Human Disease Outbreaks Research Articles

Evaluation of Vaccines and Therapeutics Against Ebolaviruses in the Domestic Ferret.

Filoviruses, including Ebola and Marburg viruses, have caused periodic outbreaks of severe hemorrhagic disease in humans and nonhuman primates (NHP), resulting in major public health emergencies primarily in endemic areas. Filovirus disease has also been exported to developed nations, where it has been equally disruptive. There are four ebolaviruses (Ebola virus, Sudan virus, Bundibugyo virus, and Taï Forest virus) and two marburgviruses [Marburg virus (MARV) and Ravn virus] known to cause disease in humans, yet vaccines and therapeutics have only been approved for Ebola virus. NHPs have long served as the "gold standard" for medical countermeasure (MCM) evaluation and will most likely be required for regulatory approval for use in humans. However, screening and refinement of MCM dosing regimens are more efficiently and ethically performed in lower-order species such as rodents. However, mouse, hamster, and guinea pig models of filovirus infection require virus adaptation to cause disease in these animal models. Nonadapted filovirus strains can be used in immune-compromised rodent systems (genetic knockouts or humanized mice), but the immune defect must be accounted for when interpreting MCM efficacy. Recently, several groups have described the use of the domestic ferret (Mustela putorius furo) as a model for several ebolaviruses using wild-type (nonadapted) virus, with disease largely reflecting what has been observed in humans and NHPs. Interestingly, no disease has been observed in ferrets challenged with MARV. Here, we describe the use of the domestic ferret for vaccine and therapeutic evaluation against ebolaviruses.

Isolation and Propagation of Marburgviruses.

Marburgviruses (Marburg virus and Ravn virus) have caused ~20 outbreaks of human Marburg virus disease since their discovery in 1967. These zoonotic viruses are categorized as priority pathogens with no licensed vaccines or treatment options. The foundation for all experimental work including deciphering disease parameters and countermeasure development is a defined virus stock. This chapter provides a guide for the isolation and growth of marburgviruses in tissue culture.

In vitro and in vivo characterization of a novel West Nile virus lineage 2 strain

Over recent decades, West Nile virus (WNV) has continued to expand its geographical range, emerging in previously non-endemic areas, including northern Europe. In Europe, WNV lineage 2 strains are most prevalent and cause sporadic outbreaks of WNV disease in humans each transmission season. Here, we assessed the virulence of a newly emerged WNV lineage 2 strain that was isolated in the Netherlands in 2020 (WNV-NL20) and caused several cases of West Nile disease in humans and used a WNV lineage 2 strain related to major outbreaks of neuroinvasive disease in humans in central and south-eastern Europe in 2010 (WNV-578/10) as a reference. Infection of primary human cells of the blood-brain barrier in vitro did not show major differences in replication kinetics between WNV-578/10 and WNV-NL20. Experimental infection of mice showed that both WNV strains induced significant weight loss, neurological signs, and lethal disease. Neurological involvement was confirmed for both WNV strains by the presence of infectious virus and viral antigen in the brain. In conclusion, we show that the recent WNV-NL20 strain that emerged in the Netherlands is neurovirulent in mice. The use of in vitro and in vivo models to characterize the pathogenesis of emerging WNV strains may aid in predicting the neurovirulence of WNV infections in humans during potential future outbreaks.

WNV and SLEV coinfection in avian and mosquito hosts: impact on viremia, antibody responses, and vector competence.

