![]() ![]() influenzae strains are unaffected by the Hib vaccine and cause ear infections ( otitis media), eye infections ( conjunctivitis), and sinusitis in children, and are associated with pneumonia. However, Hib remains a major cause of lower respiratory tract infections in infants and children in developing countries where the vaccine is not widely used. since 1990, the incidence of invasive Hib disease has decreased to 1.3/100,000 in children. ![]() ĭue to routine use of the Hib vaccine in the U.S. On occasion, it causes cellulitis, osteomyelitis, and infectious arthritis. influenzae type b (Hib) causes bacteremia, pneumonia, epiglottitis and acute bacterial meningitis. influenzae type b was responsible for more than 80% of aggressive infections, before the introduction of the vaccine. In healthy children under the age of 5, H. influenzae seems to occur in humans only. Haemophilus influenzae type b (Hib) infection They infect the host by sticking to the host cell using trimeric autotransporter adhesins. influenzae are opportunistic pathogens that is, they usually live in their host without causing disease, but cause problems only when other factors (such as a viral infection, reduced immune function or chronically inflamed tissues, e.g. Vaccination with Hib conjugate vaccine is effective in preventing Hib infection but does not prevent infection with NTHi strains. The unencapsulated strains are almost always less invasive however, they can produce an inflammatory response in humans, which can lead to many symptoms. Their capsule allows them to resist phagocytosis and complement-mediated lysis in the nonimmune host. influenzae infections is not completely understood, although the presence of the polyribosyl ribitol phosphate (PRP) capsule in encapsulated type b (Hib), a serotype causing conditions such as epiglottitis, is known to be a major factor in virulence. Unencapsulated strains are termed nontypable (NTHi) because they lack capsular serotypes however, they can be classified by multilocus sequence typing. Genetic diversity among unencapsulated strains is greater than within the encapsulated group. The six generally recognized types of encapsulated H. Encapsulated strains were classified on the basis of their distinct capsular antigens. influenzae were defined: the unencapsulated strains and the encapsulated strains. 8 Likely protective role of transformation. ![]()
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