scholarly journals Mathematical Quantification of Transmission in Experiments: FMDV Transmission in Pigs Can Be Blocked by Vaccination and Separation

2020 ◽  
Vol 7 ◽  
Author(s):  
Aldo Dekker ◽  
Herman J. W. van Roermund ◽  
Thomas J. Hagenaars ◽  
Phaedra L. Eblé ◽  
Mart C. M. de Jong
Keyword(s):  
Foot And Mouth Disease ◽  
Control Measures ◽  
Physical Separation ◽  
Block Transmission ◽  
Transmission Parameters ◽  
Mouth Disease Virus ◽  
Significant Difference ◽  
Contact Transmission ◽  
Quantitative Understanding ◽  
Transmission Studies

Quantitative understanding of transmission with and without control measures is important for the control of infectious diseases because it helps to determine which of these measures (or combinations thereof) will be effective to reduce transmission. In this paper, the statistical methods used to estimate transmission parameters are explained. To show how these methods can be used we reviewed literature for papers describing foot-and-mouth disease virus (FMDV) transmission in pigs and we used the data to estimate transmission parameters. The analysis showed that FMDV transmits very well when pigs have direct contact. Transmission, however, is reduced when a physical barrier separates infected and susceptible non-vaccinated pigs. Vaccination of pigs can prevent infection when virus is administered by a single intradermal virus injection in the bulb of the heel, but it cannot prevent infection when pigs are directly exposed to either non-vaccinated or vaccinated FMDV infected pigs. Physical separation combined with vaccination is observed to block transmission. Vaccination and separation can make a significant difference in the estimated number of new infections per day. Experimental transmission studies show that the combined effect of vaccination and physical separation can significantly reduce transmission (R < 1), which is a very relevant result for the control of between-farm transmission.

scholarly journals El componente racial influencia la resistencia a la infección con el virus de la leucosis bovina

2018 ◽  
Vol 65 (2) ◽  
Author(s):  
Cristina Úsuga-Monroy ◽  
José Julian Echeverri ◽  
Albeiro López-Herrera
Keyword(s):  
Infection Rate ◽  
Vesicular Stomatitis Virus ◽  
Bovine Leukemia Virus ◽  
Leukemia Virus ◽  
Foot And Mouth Disease ◽  
Holstein Breed ◽  
Mouth Disease Virus ◽  
Significant Difference ◽  
Vesicular Stomatitis

The bovine leukemia virus (BLV) is a retrovirus that primarily affects dairy cattle, reducing milk production between 2.5 and 5%. The Colombian Blanco Orejinegro (BON) is a well-adapted, rustic, creole breed resistant to in vitro infections of Foot-and-mouth disease virus and vesicular stomatitis virus, as well as to Brucella abortus. This study aimed to determine if the crossing of BON and Holstein breeds is resistant to infection by BLV. Blood samples of 124 individuals (59 Holstein, 40 BON, and 25 BON x HOL) of the same herd were taken. The DNA was extracted, and a nested PCR was performed related to a region of the env gene of BLV. A fragment of 444 bp was obtained for positives animals. The molecular in-herd prevalence was 33% for BLV. A significant difference for BLV infection was found among the groups (p<0.05). The infection rate for the Holstein group was 55.9%, for BON cattle 5%, and for BON x HOL cattle 24%. The latter showed a reduction in the infection rate of 32% to the Holstein breed, which can be attributed to the presence of resistance genes in the BON breed. It was found that the level of infection is lower in BON x HOL cattle in contrast with Holstein dairy cows.

scholarly journals A meta-analysis and experiment assessing phage-based FMDV vaccine

2020 ◽  
Author(s):  
Peng Wu ◽  
Ningning Yang ◽  
Yueli Wang ◽  
Mingguo Xu ◽  
Yunfeng Zhang ◽  
...  
Keyword(s):  
Meta Analysis ◽  
Foot And Mouth Disease ◽  
Fixed Effect Model ◽  
Mouth Disease ◽  
Control Group ◽  
Phage Group ◽  
Mouth Disease Virus ◽  
Significant Difference ◽  
Foot And Mouth ◽  
And Control

