 100,000 people, and a case-fatality rate of 2.4%. For country-level population health characteristics, a higher percentage rate of adults with obesity and a higher percentage rate of adults with high blood pressure was independently associated with a higher COVID-19 case rate, and a higher percentage rate of adults with obesity was associated with a higher COVID-19 death rate. For country-level economic and human development indicators, only a higher gross domestic product percentage rate spent on total health expenditure and a higher human development index was independently associated with a higher COVID-19 case rate and death rate. A higher percentage of urban population was independently associated with a higher COVID-19 death rate, whereas a higher income per capita was independently associated with a lower COVID-19 death rate. For country-level habitat-related variables, a higher average household size and a higher percentage rate of population with primary reliance on polluting fuels and technologies was independently associated with a lower COVID-19 case rate and death rate whereas a higher percentage rate of households with at least one-member age 65 years or over was associated with a higher case rate and death rates. Conclusion: This ecological study informs the need to develop country-specific public health interventions to better target populations at high risk for COVID-19, and test environmental interventions to prevent indoor transmission of SARS-CoV-2, taking into consideration population health characteristics, economic and human development indicators, and habitat-related variables that are unique to each country.
Foot-and-mouth disease (FMD) is endemic in India, where circulation of serotypes O, A and Asia 1 is frequent. In the past two decades, many of the most widespread and significant FMD lineages globally have emerged from the South Asia region. Here, we provide an epidemiological assessment of the ongoing mass vaccination programs in regard to post-vaccination monitoring and outbreak occurrence. The objective of this study was to quantify the spatiotemporal dynamics of FMD outbreaks and to assess the impact of the mass vaccination program between 2008 to 2016 with available antibody titer data from the vaccination monitoring program, alongside other risk factors that facilitate FMD spread in the country. We first conducted a descriptive analysis of epidemiological outcomes of governmental vaccination programs in India, focusing on antibody titer data from >1 million animals sampled as part of pre- and post-vaccination monitoring and estimates of standardized incidence ratios calculated from reported outbreaks per state/administrative unit. The percent of animals with inferred immunological protection (based on ELISA) was highly variable across states, but there was a general increase in the overall percent of animals with inferred protection through time. In addition, the number of outbreaks in a state was negatively correlated with the percent of animals with inferred protection. Because standardized incidence ratios of outbreaks were heterogeneously distributed over the course of eight years, we analyzed the distribution of reported FMD outbreaks using a Bayesian space-time model to map high-risk areas. This model demonstrated a ~50% reduction in the relative risk of outbreaks in states that were part of the vaccination program. In addition, states that did not have an international border experienced reduced risk of FMD outbreaks. These findings help inform risk-based control strategies for India as the country progresses towards reducing reported clinical disease.
Marek’s disease (MD) is a re-emerging viral disease of chicken and a serious economic threat to poultry industry worldwide. Continuous surveillance with molecular investigation is mandatory to monitor the emergence of virulent MDV strains and to devise any appropriate vaccination strategy and implement bio-security programs. In the present study, we investigated the cases of MD outbreaks in vaccinated poultry flocks. The MD outbreak was confirmed through necropsy (majorily visceral tumors), histopathology and viral gene specific PCR. The pathotypes of the field MDV strains were assessed by molecular analysis of three oncogenes -Meq, pp38 and vIL-8. The Meq sequence of the field strains analyzed in this study lacked the 59 aa unique to mild strains indicating that they are virulent strains. Mutation at position 71 and presence of five proline rich repeats in the transactivation domain, both associated with virulence were observed in these strains, however, the signature sequences specific to very virulent plus strains were absent. Phylogenetic analysis of Meq gene sequences revealed clustering of the field strains with North Indian strains and with a very virulent plus ATE 2539 strain from Hungary. Analyses of pp38 protein at positions 107 and 109 and vIL-8 protein at positions 4 and 31 showed signatures of virulence. Sequence and phylogenetic analysis of oncogenes from field MDVs from vaccinated flock indicated these strains possessing molecular features of very virulent strains. Our data shows here that Meq, vIL-8 and pp38 genes can be used as markers for molecular analysis to decipher the pathotype of MDV strains. Our present study suggests evolution of virulent MDV induced by vaccination.
We report a COVID-19 case with unprecedented viral complexity. In the first severe episode, two different SARS-CoV-2 strains (superinfection) were identified within a week. Three months after discharge, patient was readmitted and was infected in a nosocomial outbreak with a different strain, suffering a second milder COVID-19 episode.
An understanding of how infected-susceptible populations interact is critical to identify underlying causal factors and disease transmission patterns of infectious diseases. Disease transmission patterns are dynamic, non-linear, and spatially complex. This anisotropic characteristic of disease spread necessitates the ideal solution to be sensitive to the geographic context. A Spatial Diffusion Model (SDM) to predict interaction potential and COVID-19 risk probability is developed by adapting the Newtonian gravity model. This novel approach overcomes the limitations of existing epidemiological studies by characterizing the behavioral patterns of the infected population to model the spatiotemporal transmission of disease across the geographic space. The proposed model is robust as it couples a multicriteria behavioral pattern to enhance predictive capability. The model shows an 83.74% correlation with the observational COVID-19 case data. The highest risk patterns for COVID-19 are predicted in the neighborhoods of New York City (NYC), exhibiting clustered socioeconomic disparities along with racial and ethnic heterogeneity. Policymakers can use these results to identify neighborhoods at high risk for becoming hot spots; efficiently match community resources with needs, and ensure that the most vulnerable have access to equipment, personnel, and medical interventions. This study emphasizes the need for improved spatial epidemiological models including enhanced depictions of human activity patterns and the need to integrate spatial data with advanced mathematical models.