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Facilitators and barriers to community-based livestock abortion reporting for Rift Valley Fever surveillance in Uganda: A COM-B analysis.

Rift Valley Fever Disease (RVFD) causes substantial economic losses via livestock abortion storms, yet community-based abortion reporting for early warning remains suboptimal in endemic settings. This study analysed the behavioural determinants of livestock abortion reporting to inform RVF surveillance interventions in Uganda. We conducted a cross-sectional study using qualitative data collection methods in Isingiro District, Uganda, employing the Capability, Opportunity, Motivation-Behaviour (COM-B) framework. We conducted 29 key informant interviews with national/district policymakers and te…

Induction of a Th1-Type Polyfunctional T-Cell Response by the Four-segmented Rift Valley Fever Candidate Vaccine in Humans.

BACKGROUND: Rift Valley fever virus (RVFV) is a mosquito-borne virus that affects livestock and humans. The 4-segmented live-attenuated human vaccine candidate hRVFV-4s has shown a strong safety profile and excellent tolerability in healthy adults during a first-in-human clinical trial, while also eliciting both neutralizing antibody and T-cell responses. Recognizing the critical role of cellular immunity in vaccine-induced protection and immune durability, this study aimed to comprehensively characterize the cytokine secretion profile, the antigen-specific breadth of RVFV-specific T-cell resp…

Seroprevalence and Geographical Distribution of Rift Valley Fever in Small Ruminants in Mauritania: Evidence of Endemic Circulation and Regional Risk Hotspots.

Rift Valley fever (RVF) is a mosquito-borne viral zoonosis that causes severe illness in livestock and humans, with significant economic and health repercussions. Mauritania is considered an RVF focus in West Africa. A cross-sectional survey was conducted in 2023 in 12 of Mauritania's 15 provinces. Serum samples from 849 small ruminants (428 goats and 421 sheep) were analyzed by ELISA for IgG and IgM antibodies against RVF virus. Logistic regression analyses were performed to assess associations between seropositivity and species, age, sex, season, and geographic location. In total, 14.1% of t…

Intranasal infection of Rift Valley fever virus in the ferret model suggests multiple routes of neuroinvasion with consequential encephalitis and ophthalmitis.

Rift Valley fever virus (RVFV) causes haemorrhagic fever, ophthalmitis, and in severe cases, encephalitis in humans. Despite the well-recognised neurotropism, the mechanisms of central nervous system (CNS) invasion remain poorly understood. We investigated RVFV ingress into the CNS and resulting neuropathogenesis following intranasal inoculation in ferrets (Mustela putorius furo) (n = 15). At 3 DPI, before RVFV dissemination to the CNS, mild multifocal suppurative rhinitis and multifocal interstitial pneumonia were detected in the nasal cavity and lungs respectively, supported by detection of …

Gender roles in ruminant disease management in Uganda: Implications for the control of peste des petits ruminants and Rift Valley fever.

There is a distinct division of tasks and roles between men and women in livestock management in the different ruminant production systems i … estock), selected for the high prevalence of two livestock diseases (peste des petits ruminants and Rift Valley fever). Sex-disaggregated focus group discussions with livestock keepers and key informant interviews with veterinarians and other experts were conducted in six districts in the western, northeastern, and eastern regions of Uganda. Gendered livestock mana …

A Multi-Host Approach to Quantitatively Assess the Role of Dogs as Sentinels for Rift Valley Fever Virus (RVFV) Surveillance in Madagascar.

Sentinel animals may play a key role in the surveillance of arbovirus circulation, particularly in developing countries. This study aimed to assess the relevance of using dogs as sentinel animals for Rift Valley fever virus (RVFV) surveillance in Madagascar. Serological surveys were conducted on 513 dogs and 135 cattle in the Ifanadiana district, southeastern Madagascar. In addition, 486 human dry blood samples available from the same area were used. Antibodies against RVFV were detected in 23 of 513 dogs, in 86 of 486 humans, and in 33 of 135 cattle. Serocatalytic models fitted to age-stratif…

An LIR motif in the Rift Valley fever virus NSs protein is critical for the interaction with LC3 family members and inhibition of autophagy.

Rift Valley fever virus (RVFV) is a viral zoonosis that causes severe disease in ruminants and humans. The nonstructural small (NSs) protein is the primary virulence factor of RVFV that suppresses the host's antiviral innate immune response. Bioinformatic analysis and AlphaFold structural modeling identified four putative LC3-interacting regions (LIR) motifs (NSs 1-4) in the RVFV NSs protein, which suggest that NSs interacts with the host LC3-family proteins. Using, isothermal titration calorimetry, X-ray crystallography, co-immunoprecipitation, and co-localization experiments, the C-terminal …

Rift Valley fever virus is able to cross the human blood-brain barrier in vitro by direct infection with no deleterious effects.

