Haemophilus influenzae biogroup aegyptius (Hae) is a causative agent of acute and often purulent conjunctivitis, more commonly known as pink eye.
During the mid-1980s to early 1990s, a highly virulent clonal group of Haemophilus aegyptius, localized in and around the São Paulo state of Brazil, was found to be responsible for Brazilian purpuric fever, an acute septicemic fulminant illness affecting children.
[1] In 1984, 10 children in the town of Promissão in Sao Paulo, Brazil, developed a sudden and severe illness after a recent bout (within the last 30 days) of conjunctivitis – Brazilian Purpuric Fever (BPF).
After discovering another, and very similar, outbreak in Londrina (located a little under 200 miles from Promissao), scientists determined that a single H. influenzae biogroup aegyptius clone is responsible for all cases of BPF.
[1] In his classic paper, Weeks characterizes H. aegyptius by its high contagiousness, direct transmission from patient to volunteer, pathogenesis, pathology, treatment and epidemiology.
Premature use of this antibiotic without further studies (and the use of rifampin to treat sporadic cases) could result in a potential development of resistance and excessive expenses.
These control subjects did not develop Brazilian Purpuric Fever, and therefore were probably not carrying the more dangerous BPF clone of H. influenzae biogroup aegyptius.
Because children are the main victims of BPF, it is assumed that day care facilities may serve as settings for the transmission of H. influenzae biogroup aegyptius conjunctivitis.
[8] For a long time, H. aegyptius has been known to cause seasonal epidemics of acute purulent conjunctivitis (minor cases of pink eye).
Bengtson, while studying H. aegyptius in Georgia, reported that the majority of cases of acute conjunctivitis occurred during the breeding season of the eye gnat, Hippelates pusio.