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Background: In recent years, Vietnam has suffered multiple epizootics of influenza in poultry. Methods: From 10 January 2019 to 26 April 2021, we employed a One Health influenza surveillance approach at live bird markets (LBMs) and swine farms in Northern Vietnam. When the COVID-19 pandemic permitted, each month, field teams collected oral secretion samples from poultry and pigs, animal facility bioaerosol and fecal samples, and animal worker nasal washes at 4 LBMs and 5 swine farms across 5 sites. Initially samples were screened with molecular assays followed by culture in embryonated eggs (poultry swabs) or Madin-Darby canine kidney cells (human or swine swabs). Results: Many of the 3493 samples collected had either molecular or culture evidence for influenza A virus, including 314 (37.5%) of the 837 poultry oropharyngeal swabs, 144 (25.1%) of the 574 bioaerosol samples, 438 (34.9%) of the 1257 poultry fecal swab samples, and 16 (1.9%) of the 828 human nasal washes. Culturing poultry samples yielded 454 influenza A isolates, 83 of which were H5, and 70 (84.3%) of these were highly pathogenic. Additionally, a positive human sample had a H9N2 avian-like PB1 gene. In contrast, the prevalence of influenza A in the swine farms was much lower with only 6 (0.4%) of the 1700 total swine farm samples studied, having molecular evidence for influenza A virus. Conclusions: This study suggests that Vietnam's LBMs continue to harbor high prevalences of avian influenza A viruses, including many highly pathogenic H5N6 strains, which will continue to threaten poultry and humans.
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OBJECTIVES: This study sought to detect and characterize influenza A (IAV) and influenza D (IDV) viruses circulating among commercial birds and shop owners in Pakistan's live bird markets. METHODS: Oropharyngeal swabs (n = 600; n = 300 pools) collected from poultry and nasopharyngeal swabs (n = 240) collected from poultry workers were studied for molecular evidence of IAV and IDV using real-time and conventional real-time reverse transcription polymerase chain reaction protocols. RESULTS: Nineteen (6.3%) poultry pools were positive for IAV and 73.9% of these were positive for H9N2 subtypes. Two (0.83%) poultry workers had evidence of IAV, and both were also H9N2 subtypes. The poultry and human IAV-positive specimens all clustered phylogenetically by Sanger and next-generation sequencing with previously detected H9N2 poultry isolates. No field specimens were positive for IDV. CONCLUSION: H9N2 IAV is likely enzootic in Punjab Province Pakistan's live bird markets and may be colonizing the noses of workers and market visitors. Regular monitoring for avian influenza-associated human illness in Punjab seems to be a needed public measure.
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Vírus da Influenza A Subtipo H9N2 , Influenza Aviária , Influenza Humana , Filogenia , Aves Domésticas , Vírus da Influenza A Subtipo H9N2/genética , Vírus da Influenza A Subtipo H9N2/isolamento & purificação , Vírus da Influenza A Subtipo H9N2/classificação , Paquistão/epidemiologia , Animais , Humanos , Influenza Aviária/virologia , Influenza Aviária/epidemiologia , Influenza Humana/virologia , Influenza Humana/epidemiologia , Aves Domésticas/virologia , Orofaringe/virologia , Nasofaringe/virologiaRESUMO
Since the 1990s, multiple infectious diseases have "spilled over" from nonhuman animals to infect humans and cause significant global morbidity and mortality. Despite efforts to detect and respond to such threats, surveillance and mitigation efforts have been criticized as ineffective. This article describes what "spillover" and "spillback" events are and canvasses 5 ways in which clinicians can improve emerging microbial pathogen, especially viral, detection and containment responses.
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Viroses , Zoonoses , Animais , Humanos , Zoonoses/epidemiologia , Viroses/epidemiologiaRESUMO
Due to the extensive host range of influenza A viruses, it is difficult to determine the best diagnostic algorithm to efficiently screen samples from a variety of host species for influenza A viruses. While there are some influenza diagnostic algorithms that are specific to host species, to our knowledge, no single algorithm exists for the characterization of influenza A viruses across multiple host species. In this paper, we propose an algorithm that can serve as a guide for screening human, animal, and environmental samples for influenza A viruses of high human and animal health importance.
