HIB

Hib, short for Haemophilus influenzae type b, is a bacterium that can cause invasive diseases, especially in children. It belongs to the genus Haemophilus, is a small Gram-negative, nonmotile coccobacillus, and many strains are encapsulated. The type b capsule is composed of polyribosylribitol phosphate (PRP), which contributes to its virulence and is a target for vaccines.

Clinical significance: Hib disease historically caused meningitis, pneumonia, epiglottitis, septic arthritis, cellulitis, and bacteremia. Before vaccination, Hib disease was a major cause of meningitis in young children.

Vaccination and prevention: The Hib vaccine, a conjugate vaccine targeting the PRP capsule, is part of routine childhood immunization in many countries, and has dramatically reduced the incidence of invasive Hib disease.

Diagnosis and treatment: Suspected Hib disease is diagnosed by culture or PCR from blood, cerebrospinal fluid, or other sterile sites. Antibiotic therapy typically includes beta-lactams such as ceftriaxone or high-dose ampicillin in non-allergic patients; penicillin susceptibility varies by strain. Supportive care for meningitis or sepsis is essential.

Global status: Vaccination programs and herd immunity have significantly reduced disease burden, though Hib remains a concern in areas with limited vaccine access.

Other uses: Hib is primarily known in medical contexts as an abbreviation for Haemophilus influenzae type b; in other contexts, Hib may appear as an acronym or nickname without a single universal meaning.