Tuberculosis in alpaca (Lama pacos) on a farm in Ireland. 2. Results of an epidemiological investigation

Irish Veterinary Journal

SJ More⁵  A Kilroy¹  E Costello⁶  EG Ryan²  M Hayes³  J Fagan⁴  PJ Dwyer⁴  DJ Connolly⁷ 

[1]Department of Agriculture, Fisheries and Food, Kilrush Road, Ennis, Co. Clare, Ireland

[2]Section of Herd and Veterinary Public Health, UCD School of Agriculture, Food Science and Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland

[3]Department of Agriculture, Fisheries and Food, Government Offices, Davis Street, Tipperary, Co. Tipperary, Ireland

[4]Department of Agriculture, Fisheries and Food, Regional Veterinary Laboratory, Athlone, Co. Westmeath, Ireland

[5]Centre for Veterinary Epidemiology and Risk Analysis, UCD School of Agriculture, Food Science and Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland

[6]Department of Agriculture, Fisheries and Food, Central Veterinary Research Laboratory, Backweston Campus, Co. Kildare, Ireland

[7]Ballybaun, Gort, Co. Galway, Ireland

关键词: transmission;    Mycobacterium bovis;    Lama pacos;    investigation;    epidemiology;    control;    bovine tuberculosis;    alpaca;   

Others  :  1150140
DOI  :  10.1186/2046-0481-61-8-533

【 摘 要 】

Tuberculosis (TB), due to infection with Mycobacterium bovis was diagnosed in a flock of alpaca in Ireland in 2004. An epidemiological investigation was conducted to identify the risk of TB for farmed alpaca where TB is endemic, the origin of the infection, the potential for alpaca-to-alpaca transmission and appropriate control measures. The investigation focused on the alpaca flock (including the farm, animal movements and breeding, feeding and flock health practice), the disease episode (including animal disease events and subsequent control measures) and TB infection risk in the locality. The TB risk to alpaca is high in areas where infection is endemic in cattle and badgers and where biosecurity is inadequate. It is most likely that the source of infection for the alpaca was a local strain of M. bovis, present in cattle in this area since at least 2001. Genotyping of isolates identified a single variable number tandem repeat (VNTR) profile in both cattle and alpaca in this region. Although a tuberculous badger was also removed from the vicinity, bacterial isolation was not attempted. On this farm, infection in alpaca was probably derived from a common source. Alpaca-to-alpaca transmission seems unlikely. Two broad control strategies were implemented, aimed at the rapid removal of infected (and potentially infectious) animals and the implementation of measures to limit transmission. Tests that proved useful in detecting potentially-infected animals included measurement of the albumin-to-globulin ratio and regular body condition scoring. Skin testing was time consuming and unproductive, and early detection of infected animals remains a challenge. The flock was managed as a series of separate groupings, based on perceived infection risk. No further TB cases have been detected.

   

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Figure 1.

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