Biosecurity in endemic foot and mouth disease settings: a case study of foot and mouth disease vaccination in South-East Asia.

Foot and mouth disease (FMD) is a highly contagious viral infection affecting cloven-hoofed animals including cattle, buffalo, sheep, goats and pigs. The disease is endemic in several parts of Asia, as well as most of Africa and the Middle East. In 1997, the World Organisation for Animal Health (OIE) established the South-East Asia Foot and Mouth Disease Campaign with the aim of increasing livestock sector productivity and economic output through the control and eradication of FMD in South-East Asia. Large-scale vaccination of livestock against FMD has in the past led to the successful eradication (or control) of the disease, for example in the Philippines. However, despite the benefit associated with large-scale vaccination, biosecurity risks can be created by vaccination teams moving between locations. It is therefore recommended that biosecurity measures are used by vaccination teams to prevent inadvertent disease spread. The majority of existing guidelines are focused on high-risk situations such as exotic animal disease outbreaks in developed countries, or agents posing a risk to human health. This paper describes the development of novel biosecurity guidelines for vaccination teams in South-East Asia. To achieve this, available literature was scanned followed by in-country workshops and field-testing of draft materials. Entry and exit procedures are laid out within the context of five core rules that follow the biosecurity principles of situational awareness, segregation, cleaning and disinfection. Guidelines and accompanying fact sheets were translated into local languages and included in a comprehensive vaccination training programme for all vaccination teams undertaking cattle FMD vaccination programmes in the New Zealand OIE FMD control project target countries (Myanmar and Laos). The material developed has wide practical relevance to veterinarians, traditional healers and village or community animal health workers, who all pose a heightened risk of spreading infectious agents.

La fièvre aphteuse est une maladie virale extrêmement contagieuse affectant les artiodactyles (dont les bovins, les buffles, les ovins, les caprins et les porcins). La maladie est présente à l'état endémique dans plusieurs régions d'Asie, dans presque toute l'Afrique et au Moyen-Orient. En 1997, l'Organisation mondiale de la santé animale (OIE) a lancé la Campagne de lutte contre la fièvre aphteuse en Asie du Sud-Est afin d'améliorer la productivité et la rentabilité économique du secteur de l'élevage à travers la lutte contre la fièvre aphteuse voire son éradication de la sous-région. Grâce à la vaccination à grande échelle du bétail, certains pays ont pu éradiquer (ou du moins contrôler) la fièvre aphteuse dans le passé, par exemple les Philippines. Si la vaccination à grande échelle est en soi bénéfique, elle comporte certains risques de biosécurité, liés aux déplacements des équipes de vaccination d'un site à l'autre. Il est donc recommandé que ces équipes appliquent des mesures de biosécurité visant à prévenir toute propagation accidentelle de la maladie. La plupart des lignes directrices existantes sont axées sur les situations présentant un niveau de risque élevé, par exemple la survenue de foyers de maladies animales exotiques dans les pays développés, ou d'agents pathogènes qui constituent un risque pour la santé publique. Dans cet article, les auteurs décrivent la méthodologie suivie pour élaborer des lignes directrices innovantes de biosécurité en Asie du Sud-Est, destinées aux équipes de vaccination. Ces lignes directrices ont été rédigées en passant en revue la littérature sur le sujet lors d'ateliers nationaux et en testant sur le terrain les projets de documents. Les procédures d'entrée et de sortie ont été établies en suivant cinq règles fondamentales fondées sur les grands principes de la biosécurité, à savoir la connaissance de la situation, la ségrégation, le nettoyage et la désinfection. Les lignes directrices et les fiches explicatives qui les accompagnent ont été traduites en langues locales et utilisées dans le cadre d'un programme complet de formation à la vaccination destiné à l'ensemble des équipes de vaccination participant aux programmes de vaccination du cheptel bovin contre la fièvre aphteuse dans les pays couverts par le projet Nouvelle-Zélande­OIE de lutte contre la fièvre aphteuse (Myanmar et Laos). Les matériels proposés présentent une utilité concrète pour les vétérinaires, les guérisseurs traditionnels et les auxiliaires communautaires ou villageois de santé animale, qui sont tous particulièrement exposés au risque de propager involontairement des agents de maladies infectieuses.