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Vírus da Influenza A , Influenza Humana , Animais , Humanos , Vírus da Influenza A/genética , Algoritmos , Especificidade de Hospedeiro , Influenza Humana/diagnósticoRESUMO
Due to their geographical isolation and small populations, insular bats may not be able to maintain acute immunizing viruses that rely on a large population for viral maintenance. Instead, endemic transmission may rely on viruses establishing persistent infections within hosts or inducing only short-lived neutralizing immunity. Therefore, studies on insular populations are valuable for developing broader understanding of viral maintenance in bats. The Christmas Island flying-fox (CIFF; Pteropus natalis) is endemic on Christmas Island, a remote Australian territory, and is an ideal model species to understand viral maintenance in small, geographically isolated bat populations. Serum or plasma (n = 190), oral swabs (n = 199), faeces (n = 31), urine (n = 32) and urine swabs (n = 25) were collected from 228 CIFFs. Samples were tested using multiplex serological and molecular assays, and attempts at virus isolation to determine the presence of paramyxoviruses, betacoronaviruses and Australian bat lyssavirus. Analysis of serological data provides evidence that the species is maintaining a pararubulavirus and a betacoronavirus. There was little serological evidence supporting the presence of active circulation of the other viruses assessed in the present study. No viral nucleic acid was detected and no viruses were isolated. Age-seropositivity results support the hypothesis that geographically isolated bat populations can maintain some paramyxoviruses and coronaviruses. Further studies are required to elucidate infection dynamics and characterize viruses in the CIFF. Lastly, apparent absence of some pathogens could have implications for the conservation of the CIFF if a novel disease were introduced into the population through human carriage or an invasive species. Adopting increased biosecurity protocols for ships porting on Christmas Island and for researchers and bat carers working with flying-foxes are recommended to decrease the risk of pathogen introduction and contribute to the health and conservation of the species.
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Quirópteros , Lyssavirus , Ácidos Nucleicos , Animais , Austrália/epidemiologia , Betacoronavirus , HumanosRESUMO
Habitat loss and alteration are two of the biggest threats facing insular flying-foxes. Altered habitats are often re-vegetated with introduced or domestic plant species on which flying-foxes may forage. However, these alien food plants may not meet the nutritional requirements of flying-foxes. The critically endangered Christmas Island flying-fox (CIFF; Pteropus natalis) is subject to habitat alteration and the introduction of alien food plants, and therefore is a good model species to evaluate the potential impact of alien plant species on insular flying-foxes. In this study, we evaluated nutritional content of native food plants to determine how flying-foxes historically met their nutritional requirements. Furthermore, we compared the nutritional content of native and alien fruits to predict possible impacts of alien plants on insular flying-foxes. Native and alien fruits and flowers, and native foliage (leaves, petals, and petioles) commonly consumed by the CIFF were collected and evaluated for soluble sugars, crude protein, non-fiber carbohydrates, and nine minerals. Evaluation of native food plants suggests that flying-foxes meet energy requirements by consuming fruit and nectar. However, fruit and nectar are low in protein and essential minerals required for demanding life periods; therefore, flying-foxes likely supplement their diets with pollen and foliage. Thus, flying-foxes require a diverse array of plants to meet their nutritional requirements. Compared to native fruits, alien fruits contained significantly higher non-fiber carbohydrates, and this may provide an important energy source, particularly from species that bear fruit year-round. Median mineral concentrations in alien fruit species, however, were deficient compared to native fruits, suggesting major (or even seasonal) shifts in the proportion of alien species in the CIFF diet could lead to nutritional imbalances. This study confirms the need to quantify nutritional parameters in addition to feeding ecology when evaluating habitat quality to inform conservation actions that can be applied both locally and globally.
