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Foot-and-mouth disease (FMD) is a significant threat to animal health globally. Prophylactic vaccination using inactivated FMD virus (FMDV) antigen is being practised for the control in endemic countries. A major limitation of the current vaccine is its susceptibility to high environmental temperature causing loss of immunogenicity, thus necessitating the cold chain for maintenance of its efficacy. Hence, the FMD vaccine with thermostable virus particles will be highly useful in sustaining the integrity of whole virus particle (146S) during storage at 4°C. In this study, 12 recombinant mutants of Indian vaccine strain of FMDV serotype O (O/IND/R2/1975) were generated through reverse genetics approach and evaluated for thermostability. One of the mutant viruses, VP2_Y98F was more thermostable than other mutants and the parent FMDV. The oil-adjuvanted vaccine formulated with the inactivated VP2_Y98F mutant FMDV was stable up to 8 months when stored at 4°C and induced protective antibody response till dpv 180 after primary vaccination. It is concluded that the VP2_Y98F mutant FMDV was thermostable and has the potential to replace the parent vaccine strain., (© 2022 Wiley-VCH GmbH.)

Foot-and-mouth disease (FMD) is endemic in India, where circulation of serotypes O, A and Asia1 is frequent. Here, we provide an epidemiological assessment of the ongoing mass vaccination programs in regard to post-vaccination monitoring and outbreak occurrence. The objective of this study was assessing the contribution of mass vaccination campaigns in reducing the risk of FMD in India from 2008 to 2016 by evaluating sero-monitoring data and modelling the spatiotemporal dynamics of reported outbreaks. Through analyzing antibody titre data from >1 million animals sampled as part of pre- and post-vaccination monitoring, we show that the percent of animals with inferred immunological protection (based on ELISA) was highly variable across states but generally increased through time. In addition, the number of outbreaks in a state was negatively correlated with the percent of animals with inferred protection. We then analyzed the distribution of reported FMD outbreaks across states using a Bayesian space-time model. This approach provides better acuity to disentangle the effect of mass vaccination programs on outbreak occurrence, while accounting for other factors that contribute to spatiotemporal variability in outbreak counts, notably proximity to international borders and inherent spatiotemporal correlations in incidence. This model demonstrated a ∼50% reduction in the risk of outbreaks in states that were part of the vaccination program. In addition, after controlling for spatial autocorrelation in the data, states that had international borders experienced heightened risk of FMD outbreaks. These findings help inform risk-based control strategies for India as the country progresses towards reducing reported clinical disease., (© 2022 The Authors. Transboundary and Emerging Diseases published by Wiley-VCH GmbH.)

Antigenic profiling of recent field outbreak strains of foot-and-mouth disease virus (FMDV) serotype A in India has revealed considerable antigenic drift from the vaccine strain, A IND 40/2000, necessitating the selection of a new strain. The complete genome sequence of A IND 27/2011 was analysed. Vaccine quality attributes of the new candidate strain including potency as an inactivated vaccine in cattle were evaluated. The capsid coding region of A IND 27/2011 showed variation at eight antigenically critical amino acid positions from that of A IND 40/2000. The strain suited well with traits required by a vaccine in terms of its adaptability to adherent and suspension cell line, its immunogenicity, and potency as an inactivated vaccine formulation in cattle. Complete protection was observed upon homologous virus challenge at 4 weeks post-vaccination. Taken together, these data demonstrate the suitability of A IND 27/2011 as an effective vaccine strain of FMDV serotype A., (© 2021 Wiley-VCH GmbH.)