La fiebre aftosa es una infección vírica muy contagiosa que afecta a animales biungulados como el ganado vacuno, el búfalo, la oveja, la cabra o el cerdo. La enfermedad es endémica en varias zonas de Asia y en la mayor parte de África y Oriente Medio. En 1997, la Organización Mundial de Sanidad Animal (OIE) instituyó la «Campaña de lucha contra la fiebre aftosa en el Sudeste asiático¼ con el objetivo de que el control y la erradicación de la enfermedad en la región se tradujeran en un aumento de la productividad y la rentabilidad económica del sector ganadero. En ocasiones anteriores la vacunación a gran escala del ganado ya ha resultado eficaz para erradicar (o controlar) la fiebre aftosa, por ejemplo en Filipinas. Sin embargo, pese a los beneficios que depara la vacunación a gran escala, los equipos que la llevan a cabo, al desplazarse de una a otra localidad, también pueden vehicular nuevos riesgos biológicos. Por ello se recomienda que esos equipos apliquen medidas de seguridad biológica destinadas a impedir la propagación accidental de la enfermedad. La mayoría de las directrices existentes al respecto están centradas en situaciones de gran riesgo, como brotes de enfermedades animales exóticas en países desarrollados o presencia de agentes infecciosos que entrañan peligro para la salud pública. Los autores describen la elaboración de nuevas directrices de seguridad biológica dirigidas a los equipos de vacunación que operan en el Sudeste asiático. Para empezar se hizo un repaso de la bibliografía existente, tras lo cual se celebraron talleres nacionales y se ensayaron sobre el terreno las medidas preconizadas en un primer borrador. Como parte de las directrices se instauran procedimientos de entrada y salida encuadrados en cinco reglas básicas que se ajustan a los grandes principios de seguridad biológica: conocimiento de la situación, segregación, limpieza y desinfección. Las directrices y las fichas descriptivas que las acompañan, una vez traducidas a los idiomas locales, fueron incluidas en un programa integral de formación en vacunaciones dirigido a todos los equipos que se disponían a intervenir en programas de vacunación antiaftosa del ganado en Myanmar y Laos, países beneficiarios del proyecto Nueva Zelanda­OIE de lucha contra la fiebre aftosa. El material elaborado reviste gran utilidad práctica para los veterinarios, curanderos tradicionales y trabajadores zoosanitarios de aldeas y comunidades, todos ellos portadores de un riesgo especialmente importante de propagar agentes infecciosos.

Implementing large Foot and Mouth Disease vaccination programmes for smallholder farmers: lessons from Lao PDR.

This study assessed smallholder finances and their attitudes towards the Foot and Mouth Disease (FMD) vaccination programme, when 1 620 000 vaccine doses were provided for strategic administration in large ruminants in FMD 'high-risk' areas in Laos between 2012 and 2016. Farmers (n = 168) in the provinces of Xayyabouli (XYL), Xiengkhoung (XK) and Huaphan (HP), were interviewed. Over 91% of the farmers responded that their livestock were vaccinated for FMD, with over 86% ranking FMD vaccination as a good or very good intervention. No FMD cases were reported from the vaccinated provinces after May 2013. Examination of the total income per household in XYL, XK and HP indicated earnings of US$5060(±650), US$4260(±294) and US$1691(±676), respectively (P = 0.001), with 23%, 28% and 68% of the total incomes from annual sales of large ruminant, respectively. Of the farmers in XYL, XK and HP, 83%, 93% and 70% (P = 0.009) said their annual income increased compared with 2012, and 47%, 64% and 41%, respectively (P = 0.005), indicated this increase was from additional large ruminant sales. The study indicated that this large FMD vaccination programme was well regarded by participating farmers and may have provided satisfactory suppression of the disease in Laos, despite not achieving the preferred vaccination coverage. Continuation of the vaccination programme in FMD high-risk areas is suggested as desirable.

Challenges for beef production in smallholder communities with low reproductive management skills: a case study from Northern Lao PDR.

