Foot and Mouth Disease : Etiology, Epidemiology and Control Measures / 감염과화학요법

Foot and mouth disease (FMD) is highly infectious disease of cloven-hoofed animals, particularly cattle, sheep, pigs and goats. Also, it is the most important animal pathogen on the global scale because of the potential for rapid and extensive spread through susceptible animal populations. Outbreak can lead to formidable economic consequence for domestic livestock production and international trade. FMD is caused by FMD virus which is a small, non-enveloped, positive-sense RNA virus belonging to the genus Aphthovirus within the family Picornaviridae . There are seven immunologically distinct serotypes; O, A, C, SAT (Southern African Territories) 1, SAT 2, SAT 3 and Asia 1 and a diverse antigenic spectrum of virus strains within each serotype. Characteristic lesion of FMD is the formation of vesicles in the mucosal membranes of mouth, muzzle, foot, and teats. Nowadays, many developed countries have maintained FMD-free as a result of eradication efforts. However, outbreaks of FMD have occurred in several countries, even in Europe, and it is still endemic in Africa, the Middle East, Asia, and South America. Last year, three outbreaks of FMD occurred in our country. Last outbreak reported in November, 2010 induced the enormous social and economical impacts. Culling of infected animals, movement control, and vaccination are the major control measures of FMD. To control the disease, each country has their own strategies based on the current situation of FMD in their country. Therefore, I would like to discuss the causative agent, epidemiological properties and control measures of FMD in this paper.

Detection of Pathogenic Viruses in the Atmosphere during Asian Dust Events in Incheon City / 결핵및호흡기질환

BACKGROUND: Ambient particles during Asian dust events are usually less than 10micrometer in size, and known to be associated with the adverse effects on the general population. There is little evidence linking Asian dust to adverse effects on the airways. In 2002, the authors found that particulate matter during Asian dust events had an effect on the symptoms and pulmonary function of patients with bronchial asthma. An aggravating factor might be that of a viral infection, but this remains unclear. Conversely, it has been speculated that African dust may carry the virus responsible for foot and mouth disease. Asian dust events are also likely to be responsible for transporting viruses, some of which are pathogenic, and common in many environments. Therefore, in this study, air samples were screened for the presence of viruses. METHODS: Air samples were collected 20 times each during Asian dust events and under non-dust conditions, for at least 6 hours per sample, using a high volume air sampler (Sibata Model HV500F), with an airflow rate of 500L/min, between April and August 2003, and between April and August 2004. The samples were then screened for the presence of targeted viruses (Influenza A, B, Hog cholera virus, and Aphthovirus) using a polymerase chain reaction method. RESULTS: One Asian dust event occurred between April and August 2003, and 3 between April and August 2004, with a 24 hour average PM10 level of 148.0microgram/m(3). The 24 hour average PM10 level was 57microgram/m(3). There was a significant difference in?the PM10 concentration between dusty and clear days. No viruses (Influenza virus, Aphthovirus, and Hog cholera virus) were identified in the air samples obtained during the dusty days. CONCLUSIONS: Although no virus was detected in this study, further studies will be needed to identify suspected viruses carried during Asian dust events, employing more appropriate virus detection conditions.

Pasteurization of IgM-enriched immunoglobulin

Human plasma proteins are important for therapy or prophylaxis of human diseases. Due to the preparation of human plasma proteins from human plasma pools and risk of contamination with human viruses, different viral reduction treatments such as: pasteurization, solvent/detergent, dry heat treatment, steam treatment, beta-propiolactone/UV and nanofiltration have been implemented. As pasteurization can be performed for liquid protein, this method [a 10-hour heat treatment of the aqueous solutions at 60°C] was introduced into the manufacturing procedure of IgM-enriched immunoglobulin, to improve its safety further. The efficiency of this method for inactivation of viruses was evaluated by the use of Foot-and-Mouth Disease Virus [a non-enveloped virus] and Infectious Bovine Rhinotracheitis [IBR] Virus [a lipid-enveloped virus]. Pasteurization inactivated Foot-and-Mouth Disease Virus by 7 log10 and for IBR Virus by 5log10. These findings show a significant added measure of virus safety associated with pasteurization of IgM-enriched immunoglobulin preparation

Caracterización molecular de cepas del virus de la fiebre aftosa aisladas durante los años 1993-1994 en la Argentina / Molecular characterization of aphthous fever virus isolated during the years 1993-1994 in Argentina

Nucleotide sequence and phylogenetic analysis of the VP1 structural protein have been used extensively as diagnostic and epidemiological tools for foot and mouth disease virus (FMDV). In this report we have applied this methodology to the analysis of the VP1 coding sequence from FMDV strains isolated in Argentina during 1993-1994. The results demonstrated that the field isolates were related to the vaccine strains used at that time. However the involvement of the vaccine virus appeared to be different for outbreaks caused by FMD viruses type O or C. These data provide a database essential for determining the origin of new epizootics.