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Quirópteros/fisiologia , Espécies em Perigo de Extinção , Valor Nutritivo , Plantas Comestíveis , Fenômenos Fisiológicos da Nutrição Animal , Animais , Austrália , Biodiversidade , Conservação dos Recursos Naturais , Dieta/veterinária , Ecossistema , Frutas/química , Espécies Introduzidas , Necessidades Nutricionais , Plantas Comestíveis/química , Polinização , Dispersão de SementesRESUMO
The Christmas Island flying-fox (Pteropus natalis) is the last native mammal on Christmas Island and its population is in decline. Phosphate mining occurs across much of the eastern side of Christmas Island. The phosphate deposits are naturally rich in cadmium, and potentially other metals, which may be threatening the Christmas Island flying-fox population. To test this, concentrations of metals (cadmium, copper, iron, mercury, lead, and zinc) were measured in fur and urine collected from Christmas Island flying-foxes and interpreted concurrently with urinalysis and serum biochemistry data. In addition, metal concentrations in liver and kidney samples from two Christmas Island flying-foxes and associated histological findings from one of these individuals are reported. Fur cadmium concentrations were significantly higher in the Christmas Island flying-fox compared to concentrations found in flying-foxes in mainland Australia. Additionally, 30% of Christmas Island flying-foxes had urine cadmium concentrations exceeding maximum concentrations previously reported in flying-foxes in mainland Australia. Glucosuria and proteinuria were identified in two Christmas Island flying-foxes, suggestive of renal dysfunction. In one aged flying-fox, kidney cadmium concentrations were four-fold higher than toxic thresholds reported for domestic mammals. Microscopic evaluation of this individual identified bone lesions consistent with those described in laboratory animals with chronic cadmium poisoning. These results suggest that Christmas Island flying-foxes are being exposed to cadmium and identification of these sources is recommended as a focus of future research. Unexpectedly, urine iron concentrations in Christmas Island flying-foxes were higher compared to previous studies of Australian mainland flying-foxes, which suggests that urinary excretion of iron may be an important aspect of iron homeostasis in this species whose diet is iron rich.
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Quirópteros , Idoso , Animais , Austrália , Cádmio , Soro , UrináliseRESUMO
Due to their large range across diverse habitats, flying-foxes are potential bioindicator species for environmental metal exposure. To test this hypothesis, blood spots, urine, fur, liver and kidney samples were collected from grey-headed flying-foxes (Pteropus poliocephalus) and black flying-foxes (P. alecto) from the Sydney basin, Australia. Concentrations of arsenic, cadmium, copper, lead, mercury and zinc and 11 other trace metals were determined using inductively coupled plasma mass spectrometry. As predicted, kidney and fur lead concentrations were lower compared to concentrations found in flying-foxes in the early 1990's, due to reduced environmental lead emissions. Tissue cadmium concentrations in flying-foxes were higher compared to previous studies of flying-foxes and other bat species, suggesting that flying-foxes were exposed to unrecognized cadmium sources. Identification of these sources should be a focus of future research. Urine concentrations of arsenic, cadmium, mercury, and lead were proportional to kidney concentrations. Given that urine can be collected from flying-foxes without handling, this demonstrates that many flying-foxes can be assessed for metal exposure with relative ease. The analysis of blood spots was not viable because of variable metal concentrations in the filter paper used. Fur concentrations of metals correlated poorly with tissue concentrations at the low levels of metals found in this study, but fur could still be a useful sample if flying-foxes are exposed to high levels of metals. Lastly, heat inactivation had minimal impact on metal concentrations in kidney and liver samples and should be considered as a tool to protect personnel working with biohazardous samples.
