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1.
BMC Infect Dis ; 21(1): 162, 2021 Feb 09.
Artículo en Inglés | MEDLINE | ID: mdl-33563231

RESUMEN

BACKGROUND: In June 2019, Nipah virus (NiV) infection was detected in a 21-year-old male (index case) of Ernakulum, Kerala, India. This study was undertaken to determine if NiV was in circulation in Pteropus species (spp) in those areas where the index case had visit history in 1 month. METHODS: Specialized techniques were used to trap the Pteropus medius bats (random sampling) in the vicinity of the index case area. Throat and rectal swabs samples of 141 bats along with visceral organs of 92 bats were collected to detect the presence of NiV by real-time reverse transcriptase-polymerase chain reaction (qRTPCR). Serum samples of 52 bats were tested for anti-NiV Immunoglobulin (Ig) G antibodies by Enzyme-Linked Immunosorbent Assay (ELISA). The complete genome of NiV was sequenced by next-generation sequencing (NGS) from the tissues and swab samples of bats. RESULTS: One rectal swab sample and three bats visceral organs were found positive for the NiV. Interestingly, 20.68% (12/58) of Pteropus were positive for anti-NiV IgG antibodies. NiV sequences of 18,172; 17,200 and 15,100 nucleotide bps could be retrieved from three Pteropus bats. CONCLUSION: A distinct cluster of NiV sequences, with significant net-evolutionary nucleotide divergence, was obtained, suggesting the circulation of new genotype (I-India) in South India. NiV Positivity in Pteropus spp. of bats revealed that NiV is circulating in many districts of Kerala state, and active surveillance of NiV should be immediately set up to know the hotspot area for NiV infection.


Asunto(s)
Quirópteros/virología , Infecciones por Henipavirus/diagnóstico , Virus Nipah/genética , Animales , Anticuerpos Antivirales/sangre , Brotes de Enfermedades , Infecciones por Henipavirus/epidemiología , Infecciones por Henipavirus/veterinaria , Infecciones por Henipavirus/virología , Secuenciación de Nucleótidos de Alto Rendimiento , Inmunoglobulina G/sangre , India/epidemiología , Virus Nipah/clasificación , Virus Nipah/inmunología , Filogenia , ARN Viral/química , ARN Viral/metabolismo , Reacción en Cadena en Tiempo Real de la Polimerasa , Recto/virología
2.
Viruses ; 13(2)2021 01 23.
Artículo en Inglés | MEDLINE | ID: mdl-33498685

RESUMEN

Nipah virus is a bat-borne paramyxovirus that produces yearly outbreaks of fatal encephalitis in Bangladesh. Understanding the ecological conditions that lead to spillover from bats to humans can assist in designing effective interventions. To investigate the current and historical processes that drive Nipah spillover in Bangladesh, we analyzed the relationship among spillover events and climatic conditions, the spatial distribution and size of Pteropus medius roosts, and patterns of land-use change in Bangladesh over the last 300 years. We found that 53% of annual variation in winter spillovers is explained by winter temperature, which may affect bat behavior, physiology, and human risk behaviors. We infer from changes in forest cover that a progressive shift in bat roosting behavior occurred over hundreds of years, producing the current system where a majority of P. medius populations are small (median of 150 bats), occupy roost sites for 10 years or more, live in areas of high human population density, and opportunistically feed on cultivated food resources-conditions that promote viral spillover. Without interventions, continuing anthropogenic pressure on bat populations similar to what has occurred in Bangladesh could result in more regular spillovers of other bat viruses, including Hendra and Ebola viruses.


Asunto(s)
Quirópteros/virología , Conducta Alimentaria , Infecciones por Henipavirus/epidemiología , Infecciones por Henipavirus/veterinaria , Virus Nipah/genética , Animales , Bangladesh/epidemiología , Quirópteros/fisiología , Brotes de Enfermedades , Bosques , Humanos , Modelos Lineales , Estaciones del Año , Zoonosis/epidemiología , Zoonosis/virología
4.
Aust Vet J ; 98(7): 273-279, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32529687

