scholarly journals Heterogeneity of Rift Valley fever virus transmission potential across livestock hosts, quantified through a model-based analysis of host viral load and vector infection

2021 ◽  
Author(s):  
Hélène Cecilia ◽  
Roosmarie Vriens ◽  
Jeroen Kortekaas ◽  
Paul J Wichgers Schreur ◽  
Mariken de Wit ◽  
...  
Keyword(s):  
Host Species ◽  
Rift Valley ◽  
Rift Valley Fever ◽  
Viral Vector ◽  
Rift Valley Fever Virus ◽  
Virus Transmission ◽  
Ecological Factors ◽  
Host Feeding ◽  
Valley Fever ◽  
Transmission Potential

Rift Valley fever (RVF) is a viral, vector-borne, zoonotic disease. The relative contributions of livestock species to RVFV transmission has not been previously quantified. To estimate their potential to transmit the virus over the course of their infection, we 1) fitted a within-host model to viral RNA and infectious virus measures, obtained daily from infected lambs, calves, and young goats, 2) estimated the relationship between vertebrate host infectious titers and probability to infect mosquitoes, and 3) estimated the net infectiousness of each host species over the duration of their infectious periods, taking into account different survival outcomes for lambs. Our results indicate that the efficiency of viral replication, along with the lifespan of infectious particles, could be sources of heterogeneity between hosts. For similar infectious titers, we found that infection rates in Aedes spp. vectors were significantly higher than in Culex spp. vectors. Consequently, for Aedes infections, we estimated the net infectiousness of lambs to be 2.93 (median) and 3.65 times higher than that of calves and goats, respectively. Among lambs, individuals which eventually died from the infection were 1.93 times more infectious than lambs recovering. Beyond infectiousness, the relative contributions of host species to transmission depend on local ecological factors, including relative abundances and vector host-feeding preferences. Quantifying these contributions will ultimately help design efficient, targeted, surveillance and vaccination strategies.

scholarly journals Feeding behavior of Aedes (Aedimorphus) vexans arabiensis, a Rift valley fever virus vector in the Ferlo pastoral ecosystem of Senegal

2019 ◽  
Author(s):  
Biram Biteye ◽  
Assane Gueye Fall ◽  
Momar Talla Seck ◽  
Mamadou Ciss ◽  
Mariame Diop ◽  
...  
Keyword(s):  
Feeding Behavior ◽  
Blood Meal ◽  
Rift Valley ◽  
Rift Valley Fever ◽  
Rift Valley Fever Virus ◽  
Virus Transmission ◽  
Fever Virus ◽  
Host Feeding ◽  
Aedes Vexans ◽  
Valley Fever

AbstractHost-vector contact is a key factor in vectorial capacity assessment and thus the transmission of mosquito-borne viruses such as Rift Valley Fever (RVF), an emerging zoonotic disease of interest in West Africa. The knowledge of the host-feeding patterns of vector species constitutes a key element in the assessment of their epidemiological importance in a given environment. The aim of this work was to identify the blood meal origins of Aedes vexans arabiensis Patton (Diptera: Culicidae), the main vector of RVF virus in the Ferlo pastoral ecosystem of Senegal. Engorged female mosquitoes were collected in Younouféré in the pastoral ecosystem in the Ferlo region during the 2014 rainy season. CDC light CO2-baited traps were set at six sites for two consecutive nights every month from July to November. Domestic animals present around traps were identified and counted for each trapping session. Blood meal sources of engorged mosquitoes were identified using a vertebrate-specific multiplexed primer set based on cytochrome b. Blood meal sources were successfully identified for 319 out of 416 blood-fed females (76.68%), of which 163 (51.1%) were single meals, 146 (45.77%) mixed meals from two different hosts and 10 (3.13%) mixed meals from three different hosts. Aedes vexans arabiensis fed preferentially on mammals especially on horse compared to other hosts (P < 0.001). Proportions of single and mixed meals showed significant temporal (P < 0.001) and spatial variations (P < 0.001) according to hosts availability. Aedes vexans arabiensis shows an opportunistic feeding behavior depending on the host availability. Results were discussed in relation with the Rift valley fever virus transmission and vector involvement as well as its primary hosts.

Rift Valley fever virus transmission by different Egyptian mosquito species

1987 ◽  
Vol 81 (4) ◽  
pp. 694-698 ◽  
Author(s):  
Adel M. Gad ◽  
Mosaad M. Hassan ◽  
Sharif El Said ◽  
Mahmoud I. Moussa ◽  
Owen L. Wood
Keyword(s):  
Rift Valley ◽  
Rift Valley Fever ◽  
Rift Valley Fever Virus ◽  
Mosquito Species ◽  
Virus Transmission ◽  
Fever Virus ◽  
Valley Fever

scholarly journals Co-housing of Rift Valley Fever Virus Infected Lambs with Immunocompetent or Immunosuppressed Lambs Does Not Result in Virus Transmission

