Modeling the Spread of Porcine Reproductive and Respiratory Syndrome Among Pig Farms in Lira District of Northern Uganda

Emmanuel Hasahya; Krishna K Thakur; Michel M Dione; Barbara Wieland; Peter Oba; Joseph Kungu; Hu Suk Lee

doi:10.3389/fvets.2021.727895

Modeling the Spread of Porcine Reproductive and Respiratory Syndrome Among Pig Farms in Lira District of Northern Uganda

Front Vet Sci. 2021 Aug 30:8:727895. doi: 10.3389/fvets.2021.727895. eCollection 2021.

Authors

Emmanuel Hasahya^{1

2}, Krishna K Thakur³, Michel M Dione⁴, Barbara Wieland⁵, Peter Oba¹, Joseph Kungu², Hu Suk Lee⁶

Affiliations

¹ International Livestock Research Institute (ILRI), Kampala, Uganda.
² College of Veterinary Medicine, Animal Resources and Biosecurity (COVAB), Makerere University, Kampala, Uganda.
³ Department of Health Management, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada.
⁴ International Livestock Research Institute (ILRI), Dakar, Senegal.
⁵ International Livestock Research Institute (ILRI), Addis Ababa, Ethiopia.
⁶ International Livestock Research Institute (ILRI), Hanoi, Vietnam.

Abstract

Porcine Reproductive and Respiratory Syndrome (PRRS) is a viral swine disease that causes reproductive failure in breeding sows and respiratory distress in growing pigs. The main objectives were to simulate the transmission patterns of PRRS in Uganda using North American Animal Disease Spread Model (NAADSM) and to evaluate the potential effect of prevention and control options such as vaccination and movement control. The median number of infectious farms at the end of 52 weeks for the baseline scenario was 735 (36.75% of the 2,000 farms). The best effects of vaccination were observed in scenarios 60% farm coverage and 80% farm coverage, which resulted in 82 and 98.2% reduction in the median number of infectious farms at the end of the simulation, respectively. Vaccination of all medium and large farms only (33% of the farms) resulted in a 71.2% decrease in the median number of infectious farms at the end of 52 weeks. Movement control (MC) results showed that the median number of infectious farms at the end of 52 weeks decreased by 21.6, 52.3, 79.4, and 92.4% for scenarios MC 20, MC 40, MC 60, and MC 80%, respectively. This study provides new insights to the government of Uganda on how PRRS can be controlled. The large and medium farms need to be prioritized for vaccination, which would be a feasible and effective way to limit the spread of PRRS in Uganda. Scavenging pigs should be confined at all times, whether in the presence or absence of any disease outbreaks.

Keywords: Uganda; movement control; porcine reproductive and respiratory syndrome; simulation model; vaccination.