Comparative studies on immunoreactivity of truncated recombinant proteins of foot and mouth disease virus (FMDV) produced in E.coli and insect cells.

For effective FMD control programme, India needs large quantities of cheaper diagnostics in addition to vaccine. Diagnostic reagents produced through conventional methods may not be able to meet such requirements. Alternatively, rDNA technology using suitable heterologous systems that permit production of recombinant antigens to the most native form may be exploited. Studies conducted in our laboratory have led us to select carboxy terminal part of VP1 for expression and evaluation. The protein, which was purified from E.coli under denaturing conditions, was renatured and its reactivity was compared with the protein expressed in insect cells through recombinant baculovirus. The expressed protein in the insect cell whole lysate reacted more efficiently with antibodies raised against whole virus than the purified and renatured protein produced in E.coli. But for its lower reactivity, protein produced from E.coli was found to be suitable in type detection. In addition, the size of the protein is small (16 kD) and production and purification of it from E.coli may be cost effective. Hence, it may be exploited for FMDV typing.

Cloning and expression of acd genes of FMDV

RT-PCR amplification of VIA [3D] gene and protease [3C] using its primers. Legation of the PCR product with the cloning vector [using pET system]. Expression of the recombinant plasmid in E. coli expression host. Use of the expressed VIA protein in diagnosis of cattle infected with any of the 7 serotypes of FMD virus with the help of ELISA

Differentiation between infected repeatedly vaccinated and free animal with fmd virus using bio-engineered VIA

Sera from infected, vaccinated and negative cattle were tested using 3D ELISA to allow each category of animals to be clearly differentiated based on the presence of antibody to 3D antigen. The assay can recognize infected animals in countries where FMD outbreaks have occurred, specially if ring vaccination has been performed, also at the same time vaccinated animals can become infected without apparent clinical symptoms. 3D ELISA test is simple and rapid to discriminate between antibodies elicited by FMD infection or by vaccination

Development and characterization of monoclonal antibodies to foot and mouth disease virus type 'C'.

Five fusion experiments were conducted with spleen cells from Balb/c mice immunized with purified 146S antigen of foot and mouth disease virus type 'C' (vaccine strain). Monoclones (31) thus developed were isotyped as IgM (3), IgG1 (6), IgG2a (5), IgG2b (3) and IgG3 (14). Eleven clones isotyped as IgM, IgG2a and IgG2b showed neutralizing activity in virus neutralization and plaque reduction tests. Six of the neutralizing clones precipitated 146S virus in Ouchterlony reaction. On the basis of location of MAb reactive epitopes in relation to intact virus (146S), 12S particles and VP1 in ELISA test, the clones were classified as Class II (6), Class III (11) and Class IV (14). These clones may be useful for purposes of antigen detection from field isolates and for estimation of antibody titres in vaccinated animals.

Antigenic structure of foot and mouth disease virus type A22 (Indian isolates).

Variations in foot and mouth disease virus are due to amino acid substitutions in the VP1, which is a major immunogen. Analysis of this hypervariable region is essential to know the antigenic structure of the serotype and is necessary to select a suitable vaccine strain. FMDV type A22 is one of the four prevailing virus types for which the vaccine is used regularly. To understand the antigenic structure of this type, carboxy- terminal region of VP1 from two field isolates and vaccine virus were sequenced and analysed. The results indicate that, Indian A22 has distinct antigenic structure.

