scholarly journals Comparison of techniques for demonstrating antibodies to Rift Valley fever virus

1986 ◽  
Vol 97 (2) ◽  
pp. 317-329 ◽  
Author(s):  
R. Swanepoel ◽  
J. K. Struthers ◽  
M. J. Erasmus ◽  
S. P. Shepherd ◽  
G. M. McGillivray ◽  
...  
Keyword(s):  
Rift Valley ◽  
Rift Valley Fever ◽  
Rift Valley Fever Virus ◽  
Protein A ◽  
Haemagglutination Inhibition ◽  
Enzyme Linked Immunosorbent Assay ◽  
Staphylococcal Protein A ◽  
Valley Fever ◽  
Neutralization Techniques ◽  
Comparison Of Techniques

SummaryNine serological techniques were compared by monitoring the response to infection with Rift Valley fever (RVF) virus in three sheep. Antibodies were monitored daily for the first 14 days after infection, then weekly and later fortnightly up to week 24. The earliest antibody response was detected in one sheep on day 3 by a plaque reduction neutralization test, and by day 6 antibodies were demonstrable in all three sheep by haemagglutination-inhibition, reversed passive haemagglutination-inhibition, immunodiffusion, indirect immunofluorescence (IF), enzyme-linked immunosorbent assay and neutralization of cytopathic effect in cell cultures. Antibodies were demonstrable by complement fixation on day 8 at the earliest. IF and the two neutralization techniques produced the highest titres, but all tests could be used satisfactorily for the serological diagnosis of RVF. Inactivated antigen could be used for all except the neutralization tests. A radioimmunoassay technique using125I-labelIed staphylococcal protein A detected antibodies on day 8 at the earliest and produced lower mean titres than some of the other techniques. This was probably because sheep immunoglobulins bind protein A poorly.

scholarly journals Seroprevalence and associated risk factors of Rift Valley fever in cattle and selected wildlife species at the livestock/wildlife interface areas of Gonarezhou National Park, Zimbabwe

2020 ◽  
Vol 87 (1) ◽  
Author(s):  
Masimba Ndengu ◽  
Gift Matope ◽  
Musavengana Tivapasi ◽  
Davies M. Pfukenyi ◽  
Catherine Cetre-Sossah ◽  
...  
Keyword(s):  
Risk Factors ◽  
Rift Valley ◽  
National Park ◽  
Rift Valley Fever ◽  
Rift Valley Fever Virus ◽  
Enzyme Linked Immunosorbent Assay ◽  
Valley Fever ◽  
Wildlife Species ◽  
Porous Interface ◽  
Associated Risk Factors

A study was conducted to investigate the seroprevalence and associated risk factors of Rift Valley fever (RVF) infection in cattle and some selected wildlife species at selected interface areas at the periphery of the Great Limpopo Transfrontier Conservation Area in Zimbabwe. Three study sites were selected based on the type of livestock–wildlife interface: porous livestock–wildlife interface (unrestricted); non-porous livestock–wildlife interface (restricted by fencing) and livestock–wildlife non-interface (totally absent contact or control). Sera were collected from cattle aged ≥ 2 years representing both female and intact male. Sera were also collected from selected wild ungulates from Mabalauta (porous interface) and Chipinda Pools (non-interface) areas of the Gonarezhou National Park. Sera were tested for antibodies to Rift Valley fever virus (RVFV) using a competitive enzyme-linked immunosorbent assay (ELISA) test. AX2 test was used to assess differences between categories, and p 0.05 was considered as significant. In cattle, the overall seroprevalence was 1.7% (17/1011) (95% confidence interval [CI]: 1.01–2.7). The porous interface recorded a seroprevalence of 2.3% (95% CI: 1.2–4.3), the non-porous interface recorded a prevalence of 1.8% (95% CI: 0.7–4.3) and the non-interface area recorded a seroprevalence of 0.4% (955 CI: 0.02–2.5), but the difference in seroprevalence according to site was not significant (p 0.05). All impala and kudu samples tested negative. The overall seroprevalence in buffaloes was 11.7% (95% CI: 6.6–19.5), and there was no significant (p = 0.38) difference between the sites (Mabalauta, 4.4% [95% CI: 0.2–24] vs. Chipinda, 13.6% [95% CI: 7.6–23]). The overall seroprevalence in buffaloes (11.7%, 13/111) was significantly (p 0.0001) higher than in cattle (1.7%, 17/1011). The results established the presence of RVFV in cattle and selected wildlife and that sylvatic infections may be present in buffalo populations. Further studies are required to investigate if the virus is circulating between cattle and wildlife.

