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1.
Effective control and monitoring of foot‐and‐mouth disease (FMD ) relies upon rapid and accurate disease confirmation. Currently, clinical samples are usually tested in reference laboratories using standardized assays recommended by The World Organisation for Animal Health (OIE ). However, the requirements for prompt and serotype‐specific diagnosis during FMD outbreaks, and the need to establish robust laboratory testing capacity in FMD ‐endemic countries have motivated the development of simple diagnostic platforms to support local decision‐making. Using a portable thermocycler, the T‐COR ™ 8, this study describes the laboratory and field evaluation of a commercially available, lyophilized pan‐serotype‐specific real‐time RT ‐PCR (rRT ‐PCR ) assay and a newly available FMD virus (FMDV) typing assay (East Africa‐specific for serotypes: O, A, Southern African Territories [SAT ] 1 and 2). Analytical sensitivity, diagnostic sensitivity and specificity of the pan‐serotype‐specific lyophilized assay were comparable to that of an OIE ‐recommended laboratory‐based rRT ‐PCR (determined using a panel of 57 FMDV ‐positive samples and six non‐FMDV vesicular disease samples for differential diagnosis). The FMDV ‐typing assay was able to correctly identify the serotype of 33/36 FMDV ‐positive samples (no cross‐reactivity between serotypes was evident). Furthermore, the assays were able to accurately detect and type FMDV RNA in multiple sample types, including epithelial tissue suspensions, serum, oesophageal–pharyngeal (OP ) fluid and oral swabs, both with and without the use of nucleic acid extraction. When deployed in laboratory and field settings in Tanzania, Kenya and Ethiopia, both assays reliably detected and serotyped FMDV RNA in samples (n  = 144) collected from pre‐clinical, clinical and clinically recovered cattle. These data support the use of field‐ready rRT ‐PCR platforms in endemic settings for simple, highly sensitive and rapid detection and/or characterization of FMDV.  相似文献   

2.
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.  相似文献   

3.
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.  相似文献   

4.
This study reports characterization of foot‐and‐mouth disease virus (FMDV) in samples collected from Balochistan, Pakistan. FMDV was detected by pan‐FMDV real‐time RT‐PCR in 31 samples (epithelial and oral swabs) collected in 2011 from clinical suspect cases. Of these, 29 samples were serotyped by serotype‐specific real‐time RT‐PCR assays and were confirmed by sequencing the VP1 coding region. Sixteen samples were found positive for serotype A and eight for serotype Asia‐1, whereas five samples were found positive for both serotypes A and Asia‐1. Two serotype A positive samples were found positive for two different strains of serotype A FMDV each. Phylogenetic analyses of serotype A FMDVs showed circulation of at least three different sublineages within the A‐Iran05 lineage. These included two earlier reported sublineages, A‐Iran05HER−10 and A‐Iran05FAR−11, and a new sublineage, designated here as A‐Iran05BAL−11. This shows that viruses belonging to the A‐Iran05 lineage are continuously evolving in the region. Viruses belonging to the A‐Iran05FAR−11 sublineage showed close identity with the viruses circulating in 2009 in Pakistan and Afghanistan. However, viruses belonging to the A‐Iran05HER−10 detected in Balochistan, Pakistan, showed close identity with the viruses circulating in Kyrgyzstan, Iran and Kazakhstan in 2011 and 2012, showing that viruses responsible for outbreak in these countries have a common origin. Serotype Asia‐1 FMDVs reported in this study all belonged to the earlier reported Group‐VII (Sindh‐08), which is currently a dominant strain in the West Eurasian region. Detection of two different serotypes of FMDV or/and two different strains of the same serotype in one animal/sample shows complexity in occurrence of FMD in the region.  相似文献   

