Learning the lessons of Rift Valley fever: Improved detection and mitigation of outbreaks

Permanent URI for this collectionhttps://hdl.handle.net/10568/32816

This project has two components: (1) participatory assessment of Rift Valley fever (RVF) surveillance and rapid response activities and (2) economic impact assessment and identification of cost-effective mitigation measures. The first component is aimed at assessing the 2007 outbreak of RVF in Kenya in order to identify key lessons on how to better predict, detect and respond to RVF. This will also provide information on how to better engage decision-makers to act promptly and appropriately in response to future outbreaks of the disease. The second component will leverage the information generated from the participatory assessment towards developing tools that improve risk management and decision making for future RVF outbreaks. This will facilitate planning of governmental and non-governmental preparedness, develop better contingency plans and better inform public policy in case of subsequent outbreaks in terms of the impact of uncontrolled disease and cost-effectiveness of measures.

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Dissemination of the Rift Valley fever decision support framework in eastern Africa
(Report, 2015-12-30) Bett, Bernard K.
Predictive factors and risk mapping for Rift Valley fever epidemics in Kenya
(Journal Article, 2016-01-25) Munyua, P.M.; Murithi, R.M.; Ithondeka, P.M.; Hightower, A.; Thumbi, Samuel M.; Anyangu, S.A.; Kiplimo, Jusper Ronoh; Bett, Bernard K.; Vrieling, A.; Breiman, R.F.; Njenga, M.K.
Background To-date, Rift Valley fever (RVF) outbreaks have occurred in 38 of the 69 administrative districts in Kenya. Using surveillance records collected between 1951 and 2007, we determined the risk of exposure and outcome of an RVF outbreak, examined the ecological and climatic factors associated with the outbreaks, and used these data to develop an RVF risk map for Kenya. Methods Exposure to RVF was evaluated as the proportion of the total outbreak years that each district was involved in prior epizootics, whereas risk of outcome was assessed as severity of observed disease in humans and animals for each district. A probability-impact weighted score (1 to 9) of the combined exposure and outcome risks was used to classify a district as high (score ≥ 5) or medium (score ≥2 - <5) risk, a classification that was subsequently subjected to expert group analysis for final risk level determination at the division levels (total = 391 divisions). Divisions that never reported RVF disease (score < 2) were classified as low risk. Using data from the 2006/07 RVF outbreak, the predictive risk factors for an RVF outbreak were identified. The predictive probabilities from the model were further used to develop an RVF risk map for Kenya. Results The final output was a RVF risk map that classified 101 of 391 divisions (26%) located in 21 districts as high risk, and 100 of 391 divisions (26%) located in 35 districts as medium risk and 190 divisions (48%) as low risk, including all 97 divisions in Nyanza and Western provinces. The risk of RVF was positively associated with Normalized Difference Vegetation Index (NDVI), low altitude below 1000m and high precipitation in areas with solonertz, luvisols and vertisols soil types (p <0.05). Conclusion RVF risk map serves as an important tool for developing and deploying prevention and control measures against the disease.
Rift Valley fever decision support framework for eastern Africa
(Presentation, 2015-04-21) Bett, Bernard K.
In the eastern Africa region, Rift Valley fever (RVF) epidemics occur in irregular cycles that make it difficult for mitigation agents to implement effective interventions in the face of an outbreak. Furthermore, the existing prediction systems do not offer an adequate lead time given that there is inadequate knowledge on drivers and processes that promote outbreaks. The Rift Valley fever (RVF) Decision Support Framework (DSF) has therefore been developed to guide timely, evidenced based decision-making in the control of the disease considering that uncertainties on decision making can paralyse the deployment of effective response measures. The last (2006/2007) outbreak for instance caused substantial socio-economic impacts in the region due to by delays in the recognition of risk and in making decisions to control the disease. The framework breaks the RVF epidemic cycle into five explicit steps and matches them with appropriate actions. These steps identified in the framework include: (i) inter-epidemic period, (ii) pre-outbreak period (classified into early warning, localised rain, flooding and mosquito swarms), (iii) outbreak period (classified into suspected and confirmed outbreak sub-phases), (iv) recovery phase including a 45-day period when no further livestock cases are observed, and (v) post-outbreak recovery and reflection. Interventions matched to these epidemic stages are: capacity building and training, communication, advocacy and public awareness, national and regional coordination, early warning, surveillance, disease prevention, case management, regulation of trade and markets for livestock, resource mobilisation, establishing or strengthening institutions and policies, and risk and impact assessment. The development of the framework has involved multiple partners, decisionmakers to ensure ownership and relevance to the decision-making challenges that have been experienced during previous RVF outbreaks. The framework has also been aligned with the One Health principles by specifying interventions for both veterinary and human health sectors at each decision point. For the framework to be effectively operationalized, three key issues will have to be addressed: (i) a national RVF emergency fund has been established and procedures and modalities put in place to enable the fund to be made available rapidly in response to predetermined criteria, (ii) an effective communication system has been established including a clear chain of command and feedback from the Chief Veterinary/Medical Officers to field officers and communities, and (iii) that approved RVF Contingency Plans integrate the framework in their designs.
