Epidemiology of the Foot‐and‐Mouth Disease Serotype O Epidemic of November 2010 to April 2011 in the Republic Of Korea

The largest epidemic of foot‐and‐mouth disease (FMD) in Korea since the first record in 1911 occurred between November 2010 and April 2011. The outbreak was confirmed in 153 farms, and more than three million animals were destroyed. This study presents the temporal and spatial distribution patterns, epidemiological investigation and the control measures for the 2010/2011 epidemic in Korea. The index case of this 2010/2011 FMD epidemic was reported in a pig‐farming complex with five piggeries in Andong, GyeongBuk Province, on 28 November 2010, and the outbreak lasted 145 days. The largest number of new detection of the infected farms per day was recorded in mid‐January. Epidemiological investigation revealed that the FMD virus had spread from farm to farm through routine movements associated with animal husbandry operations. In contrast to FMD epidemics in other countries in which movement of the infected animals largely contributed to the spread of the disease, human behaviours were major factors in the spread of the FMD virus in the Korean epidemic. The 2010/2011 epidemic was first confirmed in a local small and medium city where share of smallholder producers is higher than that of other provinces. Although Korea had a well‐developed emergent response system with the experience of controlling infection and re‐obtaining FMD‐free status after the previous epidemics, Korea was prompted to revise their contingency plan by tailoring it to its unique livestock environment. Practical contingency plans tailored to Korea for control of FMD can be fully effective when farmers, livestock‐related agencies, veterinary service providers and the general public work together.     

Diagnosis and Control Measures of the 2010 Outbreak of Foot‐and‐Mouth Disease A Type in the Republic of Korea

In January 2010, foot‐and‐mouth disease (FMD) occurred for the first time in 8 years in Korea. The outbreaks were because of A serotype, different from the O type, which had occurred previously in 2000 and 2002. The FMD outbreaks were identified in seven farms, consisting of six cattle farms where viruses were detected and one deer farm where only FMDV antibody was detected. The seven farms were within 9.3 km of each other. All susceptible animals within 10 km radius of the outbreak farms were placed under movement restrictions for 3–11 weeks. No vaccination took place to facilitate the clinical observation of infected animals and virus detection. After clinical observations and serological tests within the control zones showed no evidence of FMD infection, the movement restrictions were lifted, followed by FMD‐free declaration (23 March) at 80 days after the first outbreak on 2 January. This communication describes the outbreak of FMD A serotype, and control measures applied to eradicate the disease in Korea.     

Emergence and Distribution of Foot‐and‐Mouth Disease Virus Serotype A and O in Bangladesh

Foot‐and‐mouth disease (FMD) is endemic in Bangladesh and is predominantly due to FMDV serotype O. In 2012, FMD outbreaks were identified in five different districts of Bangladesh. Of 56 symptomatic cattle epithelial tissue samples, diagnostic PCR assay based on 5′‐URT detected 38 FMDV infections. Viral genotyping targeting VP1‐encoding region confirmed emergence of two distinct serotypes, A and O with an abundance of serotype A in Chittagong and Gazipur districts and serotype O in Pabna and Faridpur. Only single lineage of both A and O was retrieved from samples of five different regions. Sequencing and phylogenetic analysis of VP1 sequences revealed that serotype O sequences were closely related to the Ind 2001 sublineage of Middle East–South Asia (ME‐SA) topotype that was previously circulating in Bangladesh, and serotype A sequences belonging to the genotype VII that was dominant in India during the last decade. The results suggest that extensive cross‐border animal movement from neighbouring countries is the most likely source of FMDV serotypes in Bangladesh.     

