Outbreak investigations of foot and mouth disease virus in Nepal between 2010 and 2015 in the context of historical serotype occurrence

Abstract

Foot and Mouth Disease (FMD) is endemic in Nepal and causes substantial economic losses in the livestock industry. The goal of this study was to perform an epidemiological analysis of FMD outbreaks reported to the Veterinary Epidemiology Center, Tripureshwor, Nepal during 2010–2015, in order to strengthen the National FMD Control Program. These current data were considered in the context of historical data on FMD virus (FMDV) serotypes detected in the country between 1965 and 2015. During 2010–2015, a total of 1333 livestock holdings reported FMD outbreaks in Nepal. On average, 71.2 animals were affected in each outbreak, with a case fatality rate of 3.6%. FMD was reported throughout the country, and the proportion of affected holdings was not significantly among eco‐zones, regions, or species. The Hill eco‐zone had the highest number of holdings affected (782), followed by Mountain (304), and Terai (247). When analysed by the developmental region, the Western (381) and Central (368) Developmental Regions had the highest numbers of holdings affected. Cattle were the most frequently affected species (39%), followed by buffalo (33%), and goats (19%). FMD occurred throughout the year, with peaks in winter (December/January) and in the pre‐monsoon period (April/May). Between 1965 and 2015 FMDV serotype O had the highest prevalence (81%), followed by Asia‐1 (11%), A (6%), and C (2%). Serotype C was not detected after 1996, and only serotype O was reported after 2011. These descriptive analyses provide critical landmarks to establish baselines, and document early progress of the ongoing Progressive Control Pathway of FMD (PCP‐FMD) which could be useful in Nepal and other South Asian nations.

Foot and Mouth Disease (FMD) among Animals in Nepal

“…From 2012 to 2015, there was only FMD Serotype, O, reported in Nepal, however, during 2016, there was one outbreak of FMD serotype A in Chitwan and one outbreak of FMD serotype Asia-1 in Kaski (WRLFMD, 2018). There was involvement of FMDV serotype O in >80% of the outbreaks (Adhikari et al, 2018).…”

“…It is included in FMDV pool 2, in which serotypes O is most prevalent followed by A, and Asia-1 (Brito et al, 2017). However serotype C was present in Nepal in ancient time (Ferris et al 1992), but it has not been detected since 1996 (Jha, 2012;Adhikari et al, 2018).The vaccination against one serotype does not provide cross protection against other . Due to this reason, the vaccination programme is much challenging against this disease.…”

“…Foot and Mouth Disease (FMD) is caused by FMD virus which is a filterable virus of genus apthovirus and family Picornaviridae (Adhikari et al, 2018;Chakrabarti, 2017). It is a positive sense single stranded RNA virus.…”

“…In Nepal indirect sandwich antigen-ELISA (antigen and antibody) method is widely used for the identification of serotypes of FMD virus (Ferris et al, 1992). However, PCR (Conventional & Real Time) is also used (Adhikari et al, 2018;Ferris et al, 1992). Performance is according to manufacturer's instruction.…”

“…Morbidity rate is high and mortality is low. There is the focal degeneration of skeletal and cardiac muscles leading to death in young calves ( Adhikari et al, 2018) It is endemic in Nepal causing substantial economic losses in the livestock sector ( Adhikari et al, 2018) primarily due to the reduction in milk and meat production and secondarily due to the higher cost in controlling the disease and loss of draught power. Annual economic loss due to reduction in production of milk and meat was estimated to be around 66 million US dollar (Gongal, 2002).…”