Characterisation of foot-and-mouth disease virus strains circulating in Turkey during 1996–2004

Abstract

Two genotypes of foot-and-mouth disease virus serotype A were identified as the cause of disease outbreaks in Turkey during 1996-2004, while serotype O strains, identified during the same period, seem to represent an evolutionary continuum, and Asia1 strains were only rarely identified. The data presented are concordant with the conclusion that serotype A strains are repeatedly introduced to Turkey from the east and circulate only transiently in farming communities, while type O strains persist and re-emerge from endemic areas of Turkey. The co-circulation of strains belonging to two A genotypes for 6 years, as observed in the present study, is a remarkable difference compared to previous decades in which only one A genotype was transiently circulating, successively being replaced by others. This co-circulation was observed in spite of enforcement countrywide of biannual vaccination of more than 50% of the cattle during the same period. Mean r(1) values of 0.70 +/- 0.19 and 0.39 +/- 0.04 found for A96 and A99 isolates, respectively, compared to the A96 vaccine component reveal antigenic differences but also imply that the vaccine in use in Turkey should provide protection against both genotypes. It is suggested that further studies to reveal the nature of the difference in epidemiological dynamics of type A and type O strains might lead to an understanding of the measures required to control foot-and-mouth disease in islands of persistent circulation.

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

“…1d) and A-Iran-99 ( Fig. 1c) (Klein et al, 2007;Parlak et al, 2007). Based on samples and information submitted to the FAO World Reference Laboratory for FMD (WRLFMD), the distribution of the virus isolates belonging to A-Iran-05 is shown in Fig.…”

Evolutionary analysis of serotype A foot-and-mouth disease viruses circulating in Pakistan and Afghanistan during 2002–2009

“…A 22 , IRN87, IRN96, IRN99, A 15 and A-Iran05. The IRN96 and IRN99 lineages have been circulating in Iran and Turkey (Klein et al , 2006; Parlak et al , 2007) but have never been detected in Pakistan and Afghanistan. However, this could be due to the lack of sampling from these countries.…”

The molecular epidemiology of Foot-and-Mouth Disease virus serotypes A and O from 1998 to 2004 in Turkey

“…The structural alignment of IRN99 and IRN96 (Figure 6) revealed significant conformational differences within this important immuno-dominant protein suggesting an immunological advantage of IRN 99 strains given that a member of the IRN96 is used as a vaccine component. However, antigenic comparisons based on virus neutralisation analysis and epidemiological data previously reported [12] do not substantiate such a conclusion.…”