Serological evidence of Rift Valley fever virus infection among domestic ruminant herds in Uganda

Abstract Background Prior to the first recorded outbreak of Rift Valley fever (RVF) in Uganda, in March 2016, earlier studies done until the 1970’s indicated the presence of the RVF virus (RVFV) in the country, without any recorded outbreaks in either man or animals. While severe outbreaks of RVF occurred in the neighboring countries, none were reported in Uganda despite forecasts that placed some parts of Uganda at similar risk. The Ministry of Agriculture, Animal Industry and Fisheries (MAAIF) undertook studies to determine the RVF sero-prevalence in risk prone areas. Three datasets from cattle sheep and goats were obtained; one from retrospective samples collected in 2010–2011 from the northern region; the second from the western region in 2013 while the third was from a cross-sectional survey done in 2016 in the south-western region. Laboratory analysis involved the use of the Enzyme Linked Immunosorbent Assays (ELISA). Data were subjected to descriptive statistical analyses, including non-parametric chi-square tests for comparisons between districts and species in the regions. Results During the Yellow Fever outbreak investigation of 2010–2011 in the northern region, a total sero-prevalence of 6.7% was obtained for anti RVFV reacting antibodies (IgG and IgM) among the domestic ruminant population. The 2013 sero-survey in the western region showed a prevalence of 18.6% in cattle and 2.3% in small ruminants. The 2016 sero-survey in the districts of Kabale, Kanungu, Kasese, Kisoro and Rubirizi, in the south-western region, had the respective district RVF sero-prevalence of 16.0, 2.1, 0.8, 15.1and 2.7% among the domestic ruminants combined for this region; bovines exhibited the highest cumulative sero-prevalence of 15.2%, compared to 5.3 and 4.0% respectively for sheep and goats per species for the region. Conclusions The absence of apparent outbreaks in Uganda, despite neighboring enzootic areas, having minimal restrictions to the exchange of livestock and their products across borders, suggest an unexpected RVF activity in the study areas that needs to be unraveled. Therefore, more in-depth studies are planned to mitigate the risk of an overt RVF outbreak in humans and animals as has occurred in neighboring countries.

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Investigation of Rift Valley Fever Virus Infection Serologically and Pathologically in Aborted Cattle, Sheep, Goats and in Fetuses

Annual Research & Review in Biology ◽

10.9734/arrb/2020/v35i130174 ◽

2020 ◽

pp. 1-6

Author(s):

Mehmet Kale ◽

Sibel Hasircioglu ◽

Özlem Özmen ◽

Nuri Mamak ◽

Sibel Gür ◽

...

Keyword(s):

Rift Valley ◽

Rift Valley Fever ◽

Rift Valley Fever Virus ◽

Western Mediterranean ◽

Fever Virus ◽

Pathological Findings ◽

Elisa Method ◽

Serum Samples ◽

Valley Fever ◽

Sheep And Goats

In this study, Rift Valley Fever Virus (RVFV) infection was searched serologically and pathologically in cattle (178 Holstein), sheep (160 native), goats (66 ordinary goats, 98 Honamli goats, 16 Saanen goats) with an abortion history and in unborn cattle (8), sheep (24) and goat (5) fetus. Samples were collected between July 2009 and September 2010. As a result of studying specific antibodies to RVFV by using the c-ELISA method in blood serum samples collected from cattle, sheep and goats suffering abortion, seropositivity was identified in 7 cattle (7/178; 3.93%), 4 sheep (4/160;2.50%) and 18 goats (18/180;10.0%). 18 seropositive goats were distributed according to race as 13 ordinary goats (19.70%), 2 Honamli goats (2.04%) and 3 Saanen goats (18.75%). When liver, spleen and brain samples of the unborn fetus of cattle, sheep and goats were studied histopathologically, no pathological findings on RVFV disease were obtained. Consequently, in this study, where RVFV infection in cattle, sheep and goats raised in Western Mediterranean Region of Turkey was serologically revealed, it was concluded that RVFV did not take place in the aetiology of abortion cases in relevant species.