West Nile virus (WNV) and St. Louis encephalitis virus (SLEV) are closely related flaviviruses that can cause encephalitis in humans and related diseases in animals. In nature, both are transmitted by Culex, with wild birds, including jays, sparrows, and robins, serving as vertebrate hosts. WNV and SLEV circulate in the same environments and have recently caused concurrent disease outbreaks in humans. The extent that coinfection of mosquitoes or birds may alter transmission dynamics, however, is not well characterized. We therefore sought to determine if coinfection alters infection kinetics and virus levels in birds and infection rates in mosquitoes. Accordingly, American robins (Turdus migratorius), two species of mosquitoes, and vertebrate and invertebrate cells were infected with WNV and/or SLEV to assess how simultaneous exposure may alter infection outcomes. There was variable impact of coinfection in vertebrate cells, with some evidence that SLEV can suppress WNV replication. However, robins had comparable viremia and antibody responses regardless of coinfection. Conversely, in Culex cells and mosquitoes, we saw a minimal impact of simultaneous exposure to both viruses on replication, with comparable infection, dissemination, and transmission rates in singly infected and coinfected mosquitoes. Importantly, while WNV and SLEV levels in coinfected mosquito midguts were positively correlated, we saw no correlation between them in salivary glands and saliva. These results reveal that while coinfection can occur in both avian and mosquito hosts, the viruses minimally impact one another. The potential for coinfection to alter virus population structure or the likelihood of rare genotypes emerging remains unknown.IMPORTANCEWest Nile virus (WNV) and St. Louis encephalitis virus (SLEV) are closely related viruses that are transmitted by the same mosquitoes and infect the same birds in nature. Both viruses circulate in the same regions and have caused concurrent outbreaks in humans. It is possible that mosquitoes, birds, and/or humans could be infected with both WNV and SLEV simultaneously, as has been observed with Zika, chikungunya, and dengue viruses. To study the impact of coinfection, we experimentally infected vertebrate and invertebrate cells, American robins, and two Culex species with WNV and/or SLEV. Robins were efficiently coinfected, with no impact of coinfection on virus levels or immune response. Similarly, in mosquitoes, coinfection did not impact infection rates, and mosquitoes could transmit both WNV and SLEV together. These results reveal that WNV and SLEV coinfection in birds and mosquitoes can occur in nature, which may impact public health and human disease risk.

Extended-spectrum ß-lactamase (ESBL)- and Carbapenemase-producing Enterobacterales Isolated from Fresh Herbs and Salads at Retail Level in Switzerland

Fresh produce is usually consumed raw or minimally processed, making it a potential vehicle for the transmission of antimicrobial-resistant (AMR) microorganisms to humans. The objective of the study was to assess the occurrence of extended-spectrum ß-lactamase (ESBL)- and carbapenemase-producing Enterobacterales (ESBL-E and CPE), respectively, in 118 fresh herbs and 101 bagged salads collected at retail level in Switzerland and to characterize the isolates’ phenotypic and genotypic properties using culture-based methods and whole genome sequencing (WGS).Of the fresh herbs, 6/118 contained ESBL-E and 7/118 yielded CPE. Of the salads, 13/101 contained ESBL-E and 1/101 CPE. Antimicrobial susceptibility testing (AST) identified 9/29 isolates as multidrug-resistant (MDR).ESBL-E were Escherichia coli (n = 6), Klebsiella pneumoniae (n = 4) Enterobacter chuandaensis (n = 1), and Kluyvera spp. (n = 1) carrying ß-lactamase (bla) genes belonging to the cefotaximase-München (blaCTX-M)-groups, Proteus spp. (n = 1) containing Hôpital-Universitaire-de-Genève-bla (blahugA), Raoultella ornithinolytica (n = 1) carrying sulfhydryl reagent variable bla (blaSHV), and Serratia fonticola (n = 7) carrying S. fonticula bla (blaFONA) genes. CPE were Enterobacter asburiae (n = 1) E. cloacae (n = 6) and E. vonholyi (n = 1) carrying imipenemase bla (blaIMI) genes.Several K. pneumoniae sequence types (STs) were identified (ST967, ST628, ST219, and ST1823), which have been linked to human disease and nosocomial outbreaks. They carried blaCTX-M-15 on plasmids detected globally in environmental and clinical samples. E. coli (ST10, ST48, ST609, ST2040, ST6215 and ST3580) and enterotoxigenic E. coli (ETEC) ST2040 carrying blaCTX-M-15 were found. E. cloacae (ST820 and ST1516) with blaIMI-1 have been found previously in clinical settings and community outbreaks.The occurrence and consumption of fresh produce containing MDR ESBL-E and CPE pose substantial public health risks and raise significant food safety concerns.

RNA structures within Venezuelan equine encephalitis virus E1 alter macrophage replication fitness and contribute to viral emergence.

