scholarly journals Development and Validation of a Mucosal Antibody (IgA) Test to Identify Persistent Infection with Foot-and-Mouth Disease Virus

Viruses ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 814
Author(s):  
Jitendra K. Biswal ◽  
Antonello Di Nardo ◽  
Geraldine Taylor ◽  
David J. Paton ◽  
Satya Parida
Keyword(s):  
Persistent Infection ◽  
Asymptomatic Carrier ◽  
Foot And Mouth Disease ◽  
Field Studies ◽  
Mouth Disease ◽  
Persistently Infected ◽  
Mouth Disease Virus ◽  
Foot And Mouth ◽  
High Level ◽  
Development And Validation

It is well known that approximately 50% of cattle infected with foot-and-mouth disease (FMD) virus (FMDV) may become asymptomatic carrier (persistently infected) animals. Although transmission of FMDV from carrier cattle to naïve cattle has not been demonstrated experimentally, circumstantial evidence from field studies has linked FMDV-carrier cattle to cause subsequent outbreaks. Therefore, the asymptomatic carrier state complicates the control and eradication of FMD. Current serological diagnosis using tests for antibodies to the viral non-structural proteins (NSP-ELISA) are not sensitive enough to detect all carrier animals, if persistently infected after vaccination and do not distinguish between carriers and non-carriers. The specificity of the NSP ELISA may also be reduced after vaccination, in particular after multiple vaccination. FMDV-specific mucosal antibodies (IgA) are not produced in vaccinated cattle but are elevated transiently during the acute phase of infection and can be detected at a high level in cattle persistently infected with FMDV, irrespective of their vaccination status. Therefore, detection of IgA by ELISA may be considered a diagnostic alternative to RT-PCR for assessing FMDV persistent infection in ruminants in both vaccinated and unvaccinated infected populations. This study reports on the development and validation of a new mucosal IgA ELISA for the detection of carrier animals using nasal, saliva, and oro-pharyngeal fluid (OPF) samples. The diagnostic performance of the IgA ELISA using nasal samples from experimentally vaccinated and infected cattle demonstrated a high level of specificity (99%) and an improved level of sensitivity (76.5%). Furthermore, the detection of carrier animals reached 96.9% when parallel testing of samples was carried out using both the IgA-ELISA and NSP-ELISA.

scholarly journals The Carrier Conundrum; A Review of Recent Advances and Persistent Gaps Regarding the Carrier State of Foot-and-Mouth Disease Virus

Pathogens ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 167 ◽  
Author(s):  
Carolina Stenfeldt ◽  
Jonathan Arzt
Keyword(s):  
Disease Virus ◽  
Foot And Mouth Disease ◽  
Field Studies ◽  
Carrier State ◽  
Mouth Disease ◽  
Experimental Investigations ◽  
Apparent Lack ◽  
Fmdv Infection ◽  
Mouth Disease Virus ◽  
Foot And Mouth

The existence of a prolonged, subclinical phase of foot-and-mouth disease virus (FMDV) infection in cattle was first recognized in the 1950s. Since then, the FMDV carrier state has been a subject of controversy amongst scientists and policymakers. A fundamental conundrum remains in the discordance between the detection of infectious FMDV in carriers and the apparent lack of contagiousness to in-contact animals. Although substantial progress has been made in elucidating the causal mechanisms of persistent FMDV infection, there are still critical knowledge gaps that need to be addressed in order to elucidate, predict, prevent, and model the risks associated with the carrier state. This is further complicated by the occurrence of a distinct form of neoteric subclinical infection, which is indistinguishable from the carrier state in field scenarios, but may have substantially different epidemiological properties. This review summarizes the current state of knowledge of the FMDV carrier state and identifies specific areas of research in need of further attention. Findings from experimental investigations of FMDV pathogenesis are discussed in relation to experience gained from field studies of foot-and-mouth disease.

scholarly journals Genetic and antigenic variation of foot-and-mouth disease virus during persistent infection in naturally infected cattle and Asian buffalo in India

PLoS ONE ◽  
2019 ◽  
Vol 14 (6) ◽  
pp. e0214832 ◽  
Author(s):  
Jitendra K. Biswal ◽  
Rajeev Ranjan ◽  
Saravanan Subramaniam ◽  
Jajati K. Mohapatra ◽  
Sanjay Patidar ◽  
...  
Keyword(s):  
Disease Virus ◽  
Persistent Infection ◽  
Antigenic Variation ◽  
Foot And Mouth Disease ◽  
Mouth Disease ◽  
Infected Cattle ◽  
Mouth Disease Virus ◽  
Foot And Mouth

Simultaneous and staggered foot-and-mouth disease virus coinfection of cattle

2021 ◽  
Author(s):  
Jonathan Arzt ◽  
Ian H. Fish ◽  
Miranda R. Bertram ◽  
George R. Smoliga ◽  
Ethan J. Hartwig ◽  
...  
Keyword(s):  
Disease Virus ◽  
Foot And Mouth Disease ◽  
Field Studies ◽  
Mouth Disease ◽  
Coding Regions ◽  
Mouth Disease Virus ◽  
Foot And Mouth ◽  
Heterologous Virus ◽  
Virus Exposure ◽  
Upper Respiratory

Foot-and-mouth disease (FMD) field studies have suggested the occurrence of simultaneous infection of individual hosts by multiple virus strains; however, the pathogenesis of foot-and-mouth disease virus (FMDV) coinfections is largely unknown. In the current study, cattle were experimentally exposed to two FMDV strains of different serotypes (O and A). One cohort was simultaneously infected with both viruses, while additional cohorts were initially infected with FMDV A and subsequently superinfected with FMDV O, after 21 or 35 days. Coinfections were confirmed during acute infection, with both viruses concurrently detected in blood, lesions, and secretions. Staggered exposures resulted in overlapping infections as convalescent animals with persistent subclinical FMDV infection were superinfected with a heterologous virus. Staggering virus exposure by 21 days conferred clinical protection in six of eight cattle, which were subclinically infected following the heterologous virus exposure. This effect was transient, as all animals superinfected at 35 days post initial infection developed fulminant FMD. The majority of cattle maintained persistent infection with one of the two viruses while clearing the other. Analysis of viral genomes confirmed inter-serotypic recombination events within 10 days in the upper respiratory tract of five superinfected animals from which the dominant genomes contained the capsid coding regions of the O virus, and non-structural coding regions of the A virus. By contrast, there were no dominant recombinant genomes detected in samples from simultaneously coinfected cattle. These findings inculpate persistently infected carriers as potential FMDV mixing vessels in which novel strains may rapidly emerge through superinfection and recombination. Importance Foot-and-mouth disease (FMD) is a viral infection of livestock of critical socioeconomic importance. Field studies from areas of endemic FMD suggest that animals can be simultaneously infected by more than one distinct variant of FMD virus (FMDV), potentially resulting in emergence of novel viral strains through recombination. However, there has been limited investigation of the mechanisms of in vivo FMDV coinfections under controlled experimental conditions. Our findings confirmed that cattle could be simultaneously infected by two distinct serotypes of FMDV, with different outcomes associated with the timing of exposure to the two different viruses. Additionally, dominant inter-serotypic recombinant FMDVs were discovered in multiple samples from the upper respiratory tracts of five superinfected animals, emphasizing the potential importance of persistently infected FMDV carriers as sources of novel FMDV strains.

Sign in / Sign up

Export Citation Format

Share Document