Результаты поиска

Validation of an IgM antibody capture ELISA based on a recombinant nucleoprotein for identification of domestic ruminants infected with Rift Valley fever virus.

The presence of competent vectors in some countries currently free of Rift Valley fever (RVF) and global changes in climate, travel and trade have increased the risk of RVF spreading to new regions and have emphasised the need for accurate and reliable diagnostic tools for early diagnosis during RVF outbreaks. Highly sensitive viral detection systems like PCR have a limited use during outbreaks because of the short duration of viraemia, whereas antibodies like specific IgM which are serological indicators of acute infection, can be detected for up to 50 days after infection. Using the highly c…

IgG-sandwich and IgM-capture enzyme-linked immunosorbent assay for the detection of antibody to Rift Valley fever virus in domestic ruminants.

The recent occurrence of the first confirmed outbreaks of Rift Valley fever in humans and livestock outside the African region, namely in the Kingdom of Saudi Arabia and Yemen, is of global medical and veterinary concern. Disadvantages of classical techniques for serological diagnosis of Rift Valley fever include health risk to laboratory personnel, restrictions for their use outside endemic areas and inability to distinguish between different classes of immunoglobulins. We report on the development and validation of sandwich and capture ELISAs (both based on inactivated antigen) for detection…

Arbovirus surveillance from 1990 to 1995 in the Barkedji area (Ferlo) of Senegal, a possible natural focus of Rift Valley fever virus.

Surveillance for mosquito-borne viruses was conducted in Barkedji area from 1990 to 1995, following an outbreak of Rift Valley fever (RVF) virus in southern Mauritania. Mosquitoes, sand flies, and midges were collected from human bait and trapped by solid-state U.S. Army battery-powered CDC miniature light traps baited with dry ice or animals (sheep or chickens) at four ponds. Overall, 237,091 male and female mosquitoes representing 52 species in eight genera, 214,967 Phlebotomine sand flies, and 2,527 Culicoides were collected, identified, and tested for arboviruses in 9,490 pools (7,050 pool…

[Decrease of natural immunity against Rift Valley fever in domestic ruminants of the Senegal River basin after the epizootic outbreak of 1987].

A domestic ruminants serosurvey of Rift valley fever (RVF) neutralizing antibodies has been carried out during three years after the 1987 epidemic in the Senegal River Basin. Authors present results from the 1990 serosurvey that are matched with the preview surveys. Out of 1,225 ongulate tested, 17.2% had RVF virus antibodies. There is a global decrease in the herds immunity since the epizootic manifestation associated with the 1987 epidemic. Significant differences in seroprevalence are observed from the delta (28.5%) to the lower (17.9%) and middle valley (6.1%) of the Senegal river. Cattle …

Rift Valley fever seroprevalence and associated factors in non-vaccinated livestock (cattle and small ruminants) in Arua, Lira and Apac districts, Uganda.

INTRODUCTION: Rift Valley fever (RVF) is a zoonotic viral disease of major veterinary public health and economic importance, transmitted primarily by mosquitoes and associated with significant livestock losses and human infections. Despite its epidemic potential and its demonstrated endemicity in western Uganda, data on its seroprevalence and associated factors from northern Uganda remain limited. This study determined the seroprevalence of RVF and its associated factors in unvaccinated livestock in Apac, Arua, and Lira districts. METHODS AND MATERIALS: A cross-sectional study was conducted i…

The Development of a Multivalent Capripoxvirus-Vectored Vaccine Candidate to Protect against Sheeppox, Goatpox, Peste des Petits Ruminants, and Rift Valley Fever.

Capripoxviruses are the causative agents of sheeppox, goatpox, and lumpy skin disease (LSD) in cattle, which cause economic losses to the li … tpox. Subsequently, genes encoding the protective antigens for peste des petits ruminants (PPR) and Rift Valley fever (RVF) viruses have been inserted in the LSDV WB005KO construct in three different antigen forms (native, secreted, and fusion). These three multivalent vaccine candidates were evaluated for protection against PPR using a single immunization of 104 T …

Dicer-2 mutations in Aedes aegypti cells lead to a diminished antiviral function against Rift Valley fever virus and Bunyamwera virus infection.