Venezuelan equine encephalitis virus (VEEV) is a mosquito-borne +ssRNA virus belonging to the Togaviridae. VEEV is found throughout Central and South America and is responsible for periodic epidemic/epizootic outbreaks of febrile and encephalitic disease in equines and humans. Endemic/enzootic VEEV is transmitted between Culex mosquitoes and sylvatic rodents, whereas epidemic/epizootic VEEV is transmitted between mosquitoes and equids, which serve as amplification hosts during outbreaks. Epizootic VEEV emergence has been shown to arise from mutation of enzootic VEEV strains. Specifically, epizootic VEEV has been shown to acquire amino acid mutations in the E2 viral glycoprotein that facilitate viral entry and equine amplification. However, the abundance of synonymous mutations which accumulate across the epizootic VEEV genome suggests that other viral determinants such as RNA secondary structure may also play a role in VEEV emergence. In this study we identify novel RNA structures in the E1 gene which specifically alter replication fitness of epizootic VEEV in macrophages but not other cell types. We show that SNPs are conserved within epizootic lineages and that RNA structures are conserved across different lineages. We also identified several novel RNA-binding proteins that are necessary for altered macrophage replication. These results suggest that emergence of VEEV in nature requires multiple mutations across the viral genome, some of which alter cell-type specific replication fitness in an RNA structure-dependent manner.

Vaccine Platform Comparison: Protective Efficacy against Lethal Marburg Virus Challenge in the Hamster Model.

Marburg virus (MARV), a filovirus, was first identified in 1967 in Marburg, Germany, and Belgrade, former Yugoslavia. Since then, MARV has caused sporadic outbreaks of human disease with high case fatality rates in parts of Africa, with the largest outbreak occurring in 2004/05 in Angola. From 2021 to 2023, MARV outbreaks occurred in Guinea, Ghana, New Guinea, and Tanzania, emphasizing the expansion of its endemic area into new geographical regions. There are currently no approved vaccines or therapeutics targeting MARV, but several vaccine candidates have shown promise in preclinical studies. We compared three vaccine platforms simultaneously by vaccinating hamsters with either a single dose of an adenovirus-based (ChAdOx-1 MARV) vaccine, an alphavirus replicon-based RNA (LION-MARV) vaccine, or a recombinant vesicular stomatitis virus-based (VSV-MARV) vaccine, all expressing the MARV glycoprotein as the antigen. Lethal challenge with hamster-adapted MARV 4 weeks after vaccination resulted in uniform protection of the VSV-MARV and LION-MARV groups and 83% of the ChAdOx-1 MARV group. Assessment of the antigen-specific humoral response and its functionality revealed vaccine-platform-dependent differences, particularly in the Fc effector functions.

A chimeric vaccine derived from Australian genotype IV Japanese encephalitis virus protects mice from lethal challenge

In 2022, a genotype IV (GIV) strain of Japanese encephalitis virus (JEV) caused an unprecedented and widespread outbreak of disease in pigs and humans in Australia. As no veterinary vaccines against JEV are approved in Australia and all current approved human and veterinary vaccines are derived from genotype (G) III JEV strains, we used the recently described insect-specific Binjari virus (BinJV) chimeric flavivirus vaccine technology to produce a JEV GIV vaccine candidate. Herein we describe the production of a chimeric virus displaying the structural prM and E proteins of a JEV GIV isolate obtained from a stillborn piglet (JEVNSW/22) in the genomic backbone of BinJV (BinJ/JEVNSW/22-prME). BinJ/JEVNSW/22-prME was shown to be antigenically indistinguishable from the JEVNSW/22 parental virus by KD analysis and a panel of JEV-reactive monoclonal antibodies in ELISA. BinJ/JEVNSW/22-prME replicated efficiently in C6/36 cells, reaching titres of >107 infectious units/mL - an important attribute for vaccine manufacture. As expected, BinJ/JEVNSW/22-prME failed to replicate in a variety of vertebrate cells lines. When used to immunise mice, the vaccine induced a potent virus neutralising response against JEVNSW/22 and to GII and GIII JEV strains. The BinJ/JEVNSW/22-prME vaccine provided complete protection against lethal challenge with JEVNSW/22, whilst also providing partial protection against viraemia and disease for the related Murray Valley encephalitis virus. Our results demonstrate that BinJ/JEVNSW/22-prME is a promising vaccine candidate against JEV.

Exposure to Arboviruses in Cattle: Seroprevalence of Rift Valley Fever, Bluetongue, and Epizootic Hemorrhagic Disease Viruses and Risk Factors in Baringo County, Kenya.

