scholarly journals Epidemiologic and Environmental Risk Factors of Rift Valley Fever in Southern Africa from 2008 to 2011

2015 ◽  
Vol 15 (8) ◽  
pp. 502-511 ◽  
Author(s):  
Margaret M. Glancey ◽  
Assaf Anyamba ◽  
Kenneth J. Linthicum
Keyword(s):  
Risk Factors ◽  
Southern Africa ◽  
Environmental Risk ◽  
Rift Valley ◽  
Rift Valley Fever ◽  
Environmental Risk Factors ◽  
Valley Fever

scholarly journals Retrospective Study On Rift Valley Fever in Selected States in Sudan With Reference to Spatial and Animal Patterns

2020 ◽  
Author(s):  
Mohamed Elsadig Mansour ◽  
Tamador mohamed Abdellah ◽  
Selma Kamal ◽  
Atif Alamin Abdelgadir
Keyword(s):  
Risk Factors ◽  
Retrospective Study ◽  
Environmental Risk ◽  
Rift Valley ◽  
Rift Valley Fever ◽  
P Value ◽  
Animal Population ◽  
River Nile ◽  
Valley Fever ◽  
Rain Fall

Abstract Background A retrospective study was performed in selected states of the Sudan that include Gezira state, White Nile, Blue Nile, Khartoum, River Nile and Sennar states in order to investigate the seroprevalence of Rift Valley Fever (RVF) from 2007 to 2016. The risk factors that identified for RVF were locality, species, and animal population. For example, locality and species were significantly associated with seroprevalence of RVF (P-value = 049)(P-value = 0.000) respectively, While animal population was not associated in Gezira state (P-value = .415) and χ2 value was (12.629), however it was significantly associated in other regions. The highest seroprevalence estimated for RVF was 0.7% in River Nile state, while lowest seroprevalence for RVF recorded was 0.01% in Khartoum and Sennar states, respectively. Methods The current study was carried out in selected states in Central Sudan to investigate the epidemiology of RVF. Also it was focused on livestock in particular sheep, goat and cattle. Study design was retrospective to investigate seroprevalence, risk factors and spatial and animal patterns associated with RVF from 2007 to 2016. Result Estimated seroprevalence of RVF was 0.15% (n = 905) in sheep, 0.20%( n = 776) in goats and 0.13%( n = 638) in cattle respectively. The risk factors that identified for RVF were locality, species, and animal population. For example, locality and species were significantly associated with seroprevalence of RVF (P-value = 049)(P-value = 0.000) respectively, While animal population was not associated in Gezira state (P-value = .415). Environmental risk factors i.e. annual temperature and annual rain fall were compared to RVF occurrence in study area with average mean of 29.0ºC and 398.8 mm Conclusion Rift valley fever is arthropod-born zoonosis disease. It affects livestock like sheep, goat, cattle and camel .it usually occurs following heavy rainfall and cause storm of abortion in pregnant animals. The principle vector of RVF is Mosquitoe and also it is transmitted through tissues of infected animal and human and also through of undercooked milk. In spite of there is no confirmed cases that can be transmitted from person to person by direct contact. It is characterized in human by influenza- like illness, in moderate cases can develop retinitis and eye infection and severe complication can cause hemorrhagic form with oozing of blood from natural orifices, the morbidity and mortality rate is varying from 5–100% in livestock, death rate can reach up to 10% and case fatality rate is less than one percent. The vaccination against RVF is used in case of outbreak and suspected cases in livestock; however there is no available vaccine for human usage. The current study is retrospective survey to investigate the seroprevalence, risk factor and spatial and animal patterns in selected states in Sudan. Estimated seroprevalence of RVF was 0.15% (n = 905) in sheep, 0.20%( n = 776) in goats and 0.13%( n = 638) in cattle respectively. The risk factors that identified for RVF were locality, species, and animal population. For instance, locality and species were significantly associated with seroprevalence of RVF (P-value = 049), (P-value = 0.000) respectively, While animal population was not associated in Gezira state (P-value = .415). Environmental risk factors i.e. annual temperature and annual rain fall were compared to RVF occurrence in study area with average mean of 29.0ºC and 398.8 mm respectively.