Mosquitoes are known to transmit different arthropod-borne viruses belonging to various virus families. The exogenous small interfering RNA … on the antiviral activity of two viruses belonging to different families of the Bunyaviricetes: the Rift Valley fever virus (RVFV) vaccine strain MP12 (Phenuiviridae, Phlebovirus) and the Bunyamwera orthobunyavirus (BUNV; Peribunyaviridae, Orthobunyavirus). All three domains were determined to be critical for the antiviral activity against both RVFV and BUNV. Inter …

Использование картирования результатов для мобилизации важнейших заинтересованных сторон для создания в Руанде производственно-сбытовой цепи вакцины от гендерных заболеваний в долине Рифт и Ньюкасле.

Около 752 миллионов бедняков мира удерживают скот для производства продовольствия, получения доходов и создания активов. Женщины составляют две трети (~ 400 млн. человек) лиц с низким уровнем доходов, занимающихся животноводством. Инфекционные заболевания являются одной из основных проблем, препятствующих тому, чтобы скотохозяинцы получали оптимальные производственные доходы и повышали продовольственную безопасность. В Руанде весьма заразные, но предотвратимые заболевания, которые затрагивают животных, с которыми сталкиваются женщины, такие, как лихорадка в долине Рифт в козлах и болезнь в Нью

Совпадение в аннотации оригинала
Approximately 752 million of the world's poor keep livestock to produce food, generate income, and build assets. Women represent two-thirds … n Rwanda, highly contagious yet preventable diseases that affect animals that women manage, such as Rift Valley fever in goats and Newcastle disease in chickens have a high-mortality rate and can devastate their herds. Women are disproportionately affected because they bear primary responsibility for goats and chickens. These diseases are preventable through vaccin …

Safety and immunogenicity of Rift Valley fever MP-12 and arMP-12ΔNSm21/384 vaccine candidates in goats (Capra aegagrus hircus) from Tanzania.

Vaccination of domestic ruminants is considered to be an effective strategy for protecting these animals against Rift Valley fever (RVF), but available vaccines have limitations. Therefore, the aim of this study was to determine the safety and immunogenicity of RVF virus (RVFV) mutagenesis passage 12 (MP-12) and arMP-12ΔNSm21/384 vaccine candidates in goats (Capra aegagrus hircus) in Tanzania. Goats were vaccinated intramuscularly with RVFV MP-12 or arMP-12ΔNSm21/384, and then on Day 87 post-vaccination (PV) all animals were revaccinated using the RVFV MP-12 vaccine candidate. Serum samples we…

A DNA Vaccine Encoding the Gn Ectodomain of Rift Valley Fever Virus Protects Mice via a Humoral Response Decreased by DEC205 Targeting.

The Rift Valley fever virus (RVFV) is responsible for a serious mosquito-borne viral disease in humans and ruminants. The development of a new and safer vaccine is urgently needed due to the risk of introduction of this arbovirus into RVFV-free continents. We recently showed that a DNA vaccine encoding eGn, the ectodomain of the RVFV Gn glycoprotein, conferred a substantial protection in the sheep natural host and that the anti-eGn IgG levels correlated to protection. Addressing eGn to DEC205 reduced the protective efficacy while decreasing the antibody and increasing the IFNγ T cell responses…

Evaluation of positive Rift Valley fever virus formalin-fixed paraffin embedded samples as a source of sequence data for retrospective phylogenetic analysis.

Rift Valley fever (RVF), caused by an arthropod borne Phlebovirus in the family Bunyaviridae, is a haemorrhagic disease that affects ruminants and humans. Due to the zoonotic nature of the virus, a biosafety level 3 laboratory is required for isolation of the virus. Fresh and frozen samples are the preferred sample type for isolation and acquisition of sequence data. However, these samples are scarce in addition to posing a health risk to laboratory personnel. Archived formalin-fixed, paraffin-embedded (FFPE) tissue samples are safe and readily available, however FFPE derived RNA is in most ca…

Wetlands, wild Bovidae species richness and sheep density delineate risk of Rift Valley fever outbreaks in the African continent and Arabian Peninsula.

Rift Valley fever (RVF) is an emerging, vector-borne viral zoonosis that has significantly impacted public health, livestock health and production, and food security over the last three decades across large regions of the African continent and the Arabian Peninsula. The potential for expansion of RVF outbreaks within and beyond the range of previous occurrence is unknown. Despite many large national and international epidemics, the landscape epidemiology of RVF remains obscure, particularly with respect to the ecological roles of wildlife reservoirs and surface water features. The current inve…

Rift Valley Fever Vaccine Virus Clone 13 Is Able to Cross the Ovine Placental Barrier Associated with Foetal Infections, Malformations, and Stillbirths.

