Haemophilus influenzae infection epidemiology and demographics
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Haemophilus influenzae infection Main page |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Overview
During 1980-1990, incidence was 40-100/100,000 children < 5 years old in the United States. Due to routine use of the Hib conjugate vaccine since 1990, the incidence of invasive Hib disease has decreased to 1.3/100,000 children. However, Hib remains a major cause of lower respiratory tract infections in infants and children in developing countries where vaccine is not widely used.
Epidemiology and Demographics
Invasive Hib disease is endemic throughout the world. In countries that have achieved high coverage with routine Hib vaccination programs, Hib disease has become rare. In 2004, most countries in Western Europe, South America, and Central America had initiated routine Hib vaccination (http://www.who.int/mediacentre/factsheets/fs294/en/). However, Hib disease remains common in many developing countries and is estimated to cause 2-3 million cases of serious disease in young children annually.
Hib disease is uncommon in anyone 5 years of age or older. Hib meningitis has a case-fatality ratio of 5-10% in the United States even with initiation of early antimicrobial therapy. As a result of the widespread use of conjugate Hib vaccines, the disease is now uncommon in the United States and is seen primarily in infants too young to be vaccinated and unvaccinated children. In 2004, the estimated annual incidence of Hib was 0.15 cases per 100,000 in children younger than 5 years of age.
Trends
Since licensure of conjugate vaccines for infants (1990) and children (1987), rates of disease among children <5 years old have declined by more than 95% in the United States, while rates for adults have remained stable. However, rates of disease among Alaskan natives remain higher than elsewhere in the United States.