scholarly journals Over 100 Years of Rift Valley Fever: A Patchwork of Data on Pathogen Spread and Spillover

Pathogens ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 708
Author(s):  
Gebbiena M. Bron ◽  
Kathryn Strimbu ◽  
Hélène Cecilia ◽  
Anita Lerch ◽  
Sean M. Moore ◽  
...  
Keyword(s):  
Rift Valley ◽  
Rift Valley Fever ◽  
Rift Valley Fever Virus ◽  
Economic Losses ◽  
Valley Fever ◽  
Critical Data ◽  
The Past ◽  
Data Gaps ◽  
Combined Data

During the past 100 years, Rift Valley fever virus (RVFV), a mosquito-borne virus, has caused potentially lethal disease in livestock, and has been associated with significant economic losses and trade bans. Spillover to humans occurs and can be fatal. Here, we combined data on RVF disease in humans (22 countries) and animals (37 countries) from 1931 to 2020 with seroprevalence studies from 1950 to 2020 (n = 228) from publicly available databases and publications to draw a more complete picture of the past and current RVFV epidemiology. RVFV has spread from its original locus in Kenya throughout Africa and into the Arabian Peninsula. Throughout the study period seroprevalence increased in both humans and animals, suggesting potentially increased RVFV exposure. In 24 countries, animals or humans tested positive for RVFV antibodies even though outbreaks had never been reported there, suggesting RVFV transmission may well go unnoticed. Among ruminants, sheep were the most likely to be exposed during RVF outbreaks, but not during periods of cryptic spread. We discuss critical data gaps and highlight the need for detailed study descriptions, and long-term studies using a one health approach to further convert the patchwork of data to the tale of RFV epidemiology.

scholarly journals Over 100 years of Rift Valley Fever: a patchwork of data on pathogen spread and spillover

2021 ◽  
Author(s):  
Gebbiena M. Bron ◽  
Kathryn Strimbu ◽  
Hélène Cecilia ◽  
Anita Lerch ◽  
Sean Moore ◽  
...  
Keyword(s):  
Rift Valley ◽  
Rift Valley Fever ◽  
Rift Valley Fever Virus ◽  
Economic Losses ◽  
Valley Fever ◽  
Test Characteristics ◽  
Western Asia ◽  
Study Population ◽  
Combined Data

AbstractDuring the past 100 years, Rift Valley fever virus (RVFV), a mosquito-borne virus, has caused potentially lethal disease in livestock, and has been associated with significant economic losses and trade bans. Spillover to humans occurs and can be fatal. Here, we combined data on RVF disease in humans (22 countries) and animals (37 countries) from 1931 to 2020 with seroprevalence studies from 1950 to 2020 (N=226) from publicly available databases and publications to further the understanding of RVFV epidemiology. RVFV has spread from its original focus in Kenya throughout Africa. In 2000, RVFV was first detected in the Arabian peninsula. Since then seropositive animals have been observed in additional countries in western Asia. Throughout the study period, seroprevalence increased in both humans and animals, suggesting potentially increased RVFV exposure. Among ruminants, sheep were most likely to be exposed during RVF outbreaks, but not during periods of cryptic spread. Filling data gaps, detailed study descriptions (e.g., study population details, diagnostic test characteristics), and long-term studies using a one health approach will aid to further convert the patchwork of data to the tale of RFV epidemiology and inform surveillance and intervention strategies.

scholarly journals The Change P82L in the Rift Valley Fever Virus NSs Protein Confers Attenuation in Mice Not Related with a Type-I IFN Antagonistic Phenotype

2021 ◽  
Author(s):  
Belén Borrego ◽  
Sandra Moreno ◽  
Nuria de la Losa ◽  
Friedemann Weber ◽  
Alejandro Brun
Keyword(s):  
Amino Acid ◽  
Rift Valley ◽  
Rift Valley Fever ◽  
Rift Valley Fever Virus ◽  
Fever Virus ◽  
Single Amino Acid ◽  
Economic Losses ◽  
Type I ◽  
Valley Fever

