PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “FOOT AND MOUTH DISEASE”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 433 records · Page 24Linked to original sources

Relationship of speed of slaughter on infected premises and intensity of culling of other premises to the rate of spread of the foot-and-mouth disease epidemic in Great Britain, 2001.

During the foot-and-mouth disease epidemic in the UK in 2001, two major control policies were the rapid identification of cases and the culling of animals on infected premises and on dangerous contact premises. Dangerous contact premises were divided into two groups, premises contiguous to an infected premises and non-contiguous premises. In England, the largest numbers of geographically clustered infected premises were in Cumbria, the South West (Somerset, Devon and Cornwall) and the Settle/Clitheroe area straddling the Yorkshire-Lancashire border. In each of these clusters, the rate of spread of the disease, the average time from the first lesion to slaughter on infected premises, and the intensity of culling of contiguous premises and non-contiguous premises were calculated for seven-day periods. Linear regression analysis was used to look for relationships between these factors and the rate of spread of the disease. The average time from the first lesion to slaughter had a statistically significant relationship in two of the three clusters and the intensity of culling of non-contiguous premises had a significant relationship in one. The intensity of culling of contiguous premises had no significant relationship in any of the three clusters.

Abattoirs↗

Genetic variation of foot-and-mouth disease virus from field outbreaks to laboratory isolation.

Foot-and-mouth disease virus (FMDV), by nature of its RNA genome, possesses a high rate of mutation during replication. This results in extensive genetic polymorphism of virus populations in nature. The emergence of FMDV variants during replication has been reported. Genetic changes in the viral capsid protein (VP1) gene can result in amino acid changes affecting the immunodominant epitopes of FMDV. The genetic heterogeneity of FMDV in the field and the antigenic variants observed after cell culture isolation has been investigated by PCR sequencing and reactivity with monoclonal antibodies. These methods were applied to viruses causing two different outbreaks of FMD before and after replication in cell culture and in the animal host. The VP1 region of the genome was amplified by PCR and sequenced to reveal variant sequences identified after passage and to determine their presence in the original field tissue. In one case, reactivity with monoclonal antibodies was lost after passage as a result of an amino acid change in the subpopulation. These findings suggest that host cells can select specific virus genetic and antigenic subpopulations during virus isolation and propagation.

Amino Acid Sequence↗

A review of emergency foot-and-mouth disease (FMD) vaccines.

The primary objectives of this paper are to describe emergency foot-and-mouth disease (FMD) vaccines and review literature on emergency vaccine efficacy to protect animals against (1) clinical signs and (2) infection (local virus replication). The reviewed experiments suggest that in cattle, sheep and pigs, the vaccine could be effective in preventing disease within 4-5 days post-vaccination. These studies also suggest that the risk of spreading infection decreases as the interval between vaccine and challenge increases and that vaccination could reduce the amount of virus excreted compared to non-vaccinated animals. We suggest areas of future research to improve our knowledge of emergency vaccines.

Animals↗

Selection of foot and mouth disease vaccine strains--a review.

The choice of the most appropriate strains of foot and mouth disease (FMD) virus vaccines to use in FMD control programmes and to store in vaccine antigen reserves is based on the matching of representative field isolates from outbreaks around the world to available vaccine strains. However, those involved in FMD control at a national level do not always give this work a high priority, while in countries without effective control of FMD there is little incentive to collect samples or to overcome the constraints on submission to international reference laboratories. In the short term, specific initiatives for targeted collection can provide samples on a periodic basis, but a long-term solution requires the development of FMD control measures. This must be underpinned by the strengthening of local Veterinary Services and laboratories, and by demand-driven provision of sufficient amounts of high-quality vaccine. Difficulties may be increased by commercial constraints on disclosure of the strains used for vaccine production and on the supply of reagents needed for matching tests. Vaccine matching tests are mainly based on in vitro methods - such as virus neutralisation, enzyme-linked immunosorbent assay with polyclonal antibodies and complement fixation - and are performed in a relatively small number of laboratories around the world. In addition to the difficulties of gathering representative field and vaccine strains, neither the reagents nor the methods used for vaccine matching are fully harmonised. Consequently, there is no strict equivalence in the results obtained. Alternative approaches using monoclonal antibody panels and/or viral capsid gene sequencing are being developed and could complement the currently employed serological tests. However, there is limited in vivo cross-protection information, more of which is essential for future validation of the vaccine matching methods. In response to the funding and leadership deficit for vaccine strain selection, a network of World Organisation for Animal Health (OIE) and Food and Agriculture Organization FMD reference laboratories has been established; this gives these laboratories the potential to strengthen the coordination of their work and reporting and thereby improve recommendations on vaccine strain selection.