Utilization of the Rift Valley fever decision support tool in Kenya: Successes and challenges
(Working Paper, 2015-01-30) Mbotha, Deborah; Bett, Bernard K.
Informing national Rift Valley fever control plans: An impact narrative
(Brief, 2014-11-05) International Livestock Research Institute
Developments in risk-based decision making: Responding to the threat of Rift Valley fever (RVF) and other trans-boundary diseases
(Conference Paper, 2012-08-20) Jost, Christine; Minjauw, B.; Mariner, Jeffrey C.; Bett, Bernard K.; Clark, A.
Following the 2006-2007 outbreak of RVF in East Africa, the International Livestock Research Institute (ILRI), UN-FAO and US-Centers for Disease Control and Prevention organized a series of meeting for decision-makers to discuss how responses to the outbreak could have been conducted in a more timely and effective manner. Participants observed that the ‘all or nothing’ approach used in the decision to declare the emergency and mobilize responses did not contribute to the successful mitigation of the outbreak. Stakeholders concluded that a phased approach to decision-making utilizing incremental responses to the escalating risk of an outbreak could be more effective. They built a decision framework based on a matrix of events paired with action categories. The events served as decision points, and the action categories suggested responses at each point. Initially, the framework was named a decision support tool, but the RVF Risk-Based Decision Framework (RVF-RBDF) is now recognized as a more accurate name for this innovation. The RBDF enjoyed interest and decision-makers used the framework to mobilize actions to the RVF alarm of 2008. The framework is not prescriptive and easily incorporates technical enhancements such as new generation risk maps or more efficient vaccination strategies. In 2011, representatives of the Horn of Africa and the Middle East reviewed the RVF-RBDF at a meeting held in Dubai and hosted by ILRI and the African Union Interafrican Bureau for Animal Resources. The meeting recommended that the RVF-RBDF be developed as a framework for management of RVF risk in inter-regional trade. The meeting noted that the RVF-RBDF was a new paradigm for animal health management that merited application to other health issues as well. Plans are underway to apply the framework process in the regional context of North Africa using the lessons of the 2011 RVF outbreak in Mauritania.
The 2006-2007 Rift Valley fever outbreak in Kenya: Sources of early warning messages and response measures implemented by the Department of Veterinary Services
(Journal Article, 2012-12-15) Gachohi, John M.; Bett, Bernard K.; Njogu, G.; Mariner, Jeffrey C.; Jost, Christine
The authors characterised sources of early warning messages about occurrences of Rift Valley fever (RVF) and examined the response measures that were used by the Department of Veterinary Services (DVS) to manage the 2006–2007 RVF outbreaks in Kenya. The study was conducted between November 2009 and March 2010 and it included national, provincial and district veterinary officers who were involved in the management of the outbreak. Structured questionnaires were used to collect the data. Although the majority of the respondents reported having limited capacity to implement response measures, they perceived that the measures implemented were effective. Vaccination, movement control and market closures were the main response measures implemented, particularly in districts that had cases in both livestock and humans. Vaccination, however, was implemented too late and the coverage achieved was too low to be effective. The authors suggest ways to improve the capacity of the DVS to respond to similar outbreaks in the future.
Decision support framework for managing Rift Valley fever in the Horn of Africa
(Presentation, 2012-11-13) Mariner, Jeffrey C.; Bett, Bernard K.; Gachohi, John M.
Risk-based decision-support tool for prevention and control of Rift Valley fever epizootics in the Greater Horn of Africa
(Report, 2010-10-15) International Livestock Research Institute; Food and Agriculture Organization of the United Nations
Following the 2006/07 Rift Valley fever (RVF) epizootic in East Africa, a participatory assessment carried out jointly by the International Livestock Research Institute (ILRI) and the Government of Kenya Department of Veterinary Services (GoK DVS) concluded that: “The severity of the...RVF epidemic in northern Kenya was exacerbated by delays in recognizing risk factors...and in taking decisions to prevent and control the disease.” Further, it noted that “Kenya lacks a well documented contingency/emergency plan for RVF.” Amongst factors which limited the response to the outbreak, the assessment highlighted the “lack of pre-allocated emergency funds, particularly within the livestock sector” which greatly delayed responses (ILRI 2008).
