tetano
Editor, Senior Moderator
Influenza Other Respir Viruses. 2018 Jul 25. doi: 10.1111/irv.12595. [Epub ahead of print]
[h=1]Non-annual seasonality of influenza-like illness in a tropical urban setting.[/h] Lam HM[SUP]1[/SUP], Wesolowski A[SUP]2,[/SUP][SUP]3[/SUP], Hung NT[SUP]1[/SUP], Nguyen TD[SUP]1[/SUP], Nhat NTD[SUP]1[/SUP], Todd S[SUP]1,[/SUP][SUP]4[/SUP], Vinh DN[SUP]1[/SUP], Vy NHT[SUP]1[/SUP], Thao TTN[SUP]1[/SUP], Thanh NTL[SUP]1[/SUP], Tin PT[SUP]5[/SUP], Minh NNQ[SUP]1,[/SUP][SUP]6[/SUP], Bryant JE[SUP]1,[/SUP][SUP]7[/SUP], Buckee CO[SUP]2[/SUP], Ngoc TV[SUP]8[/SUP], Chau NVV[SUP]8[/SUP], Thwaites GE[SUP]1,[/SUP][SUP]7[/SUP], Farrar J[SUP]1,[/SUP][SUP]9[/SUP], Tam DTH[SUP]1[/SUP], Vinh H[SUP]1,[/SUP][SUP]8,[/SUP][SUP]10[/SUP], Boni MF[SUP]1,[/SUP][SUP]7,[/SUP][SUP]11[/SUP].
[h=3]Author information[/h]
[h=3]Abstract[/h] [h=4]BACKGROUND:[/h] In temperate and sub-tropical climates, respiratory diseases exhibit seasonal peaks in winter. In the tropics, with no winter, peak timings are irregular.
[h=4]METHODS:[/h] To obtain a detailed picture of influenza-like illness (ILI) patterns in the tropics, we established an mHealth study in community clinics in Ho Chi Minh City (HCMC). During 2009-2015, clinics reported daily case numbers via SMS, with a subset performing molecular diagnostics for influenza virus. This real-time epidemiology network absorbs 6,000 ILI reports annually, one or two orders of magnitude more than typical surveillance systems. A real-time online ILI indicator was developed to inform clinicians of the daily ILI activity in HCMC.
[h=4]RESULTS:[/h] From August 2009 to December 2015, 63 clinics were enrolled and 37,676 SMS reports were received, covering approximately 1.8M outpatient visits. Approximately 10.6% of outpatients met the ILI case definition. ILI activity in HCMC exhibited strong non-annual dynamics with a dominant periodicity of 206 days. This was confirmed by time-series decomposition, step-wise regression, and a forecasting exercise showing that median forecasting errors are 30%-40% lower when using a 206-day cycle. In ILI patients from whom naso-pharyngeal swabs were taken, 31.2% were positive for influenza. There was no correlation between the ILI time series and the time series of influenza, influenza A, or influenza B (all p > 0.15).
[h=4]CONCLUSION:[/h] This suggests, for the first-time, that a non-annual cycle may be an essential driver of respiratory disease dynamics in the tropics. An immunological interference hypothesis is discussed as a potential underlying mechanism. This article is protected by copyright. All rights reserved.
This article is protected by copyright. All rights reserved.
PMID: 30044029 DOI: 10.1111/irv.12595
Free full text
[h=1]Non-annual seasonality of influenza-like illness in a tropical urban setting.[/h] Lam HM[SUP]1[/SUP], Wesolowski A[SUP]2,[/SUP][SUP]3[/SUP], Hung NT[SUP]1[/SUP], Nguyen TD[SUP]1[/SUP], Nhat NTD[SUP]1[/SUP], Todd S[SUP]1,[/SUP][SUP]4[/SUP], Vinh DN[SUP]1[/SUP], Vy NHT[SUP]1[/SUP], Thao TTN[SUP]1[/SUP], Thanh NTL[SUP]1[/SUP], Tin PT[SUP]5[/SUP], Minh NNQ[SUP]1,[/SUP][SUP]6[/SUP], Bryant JE[SUP]1,[/SUP][SUP]7[/SUP], Buckee CO[SUP]2[/SUP], Ngoc TV[SUP]8[/SUP], Chau NVV[SUP]8[/SUP], Thwaites GE[SUP]1,[/SUP][SUP]7[/SUP], Farrar J[SUP]1,[/SUP][SUP]9[/SUP], Tam DTH[SUP]1[/SUP], Vinh H[SUP]1,[/SUP][SUP]8,[/SUP][SUP]10[/SUP], Boni MF[SUP]1,[/SUP][SUP]7,[/SUP][SUP]11[/SUP].
[h=3]Author information[/h]
[h=3]Abstract[/h] [h=4]BACKGROUND:[/h] In temperate and sub-tropical climates, respiratory diseases exhibit seasonal peaks in winter. In the tropics, with no winter, peak timings are irregular.
[h=4]METHODS:[/h] To obtain a detailed picture of influenza-like illness (ILI) patterns in the tropics, we established an mHealth study in community clinics in Ho Chi Minh City (HCMC). During 2009-2015, clinics reported daily case numbers via SMS, with a subset performing molecular diagnostics for influenza virus. This real-time epidemiology network absorbs 6,000 ILI reports annually, one or two orders of magnitude more than typical surveillance systems. A real-time online ILI indicator was developed to inform clinicians of the daily ILI activity in HCMC.
[h=4]RESULTS:[/h] From August 2009 to December 2015, 63 clinics were enrolled and 37,676 SMS reports were received, covering approximately 1.8M outpatient visits. Approximately 10.6% of outpatients met the ILI case definition. ILI activity in HCMC exhibited strong non-annual dynamics with a dominant periodicity of 206 days. This was confirmed by time-series decomposition, step-wise regression, and a forecasting exercise showing that median forecasting errors are 30%-40% lower when using a 206-day cycle. In ILI patients from whom naso-pharyngeal swabs were taken, 31.2% were positive for influenza. There was no correlation between the ILI time series and the time series of influenza, influenza A, or influenza B (all p > 0.15).
[h=4]CONCLUSION:[/h] This suggests, for the first-time, that a non-annual cycle may be an essential driver of respiratory disease dynamics in the tropics. An immunological interference hypothesis is discussed as a potential underlying mechanism. This article is protected by copyright. All rights reserved.
This article is protected by copyright. All rights reserved.
PMID: 30044029 DOI: 10.1111/irv.12595
Free full text