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 Farm-Level Risk Factors of Increased Abortion and Mortality in Domestic Ruminants during the 2010 Rift Valley Fever Outbreak in Central South Africa

Pathogens ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 914
Author(s):  
Melinda K. Rostal ◽  
Sarah Cleaveland ◽  
Claudia Cordel ◽  
Lara van Staden ◽  
Louise Matthews ◽  
...  
Keyword(s):  
Risk Factors ◽  
South Africa ◽  
Rift Valley ◽  
Rift Valley Fever ◽  
Strong Support ◽  
Individual Risk ◽  
Valley Fever ◽  
Farm Level ◽  
Domestic Ruminants ◽  
Central South

(1) Background: Rift Valley fever (RVF) outbreaks in domestic ruminants have severe socio-economic impacts. Climate-based continental predictions providing early warnings to regions at risk for RVF outbreaks are not of a high enough resolution for ruminant owners to assess their individual risk. (2) Methods: We analyzed risk factors for RVF occurrence and severity at the farm level using the number of domestic ruminant deaths and abortions reported by farmers in central South Africa during the 2010 RVF outbreaks using a Bayesian multinomial hurdle framework. (3) Results: We found strong support that the proportion of days with precipitation, the number of water sources, and the proportion of goats in the herd were positively associated with increased severity of RVF (the numbers of deaths and abortions). We did not find an association between any risk factors and whether RVF was reported on farms. (4) Conclusions: At the farm level we identified risk factors of RVF severity; however, there was little support for risk factors of RVF occurrence. The identification of farm-level risk factors for Rift Valley fever virus (RVFV) occurrence would support and potentially improve current prediction methods and would provide animal owners with critical information needed in order to assess their herd’s risk of RVFV infection.

scholarly journals Survey of Antibodies to Rift Valley Fever Virus and Associated Risk Factors in One-Humped Camels (Camelus dromedarius) Slaughtered in Maiduguri Abattoir, Borno State, Nigeria

2021 ◽  
Author(s):  
Hassan Ismail Musa ◽  
Caleb Ayuba Kudi ◽  
Muhammad Mamman Gashua ◽  
Abubakar Sadiq Muhammad ◽  
Abdulyeken Olawale Tijjani ◽  
...  
Keyword(s):  
Risk Factors ◽  
Rift Valley ◽  
Rift Valley Fever ◽  
Body Condition Score ◽  
Rift Valley Fever Virus ◽  
Cross Sectional Study ◽  
Post Mortem ◽  
Monitoring And Control ◽  
Cross Sectional ◽  
Valley Fever

Abstract Rift Valley fever (RVF) is an emerging mosquito-borne zoonosis that threatens public health and animal agriculture in the endemic areas causing devastating epizootics characterized by abortion storms and high mortalities, especially in newborn animals. A cross-sectional study was conducted to determine the seroprevalence and investigate risk factors associated with exposure to the virus in camels slaughtered in Maiduguri abattoir, Borno state of Nigeria. Camels presented for slaughtered were sampled and data on age, sex, source or origin, utility, presence of post mortem lesions, body weights and body condition score were collected. Blood samples were collected and sera were harvested and stored at -20°C until tested. The sera were tested using a commercial ELISA kit based on the manufacturer's instructions. The overall seroprevalence in the study was 20.7% (95% CI, 13.6 – 30.0). The analysis showed no significant differences between presence of antibodies and variables that included the sex of camels (c2=0.015, df = 1, p = 0.904) and presence of post mortem lesion on the carcass (c2=0.009, df = 1, p = 0.925). There were significant differences between presence of antibodies and three variables that included the age (c2= 4.89, df = 1, p = 0.027), the source (c2= 7.077, df = 2, p = 0.029) and the main utility (c2= 8.057, df = 3, p = 0.045) of the camels. It was concluded that camels presented for slaughter at the Maiduguri abattoir have evidence of exposure to the RVF virus and may be means of transmission of the virus. Regular monitoring and control of transboundary animal movements were recommended in the study area.

scholarly journals Indigenous knowledge of Rift Valley Fever among Somali nomadic pastoralists and its implications on public health delivery approaches in Ijara sub-County, North Eastern Kenya