Foot-and-mouth disease (FMD) is, arguably, the animal disease with the most devastating global economic impact owing in part, to the severe trade restrictions imposed upon affected countries and regions. South Asia is one of the regions where widespread lineages of the FMDV virus (FMDV) have emerged. Here, we performed an integrative phylogenetic analysis of all FMDV serotypes (A, O and Asia-1) circulating in southern Asia, including viral sequences collected until 2013. Our results describe the occurrence of FMD caused by different serotypes and lineages, focusing in the cycles where a specific lineage predominates within a region for a protracted period and then are rapidly or progressively replaced by an emergent or re-emergent strain that is introduced from an adjacent region. Transmission between the two main regions in southern Asia (the Indian subcontinent and the region comprised by Afghanistan, Iran and Pakistan) has been limited. Results of time divergence estimation of lineages that currently circulate in this region indicate that the most recent common ancestor of endemic lineages are: 1992 [1989-1995] for lineage O/PanAsia; 1997 [1995-1999] for PanAsia2; 2001 [1998-2004] for O/Ind2001; 2001 [2000-2002] for A/Iran-05; 1990 [1988-1991] for A/G-18 (G-VII); 2003 [2000-2006] for Asia-1 Sindh08 and 2002 [1999-2004] for Asia-1 G-VIII. We estimated the mean of the overall substitution rate of the VP1 coding region (substitution/site/year) for serotype O (5.95 × 10 -3 ), serotype A (1.19 × 10 -2 ) and serotype Asia-1 (3.08 × 10 -3 ). The potential factors driving the lineage turnover are discussed. Our results provide insights into the ecological and evolutionary factors driving the emergence of FMDV., (© 2017 Blackwell Verlag GmbH.)

Foot-and-mouth disease (FMD) is an important transboundary disease with substantial economic impacts. Although between-herd transmission of the disease has been well studied, studies focusing on within-herd transmission using farm-level outbreak data are rare. The aim of this study was to estimate parameters associated with within-herd transmission, host physiological factors and FMD virus (FMDV) persistence using data collected from an outbreak that occurred at a large, organized dairy farm in India. Of 1,836 regularly vaccinated, adult dairy cattle, 222 had clinical signs of FMD over a 39-day period. Assuming homogenous mixing, a frequency-dependent compartmental model of disease transmission was built. The transmission coefficient and basic reproductive number were estimated to be between 16.2-18.4 and 67-88, respectively. Non-pregnant animals were more likely to manifest clinical signs of FMD as compared to pregnant cattle. Based on oropharyngeal fluid (probang) sampling and FMDV-specific RT-PCR, four of 36 longitudinally sampled animals (14%) were persistently infected carriers 10.5 months post-outbreak. There was no statistical difference between subclinical and clinically infected animals in the duration of the carrier state. However, prevalence of NSP-ELISA antibodies differed significantly between subclinical and clinically infected animals 12 months after the outbreak with 83% seroprevalence amongst clinically infected cattle compared to 69% of subclinical animals. This study further elucidates within-herd FMD transmission dynamics during the acute-phase and characterizes duration of FMDV persistence and seroprevalence of FMD under natural conditions in an endemic setting., (© 2017 Blackwell Verlag GmbH.)

The goal of this study was to characterize the properties and duration of the foot-and-mouth disease (FMD) carrier state and associated serological responses subsequent to vaccination and naturally occurring infection at two farms in northern India. Despite previous vaccination of cattle in these herds, clinical signs of FMD occurred in October 2013 within a subset of animals at the farms containing juvenile-yearling heifers and steers (Farm A) and adult dairy cattle (Farm B). Subsequent to the outbreak, FMD virus (FMDV) asymptomatic carriers were identified in both herds by seroreactivity to FMDV non-structural proteins and detection of FMDV genomic RNA in oropharyngeal fluid. Carriers' seroreactivity and FMDV genome detection status were subsequently monitored monthly for 23 months. The mean extinction time of the carrier state was 13.1 ± 0.2 months, with extinction having occurred significantly faster amongst adult dairy cattle at Farm B compared to younger animals at Farm A. The rate of decrease in the proportion of carrier animals was calculated to be 0.07 per month. Seroprevalence against FMDV non-structural proteins decreased over the course of the study period, but was found to increase transiently following repeated vaccinations. These data provide novel insights into viral and host factors associated with the FMDV carrier state under natural conditions. The findings reported herein may be relevant to field veterinarians and governmental regulatory entities engaged in FMD response and control measures., (© 2017 Blackwell Verlag GmbH.)

