Disease caused by one of the two poultry-adapted strains of Salmonella bacteria, Salmonella Pullorum, this usually only causes mortality in birds up to 3 weeks of age. Occasionally it can cause losses in adult birds, usually brown-shell egg layers. It affects chickens most commonly, but also infects turkeys, game birds, guinea fowls, sparrows, parrots, ring doves, ostriches and peafowl. It still occurs worldwide in non-commercial poultry but is now rare in most commercial systems.