Treatment of histomonosis in turkeys with tiamulin.

290 The Veterinary Record, December 22/29, 2007 1971). Transfer of virus is more likely to occur in situations of high humidity. Virus can be recovered from nasal swabs of the people exposed to affected pigs 24 hours previously. FMD virus excretion in breath occurs before the appearance of lesions in affected species and can peak in bovine breath before lesions appear. Veterinary staff closely examining the tongues of such lesion-free cattle on what appear to be uninfected premises can inhale moist bovine breath containing virus. FMD virus might remain in the liquid film lining the respiratory system and in lung residual air. They can be struggling to closely examine the tongues of cattle on a second farm, within a foot of their nostrils, within an hour of leaving the (in fact) infected first premises. I have made the case for veterinary staff to wear effective face masks in such situations in submissions to the Northumberland, Anderson and Royal Society Inquiries and on other occasions. Spread of FMD by people (‘veterinary surgeons six, other persons four’) is recorded in the 1967/68 epizootic (Northumberland Report 1969), but not the mechanism of spread. Presumably, there is no evidence of spread by the human respiratory route occurring in the field, and the authorities are confident that it could not occur in any field situation, otherwise they would have introduced changes to procedure at some point during the past 40 years. Neither could they have considered it prudent to introduce practice indicated by extrapolation of the research findings, nor to pursue the line of research recorded in 1971 if they considered the findings inconclusive. Policy has been unwavering for 40 years. However, DEFRA currently recommend the wearing of face masks by farmers visiting farms during an FMD epizootic. ‘If you do visit other farms wear a face mask if possible, as FMD virus can be carried in human throats’ (sic) (DEFRA 2007). It is not clear why the recommendation applies to farmers only, nor why the recommendation is not a rule. Clarification is essential because we are dealing with a virus that could bankrupt the UK farm livestock industry.