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

19801981

19821983

19841985

19861987

19881989

19901991

19921993

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5

10

15

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25

30

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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