AbstractFoot-and-mouth disease (FMD) is a pathological disease caused by the foot- and-mouth disease virus (FMDV), which mainly affects cloven-hoofed animals. This study was conducted to a meta-analysis and experiment on the effect of bacteriophages used in the development of FMDV vaccines. A systematic search was conducted for the collection of the protection effect for the phage-based FMDV vaccine using sensitive search strategies. The extracted data were analyzed using Rev-Man 5.4 software. This experiment used the T7 phage to express the capsid protein VP1 of the OHM-02 strain, and the recombinant VP1 phage was termed OHM-T7. Antibodies and cytokines levels were assessed after immunizing BALB/C mice with OHM-T7. The results showed that a total of 115 articles were retrieved, and 4 of them met the inclusion criteria. There was no heterogeneity with I2 = 0%, 20% or 43%. We used a fixed-effect model for meta-analysis, and the results showed a protective effect on FMDV between the phage group and control group (P<0.01) and between FMDV group and control group (P<0.01). Furthermore, when the phage group was compared to the FMDV group, there was also no significant difference (P>0.05). After successfully obtained the ohm-t7 strain and immunized the mice, it could induce high levels of IFN-γ levels in mice with little effect on IL-4 levels. OHM-T7 could be used to detect antibodies produced by mice immunized with different FMDV antigens and produce high levels of anti-FMD antibodies. In summary, these results showed the potential of phage-based FMDV vaccines in FMDV prevention.

scholarly journals Molecular detection, phylogenetic analysis and genetic diversity of recently isolated foot-and-mouth disease virus serotype A African topotype, Genotype IV

2022 ◽  
Vol 19 (1) ◽  
Author(s):  
Ayah M. Hassan ◽  
Mostafa R. Zaher ◽  
Rabab T. Hassanien ◽  
Mervat I. Abd-El-Moniem ◽  
Ahmed R. Habashi ◽  
...  
Keyword(s):  
Disease Virus ◽  
Foot And Mouth Disease ◽  
Emerging Diseases ◽  
Mouth Disease ◽  
Control Measures ◽  
Close Monitoring ◽  
Serotype A ◽  
Mouth Disease Virus ◽  
Virus Serotype ◽  
Foot And Mouth

Abstract Background Surveillance for circulating emerging diseases of economic importance has a major role in the rapid response to major pathogen outbreaks. Foot-and-mouth disease virus (FMDV) is one of the significant endemic viruses in Egypt. FMDV is periodically investigated for monitoring evolution and emergence of new variants. The genetic characterization of foot-and-mouth disease (FMD) virus serotype A responsible for recent outbreaks of FMD in Egypt was determined. Methods Samples were collected from different locations and virus isolation was performed using BHK-21 cells. Viral RNA was extracted and samples were screened for FMDV using real-time RT-PCR. DNA sequence analysis was performed and computational and bioinformatics analyses were used to determine the substitution rates and phylogenetic relationship. Results Sequence and phylogenetic analyses of full-length 1D region of FMDV samples collected from different governorates in 2020 showed close similarity to Egyptian FMDV strains from serotype A-African topotype-G-IV with genetic variation of 6.5%. Recently isolated FMDV strains showed high genetic variations from locally used vaccine strains in the major antigenic sites of VP1 region. Conclusions Although, efforts made by the veterinary authorities to implement an effective mass vaccination plan, the recently detected FMDV strains in this study could not be subtyped using the FMDV primers routinely used for molecular serotyping. These dissimilarities raise the alarm for reconsideration of the FMDV isolates used in vaccine manufacture. Clearly close monitoring of FMD in Egypt is urgently required to define the risks of future outbreaks and to ensure appropriate control measures against FMD major outbreaks.