Porcine sapelovirus (PSV) A belongs to the genus Sapelovirus, family Picornaviridae. PSV infections in pigs have been reported from European countries, United States, Japan, China, Korea and Brazil. The virus has been isolated/detected from faeces of healthy pigs as well as those affected with diarrhoea, respiratory signs, encephalitis, skin lesions and fertility disorders. This study was planned to investigate whether PSV is prevalent among pigs in India and to characterize PSV encountered in the study population. The study revealed that five of 70 (7.14%) faecal samples were found positive for PSV using RT-PCR. Three viruses were successfully isolated from faecal samples using IB-RS-2 cell line. Complete genome sequencing and analysis of one Indian PSV isolate revealed highest homology (88%) with V13 strain from England. Phylogenetic analysis of the complete polyprotein nucleotide sequences of 14 strains of PSV classified the viruses into four distinct clades. This first report from India adds to our knowledge on genetic diversity of PSV detected so far among pigs in different countries. A large-scale surveillance of the virus is required to understand its genomic diversity and economic impact., (© 2017 Blackwell Verlag GmbH.)

A systematic vaccination programme is ongoing in India to control the three prevailing serotypes (A, O, Asia1) of foot-and-mouth disease (FMD) virus. Under the programme, more than 120 million bovine (term bovine applicable to both cattle and buffalo in this study) population of 221 of the 666 districts in the country are being bi-annually vaccinated with trivalent vaccine since 2010. Although clinical disease has reduced in these districts because of the systematic vaccinations, an abrupt increase in the number of FMD cases was recorded in 2013. Hence, a longitudinal field study was conducted in the year 2014 to estimate the serological herd immunity level in bovines, the impact of systematic vaccinations and field efficacy of the vaccines used. Serum samples (n = 115 963) collected from 295 districts of the 18 states of the country were analysed to estimate antibody titres against structural proteins of the three serotypes. The efficacy of the vaccine was demonstrated in the control group (group-D) where animals of the group were identified by ear tags for the purpose of repeated sampling after vaccination. Progressive building of the herd immunity in the field after systematic vaccination was demonstrated. The mean antibody titre against the serotypes O, A and Asia1 was estimated as log 10 1.93 (95% CI 1.92-1.93), 2.02 (2.02-2.02) and 2.02 (2.02-2.02), respectively, in the states covered under the control programme. However, in other states herd immunity was significantly low [mean titre log 10 1.68 (95% CI 1.67-1.69), 1.77 (1.76-1.78) and 1.85 (1.84-1.86) against the three serotypes]. Inverse relationship between the herd immunity and FMD incidences was observed the states following different vaccination practices. The study helped in demarcation of FMD risk zones in the country with low herd immunity. Estimation of herd immunity kinetics in the field helped in refining the vaccination schedule under the control programme., (© 2016 Blackwell Verlag GmbH.)

