Herd Immunity Against Foot‐and‐Mouth Disease Under Different Vaccination Practices in India

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 log₁₀ 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 log₁₀ 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.     

Emergence of two novel sublineages Ind2001BD1 and Ind2001BD2 of foot‐and‐mouth disease virus serotype O in Bangladesh

Foot‐and‐mouth disease (FMD ) is endemic in Bangladesh, and the implementation of a control programme for this disease is at an early stage, according to the FAO ‐ and OIE ‐proposed Progressive Control Pathway for FMD (PCP ‐FMD ) Roadmap. To develop an effective control programme, understanding of foot‐and‐mouth disease virus (FMDV ) serotypes, even subtypes within the serotypes is essential. The present investigation aims at viral VP 1 coding region sequence‐based analysis of FMD samples collected from 34 FMD outbreaks during 2012–2016 in Bangladesh. Foot‐and‐mouth disease virus (FMDV ) serotype O was responsible for 82% of the outbreaks in Bangladesh, showing its dominance over serotype A and Asia1. The VP 1 phylogeny revealed the emergence of two novel sublineages of serotype O, named as Ind2001BD 1 and Ind2001BD 2, within the Ind2001 lineage along with the circulation of Ind2001d sublineage in Bangladesh, which was further supported by the multidimensional scaling with distinct clusters for each sublineage. The novel sublineages had evident genetic variability with other established sublineages within Ind2001 lineage. Ten mutations with three or more amino acid variations were detected within B‐C loop, G‐H loop and C‐terminal region of the VP 1 protein of FMDV serotype O viruses isolated exclusively from Bangladesh. Furthermore, two amino acid substitutions at positions 197 and 198 within the VP 1 C‐terminal region are unique to the novel sublineages. The existence of widespread genetic variations among circulatory FMDV serotype O viruses makes the FMD control programme complex in Bangladesh. Adequate epidemiological data, disease reporting, animal movement control, appropriate vaccination and above all stringent policies of the government are necessary to combat FMD in Bangladesh.     

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.     

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.     

Socio‐economic impact of Foot‐and‐Mouth Disease outbreaks and control measures: An analysis of Mongolian outbreaks in 2017

Mongolia is a large landlocked country in Central Asia and has one of the highest per capita livestock ratios in the world. During 2017, reported foot‐and‐mouth disease (FMD) outbreaks in Mongolia increased considerably, prompting widespread disease control measures. This study estimates the socio‐economic impact of FMD and subsequent control measures on Mongolian herders. The analysis encompassed quantification of the impact on subsistence farmers’ livelihoods and food security and estimation of the national‐level gross losses due to reaction and expenditure during 2017. Data were collected from 112 herders across eight provinces that reported disease. Seventy of these herders had cases of FMD, while 42 did not have FMD in their animals but were within quarantine zones. Overall, 86/112 herders reported not drinking milk for a period of time and 38/112 reduced their meat consumption. Furthermore, 55 herders (49.1%) had to borrow money to buy food, medicines and/or pay bills or bank loans. Among herders with FMD cases, the median attack rate was 31.7%, 3.8% and 0.59% in cattle, sheep and goats, respectively, with important differences across provinces. Herders with clinical cases before the winter had higher odds of reporting a reduction in their meat consumption. National‐level gross losses due to FMD in 2017 were estimated using government data. The estimate of gross economic loss was 18.4 billion Mongolian‐tugriks (US$7.35 million) which equates to approximately 0.65% of the Mongolian GDP. The FMD outbreaks combined with current control measures have negatively impacted herders’ livelihoods (including herders with and without cases of FMD) which are likely to reduce stakeholder advocacy. Possible strategies that could be employed to ameliorate the negative effects of the current control policy were identified. The findings and approach are relevant to other FMD endemic regions aiming to control the disease.     

Dynamics of widespread foot‐and‐mouth disease virus serotypes A,O and Asia‐1 in southern Asia: A Bayesian phylogenetic perspective

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 VP 1 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 .     

