97 research outputs found
Emerg Infect Dis
No full textThe 1999 introduction and rapid spread of West Nile virus (WNV) across the United States demonstrated our vulnerability to emerging mosquito-borne viruses, but also showed the abilities of the US public health and animal health systems to identify weaknesses and develop strategies to reduce them. For example, although many counties already had vector and disease surveillance programs, the arrival of WNV compelled more communities to act. Unfortunately, the protective infrastructure that grew during our reaction to WNV is dissolving as funding is repositioned to new threats. With each new threat, public health and animal health agencies are charged with developing response plans and disbursing funds to a tangled web of bench scientists and "boots on the ground." Two key shortfalls in our approach to emerging disease threats have come out of this: 1) US public health and animal health agencies have become reactive rather than proactive\u2014new committees and infrastructure are formed to deal with new threats and wheels are reinvented; and 2) because agencies tend to work independently, wheels are reinvented in parallel.Given these shortfalls, on December 5, 2006, the Animal and Plant Health Inspection Service (APHIS) Centers for Epidemiology and Animal Health in Fort Collins, Colorado, hosted a multi-agency and university working group to confront the issue of Rift Valley fever (RVF), a mosquito-borne zoonotic hemorrhagic viral disease confined mainly to sub-Saharan Africa. In these countries, human and livestock populations bear prominent health and economic effects during an RVF outbreak (1). Sheep, goats, and cattle are particularly susceptible to the disease. RVF virus (RVFV) is classified as an overlap select agent, i.e., affecting both humans and non-human animals, by both the Centers for Disease Control and Prevention (CDC) and APHIS (2,3). If introduced into the United States RVFV could be spread by mosquitoes like WNV is, but could also be spread by contact with infected vertebrate tissues or aerosols (4). No approved human or animal vaccines exist for use in the United States.The Rift Valley Fever Working Group comprises >30 participants from more than a dozen US government agencies and universities. It was launched by scientists from the US Department of Agriculture-Agricultural Research Service (USDA-ARS) and the University of Wyoming during a smaller spring meeting in 2006. At that meeting, participants discussed RVF research, ranging from vaccine and diagnostics development to spatially explicit geographic information system (GIS)\u2013based modeling of potential US vector mosquitoes, as well as new collaborative initiatives focused on the risk for mosquito transmission of RVFV after natural or intentional introduction. The capstone of the spring meeting was the development of an outline for an interagency RVF research and response group. This led to the winter meeting with over 20 presentations and facilitated discussions covering a broad scope of RVF issues. Several presentations highlighted areas of research that would improve our response to RVF, for example, ecologic modeling of vectors; communications and reporting models; surveillance, response, and control models; and vaccine and diagnostics development. Many presentations showed how individual agencies have responded to RVF in the past, and recommendations for future collaborations were discussed. The group also detailed how other emerging infectious disease (EID) response plans or unique agency services could be applied to RVF outbreak
Biologically Informed Individual-Based Network Model for Rift Valley Fever in the US and Evaluation of Mitigation Strategies
No full textCitation: Scoglio, C. M., Bosca, C., Riad, M. H., Sahneh, F. D., Britch, S. C., Cohnstaedt, L. W., & Linthicum, K. J. (2016). Biologically Informed Individual-Based Network Model for Rift Valley Fever in the US and Evaluation of Mitigation Strategies. Plos One, 11(9), 26. doi:10.1371/journal.pone.0162759Rift Valley fever (RVF) is a zoonotic disease endemic in sub-Saharan Africa with periodic outbreaks in human and animal populations. Mosquitoes are the primary disease vectors; however, Rift Valley fever virus (RVFV) can also spread by direct contact with infected tissues. The transmission cycle is complex, involving humans, livestock, and multiple species of mosquitoes. The epidemiology of RVFV in endemic areas is strongly affected by climatic conditions and environmental variables. In this research, we adapt and use a network-based modeling framework to simulate the transmission of RVFV among hypothetical cattle operations in Kansas, US. Our model considers geo-located livestock populations at the individual level while incorporating the role of mosquito populations and the environment at a coarse resolution. Extensive simulations show the flexibility of our modeling framework when applied to specific scenarios to quantitatively evaluate the efficacy of mosquito control and livestock movement regulations in reducing the extent and intensity of RVF outbreaks in the United States
