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United States Department of Agriculture

Agricultural Research Service

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Location: Foreign Animal Disease Research

2013 Annual Report

1a. Objectives (from AD-416):
The Ohio State University Disease Ecology and Computer Modeling Laboratory (DECML) is engaged in projects to model the transmission of infectious diseases of livestock, inclusive of Foot-and-Mouth Disease (FMD), to identify behaviors that prevent or increase risk of disease transmission in the Lake Chad Basin of Africa. This work includes modeling animal movements, zoonotic disease transmission, environmental and spatial factors related to disease transmission, molecular evolution of viruses and human factors related to animal disease incidence and persistence. ARS, PIADC will conduct genetic sequence analysis of field isolates to identify carrier animals, viral determinants and associated epidemiological information.

1b. Approach (from AD-416):
DECML will provide new field isolates along with detailed epidemiological information and expertise to ARS, PIADC. FMDV carrier states and viral evolution in the endemic settings will be determined through sequence analysis conducted by ARS, PIADC and results will be shared with DECML. ARS, PIADC will provide training and/or materials to the local partner laboratory (Laboratoire National Veterinaire, Garoua, Cameroon) to assist in this project.

3. Progress Report:
The goal of this project is to understand the ecology of infectious diseases in the context of pastoral mobility in the Lake Chad Basin. Specifically we want to know how livestock movements affect the ecology of endemic foot-and-mouth disease (FMD) and the Foot-and-Mouth Disease Virus (FMDV). Specific objectives include estimating the disease prevalence, determination of the phylogency and phylogeography of FMDV circulating in the Lake Chad Basin, examination of the role of animal movement in disease transmission and viral evolution and estimate the cost of FMDV to livestock producers in the Lake Chad Basin. Sampling continued, including whole herd samples. During the whole-herd sampling, ear tags were applied to some animals, which will aid in identifying animals in the future. At the end of each of these rounds of sampling we sent additional samples to ARS, PIADC for serology and PCR testing. Sero-positive levels are similar to what we initially observed and serotyping revealed five different serotypes circulating in cattle in the area. We have begun analyzing these data to determine whether different serotypes co-circulate and to gain more insight into immunity for FMD. Based on analysis of incomplete data, it appears that serotypes O and A provide lasting immunity while immunity for SAT serotypes fades rapidly in cattle. Due to our findings last year that swine and small ruminants had much lower seroprevalence than cattle, we have expanded swine sampling this year and hope to have a statistically meaningful sample to analyze. A research fellow from ARS, PIADC will travel to Cameroon August of 2013 to help in improving our molecular methods. In 2012-2013, we enrolled another 6 students in the fellowship program with the University of Maroua and the University of Ngaoundere to conduct independent research including work on trypanosomiasis and expanding work on swine. We continue to develop agent-based and metapopulation-based models of FMD in the endemic state to use with our data to simulate the endemic setting and expected disease outcomes. Some initial results include better characterization of the potential role of carriers and maternal immunity in the endemic setting and the role of movement in endemicity. One of our main goals is to develop an integrated model of epidemiology of infectious diseases in the ecological context of networks of host movements. The model will be useful to researchers that study other infectious diseases with networks of host. All these disease ecologies involve mobile host that move in overlapping networks and require the integration of spatial and epidemiological models. Initial agent-based movement and differential equation transmission models are being tested but have yet to be merged at this time. No technologies were transferred in FY 2013. Publications for FY 2013 include: 1. Healy Profitós, Jessica, Mark Moritz, and Rebecca B. Garabed. (2013). What to do with chronically sick animals? Pastoralists' Management Strategies in the Far North Region of Cameroon. Pastoralism: Research, Policy and Practice 3:8. doi:10.1186/2041-7136-3-8 2. Moritz, Mark, Daniel Ewing, and Rebecca B. Garabed. (2013). On Not Knowing Zoonotic Diseases: Pastoralists' Ethnoveterinary Knowledge in the Far North Region of Cameroon. Human Organization. 72(1):1-11. 3. Moritz, Mark, Zachary Galehouse, Qian Hao, Rebecca Garabed. (2012). Can One Animal Represent an Entire Herd? Modeling Pastoral Mobility using GPS/GIS Technology. Human Ecology. 40(4):623-630.

4. Accomplishments

Last Modified: 10/16/2017
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