Rift valley fever virus (RVFV) is a mosquito-borne bunyavirus that causes an important disease in ruminants, with great economic losses. The infection can be also transmitted to humans; therefore it is considered a major threat to both human and animal health. In a previous work, we described a novel RVFV variant selected in cell culture in the presence of the antiviral agent favipiravir that was highly attenuated in vivo. This variant displayed 24 amino acid substitutions in different viral proteins when compared to its parental viral strain, two of them located in the NSs protein that is known to be the major virulence factor of RVFV. By means of a reverse genetics system, in this work we have analyzed the effect that one of these substitutions, P82L, has in viral attenuation in vivo. Rescued viruses carrying this single amino acid change were clearly attenuated in BALB/c mice while their growth in an IFN-competent cell line as well as the production of IFN-β did not seem to be affected. However, the pattern of nuclear NSs accumulation was modified in cells infected with the mutant viruses. These results unveil a new RVFV virulence marker highlighting the multiple ways of NSs protein to modulate viral infectivity.

scholarly journals Interacting Factors That Influence Long-term Storage of Live Pasteurella tularensis Vaccine and Rift Valley Fever Virus

1969 ◽  
Vol 17 (3) ◽  
pp. 427-434
Author(s):  
Frederick Klein ◽  
Jerry S. Walker ◽  
Bill G. Mahlandt ◽  
Richard C. Carter ◽  
Michael D. Orlando ◽  
...  
Keyword(s):  
Rift Valley ◽  
Rift Valley Fever ◽  
Rift Valley Fever Virus ◽  
Fever Virus ◽  
Valley Fever ◽  
Long Term Storage ◽  
Term Storage

scholarly journals Interacting Factors That Influence Long-term Storage of Live Pasteurella tularensis Vaccine and Rift Valley Fever Virus

1969 ◽  
Vol 17 (3) ◽  
pp. 427-434 ◽  
Author(s):  
Frederick Klein ◽  
Jerry S. Walker ◽  
Bill G. Mahlandt ◽  
Richard C. Carter ◽  
Michael D. Orlando ◽  
...  
Keyword(s):  
Rift Valley ◽  
Rift Valley Fever ◽  
Rift Valley Fever Virus ◽  
Fever Virus ◽  
Valley Fever ◽  
Long Term Storage ◽  
Term Storage

scholarly journals The Change P82L in the Rift Valley Fever Virus NSs Protein Confers Attenuation in Mice

Viruses ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 542
Author(s):  
Belén Borrego ◽  
Sandra Moreno ◽  
Nuria de la Losa ◽  
Friedemann Weber ◽  
Alejandro Brun
Keyword(s):  
Amino Acid ◽  
Rift Valley ◽  
Rift Valley Fever ◽  
Rift Valley Fever Virus ◽  
Fever Virus ◽  
Single Amino Acid ◽  
Economic Losses ◽  
Valley Fever ◽  
Single Amino Acid Change

Rift Valley fever virus (RVFV) is a mosquito-borne bunyavirus that causes an important disease in ruminants, with great economic losses. The infection can be also transmitted to humans; therefore, it is considered a major threat to both human and animal health. In a previous work, we described a novel RVFV variant selected in cell culture in the presence of the antiviral agent favipiravir that was highly attenuated in vivo. This variant displayed 24 amino acid substitutions in different viral proteins when compared to its parental viral strain, two of them located in the NSs protein that is known to be the major virulence factor of RVFV. By means of a reverse genetics system, in this work we have analyzed the effect that one of these substitutions, P82L, has in viral attenuation in vivo. Rescued viruses carrying this single amino acid change were clearly attenuated in BALB/c mice while their growth in an interferon (IFN)-competent cell line as well as the production of interferon beta (IFN-β) did not seem to be affected. However, the pattern of nuclear NSs accumulation was modified in cells infected with the mutant viruses. These results highlight the key role of the NSs protein in the modulation of viral infectivity.

