Six cases of malignant catarrhal fever (MCF) observed from 2000 to 2005, and one outbreak occurred from 1986 to 1987 are reported in the state of Paraíba, northeastern Brazil. In one case the disease was diagnosed clinically and in 5 cases also by histopathology consisting of diffuse vasculitis with fibrinoid degeneration and perivascular infiltration of mononuclear cells in many organs. In 5 cases only one cattle was affected, and in one, 2 out of 6 cattle were affected. Five cases occurred from May to August, at the end of the raining season during the lambing season. Clinical signs and pathology were characteristics of the disease. Four cattle died after a clinical manifestation period of 5-8 days, another was euthanized after 40 days, and another recovered. The outbreak reported in the municipality of Taperoá occurred from August 1986 to December 1987, with a morbidity rate of 8.22% and a fatality rate of 100%. The disease occurred after the introduction of a ram in the farm. The outbreak was controlled after the slaughter of all sheep in the farm. These results demonstrated that MCF is endemic in Paraíba, and outbreaks with high morbidity and fatality rates can also occur. As it was previously reported in the state of Rio Grande do Sul few affected cattle can recovered. Because the 6 cases of MCF represent 3.1% of the 190 cases of different diseases diagnosed by the Veterinary Hospital from 2000 to 2005, it can be estimated that the disease affects 0.125% of cattle population in the state of Paraíba.
Malignant catarrhal fever; vasculitis; diseases of cattle; viral diseases; semiarid