scholarly journals Detection of the Northeastern African Rift Valley Fever Virus Lineage During the 2015 Outbreak in Mauritania

2017 ◽  
Vol 4 (2) ◽  
Author(s):  
Ndeye Sakha Bob ◽  
Hampâté Bâ ◽  
Gamou Fall ◽  
Elkhalil Ishagh ◽  
Mamadou Y. Diallo ◽  
...  
Keyword(s):  
Rift Valley ◽  
Rift Valley Fever ◽  
Rift Valley Fever Virus ◽  
Hemorrhagic Fever ◽  
Enzyme Linked Immunosorbent Assay ◽  
Rt Pcr ◽  
West Nile ◽  
Valley Fever ◽  
Blood Samples ◽  
Crimean Congo Hemorrhagic Fever

Abstract Background Rift Valley fever (RVF) is an acute viral anthropozoonosis that causes epizootics and epidemics among livestock population and humans. Multiple emergences and reemergences of the virus have occurred in Mauritania over the last decade. This article describes the outbreak that occurred in 2015 in Mauritania and reports the results of serological and molecular investigations of blood samples collected from suspected RVF patients. Methods An RVF outbreak was reported from 14 September to 26 November 2015 in Mauritania. Overall, 184 suspected cases from different localities were identified by 26 health facilities. Blood samples were collected and tested by enzyme-linked immunosorbent assay (ELISA) and real-time reverse-transcription polymerase chain reaction (RT-PCR) at the Institut Pasteur de Dakar (IPD). Sequencing of partial genomes and phylogenetic analyses were performed on RT-PCR–positive samples. As part of routine surveillance at IPD, samples were also screened for dengue, yellow fever, West Nile, Crimean Congo hemorrhagic fever, Zika, and Chikungunya viruses by ELISA and RT-PCR. Results Of the 184 suspected cases, there were 57 confirmed cases and 12 deaths. Phylogenetic analysis of the sequences indicated an emergence of a virus that originated from Northeastern Africa. Our results show co-circulation of other arboviruses in Mauritania—dengue, Crimean Congo hemorrhagic fever, and West Nile viruses. Conclusion The Northeastern Africa lineage of RVF was responsible for the outbreak in Mauritania in 2015. Co-circulation of multiples arboviruses was detected. This calls for systematic differential diagnosis and highlights the need to strengthen arbovirus surveillance in Africa.

scholarly journals Severe Human Illness Caused by Rift Valley Fever Virus in Mauritania, 2015

2016 ◽  
Vol 3 (4) ◽  
Author(s):  
Boushab Mohamed Boushab ◽  
Fatima Zahra Fall-Malick ◽  
Sidi El Wafi Ould Baba ◽  
Mohamed Lemine Ould Salem ◽  
Marie Roseline Darnycka Belizaire ◽  
...  
Keyword(s):  
Rift Valley ◽  
Rift Valley Fever ◽  
Rift Valley Fever Virus ◽  
Neurological Complication ◽  
Clinical Signs ◽  
Febrile Illness ◽  
Signs And Symptoms ◽  
Epidemiological Surveillance ◽  
Enzyme Linked Immunosorbent Assay ◽  
Valley Fever

