Molecular Tracking of the Origin of Vesicular Stomatitis Outbreaks in 2004 and 2018, Ecuador

Abstract

The Vesicular Stomatitis Virus (VSV) is an arbovirus causing vesicular stomatitis (VS) in livestock. There are two serotypes recognized: New Jersey (VSNJV) and Indiana (VSIV). The virus can be transmitted directly by contact or by vectors. In 2018, Ecuador experienced an outbreak of Vesicular Stomatitis (VS) in cattle, caused by VSNJV and VSVIV, with 399 cases reported distributed over 18 provinces. We determined the phylogenetic relationships among 67 strains. For the construction of phylogenetic trees, the viral phosphoprotein gene was sequenced, and trees were constructed based on the Maximum Likelihood method using 2004 outbreak strains from Ecuador (GenBank) and the 2018 sequences (this article). We built a haplotype network for VSNJV to trace the origin of the 2004 and 2018 epizootics through topology and mutation connections. These analyses suggest two different origins, one related to the 2004 outbreak and the other from a transmission source in 2018. Our analysis also suggests different transmission patterns; several small and independent outbreaks, most probably transmitted by vectors in the Amazon, and another outbreak caused by the movement of livestock in the Andean and Coastal regions. We recommend further research into vectors and vertebrate reservoirs in Ecuador to clarify the mechanisms of the reemergence of the virus.

Livestock and environmental characterization of Colombian municipalities: study of vesicular stomatitis

“…In Andean communities, due to the high degree of contact among different farms, transmission is facilitated primarily through animal movement and fomites. In areas such as the Amazon, due to climatic characteristics, transmission through vectors is favored ( 19 , 34 ). Furthermore, other researchers point to a significant genetic similarity between strains found in Ecuador and those found in Colombia ( 19 ).…”

“…In areas such as the Amazon, due to climatic characteristics, transmission through vectors is favored ( 19 , 34 ). Furthermore, other researchers point to a significant genetic similarity between strains found in Ecuador and those found in Colombia ( 19 ). Distinct results were observed in Costa Rica by Rodriguez ( 18 ), where moist highlands and dry lowlands areas have been identified as regions with a higher disease prevalence in Costa Rica, both in wildlife and livestock.…”

“…Some researchers suggest sandflies, black flies and biting midges may be potential vectors ( 16 ), or at least a stress factor that favors immunosuppression contributing for clinical appearance of the disease ( 15 ). However, there are clear indications that there are at least two distinct major components: the first concerns the disease’s relationship with the environment, particularly the presence of favorable climatic conditions for possible vector proliferation and its association with livestock ( 17–19 ); the second component involves animal to animal transmission, occurring both through direct contact and through indirect transmission, via fomites or animal movement ( 11 , 19 , 20 ).…”

Mcl-1 Protein and Viral Infections: A Narrative Review

“…The severe ulceration and/or vesiculation of the muzzle, tongue, and oral tissues as well as udder, prepuce, and feet, translate into a significant loss of productivity [163]. In addition to cattle, horses, pigs, and arthropods, which are vectors for the virus, VSV can also easily infect humans and cause a temporarily debilitating influenza-like disease [163,165], or, due to its neurovirulence, cause severe encephalitis [166]. VSV is widely used as a platform for oncolytic vectors or vaccine delivery agent, e.g., against SARS-CoV-2 and influenza A virus infections [167,168].…”