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Cádmio/metabolismo , Quirópteros/fisiologia , Biomarcadores Ambientais/fisiologia , Chumbo/metabolismo , Animais , Austrália , Cádmio/toxicidade , Ecossistema , Poluição Ambiental , Chumbo/toxicidadeRESUMO
Twenty-six per cent of Mongolians live pastoral lifestyles, increasing their likelihood of exposure to ticks and placing them at a higher risk for contracting tick-borne diseases (TBDs). Anaplasma spp. and Rickettsia spp. have been identified in ticks, livestock and humans in Mongolia, but no known qualitative research has been conducted investigating the association between nomadic herder characteristics, tick bite history and exposure to TBDs. To better understand the association between self-reported tick bites and symptoms versus actual exposure to TBDs, this study paired serological data with 335 surveys administered to Mongolian herders, ages 12-69, from 2014 to 2015. Logistic regression results identified no significant associations between reported tick bites or symptoms with serological evidence of Anaplasma spp. and Rickettsia spp. controlling for age, gender and aimag. Among the 335 respondents who were seropositive to either Anaplasma spp. or Rickettsia spp., 32.9% self-reported experiencing abnormal symptoms such as redness, inflammation, headache, arthritis or fever after being bitten. Alternatively, 17.3% (58/335) of individuals reported experiencing symptoms following a tick bite in instances where serological results indicated no exposure to Anaplasma spp. or Rickettsia spp. Results also identified inconsistencies in reporting and seroprevalence among different age groups, with children having the highest reporting and treatment seeking rates but low levels of exposure in comparison with other groups. While survey results showed that individuals were aware of peak tick seasons and tick species that inhabit specific areas, 58% of heads of households (49/84) were unaware that ticks can cause disease in livestock or dogs. This study suggests that herders are an at-risk population in Mongolia with gaps in awareness of TBD risk. Increased surveillance paired with focused outreach to prevent TBDs targeted to the herder population is encouraged.
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Anaplasmose/epidemiologia , Infecções por Rickettsia/epidemiologia , Picadas de Carrapatos/epidemiologia , Migrantes , Adolescente , Adulto , Idoso , Anaplasma/imunologia , Anaplasmose/sangue , Anaplasmose/transmissão , Criação de Animais Domésticos , Animais , Anticorpos Antibacterianos/sangue , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Mongólia/epidemiologia , Rickettsia/imunologia , Infecções por Rickettsia/sangue , Infecções por Rickettsia/transmissão , Estações do Ano , Carrapatos/classificação , Adulto Jovem , Zoonoses/epidemiologiaRESUMO
Porcine reproductive and respiratory syndrome virus (PRRSV) is a highly contagious respiratory virus causing severe morbidity in pigs worldwide. Control strategies for PRRSV often rely on detecting PRRSV, culling or isolating sick pigs, disinfecting pig barns, vaccination, and monitoring for virus spread. Given the high economic impact of PRRSV on pig farms, there is a great need for rapid and reliable PRRSV detection assays. We compared the performance of 2 commercial reverse-transcription real-time PCR (RT-rtPCR) assays, the VetMAX PRRSV NA and EU reagents (ABI assay) and the PRRSV general RT-rtPCR kit (Anheal assay), for the molecular detection of PRRSV in sera collected from pigs in China. Between June and September 2015, sera were collected from 219 healthy and 104 suspected PRRSV-infected pigs on 4 farms in China. Employing blinding, the 2 assays were run by 2 laboratories (Guangzhou Animal Health Inspection Institute [GAHII] and Sun Yat-sen University [SYSU] laboratories) and compared. Although both assays detected PRRSV with 100% specificity at both laboratories, the sensitivity (95% vs. 78% at GAHII; 94% vs. 72% at SYSU Laboratory) and the reproducibility (kappa value 0.933 vs. 0.931) were slightly better for the ABI assay compared to the Anheal assay.
