Overview of Haemophilus influenzae and related bacteria
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Transcript of Overview of Haemophilus influenzae and related bacteria
Overview of Haemophilus influenzae and related bacteria
Leonard Mayer, Ph. D.Chief, Meningitis Laboratory
MVPDB/DBD/CDC
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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
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Decline of Hib Meningitis Related to Vaccine Distribution
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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
OR
CA
MN
NM
CO
TN
GA
MD
NYCT
(pop. = 38.6 million)
Participating counties or states
• 2010 5 / 392• 1999+2000 4 / 234• Blood, knee fluid, peritoneal fluid……….
no CSF