Detection and genetic characterization of foot-and-mouth disease viruses in samples from clinically healthy animals in endemic settings

Abstract

A total of 1501 oral swab samples from Pakistan, Afghanistan and Tajikistan were collected from clinically healthy animals between July 2008 and August 2009 and assayed for the presence of foot-and-mouth disease virus (FMDV) RNA. The oral swab samples from two (of four) live animal markets in Pakistan (n = 245), one (of three) live animal market in Afghanistan (n=61) and both the live animal markets in Tajikistan (n=120) all tested negative. However, 2 of 129 (∼2%) samples from Gondal and 11 of 123 (9%) from Chichawatni markets in Pakistan were positive for FMDV RNA. Similarly, 12 of 81 (15%) samples from Kabul and 10 of 20 (50%) from Badakhshan in Afghanistan were found to be positive. Serotypes A and O of FMDV were identified within these samples. Oral swab samples were also collected from dairy colonies in Harbanspura, Lahore (n=232) and Nagori, Karachi (n=136), but all tested negative for FMDV. In the Landhi dairy colony, Pakistan, a cohort of 179 apparently healthy animals was studied. On their arrival within the colony, thirty-nine (22%) of these animals were found positive for FMDV RNA (serotype A was identified), while 130 (72.6%) had antibodies to FMDV non-structural proteins. Thus, newly introduced animals may be a significant source of the disease in the colony. Only two animals from the cohort were detected as becoming positive for FMDV RNA during a follow-up period of 4months; however, only 10 animals remained negative for anti-NSP antibodies during this period.

Evidence for multiple recombination events within foot‐and‐mouth disease viruses circulating in West Eurasia

“…Oral swab and epithelial samples were collected from apparently healthy animals and also from suspected clinical cases of FMD in Pakistan and Afghanistan under an Italian‐funded FAO Regional Project (GTFS/INT/907/ITA), as described previously (Jamal et al, ; Jamal et al, ). In addition, samples from suspected cases of FMD were collected in Iran and Turkey.…”

Foot-and-mouth disease: past, present and future

“…Vaccination alone may well not be able to contain the disease unless it is coupled with restrictions on animal movement. Control of animal movements is, however, complicated by many factors including social customs [52], religious festivals [17], trade of animals in live animal markets [10] and both formal and informal animal movement. Progression from Stage 4 to 5, and from Stage 5 to Pathway completion, would be through the existing official OIE recognition processes of freedom from FMD with or without vaccination, respectively.…”

Genetic diversity and comparison of diagnostic tests for characterization of foot‐and‐mouth disease virus strains from Pakistan 2008–2012

“…Clinically infected animals develop fever, ptyalism, vesicles and later erosions in and around the mouth, on the feet and teats and lameness (Arzt, Juleff, Zhang, & Rodriguez, ; Arzt, Baxt et al., ). Most infected animals clear the virus by 21 days post‐infection (DPI); however, approximately 50% of infected ruminants continue to asymptomatically shed virus in oropharyngeal fluids beyond 28 DPI and are considered long‐term carriers (Alexandersen, Zhang, & Donaldson, ; Jamal et al., ; Klein, ; Stenfeldt, Eschbaumer, et al., ; Stenfeldt, Pacheco, et al., ).…”