Review of the Global Distribution of Foot‐and‐Mouth Disease Virus from 2007 to 2014

Foot‐and‐mouth disease (FMD) virus affects livestock worldwide. There are seven different serotypes, each with a diversity of topotypes, genetic lineages and strains. Some lineages have different properties that may contribute to sporadic spread beyond their recognized endemic areas. The objective of this study was to review the most significant FMD epidemiological events that took place worldwide between 2007 and 2014. Severe epidemics were caused by FMD virus (FMDV) lineage O/Asia/Mya‐98 in Japan and South Korea in 2010, both previously free of disease. In India, where FMD is endemic, the most important event was the re‐emergence of lineage O/ME‐SA/Ind‐2001 in 2008. Notably, this lineage, normally restricted to India, Bangladesh, Nepal and Bhutan, was also found in Saudi Arabia and Libya in 2013 and has caused several outbreaks in Tunisia and Algeria in 2014–2015. In January 2011, FMDV‐positive wild boars were found in Bulgaria, where the disease last occurred in 1996, followed by 12 outbreaks in livestock infected with FMDV O/ME‐SA/PanAsia2. In 2012, FMDV SAT2 caused outbreaks in Egypt and the Palestinian Autonomous Territories. Another significant event was the emergence of FMDV Asia1 Sindh‐08 in the Middle East. In South America, one outbreak of FMDV serotype O, topotype Euro‐SA was reported in Paraguay in 2011, which was recognized as FMD‐free with vaccination at the time. Lessons learned from past events, point out the need for an integrated strategy that comprises coordinated global and regional efforts for FMDV control and surveillance. Specific local characteristics related to host, environment and virus that condition FMD occurrence should be carefully considered and incorporated to adapt appropriate strategies into local plans. In this review, we compiled relevant epidemiological FMD events to provide a global overview of the current situation. We further discussed current challenges present in different FMD areas.     

Characterization of Foot‐and‐Mouth Disease Viruses Collected in Nigeria Between 2007 and 2014: Evidence for Epidemiological Links Between West and East Africa

This study describes the molecular characterization of 47 foot‐and‐mouth disease (FMD) viruses recovered from field outbreaks in Nigeria between 2007 and 2014. Antigen ELISA of viral isolates was used to identify FMD virus serotypes O, A and SAT 2. Phylogenetic analyses of VP1 nucleotide sequences provide evidence for the presence of multiple sublineages of serotype SAT 2, and O/EAST AFRICA 3 (EA‐3) and O/WEST AFRICA topotypes in the country. In contrast, for serotype A, a single monophyletic cluster of viruses has persisted within Nigeria (2009–2013). These results demonstrate the close genetic relatedness of viruses in Nigeria to those from other African countries, including the first formal characterization of serotype O/EA‐3 viruses in Nigeria. The introductions and persistence of certain viral lineages in Nigeria may reflect transmission patterns via nomadic pastoralism and animal trade. Continuous monitoring of field outbreaks is necessary to dissect the complexity of FMD epidemiology in sub‐Saharan Africa.     

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.     

Temporal patterns and space‐time cluster analysis of foot‐and‐mouth disease (FMD) cases from 2007 to 2017 in Vietnam

In Vietnam, Foot‐and‐mouth disease (FMD) is endemic, but no nationwide studies have been conducted to assess the monthly variations and space‐time clusters of FMD. The main objective was to identify the temporal patterns and space‐time clusters of FMD from 2007 to 2017 using national surveillance data in Vietnam. A total of 163,733 cases were reported from 2007 to 2017. Among them, the proportion of buffaloes (43.31% of total reported cases; 70,909 cases) was highest followed by cattle (30.11%; 49,306 cases), pigs (26.67%; 43,662 cases) and sheep/goats (0.41%; 675 cases). The serotype O was widely distributed across the country while serotype A was observed in Northeast, Central and Southern part of Vietnam while Asia 1 has been not identified since 2007. For monthly variations, most cases were observed during the dry season (from November to March) except Central Highlands. Under the spatial window was set at 50%, a total of seven clusters were identified. The primary cluster was observed from Dec 2009 to Dec 2010 in the northwest (radius: 101.67 km), showing a ratio of 3.75. The secondary cluster was detected in the northeast region (radius: 76.54 km) with a ratio of 3.53 in Feb 2017. The 3rd cluster was the largest with a radius of 176.69 km and located in the southern part of Vietnam. Interestingly, the most temporal clusters included between December and March during the study period. Our findings provide better insight into the temporal patterns and distribution of clusters of FMD in Vietnam. This study provides useful information to policymakers on the hotspot areas and timing of outbreaks. It also identifies when and where national surveillance and control programmes could be implemented more efficiently for the prevention and control of FMD.     