RESUMEN

BACKGROUND: Hendra virus (HeV) is endemic in Australian flying foxes, posing a threat to equine and human health. Equine vaccination remains the most effective risk mitigation strategy. Many horses remain unvaccinated - even in higher-risk regions. Debate surrounding the vaccine's use is characterised by conflicting perspectives, misunderstanding and mistrust. Private veterinary practitioners are critical to early identification of public health risk through recognition, sampling and management of suspect-equine-HeV-cases. However, managing such cases can be burdensome, with some veterinarians opting not to attend unvaccinated horses or to abandon equine practice because of risk posed by HeV disease and liability. OBJECTIVE: Ascertain the perspectives of informed citizens on what obligations (if any) private veterinarians have to attend unvaccinated horses with HeV or HeV-like disease. METHODS: Three citizens' juries were tasked with considering approaches to managing HeV risk in Australia, including (reported here) roles and obligations of private veterinarians in responding to HeV-suspect-cases. RESULTS: Jurors acknowledged that HeV management posed an important challenge for private veterinarians. A clear majority (27 of 31 jurors) voted that veterinarians should not be obliged to attend unvaccinated horses. All recognised that greater support for veterinarians should be a priority. CONCLUSIONS: When informed of HeV risks and strategies for control and management, citizens appreciated the need to support veterinarians performing this critical 'One Health' role for public benefit. The current governance framework within which zoonotic disease recognition and response operates limits the contingency and scope for increasing support and efficacy of these important veterinary public health practices.


Asunto(s)
Virus Hendra , Infecciones por Henipavirus/veterinaria , Enfermedades de los Caballos , Veterinarios , Animales , Australia , Caballos , Humanos , Práctica Privada , Zoonosis
5.
J Virol Methods ; 274: 113731, 2019 12.
Artículo en Inglés | MEDLINE | ID: mdl-31513861

RESUMEN

Maintenance of Hendra virus (HeV) in pteropid bat populations has been associated with spillover events in horses, humans and dogs. Experimental studies have demonstrated infections for several other species including guinea pigs, cats and ferrets. The criteria of a sensitive and specific serological test that is effective for a range of species, but which does not require use of live virus, has not been satisfactorily addressed by currently available tests. We have evaluated the use of two HeV neutralizing monoclonal antibodies (mAbs) in a blocking format enzyme-linked immunosorbent assay (bELISA) to detect serum antibody against a recombinant expressed HeV G protein (sol G) in several animal species. The human mAb m102.4 neutralises both HeV and the closely related Nipah virus (NiV); the mouse mAb 1.2 neutralises only HeV. Given these functional differences, we have investigated both antibodies using a bELISA format. Diagnostic sensitivity (DSe) and diagnostic specificity (DSp) were optimized using individual thresholds for mAb 1.2 and m102.4. For mAb 1.2 the positive threshold of >33% inhibition yielded DSe and DSp values of 100% (95% CI 95.3-100.0) and 99.5 (95% CI 98.8-99.8) respectively; for mAb m102.4 a positive threshold of >49% inhibition gave DSe and DSp values of 100 (95% CI 95.3-100.0) and 99.8 (95% CI 99.2-100.0) respectively. At these thresholds the DSe was 100% for both tests relative to the virus neutralization test. Importantly, the occurrence of false positive reactions did not overlap across the assays. Therefore, by sequential and selective application of these assays, it is possible to identify false positive reactions and achieve a DSp that approximates 100% in the test population.


Asunto(s)
Anticuerpos Neutralizantes/sangre , Anticuerpos Antivirales/sangre , Ensayo de Inmunoadsorción Enzimática/métodos , Virus Hendra/inmunología , Infecciones por Henipavirus/diagnóstico , Infecciones por Henipavirus/veterinaria , Animales , Anticuerpos Monoclonales/inmunología , Antígenos Virales/inmunología , Humanos , Sensibilidad y Especificidad
6.
Philos Trans R Soc Lond B Biol Sci ; 374(1782): 20190021, 2019 09 30.
Artículo en Inglés | MEDLINE | ID: mdl-31401962