Improved large ruminant productivity is increasingly acknowledged as a pathway for the alleviation of rural poverty and food insecurity in smallholder communities in Southeast Asia; yet, in much of Laos, bovine reproductive management is practically absent. Large ruminant reproduction skills were studied, using face-to-face surveys (n=60) of the knowledge, attitudes, and practices (KAP) of farmers, plus an extension of an examination of parameters of reproductive efficiency (n = 1786 cattle and 434 buffalo) in the northern provinces of Luang Prabang and Xieng Khouang. The surveys particularly involved female farmers to provide gender-disaggregated data, with females making up 38.3 % of participants. Results confirmed that KAPs of smallholder farmers on bovine reproductive management were low (34-46 %) with trends toward higher KAP scores in male survey respondents. Poor reproductive parameters were identified in both provinces, with low calving percentages of 54-75 and 45-54 % in cattle and buffalo groups, respectively, and prolonged inter-calving intervals of 14.1-19.8 and 26.0 months for the cattle and buffalo groups, respectively. Improving the reproductive efficiency of large ruminants in the northern upland regions would enable smallholder farmers to be more effectively engaged in the dramatic economic growth of the Southeast Asia region, although these findings indicate that intensive training and supportive interventions are required to improve large ruminant reproductive outcomes in communities that have low-level large ruminant husbandry skills.

Livestock movement patterns in the main livestock production provinces of Lao PDR.

Foot-and-mouth disease (FMD) is a highly infectious transboundary disease that is endemic and affects the livelihood of smallholder farmers in Lao People's Democratic Republic (PDR). Knowledge about livestock movement patterns is important for preventing the spread of FMD between villages. This study describes the livestock movement patterns in Champasak, Savannakhet and Xiangkhouang provinces of Lao PDR. Face-to-face interviews were conducted with randomly selected villagers (n = 195) and traders (n = 169) in 115 villages between February and March 2019. Livestock owners commonly purchased (mainly breeding) animals from other smallholders (81%) and sold (mainly slaughter) animals to traders (76%) or other smallholders (16%), typically within the same district and province. The median inter-village trade distance was 20-30 km, with an average frequency of 4 trades per village per month. Traders purchased animals from smallholders (71%) and middlemen (25%) located within their district. It was common for many traders (74%) to retain animals at their property before selling, typically a median of 4 beef cattle per trader. Local trades within the district were far more common (72%) than distant trades. The movements of grazing/fattening large ruminants between villages were reported in 30% of the villages in all three provinces and occurred mostly within the same district or province in short distance (6 km). Social Network Analysis has identified animal movement hubs in the three provinces which could be targeted for FMD control and surveillance. Movements of animals for further use (fattening/ reproduction), long-distance movements and frequent local movements described in this area have important implications for FMD circulation. The findings from the study will inform FMD spread simulation models for Lao PDR. The knowledge gained from these data will also help the Lao PDR authorities understand the patterns of animal movements associated with disease spread.

Foot and mouth disease in the Lao People's Democratic Republic: II. Seroprevalence estimates, using structured surveillance and surveys of abattoirs.

An examination of the seroprevalence of foot and mouth disease (FMD) virus was conducted in the Lao People's Democratic Republic (Lao PDR) from 1996 to 2005, using structured surveillance and abattoir-based studies. Under structured surveillance, seropositivity ranged from 65.7% (Vientiane Capital, 1996) to 3% (Houaphan, 2005) for cattle and buffalo; and from 2.8% (Vientiane Capital, 1998) to 0% in separate studies of pigs. In each study, species composition was significantly associated with seroprevalence rates. For abattoir surveys, the majority of samples (60.5%) came from Vientiane Capital (33.0%), Savannakhet (14.0%) and Champasak (13.5%) provinces. The overall proportion of animals testing positive for the presence of antibodies against the FMD virus was 18.7% (ranging from 50.8% in Vientiane Province to 1% in Phongsali). Generally, antibodies against serotype O were the most prevalent. Cattle and buffalo that tested as seropositive were significantly older than the seronegative animals (p < 0.00005). The overall proportional seropositivity was significantly different for different species, as was the case with the antibodies against serotypes O, A and Asia 1. Some 22% of cattle, 55% of buffalo and 23% of pigs demonstrated seropositivity but this varied significantly between provinces.