Developing a Research Agenda and a Comprehensive National Prevention and Response Plan for Rift Valley Fever in the United States
No full textPLoS Negl Trop Dis
No full textBackgroundRecent clusters of outbreaks of mosquito-borne diseases (Rift Valley fever and chikungunya) in Africa and parts of the Indian Ocean islands illustrate how interannual climate variability influences the changing risk patterns of disease outbreaks. Although Rift Valley fever outbreaks have been known to follow periods of above-normal rainfall, the timing of the outbreak events has largely been unknown. Similarly, there is inadequate knowledge on climate drivers of chikungunya outbreaks. We analyze a variety of climate and satellite-derived vegetation measurements to explain the coupling between patterns of climate variability and disease outbreaks of Rift Valley fever and chikungunya.Methods and FindingsWe derived a teleconnections map by correlating long-term monthly global precipitation data with the NINO3.4 sea surface temperature (SST) anomaly index. This map identifies regional hot-spots where rainfall variability may have an influence on the ecology of vector borne disease. Among the regions are Eastern and Southern Africa where outbreaks of chikungunya and Rift Valley fever occurred 2004\u20132009. Chikungunya and Rift Valley fever case locations were mapped to corresponding climate data anomalies to understand associations between specific anomaly patterns in ecological and climate variables and disease outbreak patterns through space and time. From these maps we explored associations among Rift Valley fever disease occurrence locations and cumulative rainfall and vegetation index anomalies. We illustrated the time lag between the driving climate conditions and the timing of the first case of Rift Valley fever. Results showed that reported outbreaks of Rift Valley fever occurred after 3c3\u20134 months of sustained above-normal rainfall and associated green-up in vegetation, conditions ideal for Rift Valley fever mosquito vectors. For chikungunya we explored associations among surface air temperature, precipitation anomalies, and chikungunya outbreak locations. We found that chikungunya outbreaks occurred under conditions of anomalously high temperatures and drought over Eastern Africa. However, in Southeast Asia, chikungunya outbreaks were negatively correlated (p<0.05) with drought conditions, but positively correlated with warmer-than-normal temperatures and rainfall.Conclusions/SignificanceExtremes in climate conditions forced by the El Ni\uf1o/Southern Oscillation (ENSO) lead to severe droughts or floods, ideal ecological conditions for disease vectors to emerge, and may result in epizootics and epidemics of Rift Valley fever and chikungunya. However, the immune status of livestock (Rift Valley fever) and human (chikungunya) populations is a factor that is largely unknown but very likely plays a role in the spatial-temporal patterns of these disease outbreaks. As the frequency and severity of extremes in climate increase, the potential for globalization of vectors and disease is likely to accelerate. Understanding the underlying patterns of global and regional climate variability and their impacts on ecological drivers of vector-borne diseases is critical in long-range planning of appropriate disease and disease-vector response, control, and mitigation strategies.20121021
Environmental Biosurveillance for Epidemic Prediction: Experience with Rift Valley Fever
No full textTRUCK-MOUNTED NATULAR 2EC (SPINOSAD) ULV RESIDUAL TREATMENT IN A SIMULATED URBAN ENVIRONMENT TO CONTROL AEDES AEGYPTI AND AEDES ALBOPICTUS IN NORTH FLORIDA
No full textABSTRACT
Preemptive treatment of dry habitats with an ultra-low volume (ULV) residual larvicide may be effective in an integrated vector management program to control populations of container-inhabiting Aedes mosquitoes, key vectors of Zika, dengue, and chikungunya viruses. We exposed dry, artificial containers placed in exposed and protected locations to Natular 2EC (spinosad) larvicide applied with a truck-mounted ULV sprayer in a simulated urban setting in North Florida, and later introduced water and Ae. aegypti or Ae. albopictus larvae to conduct bioassays. Up to 50% mortality was observed in bioassays, indicating further analysis of spinosad as a residual treatment application.</jats:p
The Role of Global Climate Patterns in the Spatial and Temporal Distribution of Vector-Borne Disease
No full text
Comparison between fraction of infected population for Exponential and Power Law model.
No full text(A) Comparison between fractions of infected in Gpl100 and Gexp100. (B) Comparison between fractions of infected in Gpl40 and Gexp40. (C) Comparison between fractions of infected in Gpl20 and Gexp20.</p
- …