2021 ◽  
Vol 15 (2) ◽  
pp. e0009166
Author(s):  
Geoffrey Otieno Muga ◽  
Washington Onyango-Ouma ◽  
Rosemary Sang ◽  
Hippolyte Affognon
Keyword(s):  
Public Health ◽  
Risk Factors ◽  
Indigenous Knowledge ◽  
Rift Valley ◽  
Rift Valley Fever ◽  
Signs And Symptoms ◽  
Early Warning Systems ◽  
Valley Fever ◽  
Health Delivery ◽  
Nomadic Pastoralists

Rift Valley Fever (RVF) is a zoonotic disease whose outbreak results in heavy economic and public health burdens. In East Africa, RVF is mainly experienced in arid and semi-arid areas predominantly inhabited by the pastoralists. These areas experience sudden, dramatic epidemics of the disease at intervals of approximately 10 years, associated with widespread flooding and the resultant swarms of mosquitoes. Pastoralists’ indigenous knowledge and experience of RVF is critical for public health interventions targeting prevention and control of RVF. The study adopted a descriptive cross-sectional design combining both quantitative and qualitative methods of data collection. A total of 204 respondents participated in questionnaire survey and 15 key informants and 4 focus group discussions were interviewed and conducted respectively. In addition, secondary data mainly journal publications, books, policy documents and research reports from conferences and government departments were reviewed. Findings indicated that the Somali pastoralists possess immense knowledge of RVF including signs and symptoms, risk factors, and risk pathways associated with RVF. Ninety eight percent (98%) of respondents identified signs and symptoms such as bloody nose, diarrhea, foul smell and discharge of blood from the orifices which are consistent with RVF. Heavy rains and floods (85%) and sudden emergence of mosquito swarms (91%) were also cited as the major RVF risk factors while mosquito bites (85%), drinking raw milk and blood (78%) and contact with animal fluids during mobility, slaughter and obstetric procedures (77%) were mentioned as the RVF entry risk pathways. Despite this immense knowledge, the study found that the pastoralists did not translate the knowledge into safer health practices because of the deep-seated socio-cultural practices associated with pastoralist production system and religious beliefs. On top of these practices, food preparation and consumption practices such as drinking raw blood and milk and animal ritual sacrifices continue to account for most of the mortality and morbidity cases experienced in humans and animals during RVF outbreaks. This article concludes that pastoralists’ indigenous knowledge on RVF has implications on public health delivery approaches. Since the pastoralists’ knowledge on RVF was definitive, integrating the community into early warning systems through training on reporting mechanisms and empowering the nomads to use their mobile phone devices to report observable changes in their livestock and environment could prove very effective in providing information for timely mobilization of public health responses. Public health advocacy based on targeted and contextually appropriate health messaging and disseminated through popular communication channels in the community such as the religious leaders and local radio stations would also be needed to reverse the drivers of RVF occurrence in the study area.

scholarly journals Serological evidence of Rift Valley fever infection and risk factors among one-humped camels (Camelus dromedarius) in Northern Nigeria

2020 ◽  
Author(s):  
Adamu Andrew Musa ◽  
Yila Simon Ayo ◽  
Allam Lushakyaa ◽  
Sackey Anthony ◽  
Alhaji Nma Bida ◽  
...  
Keyword(s):  
Risk Factors ◽  
High Risk ◽  
Local Government ◽  
Rift Valley ◽  
Rift Valley Fever ◽  
Animal Species ◽  
Serological Evidence ◽  
Cross Sectional ◽  
Valley Fever ◽  
Factors Associated