Foot and mouth disease in the Lao People's Democratic Republic: I. A review of recent outbreaks and lessons from control programmes.

Foot and mouth disease (FMD) causes sporadic disease outbreaks in the Lao People's Democratic Republic (Lao PDR). As the Lao PDR is a major thoroughfare for transboundary animal movements, regular FMD outbreaks occur, causing economic hardship for farmers and their families. In this review of the recent history of FMD in the Lao PDR between 1997 and 2006, the authors examine the virological and epidemiological aspects of the disease and appropriate control measures, including the distribution of outbreaks, causative serotypes and the molecular epidemiology of the viruses, as well as large-scale vaccination programmes. The dominant serotype, type O, was reported every year from 1998 to 2005. The majority of outbreaks occurred in Vientiane Capital (n = 42; 28%) and the highest number of outbreaks were reported in cattle (n = 94; 61%); followed by buffalo (n = 41; 27%) and pigs (n = 18; 12%). All type A outbreaks occurred in cattle. Type Asia 1 outbreaks were reported in the central provinces around Vientiane Capital between 1996 and 1998.

The endoparasitism challenge in developing countries as goat raising develops from smallholder to commercial production systems: A study from Laos.

Progressing economic development in Southeast Asia has increased regional demand for goat meat, leading to expanding production by smallholders and recently, development of commercial farms. In Laos, an emerging export market for goats into Vietnam has led to increased goat numbers, with potential increases in risk of disease, particularly endoparasitism. A cross-sectional survey investigated the prevalence of gastrointestinal parasites in indigenous Kambing-Katjang goats on smallholder farms (n = 389) in 8 villages where no anthelmintic treatments were in use, providing comparisons with a case study of imported Boer crossbred goats (n = 45) on a commercial farm where intensive anthelmintic treatments were required to manage mortalities attributable to Haemonchosis. Clinical examinations, collection of faecal samples, and pathological examination on the commercial farm, accompanied collection of information on animal gender, age and body weight, with data analyses performed in Genstat. Faecal samples contained eggs of multiple endoparasitic species, with Strongyles spp. and coccidian oocysts of Eimeria spp. most prevalent. Significant associations between the presence of endoparasites and the farm type (smallholder versus commercial; p < 0.008 and 0.001) were observed, with the odds ratios of the commercial farm having Stronglyes spp. and Eimeria spp. of 1.3 (CI = 0.6-2.9) and 4.8 (CI = 2.5-9.1). Mortalities from endoparasitism were only recorded at the commercial farm, with the loss of 24 goats in the final 3 months of the dry season (Feb-April). This study identified a moderate prevalence of multiple endoparasitic species in smallholder goat farms that appeared well-tolerated, whereas in the developing commercial system, endoparasites posed significant risks to enterprise viability, even with use of anthelmintics. Further studies on endoparasite control are required if commercial tropical goat meat production is to prove sustainable and assist in addressing regional food security, plus provide a pathway to improve the livelihoods of Lao goat smallholders seeking to expand and intensify their enterprises.

Emergence of an exotic strain of serotype O foot-and-mouth disease virus O/ME-SA/Ind-2001d in South-East Asia in 2015.

