Foot‐and‐mouth disease outbreaks due to an exotic serotype Asia 1 virus in Myanmar in 2017

Abstract

In January 2017, two villages located in Rakhine State of Myanmar reported clinical signs in cattle suggestive of foot‐and‐mouth disease virus (FMDV) infection. Laboratory analysis identified the outbreak virus as FMDV serotype Asia 1, which represented the first detection of this serotype in Myanmar since 2005 and in the region of South‐East Asia (SEA) since 2007. Genetic analysis revealed that the outbreak virus was different from historical viruses from Myanmar and was more closely related to viruses circulating in Bangladesh and India during 2012–2013, indicating that a novel viral introduction had occurred. The precise origin of the outbreaks was not clear, but frequent informal livestock trade with South Asia was reported. Responses to the outbreaks involved disinfection, quarantine and animal movement restrictions; no further outbreaks were detected under the present passive surveillance system. Detection of serotype Asia 1 highlights the complex and dynamic nature of FMDV in SEA. Active surveillance is needed to assess the extent and distribution of this exotic Asia 1 strain and continued vigilance to timely detect the occurrence of emerging and re‐emerging FMDV strains is essential.

Emergence of novel lineage of foot‐and‐mouth disease virus serotype Asia1 BD‐18 (G‐IX) in Bangladesh

“…Underlying evolutionary insights for the genesis of novel lineage and spatial dynamics related to G‐IX might occur due to steady abstruse transmission and viral diversity due to poor surveillance of this semi‐extinct virus type in recent years from Bangladesh. Notably, the possible chance and significant risk due to the intrusions of exotic and novel FMDV strains into previously non‐circulating zone for those viruses were demonstrated in a recent risk analysis study (Bo et al, ). Therefore, current FMD situation needs to be monitored closely, especially focusing on the entry and spread of this novel strain, which will give time to adjust vaccine compositions.…”

“…Moreover, the clade of G‐IX and its closest genetic lineage G‐VIII (Table S4) separated in the distance tree with an ND of > 5% demonstrating the presence of two separate lineages (Figure S2). Significantly, the most recent G‐VIII strain (MYA/3/2017) isolated from Myanmar in April 2017 (Bo et al, ) showed only ~ 90% nucleotide identity with strains of lineage G‐IX. Before the emergence of this lineage, lineage G‐VIII was sporadically circulating in Bangladesh and its neighbouring countries (Subramaniam et al, ; Ullah et al, ; WRLFMD, ).…”

“…Notably, the possible chance and significant risk due to the intrusions of exotic and novel FMDV strains into previously non-circulating zone for those viruses were demonstrated in a recent risk analysis study (Bo et al, 2019). Therefore, current FMD situation needs to be monitored closely, especially focusing on the entry and spread of this novel strain, which will give time to adjust vaccine compositions.…”

“…Notably, Valarcher et al () designated previous lineage D as G‐III and Subramaniam et al () designated strains circulating after 2005 under previous lineage C as G‐VIII, while both lineages were endemic in Indian subcontinent (Sanyal et al, ). In recent years (2016–2017), Sindh‐08 (G‐VII) is the only lineage of serotype Asia1 that is in continuous circulation in its endemic region (Ali et al, ) whereas outbreaks with other lineage G‐VIII were reported sporadically (Ullah et al, ; WRLFMD, ), with the latest report from Myanmar in 2017 (Bo et al, ).…”

Evaluation of novel inactivated vaccines for the SAT 1, SAT 2 and SAT 3 serotypes of foot-and-mouth disease in pigs

“…If the rate of change in the virus, as seen in the evolution of FMD viruses or the introduction of new viruses, outpaces vaccine development research, it will become more difficult to protect against the virus [22, 23]. In this respect, this study provided a framework for rapid development of new vaccines, proposing that the establishment of a more reliable method for vaccine development that surpasses the evolution rate of the virus can be a means to advance the vaccine research a step further [22, 23]. Thus far, the SAT serotype viruses are known to mainly infect cattle and African buffalos [24–26].…”