Clinical Manifestations of Foot‐and‐Mouth Disease During the 2010/2011 Epidemic in the Republic of Korea

We reviewed the clinical signs of the foot‐and‐mouth disease (FMD) incidences in the Republic of Korea occurring from November 2010 to April 2011. Profuse salivation, vesiculation, lameness or ataxia, and ulceration were the most commonly observed clinical signs of FMD among the infected animals, irrespective of the species. The clinical signs of FMD manifested more clearly in the dairy cattle and pigs compared to the beef cattle, deer and goats on infected farms. About 54% of the infected dairy farms reported vesicles on the teats as the primary clinical sign, while vesiculation on the nose, including the snout and muzzle, was the major lesion observed in infected beef cattle and pig farms. The teat and feet were the second most frequently vesiculated body parts on infected pigs. Although the average age of the first‐to‐appear clinical lesion in the animals in the beef and dairy cattle farms subjected to vaccination was higher than that observed in the animals in the farms not subjected to vaccination, a reverse pattern was observed in the pig farms. In this study, the clinical signs of FMD were described on the basis of the subjective observations by the farm workers. The present results highlight the clinical signs expected on specific body parts of different types of susceptible animals, and therefore, they may be useful for generating public awareness, particularly among farm workers, as well as for early detection of future FMD outbreaks.     

Serotype Specificity of Antibodies against Foot‐and‐Mouth Disease Virus in Cattle in Selected Districts in Uganda

Uganda had an unusually large number of foot‐and‐mouth disease (FMD) outbreaks in 2006, and all clinical reports were in cattle. A serological investigation was carried out to confirm circulating antibodies against foot‐and‐mouth disease virus (FMDV) by ELISA for antibodies against non‐structural proteins and structural proteins. Three hundred and forty‐nine cattle sera were collected from seven districts in Uganda, and 65% of these were found positive for antibodies against the non‐structural proteins of FMDV. A subset of these samples were analysed for serotype specificity of the identified antibodies. High prevalences of antibodies against non‐structural proteins and structural proteins of FMDV serotype O were demonstrated in herds with typical visible clinical signs of FMD, while prevalences were low in herds without clinical signs of FMD. Antibody titres were higher against serotype O than against serotypes SAT 1, SAT 2 and SAT 3 in the sera investigated for serotype‐specific antibodies. Only FMDV serotype O virus was isolated from one probang sample. This study shows that the majority of the FMD outbreaks in 2006 in the region studied were caused by FMDV serotype O; however, there was also evidence of antibodies to both SAT 1 and SAT 3 in one outbreak in a herd inside Queen Elizabeth national park area.     

Epidemiological Patterns of Foot‐and‐Mouth Disease Worldwide

Foot‐and‐Mouth Disease (FMD) is a clinical syndrome in animals due to FMD virus that exists in seven serotypes, whereby recovery from one sero‐type does not confer immunity against the other six. So when considering intervention strategies in endemic settings, it is important to take account of the characteristics of the different serotypes in different ecological systems. FMD serotypes are not uniformly distributed in the regions of the world where the disease still occurs. For example, the cumulative incidence of FMD serotypes show that six of the seven serotypes of FMD (O, A, C, SAT‐1, SAT‐2, SAT‐3) have occurred in Africa, while Asia contends with four sero‐types (O, A, C, Asia‐1), and South America with only three (O, A, C). Periodically there have been incursions of Types SAT‐1 and SAT‐2 from Africa into the Middle East. This paper describes the global dynamics for the seven sero‐types and attempts to define FMD epidemiological clusters in the different regions of the world. These have been described on a continent by continent basis. The review has reaffirmed that the movement of infected animals is the most important factor in the spread of FMD within the endemically infected regions. It also shows that the eco‐system based approach for defining the epidemiological patterns of FMD in endemic, which was originally described in South America, can apply readily to other parts of the world. It is proposed that any coordinated regional or global strategy for FMD control should be based on a sound epidemiological assessment of the incidence and distribution of FMD, identifying risk sources as either primary or secondary endemic eco‐systems.     