RESUMEN

Pathogen circulation among reservoir hosts is a precondition for zoonotic spillover. Unlike the acute, high morbidity infections typical in spillover hosts, infected reservoir hosts often exhibit low morbidity and mortality. Although it has been proposed that reservoir host infections may be persistent with recurrent episodes of shedding, direct evidence is often lacking. We construct a generalized SEIR (susceptible, exposed, infectious, recovered) framework encompassing 46 sub-models representing the full range of possible transitions among those four states of infection and immunity. We then use likelihood-based methods to fit these models to nine years of longitudinal data on henipavirus serology from a captive colony of Eidolon helvum bats in Ghana. We find that reinfection is necessary to explain observed dynamics; that acute infectious periods may be very short (hours to days); that immunity, if present, lasts about 1-2 years; and that recurring latent infection is likely. Although quantitative inference is sensitive to assumptions about serology, qualitative predictions are robust. Our novel approach helps clarify mechanisms of viral persistence and circulation in wild bats, including estimated ranges for key parameters such as the basic reproduction number and the duration of the infectious period. Our results inform how future field-based and experimental work could differentiate the processes of viral recurrence and reinfection in reservoir hosts. This article is part of the theme issue 'Dynamic and integrative approaches to understanding pathogen spillover'.


Asunto(s)
Quirópteros , Reservorios de Enfermedades/veterinaria , Infecciones por Henipavirus/veterinaria , Henipavirus/fisiología , Animales , Animales de Zoológico , Reservorios de Enfermedades/virología , Ghana/epidemiología , Infecciones por Henipavirus/epidemiología , Infecciones por Henipavirus/transmisión , Infecciones por Henipavirus/virología , Prevalencia , Estudios Seroepidemiológicos
7.
Infez Med ; 27(2): 117-127, 2019 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-31205033

RESUMEN

The Nipah virus was discovered twenty years ago, and there is considerable information available regarding the specificities surrounding this virus such as transmission, pathogenesis and genome. Belonging to the Henipavirus genus, this virus can cause fever, encephalitis and respiratory disorders. The first cases were reported in Malaysia and Singapore in 1998, when affected individuals presented with severe febrile encephalitis. Since then, much has been identified about this virus. These single-stranded RNA viruses gain entry into target cells via a process known as macropinocytosis. The viral genome is released into the cell cytoplasm via a cascade of processes that involves conformational changes in G and F proteins which allow for attachment of the viral membrane to the cell membrane. In addition to this, the natural reservoirs of this virus have been identified to be fruit bats from the genus Pteropus. Five of the 14 species of bats in Malaysia have been identified as carriers, and this virus affects horses, cats, dogs, pigs and humans. Various mechanisms of transmission have been proposed such as contamination of date palm saps by bat feces and saliva, nosocomial and human-to-human transmissions. Physical contact was identified as the strongest risk factor for developing an infection in the 2004 Faridpur outbreak. Geographically, the virus seems to favor the Indian sub-continent, Indonesia, Southeast Asia, Pakistan, southern China, northern Australia and the Philippines, as demonstrated by the multiple outbreaks in 2001, 2004, 2007, 2012 in Bangladesh, India and Pakistan as well as the initial outbreaks in Malaysia and Singapore. Multiple routes of the viremic spread in the human body have been identified such as the central nervous system (CNS) and respiratory system, while virus levels in the body remain low, detection in the cerebrospinal fluid is comparatively high. The virus follows an incubation period of 4 days to 2 weeks which is followed by the development of symptoms. The primary clinical signs include fever, headache, vomiting and dizziness, while the characteristic symptoms consist of segmental myoclonus, tachycardia, areflexia, hypotonia, abnormal pupillary reflexes and hypertension. The serum neutralization test (SNT) is the gold standard of diagnosis followed by ELISA if SNT cannot be carried out. On the other hand, treatment is supportive since there a lack of effective pharmacological therapy and only one equine vaccine is currently licensed for use. Prevention of outbreaks seems to be a more viable approach until specific therapeutic strategies are devised.


Asunto(s)
Enfermedades Transmisibles Emergentes/epidemiología , Epidemias/estadística & datos numéricos , Infecciones por Henipavirus/epidemiología , Virus Nipah , Animales , Asia/epidemiología , Gatos , Quirópteros/virología , Enfermedades Transmisibles Emergentes/terapia , Enfermedades Transmisibles Emergentes/transmisión , Enfermedades Transmisibles Emergentes/veterinaria , Reservorios de Enfermedades , Perros , Infecciones por Henipavirus/terapia , Infecciones por Henipavirus/transmisión , Infecciones por Henipavirus/veterinaria , Caballos , Humanos , Virus Nipah/genética , Virus Nipah/aislamiento & purificación , Pinocitosis , Porcinos , Evaluación de Síntomas , Vacunación/métodos , Vacunación/veterinaria , Internalización del Virus
8.
PLoS Negl Trop Dis ; 13(6): e0007393, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-31246966