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Síndrome Respiratória e Reprodutiva Suína/diagnóstico , Vírus da Síndrome Respiratória e Reprodutiva Suína/isolamento & purificação , Reação em Cadeia da Polimerase em Tempo Real/veterinária , Reação em Cadeia da Polimerase Via Transcriptase Reversa/veterinária , Animais , China , Feminino , Masculino , Síndrome Respiratória e Reprodutiva Suína/sangue , Síndrome Respiratória e Reprodutiva Suína/microbiologia , Reação em Cadeia da Polimerase em Tempo Real/instrumentação , Reação em Cadeia da Polimerase em Tempo Real/métodos , Reprodutibilidade dos Testes , Reação em Cadeia da Polimerase Via Transcriptase Reversa/instrumentação , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Sensibilidade e Especificidade , SuínosRESUMO
Transstadial transmission of tick-borne rickettsiae has been well documented. Few studies, however, have evaluated the role of transovarial transmission of tick-borne rickettsiae, particularly in nature within the host-vector ecosystem. This cross-sectional study aimed to understand the role of transovarial transmission of tick-borne rickettsiae among feeding ticks at different life stages. Tick eggs laid by engorged wild-caught adult female ticks were pooled and tested for Rickettsia spp. and Anaplasma/Ehrlichia spp. using molecular techniques, while adult fed ticks were tested individually. Additionally, larval and nymphal ticks were collected in the wild from small mammals, pooled and tested for Rickettsia spp. and Anaplasma/Ehrlichia spp. There were 38 fed adult and 618 larvae/nymphs (60 pools total) Dermacentor spp. ticks collected from livestock and rodents. All individual adult ticks and tick pools were positive for Rickettsia spp. While none of the larvae/nymphs were positive for Anaplasma/Ehrlichia spp., two adult fed ticks were positive. Rickettsia spp. DNA was detected in 91% (30/33) of the pooled eggs tested, and one pool of eggs tested positive for Anaplasma/Ehrlichia spp. Sequencing data revealed Rickettsia spp. shared ≥99% identity with R. raoultii ompA. Anaplasma/Ehrlichia spp. shared ≥89% identity with A. ovis 16S ribosomal RNA. This study identified potential transovarial transmission of Rickettsia spp. and Anaplasma spp. among D. nuttalli ticks. Additional studies are needed to further assess the proportion of transovarial transmission occurring in nature to better understand the burden and disease ecology of tick-borne rickettsiae in Mongolia.
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Dermacentor/microbiologia , Rickettsia/fisiologia , Animais , Feminino , Interações Hospedeiro-Patógeno , Larva/microbiologia , Mongólia , Ninfa/microbiologia , Ovário/microbiologiaRESUMO
Background: Tick-borne pathogens (TBPs) are frequently studied in developed nations but are often neglected in emerging countries. In Mongolia, TBP research is especially sparse, with few research reports focusing upon human and domestic animal disease and tick ecology. However, little information exists on TBPs in small mammals. Methods: In this 2016 cross-sectional pilot study, we sought to uniquely study wildlife for TBPs. We live-trapped small mammals, and tested their whole blood, serum and ear biopsy samples for molecular or serological evidence of Borrelia spp., Rickettsia spp., and Anaplasma spp./Ehrlichia spp. Results: Of 64 small mammals collected, 56.0%, 39.0% and 0.0% of animals were positive by molecular assays for Borrelia spp., Rickettsia spp., and Anaplasma spp./Erhlicia spp., respectively. 41.9% were seropositive for A. phagocytophilum and 24.2% of animals were seropositive for Rickettsia rickettsii. Conclusion: This pilot data demonstrates evidence of a number of TBPs among small mammal populations in northern Mongolia and suggests the need to further investigate what role these mammals play in human and domestic animal disease.
