Prevalence and clustering of louse infestation in Queensland sheep flocks

Information provided by wool growers in Queensland, Australia between 1995 and 1997 was used to assess the prevalence and spatial distribution of lous e (Bovicola ovis) infestation in sheep flocks. The estimated prevalence of louse-infested flocks was 40% (95% confidence interval, 35-46%). Although t he prevalence of infestation was higher in western regions (41-50%) compare d to the south region of Queensland (31%), the difference was not statistic ally significant (P > 0.05). Significant (P = 0.02) clustering of infested flocks was detected in the south region where two foci were apparent. We co nclude that Queensland sheep flocks have a moderate prevalence of louse inf estation, and that clustering of infestation is not strong. The control of lice is an industry-wide issue that needs to be addressed by most wool grow ers in Queensland. (C) 1999 Elsevier Science B.V. All rights reserved.