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Safety and efficacy of ChAdOx1 RVF vaccine against Rift Valley fever in pregnant sheep and goats

npj Vaccines ◽

10.1038/s41541-019-0138-0 ◽

2019 ◽

Vol 4 (1) ◽

Cited By ~ 4

Author(s):

Anna Stedman ◽

Daniel Wright ◽

Paul J. Wichgers Schreur ◽

Madeleine H. A. Clark ◽

Adrian V. S. Hill ◽

...

Keyword(s):

Rift Valley ◽

Rift Valley Fever ◽

Rift Valley Fever Virus ◽

Febrile Illness ◽

Neutralizing Antibody ◽

High Titre ◽

Valley Fever ◽

Sheep And Goats ◽

Pregnant Sheep ◽

Human Use

Abstract Rift Valley fever virus (RVFV) is a zoonotic mosquito-borne virus that was first discovered in Kenya in 1930 and has since spread to become endemic in much of Africa and the Arabian Peninsula. Rift Valley fever (RVF) causes recurrent outbreaks of febrile illness associated with high levels of mortality and poor outcomes during pregnancy—including foetal malformations, spontaneous abortion and stillbirths—in livestock, and associated with miscarriage in humans. No vaccines are available for human use and those licensed for veterinary use have potential drawbacks, including residual virulence that may contraindicate their use in pregnancy. To address this gap, we previously developed a simian adenovirus vectored vaccine, ChAdOx1 RVF, that encodes RVFV envelope glycoproteins. ChAdOx1 RVF is fully protective against RVF in non-pregnant livestock and is also under development for human use. Here, we now demonstrate that when administered to pregnant sheep and goats, ChAdOx1 RVF is safe, elicits high titre RVFV neutralizing antibody, and provides protection against viraemia and foetal loss, although this protection is not as robust for the goats. In addition, we provide a description of RVFV challenge in pregnant goats and contrast this to the pathology observed in pregnant sheep. Together, our data further support the ongoing development of ChAdOx1 RVF vaccine for use in livestock and humans.

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Seroprevalence of Rift Valley fever virus in sheep and goats in Zambézia, Mozambique

Infection Ecology & Epidemiology ◽

10.3402/iee.v6.31343 ◽

2016 ◽

Vol 6 (1) ◽

pp. 31343 ◽

Cited By ~ 11

Author(s):

Anne-Lie Blomström ◽

Isabelle Scharin ◽

Hedvig Stenberg ◽

Jaquline Figueiredo ◽

Ofélia Nhambirre ◽

...

Keyword(s):

Rift Valley ◽

Rift Valley Fever ◽

Rift Valley Fever Virus ◽

Fever Virus ◽

Valley Fever ◽

Sheep And Goats

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Rift Valley fever virus in small ruminants in the Democratic Republic of the Congo

Onderstepoort Journal of Veterinary Research ◽

10.4102/ojvr.v86i1.1737 ◽

2019 ◽

Vol 86 (1) ◽

Author(s):

Georges M. Tshilenge ◽

Mfumu L.K Mulumba ◽

Gerald Misinzo ◽

Rob Noad ◽

William G. Dundon

Keyword(s):