Foot‐and‐mouth disease outbreaks in captive scimitar‐horned oryx (Oryx dammah)

This paper describes three episodes of foot‐and‐mouth disease (FMD) that were detected during 2013–2015 in scimitar‐horned oryx (Oryx dammah) (SHO), a large Sahelo‐Saharan antelope extinct in the wild housed in a wild ungulate breeding facility located 50 km east of Abu Dhabi, United Arab Emirates. While no mortality attributable to FMD was noted in the population of nearly 4,000 SHO during two of the three outbreaks, the morbidity varied according to the circulating strains and seroconversion reached a plateau of 78.0% within two weeks and remained at this level for at least nine months. Partial or complete sequencing of the VP1 encoding region demonstrated that the three outbreaks were caused by three different FMDV lineages (O/ME‐SA/PanAsia‐2, A/ASIA/Iran‐05 and O/ME‐SA/Ind‐2001), consistent with FMD viruses that are circulating elsewhere in the region. These findings demonstrate that SHO are susceptible to FMD and highlight the risks of virus incursion into zoos and captive facilities in the Arabian Peninsula.     

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.     

Genetic diversity and comparison of diagnostic tests for characterization of foot‐and‐mouth disease virus strains from Pakistan 2008–2012

We report the laboratory analysis of 125 clinical samples from suspected cases of foot‐and‐mouth disease (FMD ) in cattle and Asian buffalo collected in Pakistan between 2008 and 2012. Of these samples, 89 were found to contain viral RNA by rRT ‐PCR , of which 88 were also found to contain infectious FMD virus (FMDV ) by virus isolation (VI ), with strong correlation between these tests (κ = 0.96). Samples that were VI ‐positive were serotyped by antigen detection ELISA (Ag‐ELISA ) and VP 1 sequence acquisition and analysis. Sequence data identified FMDV serotypes A (n  = 13), O (n  = 36) and Asia‐1 (n  = 41), including three samples from which both serotypes Asia‐1 and O were detected. Serotype A viruses were classified within three different Iran‐05 sublineages: HER ‐10, FAR ‐11 and ESF ‐10. All serotype Asia‐1 were within Group VII (Sindh‐08 lineage), in a genetic clade that differs from viruses isolated prior to 2010. All serotypes O were classified as PanAsia‐2 within two different sublineages: ANT ‐10 and BAL ‐09. Using VP 1 sequencing as the gold standard for serotype determination, the overall sensitivity of Ag‐ELISA to correctly determine serotype was 74%, and serotype‐specific sensitivity was 8% for serotype A, 88% for Asia‐1 and 89% for O. Serotype‐specific specificity was 100% for serotype A, 93% for Asia‐1 and 94% for O. Interestingly, 12 of 13 serotype A viruses were not detected by Ag‐ELISA . This study confirms earlier accounts of regional genetic diversity of FMDV in Pakistan and highlights the importance of continued validation of diagnostic tests for rapidly evolving pathogens such as FMDV .     

Challenges for Serology‐Based Characterization of Foot‐and‐Mouth Disease Outbreaks in Endemic Areas; Identification of Two Separate Lineages of Serotype O FMDV in Uganda in 2011

Control of foot‐and‐mouth disease (FMD) in Uganda by ring vaccination largely depends on costly trivalent vaccines, and use of monovalent vaccines could improve the cost effectiveness. This, however, requires application of highly specific diagnostic tests. This study investigated outbreaks of FMD in seven Ugandan districts, during 2011, using the PrioCHECK^® FMDV NS ELISA, solid‐phase blocking ELISAs (SPBEs) and virus neutralization tests (VNTs), together with virological analyses for characterization of the responsible viruses. Two hundred and eighteen (218) cattle and 23 goat sera as well as 82 oropharyngeal fluid/epithelial tissue samples were collected. Some 50% of the cattle and 17% of the goat sera were positive by the PrioCHECK^® FMDV NS ELISA, while SPBEs identified titres ≥80 for antibodies against serotype O FMD virus (FMDV) in 51% of the anti‐NSP positive cattle sera. However, 35% of the anti‐NSP positive cattle sera had SPBE titres ≥80 against multiple serotypes, primarily against serotypes O, SAT 1 and SAT 3. Comparison of SPBEs and VNTs for the detection of antibodies against serotypes O, SAT 1 and SAT 3 in 72 NSP positive cattle sera showed comparable results against serotype O (P = 0.181), while VNTs detected significantly fewer samples positive for antibodies against SAT 1 and SAT 3 than the SPBEs (P < 0.001). Detection of antibodies against serotype O was consistent with the isolation of serotype O FMDVs from 13 samples. Four of these viruses were sequenced and belonged to two distinct lineages within the East Africa‐2 (EA‐2) topotype, each differing from the currently used vaccine strain (EA‐1 topotype). The relationships of these lineages to other serotype O viruses in the Eastern Africa region are discussed. To enhance the control of FMD in Uganda, there is need to improve the specificity of the SAT‐SPBEs, perform vaccine matching and implement improved regional FMD control.     

