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Streptococcus pneumoniae serotype-2 childhood meningitis in Bangladesh: a newly recognized pneumococcal infection threat.

Saha SK, Al Emran HM, Hossain B, Darmstadt GL, Saha S, Islam M, Chowdhury AI, Foster D, Naheed A, El Arifeen S, Baqui AH, Qazi SA, Luby SP, Breiman RF, Santosham M, Black RE, Crook DW, Pneumococcal Study Gro - PLoS ONE (2012)

Bottom Line: However, effectiveness of PCV would be jeopardized by emergence of invasive pneumococcal diseases (IPD) caused by serotypes which are not included in PCV.This also provided the foundation for determining the spectrum of serotypes causing IPD.Persisting disease occurrence or progressive spread would represent a major potential infection threat since serotype-2 is not included in PCVs currently licensed or under development.

View Article: PubMed Central - PubMed

Affiliation: Department of Microbiology, Dhaka Shishu (Children) Hospital, Child Health Research Foundation, Dhaka, Bangladesh. samirk.sks@gmail.com

ABSTRACT

Background: Streptococcus pneumoniae is a leading cause of meningitis in countries where pneumococcal conjugate vaccines (PCV) targeting commonly occurring serotypes are not routinely used. However, effectiveness of PCV would be jeopardized by emergence of invasive pneumococcal diseases (IPD) caused by serotypes which are not included in PCV. Systematic hospital based surveillance in Bangladesh was established and progressively improved to determine the pathogens causing childhood sepsis and meningitis. This also provided the foundation for determining the spectrum of serotypes causing IPD. This article reports an unprecedented upsurge of serotype 2, an uncommon pneumococcal serotype, without any known intervention.

Methods and findings: Cases with suspected IPD had blood or cerebrospinal fluid (CSF) collected from the beginning of 2001 till 2009. Pneumococcal serotypes were determined by capsular swelling of isolates or PCR of culture-negative CSF specimens. Multicenter national surveillance, expanded from 2004, identified 45,437 patients with suspected bacteremia who were blood cultured and 10,618 suspected meningitis cases who had a lumber puncture. Pneumococcus accounted for 230 culture positive cases of meningitis in children <5 years. Serotype-2 was the leading cause of pneumococcal meningitis, accounting for 20.4% (45/221; 95% CI 15%-26%) of cases. Ninety eight percent (45/46) of these serotype-2 strains were isolated from meningitis cases, yielding the highest serotype-specific odds ratio for meningitis (29.6; 95% CI 3.4-256.3). The serotype-2 strains had three closely related pulsed field gel electrophoresis types.

Conclusions: S. pneumoniae serotype-2 was found to possess an unusually high potential for causing meningitis and was the leading serotype-specific cause of childhood meningitis in Bangladesh over the past decade. Persisting disease occurrence or progressive spread would represent a major potential infection threat since serotype-2 is not included in PCVs currently licensed or under development.

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Restriction Fragments Generated by Pulsed-Field Gel Electrophoresis.Showing banding patterns of serotype 2 representing 3 different pulsetypes, A (N = 36), B (N = 4)& C (N = 1), detected from Sma1 digested genomic DNA.
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pone-0032134-g003: Restriction Fragments Generated by Pulsed-Field Gel Electrophoresis.Showing banding patterns of serotype 2 representing 3 different pulsetypes, A (N = 36), B (N = 4)& C (N = 1), detected from Sma1 digested genomic DNA.

Mentions: Of the 46 serotype-2 isolates cultured, 41 were available for genotyping (Figure 3). PFGE identified three types (A, B & C) differing by only 2 or 3 bands and, therefore, would be regarded as closely related [9]. By MLST, these 41 isolates belonged to a single clonal complex, CC74, consisting of 3 sequence types (ST): ST 74 (n = 23) the ancestral type, a single locus variant ST 5083 (n = 3) and a double locus variant ST 5199 (n = 15). These latter two STs are unique to this study. This serotype-2 clonal complex is genetically unrelated to other rare serotype-2 sequence types on the http://www.mlst.net database; including the archetypal whole genome sequenced historic strain D39 designated ST 595(Figure 4 and Table S5).