RESUMEN

The 2018 outbreak of Nipah virus in Kerala, India, highlights the need for global surveillance of henipaviruses in bats, which are the reservoir hosts for this and other viruses. Nipah virus, an emerging paramyxovirus in the genus Henipavirus, causes severe disease and stuttering chains of transmission in humans and is considered a potential pandemic threat. In May 2018, an outbreak of Nipah virus began in Kerala, > 1800 km from the sites of previous outbreaks in eastern India in 2001 and 2007. Twenty-three people were infected and 21 people died (16 deaths and 18 cases were laboratory confirmed). Initial surveillance focused on insectivorous bats (Megaderma spasma), whereas follow-up surveys within Kerala found evidence of Nipah virus in fruit bats (Pteropus medius). P. medius is the confirmed host in Bangladesh and is now a confirmed host in India. However, other bat species may also serve as reservoir hosts of henipaviruses. To inform surveillance of Nipah virus in bats, we reviewed and analyzed the published records of Nipah virus surveillance globally. We applied a trait-based machine learning approach to a subset of species that occur in Asia, Australia, and Oceana. In addition to seven species in Kerala that were previously identified as Nipah virus seropositive, we identified at least four bat species that, on the basis of trait similarity with known Nipah virus-seropositive species, have a relatively high likelihood of exposure to Nipah or Nipah-like viruses in India. These machine-learning approaches provide the first step in the sequence of studies required to assess the risk of Nipah virus spillover in India. Nipah virus surveillance not only within Kerala but also elsewhere in India would benefit from a research pipeline that included surveys of known and predicted reservoirs for serological evidence of past infection with Nipah virus (or cross reacting henipaviruses). Serosurveys should then be followed by longitudinal spatial and temporal studies to detect shedding and isolate virus from species with evidence of infection. Ecological studies will then be required to understand the dynamics governing prevalence and shedding in bats and the contacts that could pose a risk to public health.


Asunto(s)
Quirópteros/virología , Control de Enfermedades Transmisibles/organización & administración , Transmisión de Enfermedad Infecciosa , Monitoreo Epidemiológico , Infecciones por Henipavirus/epidemiología , Virus Nipah/crecimiento & desarrollo , Zoonosis/epidemiología , Animales , Reservorios de Enfermedades/virología , Infecciones por Henipavirus/transmisión , Infecciones por Henipavirus/veterinaria , Humanos , India/epidemiología , Virus Nipah/inmunología , Virus Nipah/aislamiento & purificación , Medición de Riesgo , Estudios Seroepidemiológicos , Zoonosis/transmisión
9.
Emerg Infect Dis ; 25(6): 1144-1152, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-31107231

RESUMEN

Nipah virus (NiV) is a zoonotic pathogen that causes high case-fatality rates (CFRs) in humans. Two NiV strains have caused outbreaks: the Malaysia strain (NiVM), discovered in 1998-1999 in Malaysia and Singapore (≈40% CFR); and the Bangladesh strain (NiVB), discovered in Bangladesh and India in 2001 (≈80% CFR). Recently, NiVB in African green monkeys resulted in a more severe and lethal disease than NiVM. No NiV vaccines or treatments are licensed for human use. We assessed replication-restricted single-injection recombinant vesicular stomatitis vaccine NiV vaccine vectors expressing the NiV glycoproteins against NiVB challenge in African green monkeys. All vaccinated animals survived to the study endpoint without signs of NiV disease; all showed development of NiV F Ig, NiV G IgG, or both, as well as neutralizing antibody titers. These data show protective efficacy against a stringent and relevant NiVB model of human infection.


Asunto(s)
Chlorocebus aethiops , Infecciones por Henipavirus/veterinaria , Virus Nipah , Vesiculovirus/inmunología , Vacunas Virales/inmunología , Zoonosis , Animales , Femenino , Infecciones por Henipavirus/mortalidad , Infecciones por Henipavirus/prevención & control , Infecciones por Henipavirus/virología , Humanos , Inmunidad Humoral , Masculino , Enfermedades de los Monos/patología , Enfermedades de los Monos/virología , Carga Viral
10.
Vet Q ; 39(1): 26-55, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31006350

