A new blocking ELISA for detection of foot-and-mouth disease non-structural protein (NSP) antibodies in a broad host range.

Large-scale monitoring of foot-and-mouth disease (FMD) in livestock is imperative in an FMD control program. Detection of antibodies against non-structural proteins (NSP) of FMD virus (FMDV) is one of the best tools to estimate the prevalence of past infection; availability of such a well-validated test is therefore essential. Using a FMDV 3B protein-specific monoclonal antibody, we have developed a new NSP antibody blocking ELISA (10H9 bELISA) and validated it on large panels of sera from different susceptible species. The diagnostic sensitivity of the ELISA was 95% with a specificity of 98%, similar to the values found using a commercial kit (PrioCHECK FMD NS test). The 10H9 bELISA can be used in a broad range of FMD susceptible species making it a very useful tool in monitoring the foot-and-mouth disease control programs by detection of virus circulation in the vaccinated populations. KEY POINTS: • A new ELISA for detection of foot and mouth disease (FMD) antibodies. • Diagnostic sensitivity of 95% and specificity of 98%. • Tested with panels of validated sera from broad host range.

First complete genome characterization of duck plague virus from India.

In this study, we report the complete genome sequencing of the Duck plague virus from India for the first time. The sequencing was done on the MinION nanopore sequencer from Oxford Nanopore Technologies. The closest relative is the European strain 2085v, with 99.98 and 99.8% identity at the amino acid and nucleotide level respectively. Moreover, 72 out of 77 ORFs are completely conserved between the 2 strains. The high similarity with the European strain over the only three other pathogenic strains reported from China points to the circulation of European strain in India. The fly pathways of migratory birds and co-habitation with native species being a probable reason. More complete genome data from diverse sampling locations are needed to characterize the genomic features, develop diagnostics, vaccines, and understand the evolution of the virus.

Evidence of Transmission of Goatpox between Domestic Goats and Wild Himalayan Goral (Naemorhedus goral) in Arunachal Pradesh, India.

Examination of carcasses of Himalayan goral (Naemorhedus goral) revealed nodular, pox-like eruptions in the skin. Similar disease was also seen in domestic goats (Capra aegagrus hircus) in the same area. Goatpox virus was identified as the etiology of the disease in both cases, with probable transmission between the species.

First complete genome characterization of swinepox virus directly from a clinical sample indicates divergence of a Eurasian-lineage virus.

In this study, we report the complete genome sequence of swinepox virus from a clinical sample from a naturally occurring infection in India. The sequencing was done on a Nanopore MinION sequencer from Oxford Nanopore Technologies. Two new annotations were added to the genome. Three of the genes were found to have frameshifts, which might be of importance in relation to infection. When compared to the only other reported whole genome sequence of swinepox virus, which was obtained from an isolate from America in 1999, our sequence is only 98.19% identical at the nucleotide level. The average amino acid sequence identity of the viral proteins, based on the common 149 annotations, is also 98.19%, demonstrating that these viruses are distinctly divergent. Owing to the fact that swinepox virus infects only swine, it could not have entered America until the introduction of swine in the 16th century from Europe. The swinepox viruses in both continents have continued to evolve independently. The sequence divergence identified here indicates a Eurasian-lineage virus that is geographically distinct from the American-lineage swinepox virus.

The extent and structure of pig rearing system in urban and peri-urban areas of Guwahati.

Livestock is common in Indian cities and contribute to food security as well as livelihoods. Urban livestock keeping has been neglected, and in India, little is known about the topic. Therefore, urban and peri-urban pig farms of Guwahati, Assam, India, were surveyed in order to understand more about the pig rearing systems and risks of diseases. A total of 34 urban and 66 peri-urbanpig farms were selected randomly. All reared cross-bred pigs. Free-range pig rearing was common in both urban (58.8%) and peri-urban (45.45%) farms. Artificial insemination was used by around half of the pig farmers. Disinfection in pig farms was practiced in 26.5% of urban and 28.8% of peri-urban farms. More urban pig farms were observed to be moderately clean in (82.4%) compared to peri-urban (69.7%). However, more urban (67.7%) than peri-urban farms (57.6%) reported ahighrodent burden. Pig sheds were mostly basic, with bricked floors in 18.2% farms in peri-urban areas, and more than 80% had corrugated iron roofing sheets. In conclusion, free-roaming pigs in both urban and peri-urban areas of Guwahati can contribute to disease transmission, and the low standard of hygiene and buildings may further increase the risk of diseases.

Identification of swinepox virus from natural outbreaks in pig population of Assam.