Abstract Background Rift Valley Fever epizootics are characterized by numerous abortions and mortality among young animals. In humans, the illness is usually characterized by a mild self-limited febrile illness, which could progress to more serious complications.Objectives. The aim of the present prospective study was to describe severe clinical signs and symptoms of Rift Valley Fever in southern Mauritania. Patients and methods Suspected cases were enrolled in Kiffa (Assaba) and Aleg (Brakna) Hospital Centers from September 1 to November 7, 2015, based on the presence of fever, hemorrhagic or meningoencephalitic syndromes, and probable contact with sick animals. Suspected cases were confirmed by enzyme-linked immunosorbent assay (ELISA) and reverse transcriptase-polymerase chain reaction (RT-PCR). Results There were thirty-one confirmed cases. The sex ratio M/F and the average age were 2.9 and 25 years old [range, 4-70 years old], respectively. Mosquito bites, direct contact with aborted or dead animals, and frequent ingestion of milk from these animals were risk factors observed in all patients. Hemorrhagic and neurological manifestations were observed in 81% and 13% of cases, respectively. The results of laboratory analysis showed high levels of transaminases, creatinine, and urea associated with thrombocytopenia, anemia, and leukopenia. All patients who died (42%) had a hemorrhagic syndrome and 3 of them had a neurological complication. Among the cured patients, none had neurologic sequelae. Conclusion The hemorrhagic form was the most common clinical manifestation of RVF found in southern Mauritania and was responsible for a high mortality rate. Our results justify the implementation of a continuous epidemiological surveillance.

scholarly journals The Nonstructural Protein NSs Induces a Variable Antibody Response in Domestic Ruminants Naturally Infected with Rift Valley Fever Virus

2011 ◽  
Vol 19 (1) ◽  
pp. 5-10 ◽  
Author(s):  
José-Carlos Fernandez ◽  
Agnès Billecocq ◽  
Jean Paul Durand ◽  
Catherine Cêtre-Sossah ◽  
Eric Cardinale ◽  
...  
Keyword(s):  
Antibody Response ◽  
Rift Valley ◽  
Rift Valley Fever ◽  
Nonstructural Protein ◽  
Rift Valley Fever Virus ◽  
High Rate ◽  
Antibody Detection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Valley Fever ◽  
Wide Range

ABSTRACTRift Valley fever (RVF) is an emerging zoonosis in Africa which has spread to Egypt, the Arabian Peninsula, Madagascar, and Comoros. RVF virus (RVFV) (Bunyaviridaefamily,Phlebovirusgenus) causes a wide range of symptoms in humans, from benign fever to fatal hemorrhagic fever. Ruminants are severely affected by the disease, which leads to a high rate of mortality in young animals and to abortions and teratogenesis in pregnant females. Diagnostic tests include virus isolation and genome or antibody detection. During RVFV infection, the nucleoprotein encapsidating the tripartite RNA genome is expressed in large amounts and raises a robust antibody response, while the envelope glycoproteins elicit neutralizing antibodies which play a major role in protection. Much less is known about the antigenicity/immunogenicity of the nonstructural protein NSs, which is a major virulence factor. Here we have developed a competitive enzyme-linked immunosorbent assay (ELISA) enabling detection of low levels of NSs-specific antibodies in naturally infected or vaccinated ruminants. Detection of the NSs antibodies was validated by Western blotting. Altogether, our data showed that the NSs antibodies were detected in only 55% of animals naturally infected by RVFV, indicating that NSs does not induce a consistently high immune response. These results are discussed in light of differentiation between infected and vaccinated animals (DIVA) tests distinguishing naturally infected animals and those vaccinated with NSs-defective vaccines.

scholarly journals Detection of Rift Valley Fever Virus Lineage H from South Africa through Syndromic Sentinel Surveillance Network in Senegal