RESUMEN

Nipah (Nee-pa) viral disease is a zoonotic infection caused by Nipah virus (NiV), a paramyxovirus belonging to the genus Henipavirus of the family Paramyxoviridae. It is a biosafety level-4 pathogen, which is transmitted by specific types of fruit bats, mainly Pteropus spp. which are natural reservoir host. The disease was reported for the first time from the Kampung Sungai Nipah village of Malaysia in 1998. Human-to-human transmission also occurs. Outbreaks have been reported also from other countries in South and Southeast Asia. Phylogenetic analysis affirmed the circulation of two major clades of NiV as based on currently available complete N and G gene sequences. NiV isolates from Malaysia and Cambodia clustered together in NiV-MY clade, whereas isolates from Bangladesh and India clusterered within NiV-BD clade. NiV isolates from Thailand harboured mixed population of sequences. In humans, the virus is responsible for causing rapidly progressing severe illness which might be characterized by severe respiratory illness and/or deadly encephalitis. In pigs below six months of age, respiratory illness along with nervous symptoms may develop. Different types of enzyme-linked immunosorbent assays along with molecular methods based on polymerase chain reaction have been developed for diagnostic purposes. Due to the expensive nature of the antibody drugs, identification of broad-spectrum antivirals is essential along with focusing on small interfering RNAs (siRNAs). High pathogenicity of NiV in humans, and lack of vaccines or therapeutics to counter this disease have attracted attention of researchers worldwide for developing effective NiV vaccine and treatment regimens.


Asunto(s)
Infecciones por Henipavirus/veterinaria , Virus Nipah/inmunología , Vacunas Virales , Zoonosis , Animales , Enfermedades de los Gatos/epidemiología , Enfermedades de los Gatos/prevención & control , Enfermedades de los Gatos/virología , Gatos , Enfermedades de los Perros/epidemiología , Enfermedades de los Perros/prevención & control , Enfermedades de los Perros/virología , Perros , Infecciones por Henipavirus/epidemiología , Infecciones por Henipavirus/prevención & control , Infecciones por Henipavirus/virología , Humanos , Virus Nipah/clasificación , Vacunas Virales/administración & dosificación , Vacunas Virales/análisis , Vacunas Virales/uso terapéutico , Zoonosis/epidemiología , Zoonosis/prevención & control , Zoonosis/virología
11.
Vector Borne Zoonotic Dis ; 19(7): 455-465, 2019 07.
Artículo en Inglés | MEDLINE | ID: mdl-30985268

RESUMEN

Nipah virus (NiV) and Hendra virus (HeV) are closely related members within the genus Henipavirus, family Paramyxoviridae, for which fruit bats serve as the reservoir. The initial emergence of NiV infections in pigs and humans in Malaysia, and HeV infections in horses and humans in Australia, posed severe impacts on human and animal health, and continues threatening lives of humans and livestock within Southeast Asia and Australia. Recently, henipavirus-specific antibodies have also been detected in fruit bats in a number of sub-Saharan African countries and in Brazil, thereby considerably increasing the known geographic distribution of henipaviruses. Africa is progressively being recognized as a new high prevalence zone for henipaviruses, as deduced from serological and molecular evidence of past infections in Madagascar, Ghana, Republic of Congo, Gulf of Guinea, Zambia, Tanzania, Cameroon, and Nigeria lately. Serological data suggest henipavirus spillover from bats to livestock and human populations in Africa without reported clinical disease in any of these species. All virus isolation attempts have been abortive, highlighting the need for further investigations. The genome of the Ghanaian bat henipavirus designated Ghana virus (GhV), which was detected in a pteropid Eidolon helvum bat, is the only African henipavirus that has been completely sequenced limiting our current knowledge on the genetic diversity and pathogenesis of African henipaviruses. In this review, we summarize the available data on the circulation of henipaviruses in Africa, discuss potential sources for virus spillover, and highlight existing research gaps.