This study was conducted to assess the impact of Foot-and-mouth Disease (FMD) outbreak in cattle and buffaloes on farming community in Kolar district, Karnataka state, India. Primary data were collected using pre-tested schedule from 178 sample farms using multistage random cluster sample technique. The results revealed that 78% of surveyed villages were affected with FMD. The FMD incidence risk was high across the herd sizes, whereas the mortality risk was high in small herds. In indigenous cattle, the highest loss due to FMD was distress sale (208 USD) followed by other losses, whereas, in Crossbred cattle, the highest loss was mortality loss (515 USD) followed by distress sale (490 USD), milk yield loss (327 USD), treatment cost (38 USD) and extra labour engagement expenses for nursing of FMD-affected bovines (30 USD). In local and upgraded buffaloes, the mean total loss per affected animal was 440 USD and 513 USD, respectively. A very high variability in the loss per animal was observed across the type of losses in the Crossbred cattle, and it may be due to differences in age of the FMD-infected animal, value of the animal, milking stage, lactation levels, herd sizes and labour engagement levels, etc. In local and upgraded buffaloes, the mean total loss per animal was 639 USD and 1008 USD, respectively. The sensitivity analysis for 5% change in price revealed that the mean total loss per animal was positively correlated with price. Further, the social impact elicitation revealed that majority of the livestock owners perceived FMD had caused permanent asset loss, which in turn increased psychological stress of the family. The estimated losses and social impact due to FMD signify the importance of the intervention to control the disease and thus socio-economic gain to the farmer and society at large., (© 2015 Blackwell Verlag GmbH.)

Foot-and-mouth disease viruses are often restricted to specific geographical regions and spread to new areas may lead to significant epidemics. Phylogenetic analysis of sequences of the VP1 genome region of recent outbreak viruses from Libya and Saudi Arabia has revealed a lineage, O-Ind-2001, normally found in the Indian subcontinent. This paper describes the characterization of field viruses collected from these cases and provides information about a new real-time RT-PCR assay that can be used to detect viruses from this lineage and discriminate them from other endemic FMD viruses that are co-circulating in North Africa and western Eurasia., (© 2014 The Authors. Transboundary and Emerging Diseases Published by Blackwell Verlag GmbH.)

Foot-and-mouth disease (FMD) is endemic in India and causes severe economic loss. Status of FMD in the country for five fiscal years is presented. Outbreaks were more in number in 2007-2008 than 2010-2011. Three serotypes of FMD virus (O, A and Asia1) are prevalent. Serotype O was responsible for 80% of the confirmed outbreaks/cases, whereas Asia1 and A caused 12% and 8%, respectively. Geographical region-wise assessment indicated varying prevalence rate in different regions viz; 43% in Eastern region, 31.5% in Southern region, 11.6% in North-eastern region, 5% Central region, 4.4% Western region and 4% in Northern region. Highest number of outbreaks/cases was recorded in the month of September and lowest in June. Emergence and re-emergence of different genotypes/lineages within the serotypes were evident in real-time investigation carried out from time to time. Continues antigenic divergence in serotype A resulted in change in the vaccine strain in 2009. As on date, all genetic diversity within the serotypes is well tolerated by the vaccine strains. Unrestricted animal movements in the country play a major role in the spread of FMD., (© 2012 Blackwell Verlag GmbH.)

India is endemic for foot-and-mouth disease (FMD), and goats constitute the second largest susceptible population of domestic livestock. FMD surveillance and control strategies in the country largely ignore small ruminants, known to be critical in the epidemiology of the disease. Here, serological investigations were carried out to generate estimates of antibody prevalence in goats of Orissa state to both non-structural (NSP-Ab) and structural proteins (SP-Ab) of FMD. The apparent overall NSP-Ab and SP-Ab seroprevalences were 38% and 20.7%, respectively, which signifies a very high level of FMD virus circulation in the goat population despite the lack of clinical signs in this species. The apparent prevalence of NSP-Ab and SP-Ab was positively correlated in the sampling areas. Interestingly, the values found for NSP-Ab prevalence were almost consistently higher than those found for SP-Ab prevalence. This could have been attributable to either issues related to sensitivity and specificity of the test systems employed or differences in the post-infection kinetics of NSP- and SP-Ab. The pattern that emerged from SP-Ab analysis indicated goats being infected with all three prevalent serotypes (O, A and Asia 1) and reinforces the concept that non-vaccinated goats can be exploited as tracer animals for detecting serotypes involved in outbreaks. The results underscore the requirement to bring caprine species under comprehensive surveillance and vaccination campaigns to check silent amplification, excretion and transmission of the virus., (© 2010 Blackwell Verlag GmbH.)