scholarly journals Quantifying the Transmission of Foot-and-Mouth Disease Virus in Cattle via a Contaminated Environment

mBio ◽  
2020 ◽  
Vol 11 (4) ◽  
Author(s):  
Claire Colenutt ◽  
Emma Brown ◽  
Noel Nelson ◽  
David J. Paton ◽  
Phaedra Eblé ◽  
...  
Keyword(s):  
Disease Virus ◽  
Clinical Signs ◽  
Foot And Mouth Disease ◽  
Mouth Disease ◽  
Control Measures ◽  
Effective Control ◽  
Environmental Transmission ◽  
Indirect Transmission ◽  
Mouth Disease Virus ◽  
Foot And Mouth

ABSTRACT Indirect transmission via a contaminated environment can occur for a number of pathogens, even those typically thought of as being directly transmitted, such as influenza virus, norovirus, bovine tuberculosis, or foot-and-mouth disease virus (FMDV). Indirect transmission facilitates spread from multiple sources beyond the infectious host, complicating the epidemiology and control of these diseases. This study carried out a series of transmission experiments to determine the dose-response relationship between environmental contamination and transmission of FMDV in cattle from measurements of viral shedding and rates of environmental contamination and survival. Seven out of ten indirect exposures resulted in successful transmission. The basic reproduction number for environmental transmission of FMDV in this experimental setting was estimated at 1.65, indicating that environmental transmission alone could sustain an outbreak. Importantly, detection of virus in the environment prior to the appearance of clinical signs in infected cattle and successful transmission from these environments highlights there is a risk of environmental transmission even before foot-and-mouth disease (FMD) is clinically apparent in cattle. Estimated viral decay rates suggest that FMDV remained viable in this environment for up to 14 days, emphasizing the requirement for stringent biosecurity procedures following outbreaks of FMD and the design of control measures that reflect the biology of a pathogen. IMPORTANCE Effective control of a disease relies on comprehensive understanding of how transmission occurs, in order to design and apply effective control measures. Foot-and-mouth disease virus (FMDV) is primarily spread by direct contact between infected and naive individuals, although the high levels of virus shed by infected animals mean that virus can also be spread through contact with contaminated environments. Using a series of transmission experiments, we demonstrate that environmental transmission alone would be sufficient to sustain an outbreak. Key observations include that a risk of transmission exists before clinical signs of foot-and-mouth disease (FMD) are apparent in cattle and that survival of virus in the environment extends the transmission risk period. This study highlights the role a contaminated environment can play in the transmission of FMDV and presents approaches that can also be applied to study the transmission of other pathogens that are able to survive in the environment.

Direct contact transmission of three different foot-and-mouth disease virus strains in swine demonstrates important strain-specific differences

2012 ◽  
Vol 193 (2) ◽  
pp. 456-463 ◽  
Author(s):  
Juan M. Pacheco ◽  
Meghan Tucker ◽  
Ethan Hartwig ◽  
Elizabeth Bishop ◽  
Jonathan Arzt ◽  
...  
Keyword(s):  
Disease Virus ◽  
Direct Contact ◽  
Foot And Mouth Disease ◽  
Mouth Disease ◽  
Mouth Disease Virus ◽  
Foot And Mouth ◽  
Contact Transmission ◽  
Virus Strains

scholarly journals Foot-and-mouth disease virus serotype O, East African Topotype 3 (EA-3) in a pastoral herd in Kaduna state, Nigeria

2021 ◽  
pp. 93-95
Keyword(s):  
Disease Virus ◽  
Foot And Mouth Disease ◽  
Mouth Disease ◽  
Control Measures ◽  
Effective Control ◽  
East African ◽  
Serotype O ◽  
Mouth Disease Virus ◽  
Virus Serotype ◽  
Foot And Mouth