Asunto(s)
Quirópteros/virología , Infecciones por Henipavirus/epidemiología , Henipavirus , África/epidemiología , Animales , Anticuerpos Antivirales , Infecciones por Henipavirus/veterinaria , Infecciones por Henipavirus/virología , Humanos , Ganado/virología , Estudios Seroepidemiológicos , Zoonosis/virología
12.
BMC Vet Res ; 15(1): 73, 2019 Mar 04.
Artículo en Inglés | MEDLINE | ID: mdl-30832676

RESUMEN

BACKGROUND: Thailand's Central Plain is identified as a contact zone between pigs and flying foxes, representing a potential zoonotic risk. Nipah virus (NiV) has been reported in flying foxes in Thailand, but it has never been found in pigs or humans. An assessment of the suitability of NiV transmission at the spatial and farm level would be useful for disease surveillance and prevention. Multi-criteria decision analysis (MCDA), a knowledge-driven model, was used to map contact zones between local epizootic risk factors as well as to quantify the suitability of NiV transmission at the pixel and farm level. RESULTS: Spatial risk factors of NiV transmission in pigs were identified by experts as being of three types, including i) natural host factors (bat preferred areas and distance to the nearest bat colony), ii) intermediate host factors (pig population density), and iii) environmental factors (distance to the nearest forest, distance to the nearest orchard, distance to the nearest water body, and human population density). The resulting high suitable areas were concentrated around the bat colonies in three provinces in the East of Thailand, including Chacheongsao, Chonburi, and Nakhonnayok. The suitability of NiV transmission in pig farms in the study area was quantified as ranging from very low to medium suitability. CONCLUSIONS: We believe that risk-based surveillance in the identified priority areas may increase the chances of finding out NiV and other bat-borne pathogens and thereby optimize the allocation of financial resources for disease surveillance. In the long run, improvements of biosecurity in those priority areas may also contribute to preventing the spread of potential emergence of NiV and other bat-borne pathogens.


Asunto(s)
Quirópteros/virología , Infecciones por Henipavirus/veterinaria , Virus Nipah , Porcinos/virología , Animales , Técnicas de Apoyo para la Decisión , Infecciones por Henipavirus/epidemiología , Infecciones por Henipavirus/transmisión , Humanos , Medición de Riesgo , Tailandia/epidemiología
13.
Rev Med Virol ; 29(1): e2010, 2019 01.
Artículo en Inglés | MEDLINE | ID: mdl-30251294

RESUMEN

Since emergence of the Nipah virus (NiV) in 1998 from Malaysia, the NiV virus has reappeared on different occasions causing severe infections in human population associated with high rate of mortality. NiV has been placed along with Hendra virus in genus Henipavirus of family Paramyxoviridae. Fruit bats (Genus Pteropus) are known to be natural host and reservoir of NiV. During the outbreaks from Malaysia and Singapore, the roles of pigs as intermediate host were confirmed. The infection transmitted from bats to pigs and subsequently from pigs to humans. Severe encephalitis was reported in NiV infection often associated with neurological disorders. First NiV outbreak in India occurred in Siliguri district of West Bengal in 2001, where direct transmission of the NiV virus from bats-to-human and human-to-human was reported in contrast to the role of pigs in the Malaysian NiV outbreak. Regular NiV outbreaks have been reported from Bangladesh since 2001 to 2015. The latest outbreak of NiV has been recorded in May, 2018 from Kerala, India which resulted in the death of 17 individuals. Due to lack of vaccines and effective antivirals, Nipah encephalitis poses a great threat to public health. Routine surveillance studies in the infected areas can be useful in detecting early signs of infection and help in containment of these outbreaks.


Asunto(s)
Infecciones por Henipavirus/epidemiología , Infecciones por Henipavirus/veterinaria , Virus Nipah/aislamiento & purificación , Enfermedades de los Porcinos/epidemiología , Enfermedades de los Porcinos/virología , Zoonosis/epidemiología , Zoonosis/virología , Animales , Asia/epidemiología , Quirópteros , Enfermedades Transmisibles Emergentes/epidemiología , Enfermedades Transmisibles Emergentes/veterinaria , Enfermedades Transmisibles Emergentes/virología , Brotes de Enfermedades , Transmisión de Enfermedad Infecciosa , Monitoreo Epidemiológico , Infecciones por Henipavirus/virología , Humanos , Análisis de Supervivencia , Porcinos
15.
Emerg Infect Dis ; 25(1): 166-170, 2019 01.
Artículo en Inglés | MEDLINE | ID: mdl-30561301

RESUMEN

Despite molecular and serologic evidence of Nipah virus in bats from various locations, attempts to isolate live virus have been largely unsuccessful. We report isolation and full-genome characterization of 10 Nipah virus isolates from Pteropus medius bats sampled in Bangladesh during 2013 and 2014.