Inquérito soroepidemiológico sobre febre aftosa realizado em bovinos no pantanal Sul-Mato-Grossense, Brasil / Serum-epidemiologic study on foot-and-mouth disease carried out in cattle in the Pantanal of State of Mato Grosso do Sul, Brazil

Para avaliar as ações de combate à febre aftosa realizadas na região do pantanal do Estado de Mato Grosso do Sul, em especial a estratégia de vacinação empregada, bem como estimar o conhecimento da comunidade sobre as características da aftosa e sua participação no sistema de vigilância local, realizou-se, no período de 1995-1996, um estudo soroepidemiológico na região em questão. O pantanal sul-mato-grossense foi dividido em 2 regiões, considerando-se para o estudo bovinos com idade entre 6 e 24 meses. Para diagnóstico laboratorial foram empregadas duas técnicas: IDGA e EITB

antigenic variation of foot and mouth disease virus of the last three isolates in Egypt

Three FMD viral isolates had been isolated from different outbreaks at three governorates [Sharquia, Suez, and Agga locality] during 1972, 1987, and 1993 from cattle respectively. The isolates were tested by coinplement fixation test [CFT] angainst the seven serotypes and the results revealed that all strains were of the type [O] FMD virus. The studied isolates were adapted after the 3[rd] and 4[th] passages to BEK cell cultures, they yielded infective titers ranging between 4 and 5.5 log 10 TCID[50] and complement fixing titers between 1.37-1.75 log[10] CFU/ml. Antigenic relationship and dominating state studies for the three isolates using the crosswise C.F.T. revealed that isolates [O[1]/72 and O[1] /87] and [O[1]/72] and O[1]/93] showing a little antigenic variation and can be classified as [Subtype similar but still different] and have a percentage between [32% to 70%] while isolates [O[1]/87 and O[1] /93] classified as [Subtype Similar] and have percentage between [70%-100%]. The dominance determination for isolated strains showed that isolate strain [O[1]/87] is dominating strain [O[1]/72 and O[1] /93] and strain O[1]/72 is dominating strain O[1]/93. The nucleotide sequence data of VPI of the isolated strains [O[1]/72, O[1]/87 and O[1]/93] revealed that the homology% FMD virus [O[1]/72, O[1] 87 with O[1]/93] were 86% and 88% respectively, while the homology% between O/87 and O/93 was 94%. This indicates a closer relationship between O[1]/87 and O[1]/93 isolates thorn to O[1]/72. The variation of the results between CF test and nucleotide sequence homology may be attnbuted to the fact that CF test is carried on the whole FMDV while the nucleotide sequence homology carried out on the level of VPI gene. However, this difference is not of a significant value that necessitates the change of the already applicable vaccinal strain

Antiviral activity of crude extracts of Guarea guidona

Crude extracts of leaves and fruits of Guarea guidona were tested antiviral activity against pseudorabies virus and foot-and-mouth disease virus in the IB-RS-2 pig cell line and against bovine herpesvirus-1 (BHV-1) in the GBK bovine Cell line. The highest nontoxic doses of extracts from fruits and leaves were 125 mug/ml and 500 mug/ml, respectively. Crude extracts presented antiviral activity against pseudorabies virus with a decrease in virus titer of 3.0 log units at 500 mug/ml. Virucidal activity was not observed at 62.5 mug/ml. Preformed cell monolayers showed no cytotoxic effect after 48 h in the presence of 500 mug/ml in pig cells. G. guidona leaves did not induce an antiviral state but exhibited antiviral effects during the early stage of viral infection.

Susceptibilidad de Picornavirus a un antiviral de origen vegetal (Meliacina) / Susceptibility of picornaviruses to an antiviral of vegetal origin (meliacine)

La planta superior Melia azederach L (MA) produce un polipéptido cíclico que puede aislarse de sus hojas y que tiene un amplio espectro antiviral contra virus con RNA de distintas familias. En este trabajo se estudió su efecto sobre dos Picornavirus: el virus fiebre aftosa (VFA) y el virus polio. Para ello se probaron las cepas A24, A87, C3 Resende, O1 Campos, O1 Caseros y O69 del VFA y los tipos 1, 2 y 3 del virus polio. Se encontró que las cepas muestran una susceptibilidad diferencial a una concentración no citotóxica del antiviral de 0,3 µg/ml, siendo las cepas A24 y A87 las más susceptibles ya que resultaron inhibidas en un 90 por ciento. Para que ello ocurra el extracto de MA debe agregarse después de la adsorción viral y conservarse en el medio de cultivo hasta la cosecha de virus ya que con todas las cepas ensayadas el pretratamiento de las monocapas no resultó efectivo. Para determinar la influencia de la multiplicidad de infección (m.i.) en la diferente susceptibilidad observada se eligió la cepa O1 Campos del VFA y la tipo 3 de polio que resultaron ser poco sensibles cuando se usó una m.i. de 1, encontrándose una inhibición del 99 por ciento para ambos virus a una m.i. de 0,001. Estos resultados indican que los Picornavirus también son susceptibles a la inhibición por meliacina, que dicha inhibición varía con la cepa ensayada y que la aparente resistencia de estos virus estaría relacionada con la velocidad del ciclo de replicación, el que es superior al establecimiento del estado antiviral, cuando todas las células son infectadas simultáneamente