Outbreaks of swinepox [caused by a swinepox virus (SWPV)] in pigs were investigated in 3 districts of Assam, a north eastern state of India. Diagnosis of the disease was carried out employing both standard virological as well as molecular methods. Three representative isolates from different places were selected for inoculation into confluent monolayers of Porcine Kidney-15 (PK-15) cell line. The cytopathic effects were characterized by cell rounding, nuclear vacuolation, cell fusion, granulation of cells and finally detachment from third blind passage onwards. The three genes viz., SPV18-20 and P42 of SWPV was targeted for confirmation of the virus. Swinepox virus was successfully adapted to the PK-15 cell line from seventh passage onwards. The isolated viruses were characterized by sequencing and phylogenetic analysis of P42 gene (extracellular envelope protein), a homologue of vaccinia virus F13L gene. In India, studies on swine pox are very limited. This is the first report on successful isolation of swinepox virus from north eastern region of India. Assam and the other north-eastern states of India being a hub for pig husbandry, isolation of swinepox virus will help in developing and formulating control strategies against the disease.

Molecular characterization of classical swine fever virus isolates from India during 2012-14.

Classical swine fever is a highly contagious and economically important viral disease of pigs. Outbreaks of classical swine fever virus (CSFV) were recorded in different places in the Kamrup district of Assam in India between the years 2012 and 2014. The nucleotide sequences of the 10 CSFV isolates were analyzed based on the partial nucleotide sequences of the E2, 5'NTR and NS5B genes. Phylogenetic analysis indicated the dominance of subgroup 2.2 along with 2.1 strains in the northeast part of India. Variation in the nucleotide sequences of E2, 5'NTR and 3'NS5B genes of CSFV allows tracking changes in the virus population over time. The study will provide epidemiological information useful for assessing CSFV circulating genogroups in India.

Experimental infection of pigs with group A rotavirus and enterotoxigenic Escherichia coli in India: gross, histopathological and immunopathological study.

The authors describe a detailed study conducted in Assam, India, of gross, histopathological and immunopathological alterations in pigs experimentally infected with rotavirus and enterotoxigenic Escherichia coli (ETEC) expressing K88 pili. A total of 30 Caesarean derived piglets were infected experimentally with rotavirus alone or in combination with ETEC to study the gross and histopathological alterations and the distribution pattern of different B- and T cell subsets in the gut. Villus atrophy, especially in the jejunum and ileum, was the consistent lesion in piglets infected with rotavirus, while in piglets simultaneously infected with rotavirus and ETEC, severe necrosis of the intestinal villi was observed. Ultrastructural studies revealed similar pathological alterations in the ileum of the infected piglets. A morphometric study of the intestinal villi and crypts showed a reduction in the ratio between the average villus height and crypt depth (VH:CD ratio) in the group infected with rotavirus (5.95±0.33) and those infected with rotavirus and ETEC (7.90±0.16). A higher (p<0.01) reduction in the VH:CD ratio was observed in the jejunum (8.83±0.79) and ileum (8.46±0.78) compared that in the duodenum (10.03±0.50) of the infected pigs. Piglets infected with rotavirus and sacrificed on day 6 post infection revealed the presence of lymphocytes containing cytoplasmic IgA+ (cIgA+) cells in the villus lamina propria and intra-epithelial CD8+ T cells in the villus epithelia. Rotavirus infection of young piglets in association with ETEC was more severe than rotavirus infection alone. Such infection resulted in marked clinico-pathological and immunological alterations in the infected piglets.

Emerging and re-emerging zoonotic buffalopox infection: a severe outbreak in Kolhapur (Maharashtra), India.

Buffalopox is an emerging and re-emerging zoonotic viral infection. The authors investigated an extensive zoonotic outbreak of buffalopox involving many human cases. High morbidity and significant productivity losses were recorded among domestic buffalo in Kolhapur (Maharashtra), India, between February and March 2009. The outbreak involved a total of 4000 buffalo from 21 villages in which over 10 000 buffalo were herded. The outbreak also involved 125 humans who were mostly animal handlers and milkers of all age groups. The disease inflicted a loss of approximately 40% in terms of reduced milk production and a decline in animal trade. Although pox lesions were observed on all parts of the body, the most severe were found on the inner ear. This led to otitis and pyrexia in most of the affected animals. Milkers developed pox-like lesions on the skin of their fingers, hands, forearms, forehead, ears and face, along with pyrexia, malaise and axillary lymphadenitis and lymphadenopathy. The causal agent, buffalopox virus, was confirmed using counter-immuno-electrophoresis, the serum neutralisation test, virus isolation and buffalopox virus-specific ankyrin repeat protein (C18L) gene-based polymerase chain reaction. Considering the emergence and re-emergence of buffalopox virus in buffalo, cows and humans, not only in India but also in other buffalo rearing countries, regular monitoring of outbreaks and control measures are necessary to curb economic losses and also to reduce the public health impact of the disease.