Rift Valley fever (RVF) is a zoonotic arboviral disease that causes recurrent epidemics in Africa that may trigger fatal neurological disorders. However, the mechanisms of neuroinvasion by which the RVF virus (RVFV) reaches the human central nervous system (CNS) remain poorly characterized. In particular, it is not clear how RVFV is able to cross the human blood-brain barrier (hBBB), which is a neurovascular endothelium that protects the brain by regulating brain and blood exchanges. To explore these mechanisms, we used an in vitro hBBB model to mimic in vivo hBBB selectiveness and apicobasal …

Nuclear pore protein Nup98 is involved in replication of Rift Valley fever virus and nuclear import of virulence factor NSs.

The non-structural protein NSs is the main virulence factor of Rift Valley fever virus, a major zoonotic pathogen in Africa. NSs forms large aggregates in the nucleus and impairs induction of the antiviral type I IFN system by several mechanisms, including degradation of subunit p62 of the general RNA polymerase II transcription factor TFIIH. Here, we show that depletion of the nuclear pore protein Nup98 affects the nuclear import of NSs. Nonetheless, NSs was still able to degrade TFIIH-p62 under these conditions. Depletion of Nup98, however, had a negative effect on Rift Valley fever virus mu…

Effect of Environmental Temperature on the Ability of Culex tarsalis and Aedes taeniorhynchus (Diptera: Culicidae) to Transmit Rift Valley Fever Virus.

Rift Valley fever virus (RVFV) causes severe disease in domestic ungulates (cattle, goats, and sheep) and a febrile illness in humans (with ∼1% case fatality rate). This virus has been spreading geographically, and there is concern of it spreading to Europe or the Americas. Environmental temperature can significantly affect the ability of mosquitoes to transmit an arbovirus. However, these effects are not consistent among viruses or mosquito species. Therefore, we evaluated the effect of incubation temperatures ranging from 14°C to 30°C on infection and dissemination rates for Culex tarsalis a…

Вспышка лихорадки Рифт долины коррелирует с воспалительной реакцией человека и аномалиями коагуляции у людей с геморрагическими проявлениями.

Вирус лихорадки Рифт-Вэлли — это арбовирус, который затрагивает как скот, так и людей в Африке и на Ближнем Востоке. Несмотря на ее эндемию по всей Африке, редко можно обнаружить инфицированного человека на острой стадии заболевания и еще более редкое событие, связанное с сбором серийных образцов крови у пострадавшего пациента. Пациенты, страдающие серьезными заболеваниями, могут испытывать геморрагические симптомы. В этом исследовании мы выявили трех угандийцев с заболеванием RVFV, которое сопровождалось геморрагическими проявлениями. Серийные образцы крови этих людей были проанализированы на

Совпадение в аннотации оригинала
Rift Valley fever virus is an arbovirus that affects both livestock and humans throughout Africa and in the Middle East. Despite its endemicity throughout Africa, it is a rare event to identify an infected individual during the acute phase of the disease and an even rarer event to collect serial blood samples from the affected patient. Severely affected pati…

Culex flavivirus infection in a Culex pipiens mosquito colony and its effects on vector competence for Rift Valley fever phlebovirus.

BACKGROUND: Rift Valley fever is a mosquito-borne zoonotic disease that affects domestic ruminants and humans. Culex flavivirus is an insect-specific flavivirus that naturally exists in field mosquito populations. The influence of Culex flavivirus on Rift Valley fever phlebovirus (RVFV) vector competence of Culex pipiens has not been investigated. METHODS: Culex flavivirus infection in a Cx. pipiens colony was studied by Culex flavivirus oral feeding and intrathoracical inoculation. Similarly, vector competence of Cx. pipiens infected with Culex flavivirus was evaluated for RVFV. Infection, d…

Participatory survey of Rift Valley fever in nomadic pastoral communities of North-central Nigeria: The associated risk pathways and factors.

BACKGROUND: Rift Valley fever (RVF) is an emerging neglected mosquito-borne viral zoonotic disease of domestic animals and humans, with potential for global expansion. The objectives of this study were: to assess perceived relative burden and seasonality of RVF in nomadic cattle herds and validate the burden with sero-prevalence impact; and assess perceived risk factors associated with the disease and risk pathways for RVF virus in nomadic pastoral herds of North-central Nigeria using pastoralists' existing veterinary knowledge. METHODS: Participatory Epidemiology (PE) survey was conducted in…

The One Health approach to identify knowledge, attitudes and practices that affect community involvement in the control of Rift Valley fever outbreaks.