Rift Valley fever virus (RVFV) causes disease outbreaks in livestock and humans; however, its inter-epidemic circulation is poorly understood, similar to other arboviruses affecting cattle such as bluetongue virus (BTV) and epizootic hemorrhagic disease virus (EHDV). Serum samples were collected in Baringo County, Kenya from 400 cattle, accompanied by a risk factor questionnaire. Serological tests were then conducted to determine the exposure of cattle to RVFV, BTV, and EHDV. RVFV, BTV, and EHDV IgG seroprevalence rates were 15.5%, 91.5%, and 91%, respectively. Seropositivity for RVFV, BTV, and EHDV was significantly higher in adult cattle, as well as in females for RVFV. Cattle with herd owners aged between 30-39 years were less likely to be seropositive for RVFV compared to those with owners over the age of 60 years. High seroprevalence of BTV and EHDV in cattle indicates significant exposure and the subclinical circulation of these viruses, presenting a risk of outbreaks to sheep and naïve cattle. Moreover, the detection of RVFV-seropositive young cattle born after the last reported outbreak suggests inter-epidemic circulation of the virus. Overall, monitoring these arboviruses in cattle is crucial in understanding their distribution and seroprevalence during inter-epidemic periods.

AWARENESS ABOUT CLIMATE CHANGE AMONG THE FARMER FRIENDS

Climate change is a burning issue in the global discussions on agriculture as it affects all other sectors of development. Agriculture system responds to changing climate through the process of adaptation. Awareness of farmers about the climate changes, its causes and consequences are the important aspect to deal with changing climatic conditions. Despite availability of adaptation measures like HYVs, mixed cropping, integrated farming, change in irrigation, crop insurance etc., farmers were not adapting them due to lack of knowledge and awareness about climate change. Among the different extension functionaries farmer friends are the key communicator for dissemination of agriculture technologies therefore awareness of them about the climate changes is very important. 300 farmer friends from Dahod District of Gujarat were selected randomly. Majority of the respondents were aware of the major indicators of climate change i.e. irregular rainfall and increase in temperature. In case of awareness about the causes of climate change it was deforestation, use of vehicles, while awareness about the major impact were found as human disease outbreak and livestock disease outbreak. Overall awareness about climate change high to very high. Majority of respondents had a very high level of risk perception in agriculture due to climate change.

Spatial and temporal analysis on the impact of ultra-low volume indoor insecticide spraying on Aedes aegypti household density

BackgroundAedes aegypti is the primary mosquito vector for several arboviruses, such as dengue, chikungunya and Zika viruses, which cause frequent outbreaks of human disease in tropical and subtropical regions. Control of these outbreaks relies on vector control, commonly in the form of insecticide sprays that target adult female mosquitoes. However, the spatial coverage and frequency of sprays needed to optimize effectiveness are unclear. In this study, we characterize the effect of ultra-low-volume (ULV) indoor spraying of pyrethroid insecticides on Ae. aegypti abundance within households. We also evaluate the effects of spray events during recent time periods or in neighboring households. Improved understanding of the duration and distance of the impact of a spray intervention on Ae. aegypti populations can inform vector control interventions, in addition to modeling efforts that contrast vector control strategies.MethodsThis project analyzes data from two large-scale experiments that involved six cycles of indoor pyrethroid spray applications in 2 years in the Amazonian city of Iquitos, Peru. We developed spatial multi-level models to disentangle the reduction in Ae. aegypti abundance that resulted from (i) recent ULV treatment within households and (ii) ULV treatment of adjacent or nearby households. We compared fits of models across a range of candidate weighting schemes for the spray effect, based on different temporal and spatial decay functions to understand lagged ULV effects.ResultsOur results suggested that the reduction of Ae. aegypti in a household was mainly due to spray events occurring within the same household, with no additional effect of sprays that occurred in neighboring households. Effectiveness of a spray intervention should be measured based on time since the most recent spray event, as we found no cumulative effect of sequential sprays. Based on our model, we estimated the spray effect is reduced by 50% approximately 28 days after the spray event.ConclusionsThe reduction of Ae. aegypti in a household was mainly determined by the number of days since the last spray intervention in that same household, highlighting the importance of spray coverage in high-risk areas with a spray frequency determined by local viral transmission dynamics.Graphical abstract

Forensic Identification and Isolation of Pathogenic Bacteria From Raw Vegetables and Fruits