Asunto(s)
Quirópteros/virología , Reservorios de Enfermedades/virología , Genoma Viral/genética , Infecciones por Henipavirus/veterinaria , Virus Nipah/genética , Animales , Bangladesh , Geografía , Infecciones por Henipavirus/virología , Humanos , Virus Nipah/aislamiento & purificación , Filogenia , Zoonosis
16.
Transbound Emerg Dis ; 66(2): 921-928, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30576076

RESUMEN

Hendra virus (HeV) and Nipah virus (NiV), belonging to the genus Henipavirus, are among the most pathogenic of viruses in humans. Old World fruit bats (family Pteropodidae) are the natural reservoir hosts. Molecular and serological studies found evidence of henipavirus infection in fruit bats from several African countries. However, little is known about the potential for spillover into domestic animals in East Africa, particularly pigs, which served as amplifying hosts during the first outbreak of NiV in Malaysia and Singapore. We collected sera from 661 pigs presented for slaughter in Uganda between December 2015 and October 2016. Using HeV G and NiV G indirect ELISAs, 14 pigs (2%) were seroreactive in at least one ELISA. Seroprevalence increased to 5.4% in October 2016, when pigs were 9.5 times more likely to be seroreactive than pigs sampled in December 2015 (p = 0.04). Eight of the 14 ELISA-positive samples reacted with HeV N antigen in Western blot. None of the sera neutralized HeV or NiV in plaque reduction neutralization tests. Although we did not detect neutralizing antibodies, our results suggest that pigs in Uganda are exposed to henipaviruses or henipa-like viruses. Pigs in this study were sourced from many farms throughout Uganda, suggesting multiple (albeit rare) introductions of henipaviruses into the pig population. We postulate that given the widespread distribution of Old World fruit bats in Africa, spillover of henipaviruses from fruit bats to pigs in Uganda could result in exposure of pigs at multiple locations. A higher risk of a spillover event at the end of the dry season might be explained by higher densities of bats and contact with pigs at this time of the year, exacerbated by nutritional stress in bat populations and their reproductive cycle. Future studies should prioritize determining the risk of spillover of henipaviruses from pigs to people, so that potential risks can be mitigated.


Asunto(s)
Virus Hendra/aislamiento & purificación , Infecciones por Henipavirus/veterinaria , Virus Nipah/aislamiento & purificación , Enfermedades de los Porcinos/epidemiología , Animales , Ensayo de Inmunoadsorción Enzimática , Femenino , Infecciones por Henipavirus/epidemiología , Infecciones por Henipavirus/virología , Masculino , Prevalencia , Factores de Riesgo , Estudios Seroepidemiológicos , Sus scrofa , Porcinos , Enfermedades de los Porcinos/virología , Uganda/epidemiología
17.
Ann N Y Acad Sci ; 1429(1): 78-99, 2018 10.
Artículo en Inglés | MEDLINE | ID: mdl-30138535

RESUMEN

Old World fruit bats (Chiroptera: Pteropodidae) provide critical pollination and seed dispersal services to forest ecosystems across Africa, Asia, and Australia. In each of these regions, pteropodids have been identified as natural reservoir hosts for henipaviruses. The genus Henipavirus includes Hendra virus and Nipah virus, which regularly spill over from bats to domestic animals and humans in Australia and Asia, and a suite of largely uncharacterized African henipaviruses. Rapid change in fruit bat habitat and associated shifts in their ecology and behavior are well documented, with evidence suggesting that altered diet, roosting habitat, and movement behaviors are increasing spillover risk of bat-borne viruses. We review the ways that changing resource landscapes affect the processes that culminate in cross-species transmission of henipaviruses, from reservoir host density and distribution to within-host immunity and recipient host exposure. We evaluate existing evidence and highlight gaps in knowledge that are limiting our understanding of the ecological drivers of henipavirus spillover. When considering spillover in the context of land-use change, we emphasize that it is especially important to disentangle the effects of habitat loss and resource provisioning on these processes, and to jointly consider changes in resource abundance, quality, and composition.