2021 ◽  
Author(s):  
Ndeye Sakha Bob ◽  
Mamadou Aliou Barry ◽  
Moussa Moise Diagne ◽  
Martin Faye ◽  
Marie Henriette Dior Ndione ◽  
...  
Keyword(s):  
South Africa ◽  
Rift Valley ◽  
Surveillance System ◽  
Rift Valley Fever ◽  
Rift Valley Fever Virus ◽  
Fever Virus ◽  
Enzyme Linked Immunosorbent Assay ◽  
Rt Pcr ◽  
Surveillance Network ◽  
Valley Fever

Abstract Background Rift Valley fever virus (RVFV) is an arbovirus that causes epizootics and epidemics among livestock population and humans. Our surveillance system has revealed multiple emergences and re-emergences of RVFV in West Africa over the last decade. Methods In Senegal a sentinel syndromic surveillance network (4S) has been implemented since 2011. Samples from human suspected arbovirus infection in 4S sentinel sites were sent to Institut Pasteur de Dakar (IPD) where arbovirus diagnosis by enzyme-linked immunosorbent assay (ELISA), real-time reverse transcription polymerase chain reaction (RT-PCR), and virus isolation were performed. Overall, IPD has received a total of 1,149 samples from arboviral suspected patients through the 4S network from January to December 2020. These samples were screened for seven arboviruses including RVFV. Whole genome sequencing of positive RVFV samples by RT-PCR were performed using Illumina Miseq platform followed by genome assembly. Phylogenetic analysis were performed using MEGA X. Results Out of the 1,149 arbovirus suspected cases, four RVFV positive samples were detected with RT-PCR while five RVFV positive samples were detected by ELISA. Complete genome sequences were obtained for three strains among the four positive samples by RT-PCR. Phylogenetic analyses indicated an emergence of a virus first described in South Africa during a major outbreak. Conclusion Strong surveillance system allowed the detection of RVFV outbreak in Senegal in 2020. The obtained genomes clustered with strains from South Africa belonging to lineage H. This calls for an implementation of a strong surveillance system in wild animals, humans, and livestock simultaneously in all African Countrries.

scholarly journals Association between Rift Valley fever virus seroprevalences in livestock and humans and their respective intra-cluster correlation coefficients, Tana River County, Kenya

2018 ◽  
Vol 147 ◽  
Author(s):  
B. Bett ◽  
J. Lindahl ◽  
R. Sang ◽  
M. Wainaina ◽  
S. Kairu-Wanyoike ◽  
...  
Keyword(s):  
Rift Valley ◽  
Rift Valley Fever ◽  
Rift Valley Fever Virus ◽  
Correlation Coefficients ◽  
Enzyme Linked Immunosorbent Assay ◽  
Cross Sectional ◽  
Valley Fever ◽  
Tana River ◽  
Seropositive Animal ◽  
Cluster Correlation

AbstractWe implemented a cross-sectional study in Tana River County, Kenya, a Rift Valley fever (RVF)-endemic area, to quantify the strength of association between RVF virus (RVFv) seroprevalences in livestock and humans, and their respective intra-cluster correlation coefficients (ICCs). The study involved 1932 livestock from 152 households and 552 humans from 170 households. Serum samples were collected and screened for anti-RVFv immunoglobulin G (IgG) antibodies using inhibition IgG enzyme-linked immunosorbent assay (ELISA). Data collected were analysed using generalised linear mixed effects models, with herd/household and village being fitted as random variables. The overall RVFv seroprevalences in livestock and humans were 25.41% (95% confidence interval (CI) 23.49–27.42%) and 21.20% (17.86–24.85%), respectively. The presence of at least one seropositive animal in a household was associated with an increased odds of exposure in people of 2.23 (95% CI 1.03–4.84). The ICCs associated with RVF virus seroprevalence in livestock were 0.30 (95% CI 0.19–0.44) and 0.22 (95% CI 0.12–0.38) within and between herds, respectively. These findings suggest that there is a greater variability of RVF virus exposure between than within herds. We discuss ways of using these ICC estimates in observational surveys for RVF in endemic areas and postulate that the design of the sentinel herd surveillance should consider patterns of RVF clustering to enhance its effectiveness as an early warning system for RVF epidemics.

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