Brazilian purpuric fever (BPF) is an illness of children caused by the bacterium Haemophilus influenzae biogroup aegyptius which is ultimately fatal due to sepsis. BPF was first recognized in the São Paulo state of Brazil in 1984. At this time, young children between the ages of 3 months and 10 years were contracting a strange illness which was characterized by high fever and purpuric lesions on the body. These cases were all fatal, and originally thought to be due to meningitis. It was not until the autopsies were conducted that the cause of these deaths was confirmed to be infection by H. influenzae aegyptius. Although BPF was thought to be confined to Brazil, other cases occurred in  Australia and the United States during 1984–1990. Haemophilus species are non-spore-forming gram-negative coccobacilli . They lack motility and are aerobic or facultatively anaerobic. They require preformed growth factors that are present in blood, specifically hemin (X factor) and NAD or NADP (V factor). The bacterium grows best at 35–37 °C and has an optimal pH of 7.6. Haemophilus species are obligate parasites and are part of the normal flora of the human upper respiratory tract. Presentation
In documented BPF cases, the symptoms include high fever (101.3 °F/38,5 °C or higher), nausea, vomiting, severe abdominal pain, septic shock, and ultimately death. A history of conjunctivitis 30 days prior to the onset of fever was also present in the documented BPF cases.
This hypothesis is supported by the isolation of from both the conjunctiva and oropharynx of documented BPF cases with H. aegyptius bacteremia. Possible virulence factors of H. aegyptius include lipooligosaccharides (LOS), capsular polysaccharides, pilus proteins (mediates adhesion to mucosal membrane), immunoglobulin A1 (IgA1), membrane associated proteins, and extracellular proteins. In a study conducted by Barbosa et al., a 60 kilodalton hemagglutinating extracellular product was suggested to be the major pathogenic factor linked to the hemorrhagic manifestations of BPF. This molecule was found to be absorbable by human O-type erythrocytes. After the molecule had been injected into rabbits, they showed reactions similar to that of BPF patients. Further research is being conducted to determine the mechanisms involved with the other virulence factors of H. aegyptius. The overall pathogenesis of BPF probably involves multiple steps and a number of bacterial factors. Diagnosis
A positive BPF diagnosis includes the clinical symptoms (mainly the fever, purpuric lesions, and rapid progression of the disease), isolation of Haemophilus Influenzae Biogroup aegyptius from blood, and negative laboratory tests for Neisseria meningitidis. The negative tests for Neisseria meningitidis rules out the possibility of the symptoms being caused by meningitis, since the clinical presentations of the two diseases are similar. Prevention
The basic method for control of the conjunctivitis includes proper hygiene and care for the affected eye. If the conjunctivitis is found to be caused by H. aegyptius Biogroup III then prompt antibiotic treatment preferably with rifampin has been shown to prevent progression to BPF.