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United States Department of Agriculture

Agricultural Research Service

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Location: Foreign Animal Disease Research

2012 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). Because there are currently no legislated interventions for FMD being practiced in the region, and no vaccines are available we are using this natural experiment as a model of uncontrolled FMD to understand the ecology and genetic variability of the virus.

During FY 2012, we collected serum and probang samples from the 30 herds in our study, as well as began whole herd sampling. During the whole-herd sampling, we applied ear tags 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. Incongruously, small ruminants and pigs do not seem to have high antibody levels to FMD.

We also began collecting probang and tissue samples into RNALater which has significantly improved PCR detection of virus. We plan to conduct additional sampling in through 2014 and expect to submit additional samples from these trips. We hope that these new samples will provide quality sequence data to allow for genetic analysis.

In addition to our data collection efforts, 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. 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 movements. This model will be made accessible to veterinary and human health services in Cameroon and other nations in the Chad Basin to aid in effective interventions and control of infectious diseases in the context of overlapping networks of pastoral and trade livestock movements. We will develop a web-based database and mapping application that can be used by veterinary and human health services in the Chad Basin. We will train Cameroonian veterinary students and researchers who are collaborating in this research in relatively simple but effective modeling of disease epidemiology in order to effectively intervene to control the spread of diseases. We will organize workshops in Cameroon and invite researchers and policy makers from other nations in the Chad Basin. The goal is to develop regional monitoring systems in the different nations that can quickly analyze epidemiological trends in the Chad Basin.

As part of our research program, we will train a team of local herders in assisting with the handling of the animals and the collection of biological samples. Working with local herders who are respected in the community will greatly facilitate our data collection. They can contact our Cameroonian collaborators when there is an outbreak of FMD during our study which will allow us to collect samples of the active virus and track the outbreaks throughout the study area. The combination of local surveillance system that is embedded in the pastoral system and a regional monitoring system that can analyze epidemiological trends, can greatly improve the interventions when there are epizootic or zoonotic outbreaks.

In addition to these goals of the larger project, through our work with PIADC, we hope to understand the genetic variation of endemic FMDV in a way that will be useful for vaccine design and for control of FMD and other RNA viral diseases.

No technologies have been transferred during FY 2012. Publications for FY 2012 include:

Pomeroy, L.W., Bansal, S., Tildesley, M., Moritz, M., Xiao, N., Carpenter, T.E. and Garabed, R.B. 2012. Spatial heterogeneity in foot-and-mouth disease transmission and implications for control. In review at Proceedings of the Royal Society B: Biological Sciences.

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(x):xx-xxx.

Moritz, Mark, Daniel Ewing, and Rebecca B. Garabed. 2012. On Not Knowing Zoonotic Diseases: Pastoralists' Ethnoveterinary Knowledge in the Far North Region of Cameroon. Human Organization. 71(x):xx-xxx.

Brostoff, Noah. Foot-and-Mouth Disease Virus in the Chad Basin, Cameroon. (2012) Masters Thesis. Ohio State University Department of Mathematics. Healy, Jessica M. What to do with chronically sick animals? A study of pastoralists' decision-making in the Far North Region of Cameroon. (2012) Undergraduate Thesis. The Ohio State University Department of Anthropology.

4 Abstracts accepted at International Symposium for Veterinary Epidemiology and Economics, Maastricht, Netherlands, August 2012.

Last Modified: 4/22/2015
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