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.     

Incursions of Foot‐and‐Mouth Disease Virus into Europe between 1985 and 2006

Foot‐and‐mouth disease (FMD) is one of the biggest threats to animal health in European countries. In the last 22 years (1985–2006), FMD has occurred 37 times in 14 European countries. Serotype O was most frequently involved in these outbreaks followed by A, C and Asia 1. Sometimes, epidemics were very limited and at other times, they were the cause of devastating economic losses. In most cases (22/37), the origin of the outbreaks could not be determined. For some of these outbreaks, however, routes of introduction and spread were identified through epidemiological inquiries. Moreover, in some cases, the origin of the virus was also traced by phylogenetic analysis of the partial or complete sequences of VP1 genes. Lessons learned from the outbreaks are still useful as most of the same risk factors persist. However, efforts made by FMD‐free countries to help those where the disease is endemic are a valuable strategy for the reduction of the global risk. The present and the future potential sources of FMD infection need to be identified to best focus European efforts.     

Outbreak investigations and molecular characterization of foot‐and‐mouth disease viruses circulating in south‐west Niger

In Niger, the epidemiological situation regarding foot‐and‐mouth disease is unclear as many outbreaks are unreported. This study aimed (i) to identify Foot‐and‐mouth disease virus (FMDV ) strains currently circulating in cattle herds, and (ii) to identify risk factors associated with Foot‐and‐mouth disease (FMD )‐seropositive animals in clinical outbreaks. Epithelial tissues (n  = 25) and sera (n  = 227) were collected from cattle in eight districts of the south‐western part of Niger. Testing of clinical material revealed the presence of FMDV serotype O that was characterized within the O/WEST AFRICA topotype. The antigenic relationship between one of the FMDV isolates from Niger (O/NGR /4/2015) and three reference vaccine strains was determined by the two‐dimensional virus neutralization test (2dmVNT ), revealing a close antigenic match between the field isolate from Niger and three FMDV serotype O vaccine strains. Serological analyses using a non‐structural protein (NSP ) test provided evidence for previous FMDV infection in 70% (158/227) of the sera tested. Multivariate logistic regression analysis revealed that only the herd composition (presence of both cattle and small ruminants) was significantly associated with FMDV seropositivity as defined by NSP ‐positive results (p ‐value = .006). Of these positive sera, subsequent testing by liquid‐phase blocking ELISA (LPBE ) showed that 86% (136/158) were positive for one (or more) of four FMDV serotypes (A, O, Southern African Territories (SAT ) 1 and SAT 2). This study provides epidemiological information about FMD in the south‐western part of Niger and highlights the complex transboundary nature of FMD in Africa. These findings may help to develop effective control and preventive strategies for FMD in Niger as well, as other countries in West Africa.     

Serological Evidence of Foot‐and‐Mouth Disease Virus Infection in Randomly Surveyed Goat Population of Orissa,India

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.     

Proper Quality Control of Formulated Foot‐and‐Mouth Disease Vaccines in Countries with Prophylactic Vaccination is Necessary

Vaccination is considered as an important tool to control foot‐and‐mouth disease (FMD). A good quality vaccine containing relevant serotypes and matching strains is a pre‐requisite for vaccination to be effective. The present study investigated the quality of different brands of FMD vaccine available in Pakistan, including three locally produced and two imported products. All the vaccines were found free of bacterial or fungal contamination. No adverse effects were noted in suckling mice and buffalo calves inoculated with the vaccines, showing that the vaccines were sterile and safe. The humoral immune response to the FMD vaccines was determined in buffalo calves for 234 days post‐vaccination. Very low humoral immune responses against FMD serotypes O, A and Asia 1 viruses were detected to the locally produced vaccines. The imported vaccines, however, elicited a higher antibody response which persisted for a long period in one of the 2 vaccines. The present study highlights the need of assessing an independent vaccine quality control of finished FMD vaccine products.