2016 ◽  
Vol 7 ◽  
Author(s):  
Paul J. Wichgers Schreur ◽  
Lucien van Keulen ◽  
Jet Kant ◽  
Nadia Oreshkova ◽  
Rob J. M. Moormann ◽  
...  
Keyword(s):  
Rift Valley ◽  
Rift Valley Fever ◽  
Rift Valley Fever Virus ◽  
Virus Transmission ◽  
Fever Virus ◽  
Valley Fever

scholarly journals Transmission Potential of Rift Valley Fever Virus over the Course of the 2010 Epidemic in South Africa

2013 ◽  
Vol 19 (6) ◽  
pp. 916-924 ◽  
Author(s):  
Raphaëlle Métras ◽  
Marc Baguelin ◽  
W. John Edmunds ◽  
Peter N. Thompson ◽  
Alan Kemp ◽  
...  
Keyword(s):  
South Africa ◽  
Rift Valley ◽  
Rift Valley Fever ◽  
Rift Valley Fever Virus ◽  
Fever Virus ◽  
Valley Fever ◽  
Transmission Potential

scholarly journals Threshold Dynamics in a Periodic Three-Patch Rift Valley Fever Virus Transmission Model

Complexity ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-18 ◽  
Author(s):  
Buyu Wen ◽  
Zhidong Teng ◽  
Wenlin Liu
Keyword(s):  
Rift Valley ◽  
Rift Valley Fever ◽  
Rift Valley Fever Virus ◽  
Virus Transmission ◽  
Operator Method ◽  
Fever Virus ◽  
Transmission Model ◽  
Threshold Dynamics ◽  
Valley Fever ◽  
Threshold Conditions

This paper investigates a three-patch Rift Valley fever virus transmission model with periodic coefficients. The basic reproduction number Ri0i=1,2,3 is calculated for the model by using the next infection operator method. The threshold conditions on the extinction and permanence in the mean of the disease with probability one. The Rift Valley fever disease will be permanent in the j-th j=1,2,3 patch if j≥i,Ri0>1 and dies out in the j-th patch if j<i. The numerical simulations are given to confirm the theoretical results.

scholarly journals Postepidemic Analysis of Rift Valley Fever Virus Transmission in Northeastern Kenya: A Village Cohort Study

2011 ◽  
Vol 5 (8) ◽  
pp. e1265 ◽  
Author(s):  
A. Desirée LaBeaud ◽  
Samuel Muiruri ◽  
Laura J. Sutherland ◽  
Saidi Dahir ◽  
Ginny Gildengorin ◽  
...  
Keyword(s):  
Cohort Study ◽  
Rift Valley ◽  
Rift Valley Fever ◽  
Rift Valley Fever Virus ◽  
Virus Transmission ◽  
Fever Virus ◽  
Valley Fever

scholarly journals The transmission potential of Rift Valley fever virus among livestock in the Netherlands: a modelling study

2013 ◽  
Vol 44 (1) ◽  
pp. 58 ◽  
Author(s):  
Egil AJ Fischer ◽  
Gert-Jan Boender ◽  
Gonnie Nodelijk ◽  
Aline A de Koeijer ◽  
Herman JW van Roermund
Keyword(s):  
The Netherlands ◽  
Rift Valley ◽  
Rift Valley Fever ◽  
Rift Valley Fever Virus ◽  
Fever Virus ◽  
Valley Fever ◽  
Transmission Potential ◽  
Modelling Study

scholarly journals Drivers of Rift Valley fever virus persistence and the impact of control measures in a spatially heterogeneous landscape: the case of the Comoros archipelago, 2004–2015

2021 ◽  
Author(s):  
Warren S. D. Tennant ◽  
Eric Cardinale ◽  
Catherine Cêtre-Sossah ◽  
Youssouf Moutroifi ◽  
Gilles Le Godais ◽  
...  
Keyword(s):  
Rift Valley ◽  
Rift Valley Fever ◽  
Rift Valley Fever Virus ◽  
Virus Transmission ◽  
Control Measures ◽  
Virus Persistence ◽  
Valley Fever ◽  
Grande Comore ◽  
The Many ◽  
The Impact

AbstractRift Valley fever (RVF) is one of the many zoonotic arboviral haemorrhagic fevers present in Africa. The ability of the pathogen to persist in multiple geographically distinct regions has raised concerns about its potential for spread to and persistence within currently disease-free areas. However, the mechanisms for which RVF virus persistence occurs at both local and broader geographical scales have yet to be fully understood and rigorously quantified. Here, we developed a mathematical metapopulation model describing RVF virus transmission in livestock across the four islands of the Comoros archipelago and fitted this model in a Bayesian framework to surveillance data conducted in livestock across those islands between 2004 and 2015. In doing so, we estimated the importance of island-specific environmental factors and animal movements between those islands on the persistence of RVF virus in the archipelago, and we further tested the impact of different control scenarios on reducing disease burden. We demonstrated that the archipelago network was able to sustain viral transmission over 10 years after assuming only one introduction event during early 2007. Movement restrictions were only useful to control the disease in Anjouan and Mayotte, as Grande Comore and Mohéli were able to self-sustain RVF viral persistence, probably due to local environmental conditions that are more favourable for vectors. We also evidenced that repeated outbreaks during 2004-2020 may have gone under-detected by local surveillance in Grande Comore and Mohéli. Strengthened longterm and coordinated surveillance would enable the detection of viral re-emergence and evaluation of different relevant vaccination programmes.

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