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Overview of Haemophilus influenzae and related bacteria. Leonard Mayer, Ph. D. Chief, Meningitis Laboratory MVPDB/DBD/CDC. Haemophilus influenzae (Hi). gram negative coccobacillus Serotypes a-f, and HiNT Meningitis, pneumonia, sepsis, otitis media, among others
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Overview of Haemophilus influenzae and related bacteria Leonard Mayer, Ph. D. Chief, Meningitis Laboratory MVPDB/DBD/CDC
Haemophilus influenzae (Hi) • gram negative coccobacillus • Serotypes a-f, and HiNT • Meningitis, pneumonia, sepsis, otitis media, among others • Vaccine for serotype b (Hib) • Non-b Hi cases are more visible after Hib vaccine implementation
Haemophilus influenzae (Hi) • Severe bacterial infection, particularly among infants • Before the introduction of effective vaccines, Hi type b (Hib) was a leading cause of bacterial meningitis in children <5 years • Introduction of conjugate vaccines in 1991 in U.S. led to rapid decline in Hi type b disease • Most disease in the United States and other developed countries is now due to non-b serotypes and nontypeable (NT) strains • Now in U.S., NT currently most common; serotypes a-f less common
1980 30 20 25 15 20 Doses distributed (millions) 15 10 10 5 5 0 0 1981 1983 1984 1986 1987 1989 1990 1992 1993 1982 1985 1991 1988 Decline of Hib Meningitis Related to Vaccine Distribution Incidence (per 100,000) Year Polysaccharide Vaccine Conjugate Vaccine
H. influenzae (Hi) Serotypes Encapsulated Unencapsulated Type b (Hib) Type non - b (a, c, d, e, f) Nontypeable (NT)
Encapsulated vs. Unencapsulated • Capsule related to virulence • NT genetically diverse • NT viewed as colonizers
H. aegypitus • 1st described by Robert Koch while investigating cholera in Egypt in 1883 • Causes conjuntivitis (pink eye); purulent with no permanent damage • <1986 never isolated from sterile site • Now called Haemophilus influenzae biogroup aegyptius
Brasilian Purpuric Fever (BPF) Harrison ClinMicroRev 21:594 ‘08
“He got more purple . . . . I was in a room with him and the doctor asked me to leave so I wouldn’t see. And right after the doctor came out and said he had died. It was really fast. The disease didn’t even last 24 hours. It was really fast.” Mother of a child with BPF —What’s Killing the Children?, NOVA documentary, WGBHTV, Boston, MA, 18 December 1990.
Same unique clone by: • Plasmid restriction profile • SDS-PAGE protein profile • rRNA “ribotyping” • MLEE • Seroagglutination • Antibiotic susceptibility testing
HiNT BPF
H. haemolyticus • “H. haemolyticus is nonpathogenic, in contrast to the pathogenic H. influenzae.” Wikipedia • Common in carriage isolates • Biochemically similar to H. influenzae • Require hemin (factor X) and NAD (factor V) • Lose hemolytic activity by yet un known mechanism
Active Bacterial Core Surveillance (ABCs) Sites, 2004 (pop. = 38.6 million) OR MN NY CT CA CO MD TN NM GA Participating counties or states
2010 5 / 392 • 1999+2000 4 / 234 • Blood, knee fluid, peritoneal fluid………. no CSF