Brazilian spotted fever

Abstract

Brazilian spotted fever is an infectious disease transmitted by ticks of the genus Amblyomma, having as its main etiological agent the bacterium Rickettsia rickettsii, manifesting through acute febrile condition. The first report about rickettsial disease in Brazil was in 1900, at the Bacteriological Institute of São Paulo, by Dr. Adolfo Lutz. The disease has reemerged and became an important public health problem in Brazil since the 1980s. The number of cases has increased, as well as the expansion of transmission areas, transmission in urban areas, and, in particular, high lethality rates. Rickettsiae are obligate intracellular bacteria predisposed that act as parasites in endothelial cells, which are classically divided in three groups: the typhus group, composed of Rickettsia prowazekii and Rickettsia typhi; The spotted fever group, composed of more than 20 valid species, mainly associated with ticks (e.g., R. rickettsii and R. parkeri); and a more basal group that includes R. bellii, R. monteiroi and R. canadensis. The transmission of Brazilian spotted fever is associated mainly with the ticks Amblyomma sculptum (formerly A. cajennense) and Amblyomma aureolatum. The disease is characterized by fever, myalgia and severe headache, rash, edema in hands and feet, and in some cases shows general symptoms. The disease causes sepsis with pulmonary involvement, which can cause acute respiratory failure, renal problems, such as acute renal failure, haemorrhagic diathesis, neurological lesions with meningitis, encephalitis and jaundice. The cases of death by late diagnosis and treatment usually occur between 5 and 15 days after the onset of symptoms. Diagnosis of the disease is made through the indirect immunofluorescence reaction (IFI), polymerase chain reaction (PCR) and isolation in cell culture. Treatment should initiate at the beginning of clinical signs and stop only two or three days after fever disappearance. Surveillance and control measures must focus on educational actions for the population and health professionals, passing on knowledge about the existence of the disease, its preventive measures, and the importance of sending ticks collected in patients or found in the environment to health centers for identification.