Analysis of Recent Serotype O Foot‐and‐Mouth Disease Viruses from Livestock in Kenya: Evidence of Four Independently Evolving Lineages

Foot‐and‐mouth disease (FMD) is endemic in Kenya where four serotypes (O, A, SAT 1 and SAT 2) of the virus are currently in circulation. Within 2010 and 2011, the National Laboratory recorded an increase in the number of FMD outbreaks caused by serotype O virus. The characteristics of these viruses were determined to ascertain whether these were independent outbreaks or one single strain spreading throughout the country. The sequences of the complete VP1‐coding region were analysed from viruses sampled within different areas of Kenya during 2010 and 2011. The results indicated that the 2010 to 2011 outbreaks in Kenya were caused by four independent strains. By comparison with earlier type O isolates from Eastern Africa, it was apparent that the outbreaks were caused by viruses from three different lineages of topotype EA‐2 and a fourth virus strain belonging to topotype EA‐4. The topotypes EA‐1 and EA‐3 were not detected from these outbreaks. Implications of these results for FMD control in Eastern Africa are discussed.     

Serological Evidence Indicates that Foot‐and‐Mouth Disease Virus Serotype O,C and SAT1 are most Dominant in Eritrea

Foot‐and‐mouth disease (FMD) is endemic in Eritrea and in most parts of Africa. To be able to control FMD using vaccination, information on the occurrence of various foot‐and‐mouth disease serotypes in Eritrea is needed. In this cross‐sectional study, 212 sera samples were collected from FMD infected and recovered animals in Eritrea. These samples were tested for the presence of antibodies against FMD non‐structural proteins (NSP) and neutralizing antibodies against six of the seven (all but SAT 3) serotypes of FMD virus (FMDV). Of these, 67.0% tested positive to non‐structural protein antibodies in the FMD NS ELISA. By virus neutralization, FMDV serotype O antibodies were shown to be the most dominant (approximately 50%). Virus neutralization test results indicate that infection with serotype C and SAT 1 might have occurred, although there are no reports of isolation of these two serotypes. Because the samples were not randomly selected, further random serological surveillance in all age group animals is necessary both to estimate the prevalence of FMD in the country and to confirm the serological results with serotype C and SAT 1.     

Outbreaks of Foot‐and‐Mouth Disease in Libya and Saudi Arabia During 2013 Due to an Exotic O/ME‐SA/Ind‐2001 Lineage Virus

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.     

Molecular Characterisation of Foot‐and‐Mouth Disease Viruses from Pakistan, 2005–2008

Foot‐and‐mouth disease (FMD), an economically important disease of cloven‐hoofed animals, is endemic in Pakistan where three virus serotypes are present (O, A and Asia 1). Fifty‐eight clinical samples collected between 2005 and 2008 from animals with suspected FMD in various locations in Pakistan were subjected to virus isolation on primary cell culture, antigen ELISA and real‐time RT‐PCR (rRT‐PCR). Viruses were isolated from 32 of these samples and identified as FMDV type O (n = 31) or type A (n = 1). Foot‐and‐mouth disease virus (FMDV) genome was detected in a further 11 samples by real‐time RT‐PCR. Phylogenetic analyses of the VP1 nucleotide sequences showed that all of the type O viruses belonged to the MIDDLE EAST–SOUTH ASIA topotype with the majority belonging to the PanAsia‐2 lineage; a single example of the older PanAsia lineage was identified. The single FMDV type A virus belonged to the ASIA topotype, but did not cluster with known strains that are currently circulating (such as Iran‐05) and was not closely related to other type A viruses from the region. These findings demonstrate the widespread distribution of O‐PanAsia‐2 in Pakistan and the presence of undisclosed novel type A lineages in the region.     

