Recent Spread of a New Strain (A-Iran-05) of Foot-and-Mouth Disease Virus Type A in the Middle East

Abstract

This report describes the characterization of a new genotype of foot-and-mouth disease virus (FMDV) type A responsible for recent FMD outbreaks in the Middle East. Initially identified in samples collected in 2003 from Iran, during 2005 and 2006 this FMDV lineage (proposed to be named A-Iran-05) spread into Saudi Arabia and Jordan and then further west into Turkey reaching European Thrace in January 2007. Most recently A-Iran-05 has been found in Bahrain. To the east of Iran, it has been recognized in Afghanistan (2004-07) and Pakistan (2006-07). Throughout the region, this lineage is now the predominant genotype of FMDV serotype A sampled, and has appeared to have replaced the A-Iran-96 and A-Iran-99 strains which were previously encountered. In August 2007, a new A-Iran-05 sub-lineage (which we have called A-Iran-05(ARD-07)) was identified in Ardahan, Turkey, close to the border with Georgia. This new sub-lineage appeared to predominate in Turkey in 2008, but has, so far, not been identified in any other country. Vaccine matching tests revealed that the A-Iran-05 viruses are antigenically different to A-Iran-96 and more like A(22). These findings emphasize the importance of undertaking continued surveillance in the Middle East and Central Asia in order to detect and monitor the emergence and spread of new FMDV strains.

Options for control of foot-and-mouth disease: knowledge, capability and policy

“…There are information gaps concerning our ability to predict the performance of vaccines, particularly in Africa, where there is the greatest virus diversity coupled with the least incentive to produce tailored vaccines. The repeated appearance in the Middle East, in countries such as Iran, of new serotype A FMDV variants with altered antigenicity is puzzling, as they appear to lack immediate predecessors further to the east (Arrowsmith 1975;Knowles et al 2009). There is growing evidence that inter-and intra-typic recombination occurs between FMDVs in the field (Tosh et al 2002) and the role this may have in FMDV antigenic shifts needs further examination.…”

Phylogenetic structure of serotype A foot-and-mouth disease virus: global diversity and the Indian perspective

“…So far only one complete VP1-sequence-based global genotyping study including Indian type A viruses, collected between 1977 and 2001, has been published (Tosh et al, 2002). The type A FMDV population was classified into ten major genotypes in that study, with greater than 15 % nucleotide divergence among the genotypes, but that analysis included neither any sequences from Africa nor those of any recent, unique genetic lineages such as 'A Iran 05' from the Middle East (Knowles et al, 2009) or the 'VP3 59 -deletion group' from India (Jangra et al, 2005). To overcome this gap in our knowledge, we attempted an updated and more comprehensive global genotyping to determine the extent of genetic diversity of serotype A and to assess the relationships among the geographically segregated genetic lineages worldwide.…”

Genetic and immunologic relationships between vaccine and field strains for vaccine selection of type A foot-and-mouth disease virus circulating in East Asia

“…Low-priority vaccines may be used as vaccine strains in some countries when regional outbreaks occur. Among these vaccine strains, A22 Iraq is reserved as a high-priority strain [18], while A Iran-05 is a recently added strain in the antigen bank [8]. The A Malaysia 97 strain protects against viruses prevailing in Southeast and East Asia [19] and is a widely used vaccine strain in many regions, including Korea [20].…”

“…Of these, type A has the most diverse variations [6] and is one of the most difficult to prevent [7,8]. Vaccines against FMD can be used for prevention in regions where FMD is likely to occur and for urgent immunity when FMD has occurred.…”