The O/Middle East-South Asia (ME-SA)/Ind-2001 lineage of foot-and-mouth disease virus (FMDV) is endemic in the Indian subcontinent and has been reported in the Middle East and North Africa, but it had not been detected in South-East Asia (SEA) before 2015. This study reports the recent incursions of this viral lineage into SEA, which caused outbreaks in Vientiane Capital of Lao People's Democratic Republic (PDR) in April 2015, in Dak Nong, Dak Lak and Ninh Thuan Provinces of Vietnam from May to October 2015, and in Rakhine State of Myanmar in October 2015. Disease investigations were conducted during the outbreaks and followed up after laboratory results confirmed the involvement of FMDV O/ME-SA/Ind-2001 sublineage d (O/ME-SA/Ind-2001d). Affected host species included cattle, buffalo and pig, and all the outbreaks resolved within 2 months. Animals with clinical signs were separated, and affected premises were disinfected. However, strict movement restrictions were not enforced, and emergency vaccinations were only implemented in Vientiane Capital of Lao PDR and Dak Nong and Ninh Thuan Provinces of Vietnam. Clinical samples were collected from each outbreak and examined by nucleotide sequencing of the FMDV viral protein 1 coding region. Sequence analysis revealed that the O/ME-SA/Ind-2001d isolates from Lao PDR and Vietnam were closely related to each other and similar to viruses previously circulating in India in 2013. Viruses collected from Myanmar were divergent from viruses of the same sublineage recovered from Lao PDR and Vietnam but were closely related to viruses present in Bangladesh in 2015. These findings imply that at least two independent introductions of O/ME-SA/Ind-2001d into SEA have occurred. Our study highlights the transboundary nature of foot-and-mouth disease (FMD) and reinforces the importance of improved FMD surveillance and promotion of safer cross-border trade in SEA to control the risk of introduction and spread of exotic FMDV strains.

Investigation of infectious reproductive pathogens of large ruminants: Are neosporosis, brucellosis, leptospirosis and BVDV of relevance in Lao PDR?

N. caninum, bovine viral diarrhoea virus, Brucella abortus and Leptospira interrogans serovar Hardjo are globally significant reproductive pathogens that cause abortion and reproductive loss in large ruminants. Prevalence information is lacking in Lao People's Democratic Republic (Laos) despite the poor reproductive performance of cattle and buffalo. Serological examination of frozen cattle (n=90) and buffalo (n=61) sera by commercially available enzyme-linked immunosorbent assays provided the first reported screening of some of these pathogens in Laos. Seroprevalence differed amongst these large ruminant species, with N. caninum, BVDV and L. interrogans serovar Hardjo antibodies found in 68.9% (95% CI±11.6), 4.9% (95% CI±5.4) and 3.3% (95% CI±4.5) of buffalo sera, respectively, and in 7.8% (95% CI±5.5), 10.0% (95% CI±6.2) and 22.2% (95% CI±8.6) of cattle sera, respectively. Buffalo sera had a significantly higher seroprevalence of N. caninum compared to cattle (p<0.001) and cattle sera had a significantly higher seroprevalence of L. interrogans serovar Hardjo compared to buffalo (p=0.003). Variability was also observed across provinces for N. caninum in buffalo (p=0.007) and for L. interrogans serovar Hardjo in cattle (p=0.071), suggesting provincial risk factors conducive to pathogen transmission. BVDV and N. caninum seropositivity were negatively associated in buffalo (p=0.018) and cattle (p=0.003). In buffalo, L. interrogans serovar Hardjo and BVDV seropositivity were associated (p=0.035, p=0.039). The identification of antibodies against three major abortifacient pathogens in Laos prompts further research to determine if infection is associated with low reproductive efficiency and the risk factors for infection. This is needed for the development of evidence based prevention strategies for improved large ruminant reproductive management among smallholders in Laos.

Household Financial Status and Gender Perspectives in Determining the Financial Impact of Foot and Mouth Disease in Lao PDR.

The socioeconomic impacts of foot and mouth disease (FMD) during 2011-12 outbreaks on large ruminant smallholders in Laos were investigated, including examination of data on gender, household financial status and farmer husbandry practices. A mix of participatory tools and survey questionnaires at the village and household level, respectively, were conducted, involving individual farmer interviews (n = 124) and group meetings with village elders to establish criteria for classification of household financial status as being 'poor, medium or well off' according to rice sufficiency, assets and household incomes. FMD-attributable financial losses were determined by inclusion of losses due to: mortality, morbidity and costs of treatments. The estimated mean financial losses due to FMD were USD 436 (±92) in the 'poor' and USD 949 (±76) in the 'well off' household categories (P < 0.001), being 128% and 49% of income from the sale of large ruminants, respectively. Variation in financial losses reflected differences in morbidity, farmer husbandry practices including frequency of observation of animals and thus recognition of FMD and choice of treatments. Of concern were adverse financial impacts of treatment especially where antibiotics were used; delays in reporting of FMD cases after observation of signs (mean of 2 days); admission that 10% of farmers had sold FMD-affected livestock; and that 22% of respondents claimed their large ruminants were cared for by females. The findings confirm that FMD has the most severe financial impact on poorer households and that females have a significant role in large ruminant production. It is recommended that livestock extension activities promote the benefits of prevention rather than treatment for FMD and encourage participation of women in biosecurity and disease risk management interventions including rapid reporting and regulatory compliance, particularly with animal movement controls and other biosecurity practices that reduce the negative impacts of FMD on regional food security and poverty reduction in rural communities.