The consumption of contaminated fruits and vegetables is the prime cause of outbreaks of various human diseases. Although fruits and vegetables have high nutritional value, today because of their contamination during handling while performing harvesting and post-harvesting techniques, they are harmful to human health. Most of them are eaten raw without being washed or without providing any treatment. Vegetables and fruits, being rich nutritional sources, can act as carriers or vectors of pathogenic microorganisms, which can create a serious issue for the health of the community targeted. This entire research is based on an emerging field of Forensic Microbiology. Various types of microbial agents can be utilized as bioweapons to conduct the bio crime or bioterrorism through food and water. This research also represents that the identification of microbial agents is very much necessary for the welfare of humans. Identification and isolation of different pathogenic bacteria from raw vegetables and fruits can also shed some light on the terms of the necessity of Forensic Microbiology.

Characterization of Salmonella species from poultry slaughterhouses in South Korea: carry-over transmission of Salmonella Thompson ST292 in slaughtering process.

Salmonella outbreaks linked to poultry meat have been reported continuously worldwide. Therefore, Salmonella contamination of poultry meats in slaughterhouses is one of the critical control points for reducing disease outbreaks in humans. This study examined the carry-over contamination of Salmonella species through the entire slaughtering process in South Korea. From 2018 to 2019, 1,097 samples were collected from the nine slaughterhouses distributed nationwide. One hundred and seventeen isolates of Salmonella species were identified using the invA gene-specific polymerase chain reaction, as described previously. The serotype, phylogeny, and antimicrobial resistance of isolates were examined. Among the 117 isolates, 93 were serotyped into Salmonella Mbandaka (n = 36 isolates, 30.8%), Salmonella Thompson (n = 33, 28.2%), and Salmonella Infantis (n = 24, 20.5%). Interestingly, allelic profiling showed that all S. Mbandaka isolates belonged to the lineage of the sequence type (ST) 413, whereas all S. Thompson isolates were ST292. Moreover, almost all S. Thompson isolates (97.0%, 32/33 isolates) belonging to ST292 were multidrug-resistant and possessed the major virulence genes whose products are required for full virulence. Both serotypes were distributed widely throughout the slaughtering process. Pulsed-field gel electrophoretic analysis demonstrated that seven S. Infantis showed 100% identities in their phylogenetic relatedness, indicating that they were sequentially transmitted along the slaughtering processes. This study provides more evidence of the carry-over transmission of Salmonella species during the slaughtering processes. ST292 S. Thompson is a potential pathogenic clone of Salmonella species possibly associated with foodborne outbreaks in South Korea.

Strategies for tularemia pathogen survival, spread and virulence

The bacterium Francisella tularensis is the etiological agent of tularemia, a natural focal, especially dangerous infection, which, “thanks to” its low infectious dose and ability to be transmitted to humans via all possible routes, is a potential bioterrorism agent. This pathogen has been known to mankind for over a hundred years, but it is still impossible to prevent massive human disease outbreaks and sporadic incidence cases, whereas tularemia diagnosis may be verified within several days-to-weeks. The basis for tularemia causative agent virulence is based on its ability to disrupt phagocyte function. In animals and humans, the various Francisella tularensis systems work together to bypass host immune system, attach to and enter eukaryotic cells, block phagosome-lysosome fusion, multiply in various host cells without being detected, inhibit their destruction and cause host cell death to release bacteria and infect neighboring tissue cells, thus developing an infectious disease in different organs. This is achieved through a unique complement-dependent penetration process into host cell, called loop phagocytosis, and an unusual inert endotoxin as well as variation in diverse forms of “free” lipid A modifications and lipid A in the LPS composition, its dynamic acyl chain length regulation, and specifically combined regulatory factors to induce the “pathogenicity island” protein synthesis. Accumulated point mutations, intragenomic rearrangements, deletions, insertions, duplications, transpositions, gene degradation, variation in the number of copies in repeated DNA sequences, as well as homologous and non-homologous recombinations underlie a markedly expanded potential for existence of the tularemia causative agent: they contribute to the holarctic subspecies strain survival in varying conditions, including osmotic shock, to form multiple resistance to various toxic substances and alter F. tularensis subspecies virulence. Analyzing a whole body of publications on the abovementioned aspects for tularemia causative agent life activity attempts to combine the differences, structural features and “tricks” of the F. tularensis species cells allowing them to be a powerful pathogen, with a high potential to adapt upon low pathogen variability and a limited genome length compared with other specially dangerous bacteria.