5.
Bluetongue (BT ) and peste‐des‐petits‐ruminants (PPR ) are major transboundary diseases of small ruminant, which are endemic in India. Testing of bluetongue virus (BTV ) and peste‐des‐petits‐ruminants virus (PPRV ) from recent outbreaks (2015–2016) in different regions of Haryana State of India revealed that 27.5% of the samples showed the presence of dual infection of BTV and PPRV . Analysis of Seg‐2 of BTV (the serotype‐determining protein) showed the presence of BTV ‐12w in several isolates. However, analysis of N gene fragment amplicons showed that viruses belong to lineage IV were most closely related to a pathogenic strain of PPRV from Delhi. This is the first report of co‐circulation of PPRV lineage IV and bluetongue virus serotype 12 in the state.  相似文献   

6.
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 .  相似文献   

7.
8.
Phylogenetic studies on foot‐and‐mouth disease viruses (FMDVs) circulating in the West Eurasian region have largely focused on the genomic sequences encoding the structural proteins that determine the serotype. The present study has compared near‐complete genome sequences of FMDVs representative of the viruses that circulate in this region. The near‐complete genome sequences (ca. 7,600 nt) were generated from multiple overlapping RT‐PCR products. These amplicons were from FMDVs belonging to serotypes O, A and Asia‐1, including members of the O‐PanAsia‐II and the A‐Iran05 lineages, and of Group‐II and Group‐VII (Sindh‐08) within serotype Asia‐1, which are currently predominant and widespread in West Eurasia. These new sequences were analysed together with other sequences obtained from GenBank. Comparison of different regions of the FMDVs genomes revealed evidence for multiple, inter‐serotypic, recombination events between FMDVs belonging to the serotypes O, A and Asia‐1. It is concluded from the present study that dramatic changes in virus sequences can occur in the field through recombination between different FMDV genomes. These analyses provide information about the ancestry of the serotype O, A and Asia‐1 FMDVs that are currently circulating within the West Eurasian region.  相似文献   

9.
This study investigates the historical temporal trend and geographical distribution of the foot‐and‐mouth disease virus (FMDv) serotype C in South America; discussing the findings within the context of the actions and strategies carried out for the elimination of foot‐and‐mouth disease (FMD). This is the first time that such a comprehensive historical compilation has been carried out in the Region; hence, the study is intended as a reference and source of evidence about the presence/absence of FMDv serotype C in South America. Data on the occurrence of FMD were sourced from the Weekly Epidemiological Reports submitted by the countries to Pan American Foot‐and‐Mouth Disease Center (PANAFTOSA‐PAHO/WHO) since 1972, and complemented with other sources of information from the 1968–1971 period. The temporal distribution was examined with local weighted regression (LOESS) to identify two temporal trends, that is, “smoothed” and “over‐adjusted”, utilising the time‐series with the total number of cases per year, at Regional level. Thereafter the outbreaks were aggregated by decades and mapped by the first subnational administrative level. As a result, two major peaks of occurrence were identified, one in the 70s, with up to 1,193 outbreaks, and another in the 80s, with 380. Overall, the investigations show a clear regressive trend in the occurrence of serotype C, with a reduction in the number of outbreaks over‐time, and with the subsequent reduction of affected locations. This study illustrates the contrast between the very limited presence over the last 20 years – with only one event in 2004 – and the epidemic situation in the 1970s and 1980s, and suggests that serotype C of FMDv is no longer present in the Region.  相似文献   

10.
Foot‐and‐mouth disease virus (FMDV) is a highly evolutionary divergent pathogen causing great economic havoc in many countries. Among its seven existing serotypes, Asia1 is the least divergent with a single topotype both genetically and antigenically. It is reported sporadically in Indian subcontinent and was classified under lineage G‐VIII. In 2018, serotype Asia1 re‐emerged in Bangladesh after 2013, along with circulation of a novel serotype Asia1 BD‐18 (G‐IX) lineage. VP1 phylogeny and sequence variation clearly demonstrated the novel strains which was estimated to have at least >5% nucleotide divergence with distinct clade formation. Also, the Bayesian phylogeographic inferences traced back to the origin time of lineage G‐IX in early 2017 and a possible origin in Bangladesh. Mutational analysis considering established eight lineages revealed that the virus strains belonged to lineage G‐IX contained a unique mutation at 44 position in the B‐C loop region of VP1. Inappropriate vaccination and inefficient outbreak surveillance possibly contributed to the current episode of emergence. Therefore, active surveillance and continued vigilance are essential to assess and timely detect the occurrence, extent and distribution of this novel Asia1 strains in Bangladesh and the neighbouring countries.  相似文献   