Financial Impacts of Foot-and-Mouth Disease at Village and National Levels in Lao PDR.

To assist policies on Foot-and-Mouth Disease (FMD) control in Laos and the Mekong region, the financial impact of recent outbreaks at village and national levels was examined. Village-level impacts were derived from recent research on financial losses due to FMD per smallholder household and number of households with FMD-affected livestock in the village. National-level impacts of FMD were determined from examination of 2011-2013 FMD reported to the Lao Department of Livestock and Fisheries (DLF), with the 2011 epidemic reported separately due to the large number and size of outbreaks of FMD in that year. Estimates of the national financial impact of FMD were based on (i) total FMD financial losses at the village level and (ii) the costs of FMD responses and other related costs at the DLF, provincial and district levels where FMD was reported, but excluding the costs of revenue forgone. A Monte Carlo simulation was utilized to account for likelihood of FMD over- and under-reporting. Foot-and-mouth disease was recorded in four provinces of Phonsaly, Bokeo, Xayyabouli and Champasak in three consecutive years from 2011 to 2013. However, the FMD epidemic in 2011 was more widely distributed and involved 414 villages in 14 provinces, with thousands of cases of morbidity in cattle and buffalo and some mortalities. The estimated financial losses due to FMD in 2011 were USD 30 881(±23 176) at the village level and USD 13 512 291 at the national level based on the number of villages with FMD outbreaks reported. However, when the likelihood of FMD under-reporting was accounted for, the estimated financial losses at the national level could potentially increase to USD 102 094 464 (±52 147 261), being almost 12% of the estimated farm gate value of the national large ruminant herd. These findings confirm that FMD causes substantial financial impacts in villages and to the national economy of Laos, providing justification for sustained investments in FMD control programmes.

Financial Impact of Foot and Mouth Disease on Large Ruminant Smallholder Farmers in the Greater Mekong Subregion.

A retrospective investigation of financial losses incurred by large ruminant smallholder farmers due to outbreaks of foot and mouth disease (FMD) in 2010-12 in northern Laos was conducted in 2012. The aim was to support recommendations on sustainable transboundary animal disease control strategies in the Greater Mekong Subregion (GMS). Large ruminant smallholders in the three northern provinces of Luang Prabang (LPB), Xiengkhoung (XK) and Xayyabouli (XYL) were interviewed (n = 310). Financial losses were determined, including direct losses due to mortality (100% of pre-FMD sale value) and morbidity (difference between the expected sale price pre-FMD and 1 month following onset of FMD), and indirect losses due to costs of treatments. The losses due to FMD per household varied between provinces (P < 0.001) and were USD 1124, USD 862 and USD 381 in LPB, XK and XYL, respectively, being 60, 40 and 16% of annual household income. Comparison of the costs of FMD with annual household income from sales of large ruminants indicated losses of 213, 181 and 60% of the income in LPB, XK and XYL, respectively. The variation in losses between provinces was due to differences in levels of morbidity with highest in LPB, treatment methods with antibiotic use common in LPB, age of animals sold and sale prices with higher prices in XK. Partial budget analysis of biannual FMD vaccination indicated an average net benefit of USD 22 and USD 33 for cattle and buffalo, respectively. However, vaccination alone is unlikely to control FMD in the region. Promotion of multiple large ruminant health and production intervention programmes to stimulate interest in biosecurity in addition to vaccination is recommended, providing a more sustainable pathway for poverty reduction through the current expansion of livestock investments in the GMS.