Rift Valley fever virus (RVFV) is a mosquito-borne pathogen that affects domesticated ruminants and occasionally humans. Classical RVF vaccines are based on formalin-inactivated virus or the live-attenuated Smithburn strain. The inactivated vaccine is highly safe but requires multiple administrations and yearly re-vaccinations. Although the Smithburn vaccine provides solid protection after a single vaccination, this vaccine is not safe for pregnant animals. An alternative live-attenuated vaccine, named Clone 13, carries a large natural deletion in the NSs gene which encodes the major virulence…

Trapping of Rift Valley Fever (RVF) vectors using light emitting diode (LED) CDC traps in two arboviral disease hot spots in Kenya.

BACKGROUND: Mosquitoes' response to artificial lights including color has been exploited in trap designs for improved sampling of mosquito v … ht traps for mosquito surveillance, and if so, determine the best color for attraction of important Rift Valley Fever (RFV) vectors. METHODS: The efficiency of selected colored LED CDC light traps (red, green, blue, violet, combination of blue-green-red (BGR)) to sample RVF vectors was evaluated relative to incandescent light (as control) in a CDC light trap in tw …

Re-emergence of Rift Valley fever virus in Barkedji (Senegal, West Africa) in 2002-2003: identification of new vectors and epidemiological implications.

The Rift Valley fever virus (RVFV) is a threat that must not be neglected, as the consequences of RVFV are dramatic, both for human and animal health. This virus is a zoonotic virus that already has demonstrated a real capacity for re-emerging after long periods of silence, as observed in Barkedji (Senegal, West Africa) in 2002. In this article we present the 2nd emergence in Barkedji after the 1st manifestation in 1993, and for the 1st time the circulation of RVFV during 2 consecutive years among mosquito populations in Senegal. As part of the entomological surveillance program undertaken sin…

Genetic evidence for Rift Valley fever outbreaks in Madagascar resulting from virus introductions from the East African mainland rather than enzootic maintenance.

Rift Valley fever virus (RVFV), a mosquito-borne phlebovirus, has been detected in Madagascar since 1979, with occasional outbreaks. In 2008 to 2009, a large RVFV outbreak was detected in Malagasy livestock and humans during two successive rainy seasons. To determine whether cases were due to enzootic maintenance of the virus within Madagascar or to importation from the East African mainland, nine RVFV whole genomic sequences were generated for viruses from the 1991 and 2008 Malagasy outbreaks. Bayesian coalescent analyses of available whole S, M, and L segment sequences were used to estimate …

Dual functions of Rift Valley fever virus NSs protein: inhibition of host mRNA transcription and post-transcriptional downregulation of protein kinase PKR.

Rift Valley fever virus (RVFV), which belongs to the genus Phlebovirus, family Bunyaviridae, is a negative-stranded RNA virus carrying a single-stranded, tripartite RNA genome. RVFV is an important zoonotic pathogen transmitted by mosquitoes and causes large outbreaks among ruminants and humans in Africa and the Arabian Peninsula. Human patients develop an acute febrile illness, followed by a fatal hemorrhagic fever, encephalitis, or ocular diseases. A viral nonstructural protein, NSs, is a major viral virulence factor. Past studies showed that NSs suppresses the transcription of host mRNAs, i…

Seroprevalence of rift valley fever virus and associated risk factors in small ruminants at human-livestock-wildlife interface within Uganda's conservation areas.

BACKGROUND: Following the first laboratory confirmed human Rift Valley Fever Virus (RVFV) outbreak in 48 years, Uganda has continued to detect sporadic outbreaks, particularly within the cattle corridor since 2016. Although wildlife potentially harbors RVFV strains, livestock exposure to RVFV at human-livestock-wildlife interfaces remains underexplored in major Ugandan conservation areas. METHODS: A cross-sectional quantitative study was conducted between August, 2022 and March, 2023, at Satellite Research Sites (SRS), located in Bwindi-Mgahinga, Lake Mburo, Queen Elizabeth, Murchison Falls, a…

Understanding the Rift Valley fever exposure risk: A comparative perspective from a multi-country study in East and Central Africa, 2021-24.

Rift Valley fever (RVF) is a concern in East and Central Africa, particularly following periods of heavy rainfall and flooding. However no human outbreaks have been reported in the Democratic Republic of the Congo (DRC). To assess whether this reflects a true absence of virus circulation, we estimated RVF seroprevalence in Goma (eastern DRC) and examined context-specific risk factors, comparing the findings with data from outbreak-prone countries. A two-year longitudinal study, across six health facilities in DRC, Kenya and Uganda, enrolled febrile subjects aged ≥10 years. Human serum samples …