Serological Evidence of Foot-and-Mouth Disease Infection in Goats in Lao PDR

Nagendrakumar B Singanallur,Isabel Macphillamy,Peter Windsor,Chattouphone Keokhamphet,Russell D Bush,Navneet K Dhand,Sonevilay Nampanya,Syseng Khounsy,Vilayvanh Soukvilay,Wilna Vosloo

doi:10.3389/fvets.2020.00544

Nagendrakumar B Singanallur, Isabel Macphillamy + Show 8 more

Open Access

https://doi.org/10.3389/fvets.2020.00544

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Abstract

Foot and Mouth Disease (FMD) causes significant economic loss in Lao PDR (Laos) and perpetuates the cycle of smallholder poverty mainly through large ruminant productivity losses, increased costs of production and potential limitations to market access for trade in livestock and their products. Goats are emerging as an important livestock species in Laos, and there is an increasing trend in the number of households with goats, often farmed alongside cattle and buffalo. Although an FMD susceptible species, very little is known about the role of goats in the epidemiology of the disease in Laos. A cross-sectional seroprevalence study was conducted by detecting antibodies to the non-structural proteins (NSP), an indication of a previous infection, and serotype-specific structural proteins (SP) that could be due to vaccination or infection. The study commenced in late 2017 and sera were collected from 591 goats in 26 villages of northern, central and southern Laos. For a subset of sera samples, paired oral swab samples were also collected by a simple random sampling method to detect the prevalence of FMD virus infection at the time of collection. The NSP seroprevalence in the provinces of Borkeo and Xayabouli in the north was 42 and 8%, respectively and in Khammoune in the center, it was 20%. In the other five provinces, Luang Namtha and Luang Prabang (northern Laos), Xieng Khouang and Savannaket (central Laos), and Champasak (southern Laos), the seroprevalence was close to zero. The multivariable analysis indicated that age (p < 0.001) was positively associated with animal-level seropositivity and males were less likely to be seropositive than females (OR: 0.29; 95%CI: 0.10–0.83; p = 0.017). Continued sero-surveillance for FMD in goats is recommended to improve our understanding of their role in the epidemiology of FMD in the region and to extend support to FMD control decisions, particularly regarding vaccination.

Highlights

Foot-and-mouth disease (FMD) is a major transboundary animal disease that is endemic in Southeast Asia, causing sporadic disease outbreaks mainly in large ruminants in the Lao People’s Democratic Republic (Laos) [1, 2]
Luang Prabang, Xieng Khouang and Xayabouli had villages actively involved in the AH/202/067 project, Savannakhet had villages actively involved in the AH/2012/068 project, and all provinces had been included at various stages in either the Stop Transboundary Animal Diseases and Zoonoses (STANDZ) or New Zealand Foot and Mouth Disease (FMD) control program
Seroprevalence to both non-structural proteins (NSP) and serotype O in Borkeo, Xayabouli and Khammoune indicate the likelihood of FMD viruses (FMDV) transmission and raising the possibility that caprine outbreaks occurred and were unrecognized

Summary

Introduction

Foot-and-mouth disease (FMD) is a major transboundary animal disease that is endemic in Southeast Asia, causing sporadic disease outbreaks mainly in large ruminants in the Lao People’s Democratic Republic (Laos) [1, 2]. The South East Asia and China FMD (SEACFMD) campaign has facilitated significant national and multilateral efforts to control FMD in the region over the past two decades [2]. In partnership with SEACFMD, the Australian government funded the Stop Transboundary Animal Diseases and Zoonoses (STANDZ; 2011– 2016) initiative providing important technical and financial contributions toward control of FMD in South East Asia [6]. Due to the lack of resources at the government level in Laos, these activities have not been continued and endemic FMD viruses (FMDV) continue to circulate in Laos, with exotic serotypes occasionally emerging [6, 9]

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