A case of foot and mouth disease involving an uncommon serotype of the Foot and Mouth disease virus (FMDV) is reported in a 6-year-old Bunaji bull from a pastoralist herd in Tohu, Sabon Gari Local Government Area of Kaduna State, Nigeria. Clinical examination revealed erosions in the inter-digital spaces, dorsum and ventrum of the tongue and raised hair coat. The epithelial lining of the lesions on the foot and mouth were gently peeled off and used as samples for diagnosis. A confirmatory diagnosis of FMDV serotype O strain was done by virus isolation using Bovine thyroid gland primary cell line, antigen ELISA for FMD virus, while a phylogenetic analyses of VP1 nucleotide sequences revealed East African topotype 3 (EA-3). Presenting lesions in the interdigital space were cleaned with cotton wool soaked in a solution of 5% chlorhexidine and then sprayed with Oxyspray® after which Tetranor® long acting antibiotic was administered through deep intramuscular route at 20mg/kg body weight. The diagnosis of relatively alien topotype of FMDV in Nigeria calls for a holistic epidemiological survey of all the serotypes and topotypes present in the country in order to plan for effective control measures. Keywords: Bunaji bull, FMD, Nigeria, Serotype O, Topotype EA-3

scholarly journals Molecular characterization of SAT-2 foot-and-mouth disease virus isolates obtained from cattle during a four-month period in 2001 in Limpopo Province, South Africa

2008 ◽  
Vol 75 (4) ◽  
Author(s):  
B.S. Phologane ◽  
R.M. Dwarka ◽  
D.T. Haydon ◽  
L.J. Gerber ◽  
W. Vosloo
Keyword(s):  
South Africa ◽  
Amino Acid ◽  
Foot And Mouth Disease ◽  
Mouth Disease ◽  
Control Measures ◽  
High Rate ◽  
Control Zone ◽  
Nucleotide Mutation ◽  
Mouth Disease Virus ◽  
Foot And Mouth

Foot-and-mouth disease (FMD) is an acute, highly contagious viral infection of domestic and wild cloven-hoofed animals. The virus is a single-stranded RNA virus that has a high rate of nucleotide mutation and amino acid substitution. In southern Africa the South African Territories (SAT) 1-3 serotypes of FMD virus are maintained by large numbers of African buffaloes (Syncerus caffer), which provide a potential source of infection for domestic livestock and wild animals. During February 2001, an outbreak of SAT-2 was recorded in cattle in the FMD control zone of South Africa, adjacent to the Kruger National Park (KNP). They had not been vaccinated against the disease since they form the buffer between the vaccination and free zones but in the face of the outbreak, they were vaccinated as part of the control measures to contain the disease. The virus was, however, isolated from some of them on several occasions up to May 2001. These isolates were characterized to determine the rate of genetic change in the main antigenic determinant, the 1D/2A gene. Nucleotide substitutions at 12 different sites were identified of which five led to amino acid changes. Three of these occurred in known antigenic sites, viz. the GH-loop and C-terminal part of the protein, and two of these have previously been shown to be subject to positive selection. Likelihood models indicated that the ratio of non-synonymous to synonymous changes among the outbreak sequences recovered from cattle was four times higher than among comparable sequences isolated from wildlife, suggesting that the virus may be under greater selective pressure during rapid transmission events.

scholarly journals Persistent Infection of African Buffalo (Syncerus caffer) with Foot-and-Mouth Disease Virus: Limited Viral Evolution and No Evidence of Antibody Neutralization Escape

2019 ◽  
Vol 93 (15) ◽  
Author(s):  
Martí Cortey ◽  
Luca Ferretti ◽  
Eva Pérez-Martín ◽  
Fuquan Zhang ◽  
Lin-Mari de Klerk-Lorist ◽  
...  
Keyword(s):  
Disease Virus ◽  
Immune Escape ◽  
Foot And Mouth Disease ◽  
Germinal Centers ◽  
Mouth Disease ◽  
African Buffalo ◽  
Syncerus Caffer ◽  
Mouth Disease Virus ◽  
Significant Difference ◽  
Foot And Mouth

