Study of the genetic heterogeneity of SAT-2 foot-and-mouth disease virus in sub-Saharan Africa with specific focus on East Africa

The epidemiology of serotype SAT-2 foot-and-mouth disease was investigated in sub-Saharan Africa by phylogenetic analysis using the 1D gene encoding the major antigenic determinant. Fourteen genotypes were identified of which three are novel and belong to East Africa, bringing the total number of genotypes for that region to eight. The genotypes clustered into three lineages that demonstrated surprising links between East, southern and south-western Africa. One lineage was unique to West Africa. These results established numerous incursions across country borders in East Africa and long term conservation of sequences for periods up to 41 years. Ethiopia, Kenya and Uganda have all experienced outbreaks from more than one unrelated strain, demonstrating the potential for new introductions. The amount of variation observed within this serotype nearly equalled that which was found between serotypes; this has severe implications for disease control using vaccination.

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Comparison of SAT-1 foot-and-mouth disease virus isolates obtained from East Africa between 1971 and 2000 with viruses from the rest of sub-Saharan Africa

Archives of Virology ◽

10.1007/s00705-006-0893-x ◽

2006 ◽

Vol 152 (4) ◽

pp. 797-804 ◽

Cited By ~ 15

Author(s):

M. Sahle ◽

R. M. Dwarka ◽

E. H. Venter ◽

W. Vosloo

Keyword(s):

East Africa ◽

Disease Virus ◽

Foot And Mouth Disease ◽

Mouth Disease ◽

Sub Saharan Africa ◽

Mouth Disease Virus ◽

Foot And Mouth ◽

Sub Saharan ◽

Sat 1 ◽

Virus Isolates

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Infectious diseases of economic importance: Molecular biological characteristics of foot-and-mouth disease viruses collected in Tanzania from 1967 to 2009

Onderstepoort Journal of Veterinary Research ◽

10.4102/ojvr.v79i2.474 ◽

2012 ◽

Vol 79 (2) ◽

Author(s):

Christopher J. Kasanga ◽

R. Sallu ◽

C.A.R. Mpelumbe-Ngeleja ◽

J. Wadsworth ◽

N.P. Ferris ◽

...

Keyword(s):

East Africa ◽

Animal Movement ◽

Genetic Relationships ◽

Foot And Mouth Disease ◽

Mouth Disease ◽

Economic Losses ◽

Reference Laboratory ◽

Mouth Disease Virus ◽

Foot And Mouth ◽

Sub Saharan

Foot-and-mouth disease (FMD) is endemic in Tanzania. Since the first reports in 1954, FMD has caused significant economic losses in the country due to mortality and morbidity of livestock and costs associated with controlling the disease. The aim of this study was to review the serotype and genetic relationships of the FMD virus (FMDV) recovered from outbreaks in Tanzania, and compare them with viruses detected from elsewhere in the sub-Saharan region. At the World Reference Laboratory for foot-and-mouth disease (WRLFMD), a total of 106 FMD viruses have been isolated from samples collected between 1967 and 2009 from northern, southern, eastern and central parts of Tanzania. The presence of FMDV was determined by laboratory methods such as VI, CF, antigen ELISA and RT-PCR. Phylogenies of VP1 sequences were determined by the Neighbour-joining method. Foot-and-mouth disease virus SAT1 was the most frequent serotype (46.2%; n = 49) isolated in Tanzania followed by O (26.4%; n = 27), A (14.1%; n = 15) and SAT 2 (11.3%; n = 13). Genotyping showed that type O viruses fell into either the EAST AFRICA 1 (EA-1) or EA-2 topotypes, type A’s into the AFRICA topotype (genotype I), type SAT 1’s into topotype I and type SAT 2’s into topotype IV. This study reveals that serotypes A, O, SAT1 and SAT2 cause FMD outbreaks in Tanzania. Recent samples from outbreaks in 2008, 2009 and 2010 have been typed as serotypes A, O, SAT1 and SAT2. Phylogenetic analysis of FMDV isolates from Tanzania showed that they are genetically related to lineages and topotypes from West and East Africa. In Tanzania, lack of comprehensive animal movement records and inconsistent vaccination programs make it difficult to determine the exact source of FMD outbreaks or to trace the transmission of the disease over time. Therefore, further collection and analysis of samples from domestic and wild animals, together with improved local epidemiological investigation of FMD outbreaks is required to elucidate the complex epidemiology of FMD in the sub-Saharan region.