Rift Valley fever (RVF) is a viral mosquito-borne disease with the potential for global expansion, causes hemorrhagic fever, and has a high case fatality rate in young animals and in humans. Using a cross-sectional community-based study design, we investigated the knowledge, attitudes and practices of people living in small village in Sudan with respect to RVF outbreaks. A special One Health questionnaire was developed to compile data from 235 heads of household concerning their knowledge, attitudes, and practices with regard to controlling RVF. Although the 2007 RVF outbreak in Sudan had nega…

Seroepidemiological survey on Rift Valley fever among small ruminants and their close human contacts in Makkah, Saudi Arabia, in 2011.

This study describes a seroepidemiological survey on Rift Valley fever (RVF) among small ruminants and their close human contacts in Makkah, Saudi Arabia. A total of 500 small ruminants (126 local, 374 imported) were randomly selected from the sacrifice livestock yards of Al-Kaakiah slaughterhouse, in the holy city of Makkah, during the pilgrimage season 1432 H (4-9 November 2011). In addition, blood samples were collected from 100 local workers in close contact with the animals at the slaughterhouse. An RVF competition multi-species enzyme-linked immunosorbent assay (ELISA) detecting anti-RVF…

Comparison of the Potential for Different Genetic Forms in the Culex pipiens Complex in North America to Transmit Rift Valley Fever Virus.

Rift Valley fever virus (RVFV), a mosquito-borne virus, has been responsible for large outbreaks in Africa that have resulted in hundreds of thousands of human infections and major economic disruption due to loss of livestock and to trade restrictions. Culex pipiens was implicated as the principal vector of the Egyptian outbreak in 1977 that affected about 200,000 people. In the northern USA, Cx. pipiens occurs both as a mix of forms pipiens and molestus (i.e., US Culex pipiens) as well as pure Cx. pipiens form molestus, the latter mostly in underground locations such as sewers and basements. …

Inactivation of infectious virus and serological detection of virus antigen in Rift Valley fever virus-exposed mosquitoes fixed with paraformaldehyde.

Formaldehyde is routinely used to fix tissues in preparation for pathology studies, however concerns remain that treatment of tissues with cellular fixatives may not entirely inactivate infectious virus particles. This concern is of particular regulatory importance for research involving viruses that are classified as select agents such as Rift Valley fever virus (RVFV). Therefore, the specific aims of this study were to (1) assay RVFV-exposed Aedes aegypti mosquitoes fixed in 4% paraformaldehyde for the presence of infectious RVFV particles at various time points following infection and (2) d…

Seroepidemiological study of west nile virus and rift valley Fever virus in some of Mammalian species (herbivores) in northern Turkey.

BACKGROUND: West Nile virus (WNV) and Rift Valley fever virus (RVFV) are mosquito-borne viral diseases. The objective of this study was to investigate the RVFV and WNV infections as serologically in different mammalian species (cattle, horse, goat, sheep and water buffalo) in the northern Turkey. METHODS: Blood samples randomly collected from 70 each cattle, horse, sheep, goat and water buffalo were analyzed for the presence of antibodies to RVFV and WNV using an competitive enzyme-linked immunosorbent assay (C-ELISA) in northern Turkey. RESULTS: None of the animals were positive for antibod…

Risk assessment of the introduction of Rift Valley fever from the Horn of Africa to Yemen via legal trade of small ruminants.

Rift Valley fever (RVF) is a mosquito-borne viral zoonosis of increasing global importance. Occurring since 1930 across Africa, it was detected for the first time in Saudi Arabia and Yemen in September 2000, leading to human deaths and major losses in livestock populations. Assuming the virus has not survived in Yemen or has been circulating at a low level, authors qualitatively assessed the likelihood of "re-introduction" of RVF into Yemen through the legal importation of small ruminants from the Horn of Africa. The overall probability of introduction was assessed very low to medium, increasi…

Pathologic studies on suspect animal and human cases of Rift Valley fever from an outbreak in Eastern Africa, 2006-2007.

Rift Valley fever (RVF) is an important viral zoonotic disease in Africa with periodic outbreaks associated with severe disease, death, and economic hardship. During the 2006-2007 outbreaks in Eastern Africa, postmortem and necropsy tissue samples from 14 animals and 20 humans clinically suspected of RVF were studied with histopathologic evaluation and immunohistochemical (IHC) assays. Six animal and 11 human samples had IHC evidence of Rift Valley fever virus (RVFV) antigens. We found that extensive hepatocellular necrosis without prominent inflammatory cell infiltrates is the most distinctiv…