Asunto(s)
Quirópteros/virología , Ecosistema , Infecciones por Henipavirus/veterinaria , Animales , Conducta Animal , Ecología
19.
PLoS One ; 13(4): e0194385, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29708971

RESUMEN

Hendra virus (HeV) and Nipah virus (NiV) belong to the genus Henipavirus in the family Paramyxoviridae. Henipavirus infections were first reported in the 1990's causing severe and often fatal outbreaks in domestic animals and humans in Southeast Asia and Australia. NiV infections were observed in humans in Bangladesh, India and in the first outbreak in Malaysia, where pigs were also infected. HeV infections occurred in horses in the North-Eastern regions of Australia, with singular transmission events to humans. Bats of the genus Pteropus have been identified as the reservoir hosts for henipaviruses. Molecular and serological indications for the presence of henipa-like viruses in African fruit bats, pigs and humans have been published recently. In our study, truncated forms of HeV and NiV attachment (G) proteins as well as the full-length NiV nucleocapsid (N) protein were expressed using different expression systems. Based on these recombinant proteins, Enzyme-linked Immunosorbent Assays (ELISA) were developed for the detection of HeV or NiV specific antibodies in porcine serum samples. We used the NiV N ELISA for initial serum screening considering the general reactivity against henipaviruses. The G protein based ELISAs enabled the differentiation between HeV and NiV infections, since as expected, the sera displayed higher reactivity with the respective homologous antigens. In the future, these assays will present valuable tools for serosurveillance of swine and possibly other livestock or wildlife species in affected areas. Such studies will help assessing the potential risk for human and animal health worldwide by elucidating the distribution of henipaviruses.


Asunto(s)
Anticuerpos Antivirales/sangre , Virus Hendra/metabolismo , Virus Nipah/metabolismo , Proteínas de la Nucleocápside/inmunología , Proteínas Virales/inmunología , Animales , Anticuerpos Monoclonales/inmunología , Anticuerpos Antivirales/inmunología , Ensayo de Inmunoadsorción Enzimática , Femenino , Infecciones por Henipavirus/inmunología , Infecciones por Henipavirus/patología , Infecciones por Henipavirus/veterinaria , Leishmania/metabolismo , Ratones , Ratones Endogámicos BALB C , Microscopía Fluorescente , Pruebas de Neutralización , Proteínas de la Nucleocápside/genética , Proteínas de la Nucleocápside/metabolismo , Proteínas Recombinantes/biosíntesis , Proteínas Recombinantes/inmunología , Proteínas Recombinantes/aislamiento & purificación , Porcinos , Proteínas Virales/genética , Proteínas Virales/metabolismo
20.
Aust Vet J ; 96(5): 161-166, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-29691855

RESUMEN

OBJECTIVE: To determine the antibody responses to a commercial Hendra virus vaccine (Equivac® HeV) in a field environment. METHODS: A group of 61 horses received a primary vaccination course comprising two doses administered 3-6 weeks apart (V1, V2) and a 3rd dose (V3) given 6 months after the second. This was followed by booster vaccinations at 12 monthly intervals (V4, V5). Antibody titres were assessed using a virus-neutralisation test. RESULTS: Neutralising antibodies against HeV were not detected prior to vaccination. Antibodies were detected in 54/57 horses at 3 weeks after V1 and 51/51 had titres ≥ 32 at 8 weeks after V2. At 6 months after V2, antibody titres decreased in most (31/34) horses and were not detected in three horses. A rapid increase in antibody titres was recorded in 35/36 horses at 1 week following V3. By the first annual booster vaccination (V4), antibodies were still detectable in 29/29 horses, although titres had decreased; in 26/29 horses, titres remained ≥ 32. All horses showed an increase in antibody titres after V4. There was no statistically significant increase in mean antibody titre after V5, compared with after V4. CONCLUSION: Horses administered Equivac® HeV, using a primary vaccination course followed by annual booster vaccinations, mounted an effective secondary immune response and acquired antibody responses that were consistent with protective immunity against HeV in the form of virus-neutralising antibodies. No adverse events were observed after vaccine administration.


Asunto(s)
Anticuerpos Neutralizantes/sangre , Virus Hendra/inmunología , Infecciones por Henipavirus/veterinaria , Enfermedades de los Caballos/inmunología , Enfermedades de los Caballos/prevención & control , Vacunas Virales/inmunología , Animales , Anticuerpos Antivirales/sangre , Infecciones por Henipavirus/sangre , Infecciones por Henipavirus/inmunología , Infecciones por Henipavirus/prevención & control , Enfermedades de los Caballos/sangre , Caballos , Inmunización Secundaria/veterinaria , Modelos Lineales , Facultades de Medicina Veterinaria , Vacunación , Vacunas Virales/administración & dosificación , Vacunas Virales/sangre
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