health
H. influenzae disease rising among adults, especially the elderly
■ A study shows that seniors have a 12-fold greater risk of infection than younger adults, highlighting the need for a vaccine.
By Christine S. Moyer — Posted Aug. 23, 2011
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Due to the success of the childhood Haemophilus influenzae type b vaccine, the disease that once was the leading cause of bacterial meningitis in youths under age 5 is almost nonexistent in children today.
Invasive H. influenzae disease, however, is on the rise among adults, a study shows.
The study, published online Aug. 10 in the Centers for Disease Control and Prevention's Emerging Infectious Diseases, highlights the importance of developing an adult H. influenzae vaccine. Particular attention should be paid to preventing the condition among the elderly, who had the highest incidence of disease, said lead study author Matthew P. Rubach, MD.
Adults 65 and older had a 12-fold greater risk of invasive disease than did patients 18 to 34, the study shows (link). Clinical syndromes of such invasive disease include meningitis, bacteremia or sepsis, and pneumonia, according to the CDC.
"No one thinks much about Haemophilus influenzae in adults," said Dr. Rubach, a fellow in the Division of Infectious Diseases at Duke University Medical Center in Durham, N.C.
He said physicians spend more time learning how to identify and treat pneumococcal infections and meningococcal infections in adults than H. influenzae. "But the fact that [invasive H. influenzae disease] is more prevalent in adults than meningococcus and is just as deadly is an important finding and one that's significant for pursuing the development of vaccines" to prevent this condition in adults, Dr. Rubach said.
Researchers examined data on 121 cases of invasive H. influenzae among adults 18 and older that were reported to the Utah Dept. of Health between 1998 and 2008. They also reviewed 94 cases among adults who were patients in Utah's Intermountain Healthcare system from 1999 to 2008.
They found that in both reviews invasive H. influenzae disease rates increased among adults.
Adults 65 and older accounted for more than half of the cases, according to Utah Dept. of Health data. Twenty-nine percent of infections in this age group were fatal.
Overall, a majority of the infected patients had bacteremia, and 12.4% had meningitis. Twenty-two percent of all infected adults died, the Dept. of Health figures show.