title: Changes in serotype distribution of Haemophilus influenzae meningitis isolates identified through laboratory-based surveillance following routine childhood vaccination against H. influenzae type b in Brazil.
abstract: Following routine childhood vaccination against Haemophilus influenzae type b (Hib) disease in Brazil in 1999, passive laboratory surveillance reported increasing numbers of non-b serotypes and nontypeable H. influenzae (NTHi) from meningitis cases. To characterize this increase, we analyzed data on 3910 H. influenzae isolated from cerebrospinal fluid or blood from meningitis cases that were sent to the national reference laboratory for serotyping from 1990 to 2008. Hib accounted for 98% of H. influenzae meningitis isolates received during 1990-1999 versus 59% during 2000-2008, while non-b serotypes increased from 1% to 19% and NTHi increased from 2% to 22% of H. influenzae isolates received during the two periods. Higher proportions of non-b serotypes and NTHi than Hib were isolated from blood rather than cerebrospinal fluid. Estimated incidence rates for H. influenzae meningitis for Sao Paulo state remained below 1 case per million population during 2000-2008, although annual incidence of NTHi meningitis (mean, 0.03 cases per 100,000 population) increased in several age groups. Changes in surveillance for H. influenzae following introduction of Hib conjugate vaccine likely contributed to increased numbers of non-b and nontypeable H. influenzae meningitis isolates received at the national reference laboratory.
authors.affiliation: Bacteriology Branch, Instituto Adolfo Lutz, Secretary of Health of the State of São Paulo, Brazil. cobo@ial.sp.gov.br
authors.forename: Rosemeire C
authors.initials: RC
authors.lastname: Zanella
authors.forename: Sérgio
authors.initials: S
authors.lastname: Bokermann
authors.forename: Ana Lúcia S S
authors.initials: AL
authors.lastname: Andrade
authors.forename: Brendan
authors.initials: B
authors.lastname: Flannery
authors.forename: Maria Cristina de C
authors.initials: MC
authors.lastname: Brandileone
mesh_terms: D000293:Adolescent; D000328:Adult; D001938:Brazil / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D018073:Haemophilus Vaccines / Q000008:administration & dosage*; D019741:Haemophilus influenzae type b / Q000145:classification* / Q000302:isolation & purification; D006801:Humans; D015994:Incidence; D007223:Infant; D032541:Mass Vaccination; D008583:Meningitis, Haemophilus / Q000097:blood / Q000134:cerebrospinal fluid / Q000453:epidemiology* / Q000382:microbiology*; D008875:Middle Aged; D011159:Population Surveillance; D012703:Serotyping; D014611:Vaccination; D055815:Young Adult
chemical_list: D018073:Haemophilus Vaccines