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Reconstructing Geographical Movements and Host Species Transitions of Foot-and-Mouth Disease Virus Serotype SAT 2

mBio ◽

10.1128/mbio.00591-13 ◽

2013 ◽

Vol 4 (5) ◽

Cited By ~ 25

Author(s):

Matthew D. Hall ◽

Nick J. Knowles ◽

Jemma Wadsworth ◽

Andrew Rambaut ◽

Mark E. J. Woolhouse

Keyword(s):

Middle East ◽

Disease Virus ◽

North Africa ◽

Host Species ◽

Foot And Mouth Disease ◽

Mouth Disease ◽

Sub Saharan Africa ◽

Mouth Disease Virus ◽

Foot And Mouth ◽

Sub Saharan

ABSTRACT Of the three foot-and-mouth-disease virus SAT serotypes mainly confined to sub-Saharan Africa, SAT 2 is the strain most often recorded in domestic animals and has caused outbreaks in North Africa and the Middle East six times in the last 25 years, with three apparently separate events occurring in 2012. This study updates the picture of SAT 2 phylogenetics by using all available sequences for the VP1 section of the genome available at the time of writing and uses phylogeographic methods to trace the origin of all outbreaks occurring north of the Sahara since 1990 and identify patterns of spread among countries of endemicity. Transitions between different host species are also enumerated. Outbreaks in North Africa appear to have origins in countries immediately south of the Sahara, whereas those in the Middle East are more often from East Africa. The results of the analysis of spread within sub-Saharan Africa are consistent with it being driven by relatively short-distance movements of animals across national borders, and the analysis of host species transitions supports the role of the African buffalo (Syncerus caffer) as an important natural reservoir. IMPORTANCE Foot-and-mouth disease virus is a livestock pathogen of major economic importance, with seven distinct serotypes occurring globally. The SAT 2 serotype, endemic in sub-Saharan Africa, has caused a number of outbreaks in North Africa and the Middle East during the last decades, including three separate incidents in 2012. A comprehensive analysis of all available RNA sequences for SAT 2 has not been published for some years. In this work, we performed this analysis using all previously published sequences and 49 newly determined examples. We also used phylogenetic methods to infer the source country for all outbreaks occurring outside sub-Saharan Africa since 1990 and to reconstruct the spread of viral lineages between countries where it is endemic and movements between different host species.

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Endemic foot and mouth disease: pastoral in-herd disease dynamics in sub-Saharan Africa

Scientific Reports ◽

10.1038/s41598-019-53658-5 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 2

Author(s):

I. McLachlan ◽

G. Marion ◽

I. J. McKendrick ◽

T. Porphyre ◽

I. G. Handel ◽

...

Keyword(s):

Disease Burden ◽

Foot And Mouth Disease ◽

Mouth Disease ◽

Sub Saharan Africa ◽

Herd Level ◽

Population Turnover ◽

Foot And Mouth ◽

Sub Saharan ◽

Multiple Strains ◽

Reduced Risk

AbstractFoot and mouth disease (FMD) burden disproportionally affects Africa where it is considered endemic. Smallholder livestock keepers experience significant losses due to disease, but the dynamics and mechanisms underlying persistence at the herd-level and beyond remain poorly understood. We address this knowledge gap using stochastic, compartmental modelling to explore FMD virus (FMDV) persistence, outbreak dynamics and disease burden in individual cattle herds within an endemic setting. Our analysis suggests repeated introduction of virus from outside the herd is required for long-term viral persistence, irrespective of carrier presence. Risk of new disease exposures resulting in significant secondary outbreaks is reduced by the presence of immune individuals giving rise to a period of reduced risk, the predicted duration of which suggests that multiple strains of FMDV are responsible for observed yearly herd-level outbreaks. Our analysis suggests management of population turnover could potentially reduce disease burden and deliberate infection of cattle, practiced by local livestock keepers in parts of Africa, has little effect on the duration of the reduced risk period but increases disease burden. This work suggests that FMD control should be implemented beyond individual herds but, in the interim, herd management may be used to reduced FMD impact to livestock keepers.