Serological Evidence of Crimean-Congo Haemorrhagic Fever in Livestock in the Omaheke Region of Namibia.

This research examined the positivity ratio of Crimean-Congo haemorrhagic fever (CCHF) antibodies in cattle and sheep within Namibia's Omaheke region after a human disease outbreak in the same geographical area. A total of 200 samples (100 cattle and 100 sheep) were randomly collected from animals brought to two regional auction sites, and then tested using the ID Screen® CCHF Double Antigen Multi-Species Enzyme-Linked Immunosorbent Assay kit. Of the cattle samples, 36% tested positive, while 22% of the sheep samples were seropositive. The cattle had a significantly higher positivity ratio than sheep at the individual animal level (p = 0.0291). At the herd level, 62.5% of cattle herds and 45.5% of sheep flocks had at least one positive animal, but this difference was statistically insignificant (p = 0.2475). The fourteen cattle farms with at least one seropositive animal were dispersed across the Omaheke region. In contrast, the ten sheep farms with seropositive cases were predominantly situated in the southern half of the region. The study concluded that the CCHF is endemic in the Omaheke region and likely in most of Namibia, underscoring the importance of continued surveillance and preventive measures to mitigate the impact of CCHFV on animal health and potential spillover into human populations.

Experimental Infection of Bundibugyo Virus in Domestic Swine Leads to Viral Shedding with Evidence of Intraspecies Transmission

The Ebolavirus genus contains several of the deadliest zoonotic viruses known. One of these, Bundibugyo virus (BDBV), has been the causative agent of two outbreaks of human disease that have resulted in 211 known cases with a case fatality rate of 33.6%. Although bats are routinely implicated as the possible reservoir species for the ebolaviruses, the source of infection for index cases in almost all outbreaks is unknown with only limited epidemiological evidence directly linking human cases to bats. This lack of evidence leaves open the possibility that maintenance of one or more of these viruses could involve multiple host species or more complex spillover dynamics. Domestic pigs have been found naturally infected with Reston virus (RESTV) and are experimentally susceptible to infection with Ebola virus (EBOV), two other members of the Ebolavirus genus. Infection of pigs resulted in shedding of infectious virus with subsequent transmission to naïve animals being documented, including transmission to humans for RESTV and to nonhuman primates for EBOV. The susceptibility and subsequent viral shedding and pathogenesis of domestic pigs to other ebolaviruses and the potential role this species may play in virus ecology, spillover dynamics, and human public health risk is unknown. For these reasons, we conducted a series of studies aimed at determining the susceptibility of domestic pigs to BDBV thereby demonstrating that pigs are not only susceptible to experimental infection but that the development of productive infection, tissue dissemination, and shedding of infectious virus can also occur while animals remain clinically normal. The role of pigs as a possible interim or amplifying host for ebolaviruses is a concern for both human public health and food security.

Discovery and characterization of BRBV-sheep virus in nasal swabs from domestic sheep in China.

The escalating occurrence of infectious disease outbreaks in humans and animals necessitates innovative, effective, and integrated research to better comprehend their transmission and dynamics. Viral infection in livestock has led to profound economic losses globally. Pneumonia is the prevalent cause of death in sheep. However, very few studies exist regarding virus-related pathogens in sheep. Metagenomics sequencing technologies in livestock research hold significant potential to elucidate these contingencies and enhance our understanding. Therefore, this study aims to characterize respiratory viromes in paired nasal swabs from Inner Mongolian feedlot sheep in China using metaviromic sequencing. Through deep sequencing, de novo assembly, and similarity searches using translated protein sequences, several previously uncharacterized and known viruses were identified in this study. Among these discoveries, a novel Bovine Rhinitis B Virus (BRBV) (BRBV-sheep) strain was serendipitously detected in the nasal swabs of domestic sheep (Ovis aries). To facilitate further molecular epidemiological studies, the entire genome of BRBV-sheep was also determined. Owing to the unique sequence characteristics and phylogenetic position of BRBV-sheep, genetically distinct lineages of BRBV in sheep may exist. A TaqMan-based qRT-PCR assay targeting the 3D polymerase gene was developed and used to screen 592 clinical sheep specimens. The results showed that 44.59% of the samples (264/592) were positive. These findings suggest that BRBV sheep are widespread among Inner Mongolian herds. This discovery marks the initial identification of BRBV in sheep within Inner Mongolia, China. These findings contribute to our understanding of the epidemiology and genetic evolution of BRBV. Recognizing the presence of BRBV in sheep informs strategies for disease management and surveillance and the potential development of targeted interventions to control its spread.