Streptococcus pneumoniae serotype-2 childhood meningitis in Bangladesh: a newly recognized pneumococcal infection threat.

Saha SK, Al Emran HM, Hossain B, Darmstadt GL, Saha S, Islam M, Chowdhury AI, Foster D, Naheed A, El Arifeen S, Baqui AH, Qazi SA, Luby SP, Breiman RF, Santosham M, Black RE, Crook DW, Pneumococcal Study Gro - PLoS ONE (2012)

Restriction Fragments Generated by Pulsed-Field Gel Electrophoresis.Showing banding patterns of serotype 2 representing 3 different pulsetypes, A (N = 36), B (N = 4)& C (N = 1), detected from Sma1 digested genomic DNA.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3316528&req=5

pone-0032134-g003: Restriction Fragments Generated by Pulsed-Field Gel Electrophoresis.Showing banding patterns of serotype 2 representing 3 different pulsetypes, A (N = 36), B (N = 4)& C (N = 1), detected from Sma1 digested genomic DNA.
Mentions: Of the 46 serotype-2 isolates cultured, 41 were available for genotyping (Figure 3). PFGE identified three types (A, B & C) differing by only 2 or 3 bands and, therefore, would be regarded as closely related [9]. By MLST, these 41 isolates belonged to a single clonal complex, CC74, consisting of 3 sequence types (ST): ST 74 (n = 23) the ancestral type, a single locus variant ST 5083 (n = 3) and a double locus variant ST 5199 (n = 15). These latter two STs are unique to this study. This serotype-2 clonal complex is genetically unrelated to other rare serotype-2 sequence types on the http://www.mlst.net database; including the archetypal whole genome sequenced historic strain D39 designated ST 595(Figure 4 and Table S5).

Bottom Line: However, effectiveness of PCV would be jeopardized by emergence of invasive pneumococcal diseases (IPD) caused by serotypes which are not included in PCV.This also provided the foundation for determining the spectrum of serotypes causing IPD.Persisting disease occurrence or progressive spread would represent a major potential infection threat since serotype-2 is not included in PCVs currently licensed or under development.

View Article: PubMed Central - PubMed

Affiliation: Department of Microbiology, Dhaka Shishu (Children) Hospital, Child Health Research Foundation, Dhaka, Bangladesh. samirk.sks@gmail.com

ABSTRACT

Background: Streptococcus pneumoniae is a leading cause of meningitis in countries where pneumococcal conjugate vaccines (PCV) targeting commonly occurring serotypes are not routinely used. However, effectiveness of PCV would be jeopardized by emergence of invasive pneumococcal diseases (IPD) caused by serotypes which are not included in PCV. Systematic hospital based surveillance in Bangladesh was established and progressively improved to determine the pathogens causing childhood sepsis and meningitis. This also provided the foundation for determining the spectrum of serotypes causing IPD. This article reports an unprecedented upsurge of serotype 2, an uncommon pneumococcal serotype, without any known intervention.

Methods and findings: Cases with suspected IPD had blood or cerebrospinal fluid (CSF) collected from the beginning of 2001 till 2009. Pneumococcal serotypes were determined by capsular swelling of isolates or PCR of culture-negative CSF specimens. Multicenter national surveillance, expanded from 2004, identified 45,437 patients with suspected bacteremia who were blood cultured and 10,618 suspected meningitis cases who had a lumber puncture. Pneumococcus accounted for 230 culture positive cases of meningitis in children <5 years. Serotype-2 was the leading cause of pneumococcal meningitis, accounting for 20.4% (45/221; 95% CI 15%-26%) of cases. Ninety eight percent (45/46) of these serotype-2 strains were isolated from meningitis cases, yielding the highest serotype-specific odds ratio for meningitis (29.6; 95% CI 3.4-256.3). The serotype-2 strains had three closely related pulsed field gel electrophoresis types.

Conclusions: S. pneumoniae serotype-2 was found to possess an unusually high potential for causing meningitis and was the leading serotype-specific cause of childhood meningitis in Bangladesh over the past decade. Persisting disease occurrence or progressive spread would represent a major potential infection threat since serotype-2 is not included in PCVs currently licensed or under development.

Show MeSH
Related in: MedlinePlus