Development and validation of a 3ABC antibody ELISA in Australia for foot and mouth disease.

OBJECTIVE: To measure the diagnostic performance of an Australian-developed ELISA for the detection of antibodies against the non-structural proteins (NSP) 3ABC of the foot and mouth disease (FMD) virus. DESIGN: Test development and validation study. METHODS: The diagnostic specificity was determined using 2535 sera from naïve animals and 1112 sera from vaccinated animals. Diagnostic sensitivity was calculated from the data for 995 sera from experimentally and field-infected animals from FMD-endemic countries in South East Asia. A commercial ELISA detecting antibodies against FMD virus NSP was used as the reference test to establish relative sensitivity and specificity. Bayesian latent class analysis was performed to corroborate results. The diagnostic window and rate of detection were determined at different times using sera from cattle, sheep and pigs before and after infection, and after vaccination and subsequent infection. Repeatability and reproducibility data were established. RESULTS: At 35% test cut-off, the 3ABC ELISA had an overall diagnostic sensitivity of 91.5% and diagnostic specificity of 96.4%. The diagnostic sensitivity in vaccinated and subsequently infected cattle was 68.4% and diagnostic specificity in vaccinated cattle was 98.0%. CONCLUSIONS: The 3ABC ELISA identified field and experimentally infected animals, as well as vaccinated and subsequently infected animals. Diagnostic sensitivity and specificity estimates for other FMD NSP tests are comparable with the results obtained in this study. This NSP ELISA was found to be 'fit for purpose' as a screening assay at the herd level to detect viral infection and also to substantiate absence of infection.

Investigation of foot and mouth disease hotspots in northern Lao PDR.

Foot and mouth disease (FMD) is an endemic transboundary disease in the Mekong region, and FMD records of reports to animal health authorities in Lao PDR between 2009 and 2011 were reviewed. FMD outbreaks occurred in 2 of 3 years in eight districts in three of the eight northern Lao PDR provinces, locations suggested as FMD 'hotspots'. The relatively higher risk of recurrence of FMD in these districts was likely due to the presence of a dense large ruminant population, extensive animal trading including transboundary movements and ineffective animal movement controls. As an understanding of the epidemiology of FMD in these 'hotspots' may offer insights into improved FMD control in the region, a study of an outbreak of FMD occurring in early 2010 following failure to vaccinate was conducted in the endemic 'hotspot' area of Paek district in Xiengkhoung province where in early 2009, a major outbreak of FMD in the district had been prevented in two villages by vaccination. The 2010 outbreak included collection of tissue samples 1 week after the onset of FMD that confirmed infection with FMD virus serotype O (Myanmar topotype) in a population of 239 large ruminants, comprising 167 cattle and 72 buffalo. A survey by interview of 30 farmers conducted in July 2010 documented high morbidity in cattle and buffalo (>90%) and identified disease risk factors, including increased trading of animals at the end of the rice harvest, plus several failures of biosecurity. In late 2010 and early 2011, a total of 40 and 72 serum samples were collected from large ruminants prior to and post-FMD vaccination respectively and tested by LPB-ELISA. Antibodies were present in the pre-vaccination samples attributable to previous exposure to FMD virus and significantly rising post-vaccination titres indicated likely temporary protection against future FMDV infection. It was concluded that to provide sufficient control of FMD in this 'hotspot', regular vaccination, particularly prior to the peak risk period in December-February, plus improved farmer knowledge of disease transmission risk and biosecurity, is required. Although low rural education standards and language barriers because of multiple ethnic groups pose a challenge for the successful delivery of extension programmes in northern Lao PDR, training to improve disease recognition and reporting plus village-level biosecurity practices is considered important in FMD 'hotspots' if sustainable regional initiatives directed at FMD control are to be achieved.

Limiting the Impacts of foot and mouth disease in large ruminants in northern Lao People's Democratic Republic by vaccination: a case study.