Comparison of RT-ddPCR and RT-qPCR platforms for SARS-CoV-2 detection: Implications for future outbreaks of infectious diseases

The increased frequency of human infectious disease outbreaks caused by RNA viruses worldwide in recent years calls for enhanced public health surveillance for better future preparedness. Wastewater-based epidemiology (WBE) is emerging as a valuable epidemiological tool for providing timely population-wide surveillance for disease prevention and response complementary to the current clinical surveillance system. Here, we compared the analytical performance and practical applications between predominant molecular detection methods of RT-qPCR and RT-ddPCR on SARS-CoV-2 detection in wastewater surveillance. When pure viral RNA was tested, RT-ddPCR exhibited superior quantification accuracy at higher concentration levels and achieved more sensitive detection with reduced variation at low concentration levels. Furthermore, RT-ddPCR consistently demonstrated more robust and accurate measurement either in the background of the wastewater matrix or with the presence of mismatches in the target regions of the consensus assay. Additionally, by detecting mock variant RNA samples, we found that RT-ddPCR outperformed RT-qPCR in virus genotyping by targeting specific loci with signature mutations in allele-specific (AS) assays, especially at low levels of allele frequencies and concentrations, which increased the possibility for sensitive low-prevalence variant detection in the population. Our study provides insights for detection method selection in the WBE applications for future infectious disease outbreaks.

DOGS AS SENTINELS FOR WEST NILE VIRUS? IASI, ROMANIA EXPOSURE

"West Nile virus (WNV) is an important zoonotic flavivirus responsible for mild fever to severe, lethal neuroinvasive disease in humans, horses, birds, and other wildlife species. Since its discovery, WNV has caused multiple human and animal disease outbreaks in all continents, except Antarctica. Infections are associated with economic losses, mainly due to the cost of treatment of infected patients, control programmes, and loss of animals and animal products. This cross-sectional study explored the feasibility of domestic dogs as sentinels to better understand risks of mosquito-borne diseases in Iasi city."

Zoonotic diseases transmitted from the camels.

Zoonotic diseases, infections transmitted naturally from animals to humans, pose a significant public health challenge worldwide. After MERS-CoV was discovered, interest in camels was raised as potential intermediate hosts for zoonotic viruses. Most published review studies pay little attention to case reports or zoonotic epidemics where there is epidemiological proof of transmission from camels to humans. Accordingly, any pathogen found in camels known to cause zoonotic disease in other animals or humans is reported. Here, zoonotic diseases linked to camels are reviewed in the literature, focusing on those with epidemiological or molecular evidence of spreading from camels to humans. This review examines the risks posed by camel diseases to human health, emphasizing the need for knowledge and awareness in mitigating these risks. A search of the literature revealed that eight (36.4%) of the 22 investigations that offered convincing evidence of camel-to-human transmission involved MERS, five (22.7%) Brucellosis, four (18.2%) plague caused by Yersinia pestis, three (13.6%) camelpox, one (4.5%) hepatitis E, and one (4.5%) anthrax. The reporting of these zoonotic diseases has been steadily increasing, with the most recent period, from 2010 to the present, accounting for 59% of the reports. Additionally, camels have been associated with several other zoonotic diseases, including toxoplasmosis, Rift Valley fever, TB, Crimean-Congo hemorrhagic fever, and Q fever, despite having no evidence of a transmission event. Transmission of human zoonotic diseases primarily occurs through camel milk, meat, and direct or indirect contact with camels. The above-mentioned diseases were discussed to determine risks to human health. MERS, Brucellosis, plague caused by Y. pestis, camelpox, hepatitis E, and anthrax are the main zoonotic diseases associated with human disease events or outbreaks. Transmission to humans primarily occurs through camel milk, meat, and direct contact with camels. There is a need for comprehensive surveillance, preventive measures, and public health interventions based on a one-health approach to mitigate the risks of zoonotic infections linked to camels.