Review: Evaluation of Foot‐and‐Mouth Disease Control Using Fault Tree Analysis

An outbreak of foot‐and‐mouth disease (FMD) causes huge economic losses and animal welfare problems. Although much can be learnt from past FMD outbreaks, several countries are not satisfied with their degree of contingency planning and aiming at more assurance that their control measures will be effective. The purpose of the present article was to develop a generic fault tree framework for the control of an FMD outbreak as a basis for systematic improvement and refinement of control activities and general preparedness. Fault trees are typically used in engineering to document pathways that can lead to an undesired event, that is, ineffective FMD control. The fault tree method allows risk managers to identify immature parts of the control system and to analyse the events or steps that will most probably delay rapid and effective disease control during a real outbreak. The present developed fault tree is generic and can be tailored to fit the specific needs of countries. For instance, the specific fault tree for the 2001 FMD outbreak in the UK was refined based on control weaknesses discussed in peer‐reviewed articles. Furthermore, the specific fault tree based on the 2001 outbreak was applied to the subsequent FMD outbreak in 2007 to assess the refinement of control measures following the earlier, major outbreak. The FMD fault tree can assist risk managers to develop more refined and adequate control activities against FMD outbreaks and to find optimum strategies for rapid control. Further application using the current tree will be one of the basic measures for FMD control worldwide.     

Epidemiology of the 2010 Outbreak of Foot‐and‐Mouth Disease in Mongolia

Foot‐and‐mouth disease (FMD) occurred in five provinces and 24 counties as part of the FMD incursion into Mongolia during 2010. The first detection occurred on 21 April 2010 (confirmed 26 April 2010) with the last detection occurring approximately 8 months later on 13 December 2010. The number of livestock detected in the spring phase of the outbreak was 323 cattle and in the summer phase was 13 485 sheep, 6748 cattle, 5692 goats and 10 camels (total livestock summer phase = 25 935; for spring and summer phases combined = 26 258). Infection of livestock was confirmed by PCR for each affected county but not necessarily for every outbreak cluster involving more than one herder. It is likely that the summer phase of the outbreak was a continuation of the spring event. In the summer phase, the spatio‐temporal pattern of spread suggested an extension of infection from the main cluster in the Sukhbaatar county. There was also a number of long‐distance clusters established. The relative importance of spread by three potential pathways of gazelle, livestock, animal product and fomite movements has not been determined and will require further study. The estimated dissemination ratio (EDR) did not provide evidence of high rate of transmission of infection between herders; however, the data are limited by the quality of surveillance and the method of calculation which used the date of detection rather than the date of infection.     

Foot‐and‐Mouth Disease Seroprevalence in Cattle in Eritrea

Information about seroprevalence of foot‐and‐mouth disease (FMD) and virus serotypes in Eritrea is unavailable, but is very important as it may guide the choice of intervention measures including vaccination to be implemented. We carried out a cross‐sectional study from February to June 2011 in Eritrea with a two‐stage cluster design, sampling cattle in 155 villages with the objective of determining the seroprevalence of FMD in four administrative regions of the country. We analysed cattle sera (n = 2429) for FMD virus antibodies using the non‐structural ELISA (NS ELISA) and virus neutralization test (VNT). The overall seroprevalence was 26% and 30% for the NS ELISA and VNT, respectively. FMD virus serotypes O (14%) and A (11%) were the most prevalent. Gash Barka showed the highest (39%) seroprevalence both in NS ELISA and VNT compared to the other three administrative regions. Strategic FMD virus vaccination with type O and A (matching circulating strains) in combination of zoo‐sanitary measures would be the best control option for Eritrea which could be started in areas where the disease is less endemic.     

