Invasive Nontypable H. influenzae in Persons with HIV

Haemophilus influenzae, a small gram-negative rod, can be encapsulated or not. Strains lacking a capsule are called nontypable (NTHi). Although rarely causing invasive disease, they are now the leading cause of invasive H. influenzae (incidence, 1.22 cases/100,000 person-years). Chronic lung disease, malignancy, pregnancy, and HIV are common risk factors for invasive disease. Investigators in Atlanta observed an increase in invasive NTHi among men who have sex with men (MSM) with HIV in 2017–2018 and conducted a 10-year retrospective study.

From January 1, 2008 through December 31, 2018, 553 cases of invasive NTHi infection occurred among adults in metropolitan Atlanta (60 in persons with HIV), with a case-fatality ratio of 18%. Incidence wa…