Response planning and capacity enhancement of veterinary services for controlling and mitigating the impact of Rift Valley fever outbreaks in East Africa: ILRI outcome story 2008
(News Item, 2009-03-15) International Livestock Research Institute
An assessment of the regional and national socio-economic impacts of the 2007 Rift Valley fever outbreak in Kenya
(Journal Article, 2010-08-05) Rich, Karl M.; Wanyoike, Francis N.
Although Rift Valley fever (RVF) has significant impacts on human health and livestock production, it can also induce significant (and often overlooked) economic losses among various stakeholders in the marketing chain. This work assesses and quantifies the multi-dimensional socio-economic impacts of the 2007 RVF outbreak in Kenya based on a rapid assessment of livestock value chains in the northeast part of the country and a national macroeconomic analysis. Although study results show negative impacts among producers in terms of food insecurity and reductions in income, we also found significant losses among other downstream actors in the value chain, including livestock traders, slaughterhouses, casual laborers, and butchers, as well as other, non-agricultural sectors. The study highlights the need for greater sensitivity and analyses that address the multitude of economic losses resulting from an animal disease to better inform policy and decision making during animal health emergencies.
Epidemiological assessment of the Rift Valley fever outbreak in Kenya and Tanzania in 2006 and 2007
(Journal Article, 2010-08-05) Jost, Christine; Nzietchueng, S.; Kihu, S.; Bett, Bernard K.; Njogu, G.; Swai, E.S.; Mariner, Jeffrey C.
To capture lessons from the 2007 Rift Valley fever (RVF) outbreak, epidemiological studies were carried out in Kenya and Tanzania. Somali pastoralists proved to be adept at recognizing symptoms of RVF and risk factors such as heavy rainfall and mosquito swarms. Sandik, which means "bloody nose," was used by Somalis to denote disease consistent with RVF. Somalis reported that sandik was previously seen in 1997/98, the period of the last RVF epidemic. Pastoralists communicated valuable epidemiological information for surveillance and early warning systems that was observed before international warnings. The results indicate that an all or none approach to decision making contributed to the delay in response. In the future, a phased approach balancing actions against increasing risk of an outbreak would be more effective. Given the time required to mobilize large vaccine stocks, emergency vaccination did not contribute to the mitigation of explosive outbreaks of RVF.
Towards better control and prevention of Rift Valley fever in the greater Horn of Africa: a decision support tool for veterinary services
(Conference Paper, 2009-08) Jost, Christine; Sones, Keith R.; Bett, Bernard K.; Kihu, S.; Nzietchueng, S.; Njogu, G.; Swai, E.; Minjauw, B.; Amanfu, W.; Rocque, S. de la; Martin, V.; Mariner, Jeffrey C.
An outbreak of the viral zoonotic disease Rift Valley fever in East Africa in 2006/07 left more than 300 people dead and caused economic losses in Kenya alone estimated to exceed USD 30 million. Participatory studies undertaken shortly after the outbreaks abated enabled valuable lessons to be learned; if applied these lessons could significantly reduce the impact of future outbreaks. The lessons included the desirability of complementing and integrating international early warning systems with information from local people on the ground; the need for government-approved contingency plans and emergency funding arrangement to be in place; the need to initiate responses before the first human cases are detected; the difficulties of mounting effective livestock vaccination campaigns; and the need for clear, consistent and authoritative public health messages to be developed and tested well before an outbreak occurs. To address these issues, FAO and ILRI recently led a multi-stakeholder initiative to develop a decision support tool for the prevention and control of RVF in the Greater Horn of Africa. The tool is targeted at directors of veterinary services. The RVF outbreak is divided into a sequence made up of 12 key events: for each event a set of actions are listed that are considered appropriate at that stage. The tool is intended to facilitate timely, evidence-based decision-making that will enable RVF outbreaks to be better prevented or contained, thereby reducing the scale of impacts on lives and livelihoods as well as local, national and regional economies. In September 2008, FAO EMPRES warned that RVF could occur again in East Africa later that year. This early warning and the veterinary department’s reaction in Kenya, highlight two encouraging changes. First, the early warning was issued in September, two months earlier than in 2006. Second, the veterinary department immediately established an interdisciplinary, multistakeholder technical coordinating committee. Actions taken, informed by the new decision support tool for the prevention and control of RVF, included drafting of protocols for vaccination, livestock quarantine and vector control. The veterinary department had a limited stock of vaccine in hand, which it targeted to what it considered the highest risk areas. However, taking into consideration production and shipment delays, should these limited vaccination campaigns have had to be expanded it is unlikely that a sufficient level of population immunity from mass vaccination in high risk areas could have been achieved prior to mid-November, the time when suspected livestock cases were occurring in North Eastern Province in 2006. ILRI and partners are engaging in further research to determine what impacts the RVF Decision Support Tool had on Kenya’s 2008 response.