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Predicting antigenic sites on the foot-and-mouth disease virus capsid of the South African Territories types using virus neutralization data

Journal of General Virology ◽

10.1099/vir.0.032839-0 ◽

2011 ◽

Vol 92 (10) ◽

pp. 2297-2309 ◽

Cited By ~ 26

Author(s):

F. F. Maree ◽

B. Blignaut ◽

J. J. Esterhuysen ◽

T. A. P. de Beer ◽

J. Theron ◽

...

Keyword(s):

South African ◽

Disease Virus ◽

Foot And Mouth Disease ◽

Mouth Disease ◽

Sub Saharan Africa ◽

Antigenic Sites ◽

Mouth Disease Virus ◽

Virus Serotype ◽

Antigenic Properties ◽

Foot And Mouth

Foot-and-mouth disease virus (FMDV) outer capsid proteins 1B, 1C and 1D contribute to the virus serotype distribution and antigenic variants that exist within each of the seven serotypes. This study presents phylogenetic, genetic and antigenic analyses of South African Territories (SAT) serotypes prevalent in sub-Saharan Africa. Here, we show that the high levels of genetic diversity in the P1-coding region within the SAT serotypes are reflected in the antigenic properties of these viruses and therefore have implications for the selection of vaccine strains that would provide the best vaccine match against emerging viruses. Interestingly, although SAT1 and SAT2 viruses displayed similar genetic variation within each serotype (32 % variable amino acids), antigenic disparity, as measured by r1-values, was less pronounced for SAT1 viruses compared with SAT2 viruses within our dataset, emphasizing the high antigenic variation within the SAT2 serotype. Furthermore, we combined amino acid variation and the r1-values with crystallographic structural data and were able to predict areas on the surface of the FMD virion as antigenically relevant. These sites were mostly consistent with antigenic sites previously determined for types A, O and C using mAbs and escape mutant studies. Our methodology offers a quick alternative to determine antigenic relevant sites for FMDV field strains.

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Rapid Engineering of Foot-and-Mouth Disease Vaccine and Challenge Viruses

Journal of Virology ◽

10.1128/jvi.00155-17 ◽

2017 ◽

Vol 91 (16) ◽

Cited By ~ 11

Author(s):

Seo-Yong Lee ◽

Yeo-Joo Lee ◽

Rae-Hyung Kim ◽

Jeong-Nam Park ◽

Min-Eun Park ◽

...

Keyword(s):

Vaccine Strain ◽

Antigenic Variation ◽

Foot And Mouth Disease ◽

Vaccine Virus ◽

Mouth Disease ◽

Economic Losses ◽

Gene Encoding ◽

Virus Challenge ◽

Mouth Disease Virus ◽

Foot And Mouth

ABSTRACT There are seven antigenically distinct serotypes of foot-and-mouth disease virus (FMDV), each of which has intratypic variants. In the present study, we have developed methods to efficiently generate promising vaccines against seven serotypes or subtypes. The capsid-encoding gene (P1) of the vaccine strain O1/Manisa/Turkey/69 was replaced with the amplified or synthetic genes from the O, A, Asia1, C, SAT1, SAT2, and SAT3 serotypes. Viruses of the seven serotype were rescued successfully. Each chimeric FMDV with a replacement of P1 showed serotype-specific antigenicity and varied in terms of pathogenesis in pigs and mice. Vaccination of pigs with an experimental trivalent vaccine containing the inactivated recombinants based on the main serotypes O, A, and Asia1 effectively protected them from virus challenge. This technology could be a potential strategy for a customized vaccine with challenge tools to protect against epizootic disease caused by specific serotypes or subtypes of FMDV. IMPORTANCE Foot-and-mouth disease (FMD) virus (FMDV) causes significant economic losses. For vaccine preparation, the selection of vaccine strains was complicated by high antigenic variation. In the present study, we suggested an effective strategy to rapidly prepare and evaluate mass-produced customized vaccines against epidemic strains. The P1 gene encoding the structural proteins of the well-known vaccine virus was replaced by the synthetic or amplified genes of viruses of seven representative serotypes. These chimeric viruses generally replicated readily in cell culture and had a particle size similar to that of the original vaccine strain. Their antigenicity mirrored that of the original serotype from which their P1 gene was derived. Animal infection experiments revealed that the recombinants varied in terms of pathogenicity. This strategy will be a useful tool for rapidly generating customized FMD vaccines or challenge viruses for all serotypes, especially for FMD-free countries, which have prohibited the import of FMDVs.

