Burden of invasive disease caused by Haemophilus influenzae type b in Bamako, Mali: impetus for routine infant immunization with conjugate vaccine.
BACKGROUND
Population-based, bacteriologically confirmed disease burden data aid decision makers in African countries pondering whether to introduce Haemophilus influenzae type b (Hib) immunization for infants.


METHODS
A bacteriology laboratory was established in Hopital Gabriel Toure, serving Bamako, Mali. Children age 0-15 years with fever > or =39 degrees C or syndromes compatible with invasive bacterial disease (meningitis, etc.) were eligible. From 2 to 5 mL of blood or relevant body fluid were inoculated into Bactec Ped Plus/F medium for automated culture; body fluids were also inoculated directly onto solid media. Hib was confirmed by standard microbiologic techniques and antibiograms generated by disk diffusion.


RESULTS
From June 1, 2002 to May 31, 2004, 3592 (87.8%) of 4092 children admitted to Hopital Gabriel Toure with high fever or suspected invasive bacterial disease were cultured, including 1745 who were 0-11 months old, 1132 who were 1-4 years old and 715 who were 5-15 years old. Hib was isolated from 207 Bamako children, 81 from blood alone and 124 from cerebrospinal fluid (with or without positive blood culture). Of 207 cases 204 (98.5%) occurred in children younger than age 5 years (annual incidence, 45.2/10) and 159 (77%) in infants age 0-11 months (annual incidence, 158.4/10). Peak incidence (370.0 cases/10) and 12 of 21 Hib deaths occurred in 6- to 7-month-olds. Of the Hib isolates, 11.1% were resistant to ampicillin, 32% to chloramphenicol and 0.5% to ceftriaxone.


CONCLUSIONS
The substantial burden of invasive Hib disease documented in Bamako has prompted the Malian government to introduce routine infant immunization with Hib conjugate.
Sow
Samba O
SO
Centre pour le Développement des Vaccins, Mali (CVD-Mali).
Diallo
Souleymane
S
Campbell
James D
JD
Tapia
Milagritos D
MD
Keita
Tatiana
T
Keita
Mamadou Marouf
MM
Murray
Patrick
P
Kotloff
Karen L
KL
Levine
Myron M
MM
D000293:Adolescent; D016470:Bacteremia / Q000453:epidemiology / Q000382:microbiology / Q000517:prevention & control; D001769:Blood / Q000382:microbiology*; D002555:Cerebrospinal Fluid / Q000382:microbiology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006192:Haemophilus Infections / Q000453:epidemiology* / Q000382:microbiology / Q000517:prevention & control*; D018073:Haemophilus Vaccines / Q000008:administration & dosage; D019741:Haemophilus influenzae type b / Q000276:immunology / Q000302:isolation & purification*; D006801:Humans; D007114:Immunization; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008302:Mali / Q000453:epidemiology; D008583:Meningitis, Haemophilus / Q000453:epidemiology / Q000382:microbiology / Q000517:prevention & control; D011159:Population Surveillance; D018074:Vaccines, Conjugate / Q000008:administration & dosage
D018073:Haemophilus Vaccines; D018074:Vaccines, Conjugate