Foot and mouth disease (FMD) is the most important global transboundary livestock disease and is endemic in Lao People's Democratic Republic (Lao PDR) with outbreaks occurring regularly. Lao PDR shares borders with five countries and as a major thoroughfare for transboundary livestock movement, is vulnerable to the social and economic impacts of FMD. The FMD outbreak occurred in January 2009 in the Pek District, located in the north-eastern Lao PDR province of Xieng Khuang and involved all 111 villages in that district. In March 2009, we conducted a case study on the impacts of FMD in four villages in Pek District. In two villages cattle and buffalo were vaccinated for FMD recently and prior to the outbreak as part of an ongoing research project. In one of these villages, all cattle and buffalo were vaccinated and just over half the large ruminant population was vaccinated in the other village. The other two villages involved in the case study were located nearby but not part of the ongoing research project and no animals had been vaccinated. Data were collected from the four villages by interviewing the village animal health worker in each village using a standard questionnaire. Morbidity rates for the fully vaccinated village were 1% and 7.9% for the partially vaccinated village and were much lower compared with the two adjacent, unvaccinated villages where morbidity rates were 61% and 74.3% respectively. Estimates of the financial losses incurred were USD 1.7-1.9 per cow or buffalo for the fully vaccinated village, USD 6.9-8.1 for the partly vaccinated village and 52.4-70.8 USD in the unvaccinated villages, providing evidence that a large opportunity cost is incurred by failing to vaccinate in areas where the risk of FMD incursions is high.

Assessment of farmer knowledge of large ruminant health and production in developing village-level biosecurity in northern Lao PDR.

The purpose of this study was to determine baseline knowledge and identify knowledge gaps of farmers on biosecurity, risk of transmission of transboundary diseases and large ruminant health and production in three provinces of northern Laos, Hua Phan (HP), Luang Prabang (LPB) and Xieng Khoung (XK). The survey was conducted in six villages that are project sites for an Australian Centre for International Agricultural Research (ACIAR) project, with two villages located in each of the three provinces. A census survey was conducted by interview with all 238 farmers participating in the ACIAR project, using a structured questionnaire. The interviews were conducted in Lao language and took 1-2 h per farmer. The answers were recorded in Lao and the survey data were translated into English and transcribed into Microsoft Excel, and a linear mixed model in the Genstat statistical analysis package was used to compare quantitative traits between the target provinces. The results showed that the prediction mean of farmer knowledge scores on parasitic disorders, infectious disease, reproduction and nutrition management were significantly different between the target provinces. The prediction mean of farmer knowledge scores on infectious disease questions ranged between 5.11 in HP to 8.54 in XK of 24 marks (P < 0.001). The prediction mean of total knowledge scores was 13.48 in LPB and 19.29 in XK of 42 marks (P < 0.001). The results indicate both the need for and scope required to attain improvements in farmer knowledge of large ruminant health and production. It was concluded that a participatory research and extension programme to address village-level biosecurity and reduce disease risks, plus enhance large ruminant production capabilities of smallholder producers, is a valid and potentially important strategy to address transboundary disease risk and rural poverty in northern Laos.

Comparative susceptibility of indigenous and improved pig breeds to Classical swine fever virus infection: practical and epidemiological implications in a subsistence-based, developing country setting.

This study investigated the comparative susceptibility of indigenous Moo Laat and improved Large White/Landrace pig breeds to infection with classical swine fever virus (CSFV) under controlled conditions in the Lao People's Democratic Republic (Lao PDR). The Moo Laat (ML) and Large White/Landrace cross-breed (LWC) pigs were inoculated with a standard challenge strain designated Lao/Kham225 (infectivity titre of 10(2.75) TCID50/ml). The results demonstrated that both the native breed and an improved pig breed are fully susceptible to CSFV infection and the mortality rate is high. LWC pigs demonstrated lower (or shorter) survival times (50% survival time: 11 days), earlier and higher pyrexia and earlier onset of viraemia compared to ML pigs (50% survival time: 18 days). In the context of village-based pig production, the longer time from infection to death in native ML pigs means that incubating or early sick pigs are likely to be sold once an outbreak of CSF is recognized in a village. This increased longevity probably contributes to the maintenance and spread of disease in a population where generally the contact rate is low.