scholarly journals Development of a Lateral Flow Kit for Detection of IgG and IgM Antibodies Against Rift Valley Fever Virus in Sheep

2019 ◽  
Vol 15 (02) ◽  
pp. 63-68
Author(s):  
Rafik Hamed Sayed ◽  
Mohamed S Abousenna ◽  
Darwish Mohamoud ◽  
Mohamed A Saad
Keyword(s):  
Rift Valley ◽  
Rift Valley Fever ◽  
Test Line ◽  
Rift Valley Fever Virus ◽  
Lateral Flow ◽  
Economic Losses ◽  
Staphylococcal Protein A ◽  
Valley Fever ◽  
Igm Antibodies ◽  
Nano Gold

Rift Valley Fever (RVF) is a viral zoonosis that primarily affects animals but also has the capacity to infect humans. The disease also results in significant economic losses due to death and abortion among RVF-infected livestock. A lateral flow device (LFD) was developed for the rapid detection of IgG and IgM anti-RVF antibodies in infected and vaccinated ovine sera. The conjugated RVF antigen with nano-gold was used as a detector antigen and was laid on a conjugated pad. The staphylococcal protein A was used as the capture complex (antibodies IgG-antigen conjugated with nanogold) at the first test line of device and anti-IgM antibodies were used as the capture complex (antibodies IgM-antigen conjugated with nanogold) at the second test line of device. When compared with RVF specific ELISA, The sensitivity, specificity, and accuracy of developed LFD for detection of IgG were found to be 88.2, 96.9 and 94.0%, respectively, while the same for detection of IgM was found to be 100, 96, and 96%, respectively.

scholarly journals A Hyper-Attenuated Variant of Rift Valley Fever Virus Generated by a Mutagenic Drug (Favipiravir) Unveils Potential Virulence Markers

2021 ◽  
Vol 11 ◽  
Author(s):  
Belén Borrego ◽  
Alejandro Brun
Keyword(s):  
Rift Valley ◽  
Rift Valley Fever ◽  
Rift Valley Fever Virus ◽  
Fever Virus ◽  
Economic Losses ◽  
Type I ◽  
Valley Fever ◽  
Virulence Markers ◽  
Drug Concentrations

Rift Valley fever virus (RVFV) is a mosquito-borne bunyavirus that causes Rift Valley fever (RVF), a zoonotic disease of wild and domestic ruminants, causing serious economic losses and a threat to human health that could be controlled by vaccination. Though RVF vaccines are available for livestock, no RVF vaccines have been licensed for veterinary use in non-endemic countries nor for human populations in RVF risk areas. In a recent work, we showed that favipiravir, a promising drug with antiviral activity against a number of RNA viruses, led to the extinction of RVFV from infected cell cultures. Nevertheless, certain drug concentrations allowed the recovery of a virus variant showing increased resistance to favipiravir. In this work, we characterized this novel resistant variant both at genomic and phenotypic level in vitro and in vivo. Interestingly, the resistant virus displayed reduced growth rates in C6/36 insect cells but not in mammalian cell lines, and was highly attenuated but still immunogenic in vivo. Some amino acid substitutions were identified in the viral RNA-dependent RNA-polymerase (RdRp) gene and in the virus encoded type I-interferon (IFN-I) antagonist NSs gene, in catalytic core motifs and nuclear localization associated positions, respectively. These data may help to characterize novel potential virulence markers, offering additional strategies for further safety improvements of RVF live attenuated vaccine candidates.

Complement fixation reaction of Rift Valley fever virus

1950 ◽  
Vol 5 (5) ◽  
pp. 243-247
Author(s):  
Minoru MATSUMOTO ◽  
Saburo IWASA ◽  
Motosige ENDO
Keyword(s):  
Rift Valley ◽  
Rift Valley Fever ◽  
Complement Fixation ◽  
Rift Valley Fever Virus ◽  
Fever Virus ◽  
Valley Fever ◽  
Fixation Reaction
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