tetano
Editor, Senior Moderator
Influenza Other Respir Viruses. 2017 Jul 8. doi: 10.1111/irv.12462. [Epub ahead of print]
[h=1]Infection with influenza A(H1N1)pdm09 during the first wave of the 2009 pandemic: Evidence from a longitudinal seroepidemiologic study in Dhaka, Bangladesh.[/h] Nasreen S[SUP]1[/SUP], Rahman M[SUP]1[/SUP], Hancock K[SUP]2[/SUP], Katz JM[SUP]2[/SUP], Goswami D[SUP]1[/SUP], Sturm-Ramirez K[SUP]1,[/SUP][SUP]2[/SUP], Holiday C[SUP]2[/SUP], Jefferson S[SUP]2[/SUP], Branch A[SUP]2[/SUP], Wang D[SUP]2[/SUP], Veguilla V[SUP]2[/SUP], Widdowson MA[SUP]2[/SUP], Fry AM[SUP]2[/SUP], Brooks WA[SUP]1,[/SUP][SUP]3[/SUP].
[h=3]Author information[/h]
[h=3]Abstract[/h] [h=4]BACKGROUND:[/h] We determined influenza A(H1N1)pdm09 antibody levels before and after the first wave of the pandemic in an urban community in Dhaka, Bangladesh.
[h=4]METHODS:[/h] We identified a cohort of households by stratified random sampling. We collected baseline serum specimens during July-August 2009, just prior to the initial wave of the 2009 pandemic in this community and a second specimen during November 2009, after the pandemic peak. Paired sera was tested for antibodies against A(H1N1)pdm09 virus using microneutralization assay and hemagglutinin inhibition (HI) assay. A four-fold increase in antibody titer by either assay with a titer of ≥40 in the convalescent sera was considered a seroconversion. At baseline, an HI titer of >40 was considered seropositive. We collected information on clinical illness from weekly home visits.
[h=4]RESULTS:[/h] We tested 779 paired sera from the participants. At baseline, before the pandemic wave, 1% overall and 3% of persons >60 years old were seropositive. After the first wave of the pandemic, 211 (27%) individuals seroconverted against A(H1N1)pdm09. Children aged 5-17 years had the highest proportion (37%) of seroconversion. Among 264 (34%) persons with information on clinical illness, 191 (72%) had illness >3 weeks prior to collection of the follow-up sera and 73 (38%) seroconverted. Sixteen (22%) of these 73 seroconverted participants reported no clinical illness.
[h=4]CONCLUSION:[/h] After the first pandemic wave in Dhaka, one in four persons were infected by A(H1N1)pdm09 virus and the highest burden of infection was among the school-aged children. Seroprevalence studies supplement traditional surveillance systems to estimate infection burden. This article is protected by copyright. All rights reserved.
This article is protected by copyright. All rights reserved.
[h=4]KEYWORDS:[/h] Bangladesh; H1N1 subtype; Pandemic; Seroconversion; Seroepidemiologic studies; influenza A virus
PMID: 28688210 DOI: 10.1111/irv.12462
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[h=1]Infection with influenza A(H1N1)pdm09 during the first wave of the 2009 pandemic: Evidence from a longitudinal seroepidemiologic study in Dhaka, Bangladesh.[/h] Nasreen S[SUP]1[/SUP], Rahman M[SUP]1[/SUP], Hancock K[SUP]2[/SUP], Katz JM[SUP]2[/SUP], Goswami D[SUP]1[/SUP], Sturm-Ramirez K[SUP]1,[/SUP][SUP]2[/SUP], Holiday C[SUP]2[/SUP], Jefferson S[SUP]2[/SUP], Branch A[SUP]2[/SUP], Wang D[SUP]2[/SUP], Veguilla V[SUP]2[/SUP], Widdowson MA[SUP]2[/SUP], Fry AM[SUP]2[/SUP], Brooks WA[SUP]1,[/SUP][SUP]3[/SUP].
[h=3]Author information[/h]
[h=3]Abstract[/h] [h=4]BACKGROUND:[/h] We determined influenza A(H1N1)pdm09 antibody levels before and after the first wave of the pandemic in an urban community in Dhaka, Bangladesh.
[h=4]METHODS:[/h] We identified a cohort of households by stratified random sampling. We collected baseline serum specimens during July-August 2009, just prior to the initial wave of the 2009 pandemic in this community and a second specimen during November 2009, after the pandemic peak. Paired sera was tested for antibodies against A(H1N1)pdm09 virus using microneutralization assay and hemagglutinin inhibition (HI) assay. A four-fold increase in antibody titer by either assay with a titer of ≥40 in the convalescent sera was considered a seroconversion. At baseline, an HI titer of >40 was considered seropositive. We collected information on clinical illness from weekly home visits.
[h=4]RESULTS:[/h] We tested 779 paired sera from the participants. At baseline, before the pandemic wave, 1% overall and 3% of persons >60 years old were seropositive. After the first wave of the pandemic, 211 (27%) individuals seroconverted against A(H1N1)pdm09. Children aged 5-17 years had the highest proportion (37%) of seroconversion. Among 264 (34%) persons with information on clinical illness, 191 (72%) had illness >3 weeks prior to collection of the follow-up sera and 73 (38%) seroconverted. Sixteen (22%) of these 73 seroconverted participants reported no clinical illness.
[h=4]CONCLUSION:[/h] After the first pandemic wave in Dhaka, one in four persons were infected by A(H1N1)pdm09 virus and the highest burden of infection was among the school-aged children. Seroprevalence studies supplement traditional surveillance systems to estimate infection burden. This article is protected by copyright. All rights reserved.
This article is protected by copyright. All rights reserved.
[h=4]KEYWORDS:[/h] Bangladesh; H1N1 subtype; Pandemic; Seroconversion; Seroepidemiologic studies; influenza A virus
PMID: 28688210 DOI: 10.1111/irv.12462
Free full text