ABSTRACTAfrican buffaloes (Syncerus caffer) are the principal “carrier” hosts of foot-and-mouth disease virus (FMDV). Currently, the epithelia and lymphoid germinal centers of the oropharynx have been identified as sites for FMDV persistence. We carried out studies in FMDV SAT1 persistently infected buffaloes to characterize the diversity of viruses in oropharyngeal epithelia, germinal centers, probang samples (oropharyngeal scrapings), and tonsil swabs to determine if sufficient virus variation is generated during persistence for immune escape. Most sequencing reads of the VP1 coding region of the SAT1 virus inoculum clustered around 2 subpopulations differing by 22 single-nucleotide variants of intermediate frequency. Similarly, most sequences from oropharynx tissue clustered into two subpopulations, albeit with different proportions, depending on the day postinfection (dpi). There was a significant difference between the populations of viruses in the inoculum and in lymphoid tissue taken at 35 dpi. Thereafter, until 400 dpi, no significant variation was detected in the viral populations in samples from individual animals, germinal centers, and epithelial tissues. Deep sequencing of virus from probang or tonsil swab samples harvested prior to postmortem showed less within-sample variability of VP1 than that of tissue sample sequences analyzed at the same time. Importantly, there was no significant difference in the ability of sera collected between 14 and 400 dpi to neutralize the inoculum or viruses isolated at later time points in the study from the same animal. Therefore, based on this study, there is no evidence of escape from antibody neutralization contributing to FMDV persistent infection in African buffalo.IMPORTANCEFoot-and-mouth disease virus (FMDV) is a highly contagious virus of cloven-hoofed animals and is recognized as the most important constraint to international trade in animals and animal products. African buffaloes (Syncerus caffer) are efficient carriers of FMDV, and it has been proposed that new virus variants are produced in buffalo during the prolonged carriage after acute infection, which may spread to cause disease in livestock populations. Here, we show that despite an accumulation of low-frequency sequence variants over time, there is no evidence of significant antigenic variation leading to immune escape. Therefore, carrier buffalo are unlikely to be a major source of new virus variants.

scholarly journals Emergency FMD Serotype O Vaccines Protect Cattle against Heterologous Challenge with a Variant Foot-and-Mouth Disease Virus from the O/ME-SA/Ind2001 Lineage

Vaccines ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 1110
Author(s):  
Nagendrakumar Balasubramanian Singanallur ◽  
Aldo Dekker ◽  
Phaedra Lydia Eblé ◽  
Froukje van Hemert-Kluitenberg ◽  
Klaas Weerdmeester ◽  
...  
Keyword(s):  
Vaccine Strain ◽  
Challenge Test ◽  
Foot And Mouth Disease ◽  
Mouth Disease ◽  
Control Measures ◽  
Post Vaccination ◽  
Fmd Virus ◽  
Mouth Disease Virus ◽  
Foot And Mouth

Vaccination is one of the best approaches to control and eradicate foot-and-mouth disease (FMD). To achieve this goal, vaccines with inactivated FMD virus antigen in suitable adjuvants are being used in addition to other control measures. However, only a limited number of vaccine strains are commercially available, which often have a restricted spectrum of activity against the different FMD virus strains in circulation. As a result, when new strains emerge, it is important to measure the efficacy of the current vaccine strains against these new variants. This is important for countries where FMD is endemic but also for countries that hold an FMD vaccine bank, to ensure they are prepared for emergency vaccination. The emergence and spread of the O/ME-SA/Ind-2001 lineage of viruses posed a serious threat to countries with OIE-endorsed FMD control plans who had not reported FMD for many years. In vitro vaccine-matching results showed a poor match (r1-value < 0.3) with the more widely used vaccine strain O1 Manisa and less protection in a challenge test. This paper describes the use of the O3039 vaccine strain as an alternative, either alone or in combination with the O1 Manisa vaccine strain with virulent challenge by a O/ME-SA/Ind-2001d sub-lineage virus from Algeria (O/ALG/3/2014). The experiment included challenge at 7 days post-vaccination (to study protection and emergency use) and 21 days post-vaccination (as in standard potency studies). The results indicated that the O3039 vaccine strain alone, as well as the combination with O1 Manisa, is effective against this strain of the O/ME-SA/Ind/2001d lineage, offering protection from clinical disease even after 7 days post-vaccination with a reduction in viraemia and virus excretion.

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