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Ample evidence exists for the presence of infectious agents at the maternal-fetal interface, often with grave outcomes to the developing fetus (i.e., Zika virus, brucella, cytomegalovirus, and toxoplasma). While less studied, pregnancy-related transmissible spongiform encephalopathies (TSEs) have been implicated in several species, including humans. Our previous work has shown that prions can be transferred from mother to offspring, resulting in the development of clinical TSE disease in offspring born to muntjac dams infected with chronic wasting disease (CWD) (1). We further demonstrated protein misfolding cyclic amplification (PMCA)-competent prions within the female reproductive tract and in fetal tissues harvested from CWD experimentally and naturally exposed cervids (1, 2). To assess whether the PMCA-competent prions residing at the maternal-fetal interface were infectious and to determine if the real-time quaking-induced conversion (RT-QuIC) methodology may enhance our ability to detect amyloid fibrils within the pregnancy microenvironment, we employed a mouse bioassay and RT-QuIC. In this study, we have demonstrated RT-QuIC seeding activity in uterus, placentome, ovary, and amniotic fluid but not in allantoic fluids harvested from CWD-infected Reeves' muntjac dams showing clinical signs of infection (clinically CWD-infected) and in some placentomes from pre-clinically CWD-infected dams. Prion infectivity was confirmed within the uterus, amniotic fluid, and the placentome, the semipermeable interface that sustains the developing fetus, of CWD-infected dams. This is the first report of prion infectivity within the cervid pregnancy microenvironment, revealing a source of fetal CWD exposure prior to the birthing process, maternal grooming, or encounters with contaminated environments.IMPORTANCE The facile dissemination of chronic wasting disease within captive and free-range cervid populations has led to questions regarding the transmission dynamics of this disease. Direct contact with infected animals and indirect contact with infectious prions in bodily fluids and contaminated environments are suspected to explain the majority of this transmission. A third mode of transmission, from mother to offspring, may be underappreciated. The presence of pregnancy-related prion infectivity within the uterus, amniotic fluid, and the placental structure reveals that the developing fetus is exposed to a source of prions long before exposure to the infectious agent during and after the birthing process or via contact with contaminated environments. These findings have impact on our current concept of CWD disease transmission.
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Estruturas Animais/química , Cervo Muntjac , Complicações Infecciosas na Gravidez/veterinária , Príons/análise , Doença de Emaciação Crônica/patologia , Animais , Bioensaio , Técnicas de Química Analítica , Feminino , Camundongos , Gravidez , Complicações Infecciosas na Gravidez/patologiaRESUMO
Newcastle disease virus (NDV) is a pathogen that most often infects poultry species. In investigating a 2014 outbreak of encephalitis and death among farmed mink (Mustela vison), we found pathological and later experimental evidence that NDV can infect and cause severe encephalitic and pneumonic disease in these animals. Our findings confirm the host range of NDV.
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Encefalite/veterinária , Vison/virologia , Doença de Newcastle/complicações , Doença de Newcastle/virologia , Vírus da Doença de Newcastle/fisiologia , Pneumonia/veterinária , Animais , Animais Domésticos , China , Encefalite/etiologia , Encefalite/virologia , Especificidade de Hospedeiro , Microscopia Eletrônica de Transmissão , Doença de Newcastle/mortalidade , Doença de Newcastle/patologia , Vírus da Doença de Newcastle/classificação , Vírus da Doença de Newcastle/ultraestrutura , Filogenia , Pneumonia/etiologia , Pneumonia/virologiaRESUMO
Traditional diagnostic detection of chronic wasting disease (CWD) relies on immunodetection of misfolded CWD prion protein (PrP(CWD)) by western blotting, ELISA, or immunohistochemistry (IHC). These techniques require separate sample collections (frozen and fixed) which may result in discrepancies due to variation in prion tissue distribution and assay sensitivities that limit detection especially in early and subclinical infections. Here, we harness the power of real-time quaking induced conversion (RT-QuIC) to amplify, detect, and quantify prion amyloid seeding activity in fixed paraffin-embedded (FPE) tissue sections. We show that FPE RT-QuIC has greater detection sensitivity than IHC in tissues with low PrP(CWD) burdens, including those that are IHC-negative. We also employ amyloid formation kinetics to yield a semi-quantitative estimate of prion concentration in a given FPE tissue. We report that FPE RT-QuIC has the ability to enhance diagnostic and investigative detection of disease-associated PrP(RES) in prion, and potentially other, protein misfolding disease states.