AbstractBackgroundRift Valley fever (RVF) is a zoonotic disease that has become emerging and re-emerging in some regions of the world, infecting livestock and humans. One-humped camels are important economic livestock species in Africa used for traction, transportation, and food. Regional and international trade has continued to increase the risk of this disease, spreading widely and causing severe economic and public health catastrophes in affected regions. In spite of these risks, there is a dearth of information about the status of RVF in camels in Nigeria. This study was carried out to determine the prevalence of the RVF virus in one-humped camels in Nigeria and identify the risk factors associated with the disease.MethodsA cross-sectional study with simple random sampling was carried out in seven local government areas of Jigawa and Katsina States. The sera from camels were tested for anti-RVFV IgG. Camel owners were administered a structured questionnaire to ascertain their knowledge, attitude, and practice.ResultsAn overall prevalence of 19.9% (95% CI; 17.07-22.90) was recorded. Based on age groups, the highest prevalence of 20.9% (95% CI; 17.00-25.31) was obtained among older camels (6-10 years), while female camels recorded a high prevalence of 20.4% (95%CI; 15.71-25.80). Sule Tankar-kar recorded the highest prevalence with 33% (95%CI; 1.31-4.72, p= 0.007) and OR 2.47 in Jigawa State while Mai’adua had 24.7% (95%CI; 0.97-2.73, p=0.030) with OR 1.62 in Katsina State respectively. From the risk map, local government areas bordering Niger Republic were at a high risk of RVF. Only high rainfall was not significantly linked with RVF occurrence among nomadic camel pastoralists (95%CI 0.93-5.20; p=0.070).ConclusionThere is a need for the country to have quarantine units across borders for screening animals coming from neighbouring countries for transboundary infectious diseases such as RVF.Author SummaryRift Valley fever is a viral haemorrhagic fever that affects animals and humans with high mortality. Recently there has been increased demand in camel meat and products for food and therapeutic purposes. Climate change, coupled with insecurity in the Sahel, has had a significant impact on transhumance activities where camels and their owners move to different countries in search of pasture for their animals. Though Nigeria has not reported an outbreak of Rift Valley fever despite serological evidence in various animal species, there is a need to assess RVF in camels, which is a critical animal species, involved in transhumance with the potential of introducing transboundary diseases into new areas. The study assessed the presence of antibodies in camels, identified risk factors associated with the disease in camels and areas at risk for the disease. Our study found a seroprevalence of 19.9% in camels in two northern states of Nigeria, which shares a boundary with the Niger Republic that recently reported an outbreak. Our findings suggest that areas in proximity to Niger Republic are at a high risk to the disease and camels belonging to transhumance pastoralists are highly likely to contract Rift Valley fever since they are exposed to various ecological and environmental factors that precipitate the disease.

scholarly journals Perceived risk factors and risk pathways of Rift Valley fever in cattle in Ijara district, Kenya

2014 ◽  
Vol 81 (1) ◽  
Author(s):  
Nelson O. Owange ◽  
William O. Ogara ◽  
Jacqueline Kasiiti ◽  
Peter B. Gathura ◽  
Sam Okuthe ◽  
...  
Keyword(s):  
Risk Factors ◽  
Perceived Risk ◽  
Rift Valley ◽  
Rift Valley Fever ◽  
Close Contact ◽  
Economic Losses ◽  
Cross Sectional ◽  
Valley Fever ◽  
Key Informants ◽  
Control And Prevention

Ijara district in Kenya was one of the hotspots of Rift Valley fever (RVF) during the 2006/2007 outbreak, which led to human and animal deaths causing major economic losses. The main constraint for the control and prevention of RVF is inadequate knowledge of the risk factors for its occurrence and maintenance. This study was aimed at understanding the perceived risk factors and risk pathways of RVF in cattle in Ijara to enable the development of improved community-based disease surveillance, prediction, control and prevention. A cross-sectional study was carried out from September 2012 to June 2013. Thirty-one key informant interviews were conducted with relevant stakeholders to determine the local pastoralists’ understanding of risk factors and risk pathways of RVF in cattle in Ijara district. All the key informants perceived the presence of high numbers of mosquitoes and large numbers of cattle to be the most important risk factors contributing to the occurrence of RVF in cattle in Ijara. Key informants classified high rainfall as the most important (12/31) to an important (19/31) risk factor. The main risk pathways were infected mosquitoes that bite cattle whilst grazing and at watering points as well as close contact between domestic animals and wildlife. The likelihood of contamination of the environment as a result of poor handling of carcasses and aborted foetuses during RVF outbreaks was not considered an important pathway. There is therefore a need to conduct regular participatory community awareness sessions on handling of animal carcasses in terms of preparedness, prevention and control of any possible RVF epizootics. Additionally, monitoring of environmental conditions to detect enhanced rainfall and flooding should be prioritised for preparedness.

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