Rift Valley ◽

Rift Valley Fever ◽

Democratic Republic ◽

Rift Valley Fever Virus ◽

Small Ruminants ◽

Rt Pcr ◽

Recent Infection ◽

Valley Fever ◽

Sheep And Goats ◽

Republic Of The Congo

Rift Valley fever (RVF) is a zoonotic viral disease caused by the RVF phlebovirus (RVFV) that infects a variety of animal species including sheep and goats. Sera (n = 893) collected between 2013 and 2015 from randomly selected indigenous sheep and goats in seven provinces of the Democratic Republic of the Congo (DRC) were tested for the presence of specific immunoglobulin G (IgG) and M (IgM) against RVFV, using two commercially available enzyme-linked immunosorbent assays. The reverse transcription polymerase chain reaction (RT-PCR) was also used to detect RVFV nucleic acid. There was significant variation in true seroprevalence of RVFV for both sheep and goats between the seven provinces investigated. Values ranged from 0.0 (95% confidence interval [CI] 0.0–6.55) to 23.81 (95% CI 12.03–41.76) for goat and 0.0 (95% CI 0.0–7.56) to 37.11 (95% CI 15.48–65.94) for sheep, respectively. One serum (1.85%) out of 54 that tested positive for IgG was found to be IgM-positive. This same sample was also positive by RT-PCR indicating an active or recent infection. These findings report the presence of RVFV in small ruminants in the DRC for the first time and indicate variations in exposure to the virus in different parts of the country.

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Serological Evidence of Rift Valley Fever Virus Circulation in Sheep and Goats in Zambézia Province, Mozambique

PLoS Neglected Tropical Diseases ◽

10.1371/journal.pntd.0002065 ◽

2013 ◽

Vol 7 (2) ◽

pp. e2065 ◽

Cited By ~ 30

Author(s):

José Fafetine ◽

Luis Neves ◽

Peter N. Thompson ◽

Janusz T. Paweska ◽

Victor P. M. G. Rutten ◽

...

Keyword(s):

Rift Valley ◽

Rift Valley Fever ◽

Rift Valley Fever Virus ◽

Fever Virus ◽

Serological Evidence ◽

Valley Fever ◽

Sheep And Goats

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Epidemiological study of Rift Valley fever virus in Kigoma, Tanzania

Onderstepoort Journal of Veterinary Research ◽

10.4102/ojvr.v81i2.717 ◽

2014 ◽

Vol 81 (2) ◽

Cited By ~ 9

Author(s):

Emmanuel G. Kifaro ◽

Japhet Nkangaga ◽

Gradson Joshua ◽

Raphael Sallu ◽

Mmeta Yongolo ◽

...

Keyword(s):

Polymerase Chain Reaction ◽

Reverse Transcriptase ◽

Rift Valley ◽

Rift Valley Fever ◽

Rift Valley Fever Virus ◽

Fever Virus ◽

Chain Reaction ◽

Valley Fever ◽

Sheep And Goats ◽

Polymerase Chain

Rift Valley fever virus (RVFV) is an acute, zoonotic viral disease caused by a Phlebovirus, which belongs to the Bunyaviridae family. Among livestock, outbreaks of the disease are economically devastating. They are often characterised by large, sweeping abortion storms and have significant mortality in adult livestock. The aim of the current study was to investigate RVFV infection in the Kigoma region, which is nestled under the hills of the western arm of the Great Rift Valley on the edge of Lake Tanganyika, Tanzania. A region-wide serosurvey was conducted on non-vaccinated small ruminants (sheep and goats, n = 411). Sera samples were tested for the presence of anti-RVFV antibodies and viral antigen, using commercial enzyme-linked immunosorbent assay and reverse transcriptase polymerase chain reaction, respectively. The overall past infections were detected in 22 of the 411 animals, 5.4% (Confidence Interval (CI) 95% = 3.5% – 8.1%). The Kigoma rural area recorded the higher seroprevalence of 12.0% (CI 95% = 7.3% – 18.3%; p < 0.0001), followed by Kibondo at 2.3% (CI 95% = 0.5% – 6.5%; p > 0.05) and the Kasulu district at 0.8% (CI 95% = 0.0% – 4.2%; p > 0.05). The prevalence was 12.5% and 4.7% for sheep and goats, respectively. Reverse transcriptase polymerase chain reaction results indicated that only eight samples were found to be positive (n = 63). This study has confirmed, for the first time, the presence of the RVFV in the Kigoma region four years after the 2007 epizootic in Tanzania. The study further suggests that the virus activity exists during the inter-epizootic period, even in regions with no history of RVFV.

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