11.
In January 2017, two villages located in Rakhine State of Myanmar reported clinical signs in cattle suggestive of foot‐and‐mouth disease virus (FMDV) infection. Laboratory analysis identified the outbreak virus as FMDV serotype Asia 1, which represented the first detection of this serotype in Myanmar since 2005 and in the region of South‐East Asia (SEA) since 2007. Genetic analysis revealed that the outbreak virus was different from historical viruses from Myanmar and was more closely related to viruses circulating in Bangladesh and India during 2012–2013, indicating that a novel viral introduction had occurred. The precise origin of the outbreaks was not clear, but frequent informal livestock trade with South Asia was reported. Responses to the outbreaks involved disinfection, quarantine and animal movement restrictions; no further outbreaks were detected under the present passive surveillance system. Detection of serotype Asia 1 highlights the complex and dynamic nature of FMDV in SEA. Active surveillance is needed to assess the extent and distribution of this exotic Asia 1 strain and continued vigilance to timely detect the occurrence of emerging and re‐emerging FMDV strains is essential.  相似文献   

12.
This study describes the genetic characterization of serotype A viruses collected during outbreaks of foot‐and‐mouth disease (FMD) that occurred in Algeria in 2017. These are the first reports of clinical cases due to this serotype in the country since 1977. One complete genomic sequence (comprising 8,119 nucleotides) and three additional near‐complete genomic sequences were generated. Phylogenetic analyses demonstrated that these viruses were classified within the A/AFRICA/G‐IV lineage, most closely related to viruses circulating in Nigeria between 2009 and 2015. These unexpected results motivate further studies to define the precise pathways by which this viral lineage has been introduced into North Africa in order to understand risks of future disease incursions into the region.  相似文献   

13.
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 (= 0.181), while VNTs detected significantly fewer samples positive for antibodies against SAT 1 and SAT 3 than the SPBEs (< 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.  相似文献   

14.
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.  相似文献   

15.
Sixteen sheep and 18 cattle were followed up during 1 year to estimate the duration of immunity induced by inactivated bluetongue virus serotype 8 (BTV‐8) vaccines (sheep and cattle) and a bluetongue virus serotype 1 (BTV‐1) vaccine (cattle) under field conditions using cELISA and seroneutralization test (SNT). Four sheep never seroconverted. Those that seroconverted were all seronegative by BTV‐8 SNT at the date of last sampling [378 days post‐vaccination (dpv)]. Eight sheep were still positive by competitive ELISA (cELISA) 378 dpv. All the cattle seroconverted. At the end of the study, eight and 11 cattle were still positive by BTV‐8 SNT and cELISA, respectively (335 dpv); and nine were still positive by BTV‐1 SNT (301 dpv).  相似文献   

16.
Recent European contingency plans envisage emergency vaccination as an animal‐friendly control strategy for foot‐and‐mouth disease (FMD). Anti‐viral drugs may be used as an alternative or complementary measure. We here demonstrate that the nucleoside analogue 2′‐C‐methylcytidine (2′CMC) protects severe combined immunodeficient (SCID) mice against lethal FMD virus infection. In brief, SCID mice were inoculated with serotype A FMD virus and treated for five consecutive days with 2′CMC. All 15 treated mice remained healthy until the end of the study at 14 days post‐infection (dpi). At that time, viral RNA was no longer detected in 13 of 15 treated mice. All eight untreated mice suffered from an acute generalized disease and were euthanized for ethical reasons on average at 4 dpi. These results illustrate the potential of small molecules to control FMD.  相似文献   

17.
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.  相似文献   

18.
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.  相似文献   

19.
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.  相似文献   

20.
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.  相似文献   

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