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Challenges and Economic Implications in the Control of Foot and Mouth Disease in Sub-Saharan Africa: Lessons from the Zambian Experience

Veterinary Medicine International ◽

10.1155/2014/373921 ◽

2014 ◽

Vol 2014 ◽

pp. 1-12 ◽

Cited By ~ 11

Author(s):

Y. Sinkala ◽

M. Simuunza ◽

D. U. Pfeiffer ◽

H. M. Munang’andu ◽

M. Mulumba ◽

...

Keyword(s):

Economic Impact ◽

Foot And Mouth Disease ◽

Movement Control ◽

Personal Communication ◽

Mouth Disease ◽

Control Measures ◽

Sub Saharan Africa ◽

Economic Implications ◽

Foot And Mouth ◽

Sub Saharan

Foot and mouth disease is one of the world’s most important livestock diseases for trade. FMD infections are complex in nature and there are many epidemiological factors needing clarification. Key questions relate to the control challenges and economic impact of the disease for resource-poor FMD endemic countries like Zambia. A review of the control challenges and economic impact of FMD outbreaks in Zambia was made. Information was collected from peer-reviewed journals articles, conference proceedings, unpublished scientific reports, and personal communication with scientists and personal field experiences. The challenges of controlling FMD using mainly vaccination and movement control are discussed. Impacts include losses in income of over US$ 1.6 billion from exports of beef and sable antelopes and an annual cost of over US$ 2.7 million on preventive measures. Further impacts included unquantified losses in production and low investment in agriculture resulting in slow economic growth. FMD persistence may be a result of inadequate epidemiological understanding of the disease and ineffectiveness of the control measures that are being applied. The identified gaps may be considered in the annual appraisal of the FMD national control strategy in order to advance on the progressive control pathway.

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Phylogeographic analysis and identification of factors impacting the diffusion of Foot-and-Mouth disease virus in Africa

10.1101/358044 ◽

2018 ◽

Cited By ~ 2

Author(s):

Florian Duchatel ◽

Mark Bronsvoort ◽

Samantha Lycett

Keyword(s):

Foot And Mouth Disease ◽

Mouth Disease ◽

Sub Saharan Africa ◽

Eastern Africa ◽

Economic Losses ◽

Disease Epidemiology ◽

Fmd Virus ◽

Serotype O ◽

Mouth Disease Virus ◽

Foot And Mouth

ABSTRACTFoot and mouth disease (FMD) is endemic in sub-Saharan Africa and can lead to important and continuous economic losses for affected countries. Due to the complexity of the disease epidemiology and the lack of data there is a need to use inferential computational approaches to fill the gaps in our understanding of the circulation of FMD virus on this continent. Using a phylogeographic approach we reconstructed the circulation of FMD virus serotypes A, O and SAT2 in Africa and evaluated the influence of potential environmental and anthropological predictors of virus diffusion. Our results show that over the last hundred year the continental circulation of the tree serotypes was mainly driven by livestock trade. Whilst our analyses show that the serotypes A and O were introduced in Africa trough livestock trades, the SAT2 serotype probably originates from African wildlife population. The circulation of serotype O in eastern Africa is impacted by both indirect transmission through persistence in the environment and anthropological activities such as cattle movements.

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