Animals↗

Serological and molecular analysis of serotype O foot-and-mouth disease virus isolated from disease outbreaks in India during 1987-91.

Foot-and-mouth disease virus (FMDV) type O outbreaks have been reported frequently in vaccinated cattle in India. Twenty-five field isolates, recovered from outbreaks in vaccinated and unvaccinated cattle between 1987 and 1991, were analyzed in relation to the vaccine strain (R2/75) by complement fixation, serum neutralization and partial nucleotide sequencing of the VP1 gene. These sequences were compared with the viral sequences in GenEMBL database. Although the Indian type O viruses were close to the European type O1 viruses, they constituted a separate group of type O FMDVs. One of the field viruses, isolated from an outbreak in vaccinated cattle and designated as BAK/90, showed significant serological and nucleotide sequence variations from the vaccine strain. Phylogenetic analysis showed that the BAK/90 and R2/75 viruses belong to separate subgroups. The other isolates were found to be serologically related to both the BAK/90 and the vaccine strain. The BAK/90 strain gave broader antigenic coverage, showed better immunogenicity, and yielded larger amounts of 146S particles in suspension cultures as compared with R2/75. Taken together, these results favour inclusion of the BAK/90 strain in the vaccine to provide adequate protection against the field variants of type O FMDV currently circulating in India.

Amino Acid Sequence↗

The possible role that buffalo played in the recent outbreaks of foot-and-mouth disease in South Africa.

African buffalo (Syncerus caffer) act as maintenance hosts for foot-and-mouth disease (FMD) in southern Africa. A single buffalo can become infected with all three of the endemic serotypes of FMD virus (SAT-1, SAT-2, and SAT-3) and pose a threat of infection to other susceptible cloven-hoofed animals. The floods of 2000 in southern Africa damaged the Kruger National Park (KNP) game fence extensively, and there were several accounts of buffalo that had escaped from the park. The VP1 gene, which codes for the major antigenic determinant of the FMD virus, was used to determine phylogenetic relationships between virus isolates obtained from the outbreaks and those previously obtained from buffalo in the KNP. These results demonstrate that buffalo were most probably the source of the outbreaks, indicating that disease control using fencing as well as vaccination is extremely important to ensure that FMD does not become established in domestic livestock.

Animals↗

Spatial distribution of foot-and-mouth disease in Pakistan estimated using imperfect data.

We estimated the spatial distribution of foot-and-mouth disease (FMD) in Pakistan; we used a probability co-kriging model and the number of FMD outbreaks reported between 1996 and 2000 by Pakistan to the Office International des Epizooties. We used a k-Bessel model and small-ruminant and human densities as surrogate covariates for the population at risk and for livestock markets and movements, respectively. Compared to no or only one covariate, the co-kriging model with both densities provided the best fit to independently obtained data on the spatial distribution of virus isolations (P=0.57). The estimated probability of an FMD outbreak per 25km(2) cell ranged from 0.017 to 0.812, with the maximum relative probability of 47.8 (0.812/0.017). Areas with the highest relative probability of having an FMD outbreak were located in the Punjab region; this is a major animal-production area located along a traditional international animal-trade route.

Animals↗

Epidemiological implications of the molecular characterization of foot-and-mouth disease virus isolated between 1996 and 2000 in Bangladesh.

