Epidemiological aspects of lice (Menacanthus species) infections in laying hen flocks from the State of Minas Gerais, Brazil.

The epidemiology of chicken lice species such as Menacanthus stramineus, M. cornutus and M. pallidulus were studied during an observational, analytical and sectional survey, to determine predisposing factors for their occurrence in laying hen farms in the State of Minas Gerais, Brazil. A total of 431 houses on 43 farms were visited in 2012. M. cornutus, M. stramineus and M. pallidulus occurred in 20.9%, 11.6% and 11.6% of farms, respectively. The frequencies of occurrence of M. cornutus, M. stramineus and M.pallidulus in poultry houses were 10.4%, 8.8% and 3.7%, respectively. The epidemiological determinants for the occurrence of these species were investigated using Poisson or logistic regression models. The region of the farm, the recent use of acaricides and the presence of birds, such as saffron finch (Sicalis flaveola), feral pigeon (Columba livia) and Guira cuckoo (Guira guira) around the farms were related to the epidemiology of M. cornutus. Infestation by M. stramineus was associated with age of birds, number of birds per cage and the presence of Guira cuckoo and Chopi blackbird (Gnorimopsar chopi) near the poultry houses. The occurrence of M. pallidulus was influenced by the type of facilities, presence of cattle egret (Bubulcus ibis) and free-range domestic hens around the farm. The use of wire mesh nets in the houses and of forced moulting did not influence lice infestation.