Persistencia de anticuerpos anti-VIAA en bovinos vacunados con diferentes vacunas antiaftosa oleosas de uso comercial / Persistence of anti-VIAA antibodies in cattle vaccinated with different anti-foot-and-mouth disease oil-adjuvant vaccine of commercial use

Se estudió la persistencia de anticuerpos anti-VIAA en bovinos inmunizados con diferentes vacunas antiaftosa oleosas de uso comercial, utilizadas en la República Oriental del Uruguay. Se procesaron 726 sueros de estos animales mediante la técnica de inmunodifusión en gel de agar con antígeno VIA. Se encontró que la detección de anticuerpos anti-VIAA persitió por más de 171 días en animales inmunizados con vacunas de antigeno concentrado con hidróxido de aluminio

Desempeño de un ensayo enmunoenzimático de electrotransferencia rápida para la detección de bovinos expuestos al virus de la fiebre aftosa / Performance of a rapid enzyme-linked immunoelectrotransfer blot assay for detection of cattle exposed to foot-and-mouth disease virus

Se evaluó la efectividad de un ensayo enmunoenzimático de electrotransferencia (EITB) para la detección de anticuerpos contra antígenos de replicación del virus de la fiebre aftosa (VFA) en bovinos expuestos al mismo. El ensayo EITB, que utiliza como sondas serológicas antígenos virales no estructurales producidos por bioingeniería y altamente purificados, se comparó con la prueba tradicional de inmunodifusión en gel de agar (prueba VIAA), que emplea un antígeno asociado a la infección viral parcialmente purificado. Se recomienda el uso del EITB como una prueba sensible, segura, rápida y económica pra la detección especifica de exposición en el campo

Ensaios de infecciosidade do vírus da febre: I. Transmissão entre bovinos infectados e contatos e suínos / Foot and mouth disease virus infectivity assays: I. Transmission in infected cattle, exposed cattle and pigs

Quatro experimentos de infecção por instilação nasal dos vírus O, A e C da febre aftosa em bovinos e sua transmissão pra bovinos e suínos foram realizados com a finalidade de estudar vários parâmetros indicativos da infecção. Embora sendo oriundos de áreas endêmicas, os bovinos apresentaram padrões de replicação do vírus da febre aftosa na área faríngea e viremia, assim como o processo de transmissão entre bovinos e suínos similares àqueles encontrados por outros pesquisadores com animais de áreas livres

Supervivência do vírus da febre aftosa tipo O1 em Carcaças de ovinos infectados experimentalmente, antes e após o processo de maturação / Survival of foot and mouth disease virus O1 in carcasses of experimentally infected sheep, before and after the maturation process

Foi estudada a supervivência do vírus da febre aftosa tipo O cepa O1 Campos em carcaças de ovinos infectados experimentalmente. Enfatiza-se a importância do conhecimento epidemiológico da região de onde se originam os ovinos destinados ao abate e o rigor do exame ante-mortem

Expression of the VP3-VP1 sequence of foot-and-mouth disease virus in Escherichia coli

1. cDNA recombinants containing the VP3 and VP1 sequences of foot-and-mouth disease virus were isolated and the VP3-VP1 sequence was reconstructed. 2. The reconstructed VP3-VP1 sequence was subcloned into expression vector pEX31b and a fusion protein of about 62,000 Da was expressed. 3. When injected into mice, the fusion protein was able to elicit the production of antibodies that recognized viral VP1 and VP3. 4. Antibodies present in sera from mice immunized with VP3-VP1 protein did not neutralize the foot-and-mouth disease virus in vitro