Foot-and-mouth disease virus was collected during two years throughout Bangladesh. Viral RNA from 40 samples was subjected to reverse transcription-dependent polymerase chain reactions that amplify parts of the capsid protein encoding genome region, and the products obtained were sequenced. This showed that all virus isolates up to January 1999 belonged to a genotype of serotype O, observed here already in 1987, 1996 and 1997, and elsewhere since 1990. In February 2001, this virus variant was introduced into Great Britain and then transmitted to other European countries. The capsid protein sequences of an isolate of 2001 from the Netherlands is provided. Later isolates from Bangladesh, however, belonged to a genotype of serotype A that had been transmitted to Albania in 1996. No virus of type Asia1 was found, although it circulated in Bangladesh in 1996. Instead, this genotype of Asia1 virus was observed in Iran late in 1999, and transmitted from Turkey to Greece in July 2000. The results indicate continued intercontinental transmission of foot-and-mouth disease viruses that circulate in central Asia.

Amino Acid Sequence↗

RELATIONSHIP OF DONOR AGE TO IN VITRO PRODUCTION OF FOOT-AND-MOUTH DISEASE VIRUS BY MOUSE KIDNEY CELLS.

Multiplication of foot-and-mouth disease virus (FMDV) was compared in kidney cells from 7- to 35-day-old mice representing various degrees of age resistance to this virus. Three types of cell preparations were used: primary monolayer cultures, suspensions of dispersed cells, and suspensions of minced tissue. Virus multiplication in the two types of cell suspensions was related to the age of the donors both in regard to time when multiplication first became evident and to the amount of virus produced. While adsorption rates were similar in the cells from all age groups, virus multiplication began earlier in cells from younger mice and more virus was produced by these cells than by cells from older animals. There was no significant difference in the virus growth rates in the primary monolayer cultures of cells. The results indicate that kidney cells from mice 7 to 35 days old vary in their ability to produce virus in relation to the degree of susceptibility of the cell donors. After propagation of the cells in primary monolayer cultures, however, this difference no longer exists probably because of cell selection under the cultural conditions.

Aging↗

Potential for the transmission of foot-and-mouth disease virus from African buffalo (Syncerus caffer) to cattle.

Foot-and-mouth disease viruses of types SAT 1 and SAT 2 isolated from diseased cattle and carrier buffalo, either on the same farm or in the same ecological area within a short time of each other, were compared by T1 oligonucleotide mapping. No similarity was observed between the maps obtained, indicating that the different populations of virus were unique to each species and that no interspecies transmission had occurred.

Animals↗

Investigation of an outbreak of foot-and-mouth disease in vaccinated dairy cattle in Thailand.

An outbreak of foot-and-mouth disease that spread between two related vaccinated dairy herds was investigated. Although the cattle were of similar vaccination status, in one herd there was high morbidity, whereas in the other there was considerably lower morbidity. The relationship between the vaccine virus and the outbreak virus was expressed as an r value determined by the two-dimensional neutralisation test. Bovine serum homologous to the vaccine virus indicated a close antigenic relationship between the vaccine virus and the outbreak virus (r = 0.61). The source of the outbreak virus was not determined. The investigation suggested a requirement for close contact between stock for foot-and-mouth disease to spread in a tropical environment, in contrast to the capacity of the disease to spread considerable distances by aerosol transmission in temperate climates.

Animals↗

The foot and mouth disease (FMD) epidemic in the United Kingdom 2001.

The foot and mouth disease epidemic commenced in February 2001 when diseased pigs were identified in an abattoir. The infection had become widespread in sheep in England and Wales before this discovery. It was decided to eradicate the disease by slaughter rather than use vaccine. The virus was a Pan-Asia O strain that caused few lesions in sheep and this made the identification of infected flocks very difficult leading to a long drawn-out epidemic. Over four million animals were slaughtered in 2000 herds and flocks. The last outbreak was in September.

Animals↗