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Invasive disease caused by Haemophilus influenzae in Sweden 1997-2009; evidence of increasing incidence and clinical burden of non-type b strains

Resman, Fredrik LU ; Ristovski, Mikael LU ; Ahl, Jonas LU ; Forsgren, Arne LU ; Gilsdorf, J. R.; Jasir, Aftab LU ; Kaijser, B.; Kronvall, G. and Riesbeck, Kristian LU (2011) In Clinical Microbiology and Infection 17(11). p.1638-1645
Abstract
Introduction of a conjugated vaccine against encapsulated Haemophilus influenzae type b (Hib) has led to a dramatic reduction of invasive Hib disease. However, an increasing incidence of invasive disease by H. influenzae non-type b has recently been reported. Non-type b strains have been suggested to be opportunists in an invasive context, but information on clinical consequences and related medical conditions is scarce. In this retrospective study, all H. influenzae isolates (n = 410) from blood and cerebrospinal fluid in three metropolitan Swedish regions between 1997 and 2009 from a population of approximately 3 million individuals were identified. All available isolates were serotyped by PCR (n = 250). We observed a statistically... (More)
Introduction of a conjugated vaccine against encapsulated Haemophilus influenzae type b (Hib) has led to a dramatic reduction of invasive Hib disease. However, an increasing incidence of invasive disease by H. influenzae non-type b has recently been reported. Non-type b strains have been suggested to be opportunists in an invasive context, but information on clinical consequences and related medical conditions is scarce. In this retrospective study, all H. influenzae isolates (n = 410) from blood and cerebrospinal fluid in three metropolitan Swedish regions between 1997 and 2009 from a population of approximately 3 million individuals were identified. All available isolates were serotyped by PCR (n = 250). We observed a statistically significant increase in the incidence of invasive H. influenzae disease, ascribed to non-typeable H. influenzae (NTHi) and encapsulated strains type f (Hif) in mainly individuals >60 years of age. The medical reports from a subset of 136 cases of invasive Haemophilus disease revealed that 48% of invasive NTHi cases and 59% of invasive Hif cases, respectively, met the criteria of severe sepsis or septic shock according to the ACCP/SCCM classification of sepsis grading. One-fifth of invasive NTHi cases and more than one-third of invasive Hif cases were admitted to intensive care units. Only 37% of patients with invasive non-type b disease had evidence of immunocompromise, of which conditions related to impaired humoral immunity was the most common. The clinical burden of invasive non-type b H. influenzae disease, measured as days of hospitalization/100 000 individuals at risk and year, increased significantly throughout the study period. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Haemophilus influenzae, Hib, Hif, invasive disease, meningitis, sepsis
in
Clinical Microbiology and Infection
volume
17
issue
11
pages
1638 - 1645
publisher
Wiley-Blackwell
external identifiers
  • wos:000296916300014
  • scopus:79958818465
  • pmid:21054663
ISSN
1469-0691
DOI
10.1111/j.1469-0691.2010.03417.x
language
English
LU publication?
yes
id
f336e231-90b0-4103-bbb4-f5c4f52615b0 (old id 2254498)
date added to LUP
2012-01-02 08:07:36
date last changed
2017-10-29 03:14:45
@article{f336e231-90b0-4103-bbb4-f5c4f52615b0,
  abstract     = {Introduction of a conjugated vaccine against encapsulated Haemophilus influenzae type b (Hib) has led to a dramatic reduction of invasive Hib disease. However, an increasing incidence of invasive disease by H. influenzae non-type b has recently been reported. Non-type b strains have been suggested to be opportunists in an invasive context, but information on clinical consequences and related medical conditions is scarce. In this retrospective study, all H. influenzae isolates (n = 410) from blood and cerebrospinal fluid in three metropolitan Swedish regions between 1997 and 2009 from a population of approximately 3 million individuals were identified. All available isolates were serotyped by PCR (n = 250). We observed a statistically significant increase in the incidence of invasive H. influenzae disease, ascribed to non-typeable H. influenzae (NTHi) and encapsulated strains type f (Hif) in mainly individuals >60 years of age. The medical reports from a subset of 136 cases of invasive Haemophilus disease revealed that 48% of invasive NTHi cases and 59% of invasive Hif cases, respectively, met the criteria of severe sepsis or septic shock according to the ACCP/SCCM classification of sepsis grading. One-fifth of invasive NTHi cases and more than one-third of invasive Hif cases were admitted to intensive care units. Only 37% of patients with invasive non-type b disease had evidence of immunocompromise, of which conditions related to impaired humoral immunity was the most common. The clinical burden of invasive non-type b H. influenzae disease, measured as days of hospitalization/100 000 individuals at risk and year, increased significantly throughout the study period.},
  author       = {Resman, Fredrik and Ristovski, Mikael and Ahl, Jonas and Forsgren, Arne and Gilsdorf, J. R. and Jasir, Aftab and Kaijser, B. and Kronvall, G. and Riesbeck, Kristian},
  issn         = {1469-0691},
  keyword      = {Haemophilus influenzae,Hib,Hif,invasive disease,meningitis,sepsis},
  language     = {eng},
  number       = {11},
  pages        = {1638--1645},
  publisher    = {Wiley-Blackwell},
  series       = {Clinical Microbiology and Infection},
  title        = {Invasive disease caused by Haemophilus influenzae in Sweden 1997-2009; evidence of increasing incidence and clinical burden of non-type b strains},
  url          = {http://dx.doi.org/10.1111/j.1469-0691.2010.03417.x},
  volume       = {17},
  year         = {2011},
}