Development of an evidence-based decision support tool for Rift Valley fever surveillance and control
(Poster, 2010-04-14) Bett, Bernard K.; Hansen, F.; Gelan, Ayele; Mariner, Jeffrey C.
Towards better control and prevention of Rift Valley fever in the Greater Horn of Africa: a decision support tool for veterinary services
(Conference Paper, 2009-08-10) Jost, Christine; Sones, Keith R.; Bett, Bernard K.; Kihu, S.; Nzietchueng, S.; Njogu, G.; Swai, E.; Minjauw, B.; Amanfu, W.; Rocque, S. de la; Martin, V.; Mariner, Jeffrey C.
An outbreak of the viral zoonotic disease Rift Valley fever in East Africa in 2006/07 left more than 300 people dead and caused economic losses in Kenya alone estimated to exceed USD 30 million. Participatory studies undertaken shortly after the outbreaks abated enabled valuable lessons to be learned; if applied these lessons could significantly reduce the impact of future outbreaks. The lessons included the desirability of complementing and integrating international early warning systems with information from local people on the ground; the need for government-approved contingency plans and emergency funding arrangement to be in place; the need to initiate responses before the first human cases are detected; the difficulties of mounting effective livestock vaccination campaigns; and the need for clear, consistent and authoritative public health messages to be developed and tested well before an outbreak occurs. To address these issues, FAO and ILRI recently led a multi-stakeholder initiative to develop a decision support tool for the prevention and control of RVF in the Greater Horn of Africa. The tool is targeted at directors of veterinary services. The RVF outbreak is divided into a sequence made up of 12 key events: for each event a set of actions are listed that are considered appropriate at that stage. The tool is intended to facilitate timely, evidence-based decision-making that will enable RVF outbreaks to be better prevented or contained, thereby reducing the scale of impacts on lives and livelihoods as well as local, national and regional economies. In September 2008, FAO EMPRES warned that RVF could occur again in East Africa later that year. This early warning and the veterinary department’s reaction in Kenya, highlight two encouraging changes. First, the early warning was issued in September, two months earlier than in 2006. Second, the veterinary department immediately established an interdisciplinary, multistakeholder technical coordinating committee. Actions taken, informed by the new decision support tool for the prevention and control of RVF, included drafting of protocols for vaccination, livestock quarantine and vector control. The veterinary department had a limited stock of vaccine in hand, which it targeted to what it considered the highest risk areas. However, taking into consideration production and shipment delays, should these limited vaccination campaigns have had to be expanded it is unlikely that a sufficient level of population immunity from mass vaccination in high risk areas could have been achieved prior to mid-November, the time when suspected livestock cases were occurring in North Eastern Province in 2006. ILRI and partners are engaging in further research to determine what impacts the RVF Decision Support Tool had on Kenya’s 2008 response.
An assessment of the regional and national socio-economic impacts of the 2007 Rift Valley fever outbreak in Kenya
(Conference Paper, 2008-05-06) Wanyoike, Francis N.; Rich, Karl M.
The role of value chain analysis in animal disease impact studies: methodology and case studies of Rift Valley fever in Kenya and avian influenza in Nigeria
(Conference Paper, 2009-08-10) Rich, Karl M.; Baker, Derek; Okike, Iheanacho; Wanyoike, Francis N.
Decision-support tool for prevention and control of Rift Valley Fever epizootics in the Greater Horn of Africa. Version I
(Manual, 2009-08-07) International Livestock Research Institute; Food and Agriculture Organization of the United Nations
This publications presents study on decision-support tool for prevention and control of Rift Valley fever epizootics in the Greater Horn of Africa. The decision-support tool consists of four elements, viz. a map of areas in the GHA at risk from RVF epizootics; a list of the sequence of events related to increasing and decreasing risk of an RVF epizootic in the GHA; actions matched to the sequence of events listed in 2; and the selected information, resources and references. This tool is designed to help decision-makers lower the risk to themselves, their governments and citizens by taking action commensurate with the level of risk at the right time. As the sequence of events progresses, the probability that an RVF epizootic will occur increases; the justification for taking actions to mitigate the risk also increases, and the risk of taking unjustified actions decreases. The document further details sequence of events related to increasing and decreasing risk of an RVF epizootic in the Greater Horn of Africa, with partic. ref. to normal situation between outbreaks; early warning of RVF issued and/or early warning of heavy rain by national meteorological departments; localized, prolonged heavy rains reported by eye-witnesses; localized flooding reported by eye-witnesses; localized mosquito swarms reported by eye-witnesses; first detection of suspected RVF in livestock by active searching and/or rumors from herders; laboratory confirmation of RVF cases in livestock; first rumor or field report of human RVF case; laboratory confirmation of first human RVF case; no new human cases for six months; no clinical livestock cases for six months; and post-outbreak recovery and reflection.

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