Foot‐and‐Mouth Disease in Tanzania from 2001 to 2006

Foot‐and‐mouth disease (FMD) is endemic in Tanzania, with outbreaks occurring almost each year in different parts of the country. There is now a strong political desire to control animal diseases as part of national poverty alleviation strategies. However, FMD control requires improving the current knowledge on the disease dynamics and factors related to FMD occurrence so control measures can be implemented more efficiently. The objectives of this study were to describe the FMD dynamics in Tanzania from 2001 to 2006 and investigate the spatiotemporal patterns of transmission. Extraction maps, the space‐time K‐function and space‐time permutation models based on scan statistics were calculated for each year to evaluate the spatial distribution, the spatiotemporal interaction and the spatiotemporal clustering of FMD‐affected villages. From 2001 to 2006, 878 FMD outbreaks were reported in 605 different villages of 5815 populated places included in the database. The spatial distribution of FMD outbreaks was concentrated along the Tanzania‐Kenya, Tanzania‐Zambia borders, and the Kagera basin bordering Uganda, Rwanda and Tanzania. The spatiotemporal interaction among FMD‐affected villages was statistically significant (P ≤ 0.01) and 12 local spatiotemporal clusters were detected; however, the extent and intensity varied across the study period. Dividing the country in zones according to their epidemiological status will allow improving the control of FMD and delimiting potential FMD‐free areas.     

Temporospatial Clustering of Foot‐and‐Mouth Disease Outbreaks in Israel and Palestine, 2006–2007

Foot‐and‐mouth disease (FMD) is endemic to the Middle East and there is a perception that political instability and limited resources have led to the uncontrolled circulation of FMD virus throughout the region. Certain aspects of FMD epidemiology in the Middle East remain unknown. The goal of this study was to identify the geographical location, temporal extent and direction of spread of clusters of 70 FMD outbreaks reported in Israel and Palestine from February 4, 2006, through July 15, 2007. The space–time permutation model of the scan statistic test detected nine significant (P < 0.1) clusters. Significant (P < 0.05) direction of spread was identified in four of the nine clusters. The Gaza Strip, where no outbreaks were reported, or a nearby location, seemed to be the origin of a cluster of outbreaks located in Hadarom (April 2007); a cluster of outbreaks centered in West Bank (February 2006) may be linked with spread from Northern Israel; a cluster in Hazafon (January 2007) seemed to have originated from nearby the Jordan borders; and a cluster located in Northern Hazafon was likely related to areas next to the Lebanon and Syrian borders. The association between the clusters in West Bank and earlier Israeli samples and between the cluster in Hazafon and Jordan was also supported (P < 0.05) by phylogenetic analysis of samples collected from the outbreaks. These results suggest that the FMD outbreaks reported in Israel and Palestine in 2006 and 2007 were likely a consequence of different epidemics associated with the circulation and spread of FMD virus strains from different regions of the Middle East.     

Molecular Characterization of Foot‐and‐Mouth Disease Virus: Implications for Disease Control in Bangladesh

Foot‐and‐mouth disease (FMD) is endemic in Bangladesh, and to implement an effective FMD control programme, it is essential to understand the complex epidemiology of the disease. Here, we report on the characterization of FMD virus (FMDV) recovered from FMD outbreaks in Bangladesh in late 2009. All isolated viruses belonged to the FMDV serotype O. The phylogenetic reconstruction showed that all isolates belonged to the Middle East–South Asia (ME–SA) topotype, but fell into two distinct sublineages, one named Ind‐2001 (the other has not been named). Within both sublineages, the 2009 Bangladesh isolates were most closely related to viruses from Nepal collected during 2008 and 2009. Additionally, both sublineages contained older viruses from India collected in 2000 and 2001. In South Asia, there is extensive cross‐border cattle movement from Nepal and India to Bangladesh. Both these findings have implications for the control of FMD in Bangladesh. Because of the porous borders, a regional FMD control strategy should be developed. Further, animal identification and monitoring animal movements are necessary to identify the cross‐border movements and market chain interactions of ruminants, leading to improved border and movement controls. Additionally, a vaccination strategy should be developed with the initial objective of protecting small‐scale dairy herds from disease. For any successful FMD control programme, long‐term Government commitment and adequate resources are necessary. A sustainable programme will also need farmer education, commitment and financial contributions.