Nonannual seasonality of influenza-like illness in a tropical urban setting
<h4>Background</h4> <p>In temperate and subtropical climates, respiratory diseases exhibit seasonal peaks in winter. In the tropics, with no winter, peak timings are irregular.</p> <h4>Methods</h4> <p>To obtain a detailed picture of influenza-like illness (...
| Autores principales: | , , , , , , , , , , , , , , , , , , , , |
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| Formato: | Journal article |
| Lenguaje: | English |
| Publicado: |
Wiley
2018
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| _version_ | 1826301756958572544 |
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| author | Lam, H Wesolowski, A Hung, N Nguyen, T Nhat, N Todd, S Vinh, D Vy, N Thao, T Thanh, N Tin, P Minh, N Bryant, J Buckee, C Ngoc, T Chau, N Thwaites, G Farrar, J Tam, D Vinh, H Boni, M |
| author_facet | Lam, H Wesolowski, A Hung, N Nguyen, T Nhat, N Todd, S Vinh, D Vy, N Thao, T Thanh, N Tin, P Minh, N Bryant, J Buckee, C Ngoc, T Chau, N Thwaites, G Farrar, J Tam, D Vinh, H Boni, M |
| author_sort | Lam, H |
| collection | OXFORD |
| description | <h4>Background</h4> <p>In temperate and subtropical climates, respiratory diseases exhibit seasonal peaks in winter. In the tropics, with no winter, peak timings are irregular.</p> <h4>Methods</h4> <p>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 6000 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.</p> <h4>Results</h4> <p>From August 2009 to December 2015, 63 clinics were enrolled and 36 920 SMS reports were received, covering approximately 1.7M outpatient visits. Approximately 10.6% of outpatients met the ILI case definition. ILI activity in HCMC exhibited strong nonannual dynamics with a dominant periodicity of 206 days. This was confirmed by time series decomposition, stepwise 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 nasopharyngeal 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).</p> <h4>Conclusion</h4> <p>This suggests, for the first time, that a nonannual cycle may be an essential driver of respiratory disease dynamics in the tropics. An immunological interference hypothesis is discussed as a potential underlying mechanism.</p> |
| first_indexed | 2024-03-07T05:37:11Z |
| format | Journal article |
| id | oxford-uuid:e450afdc-18d2-4fc9-812a-3f8859494fea |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T05:37:11Z |
| publishDate | 2018 |
| publisher | Wiley |
| record_format | dspace |
| spelling | oxford-uuid:e450afdc-18d2-4fc9-812a-3f8859494fea2022-03-27T10:15:49ZNonannual seasonality of influenza-like illness in a tropical urban settingJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:e450afdc-18d2-4fc9-812a-3f8859494feaEnglishSymplectic Elements at OxfordWiley2018Lam, HWesolowski, AHung, NNguyen, TNhat, NTodd, SVinh, DVy, NThao, TThanh, NTin, PMinh, NBryant, JBuckee, CNgoc, TChau, NThwaites, GFarrar, JTam, DVinh, HBoni, M <h4>Background</h4> <p>In temperate and subtropical climates, respiratory diseases exhibit seasonal peaks in winter. In the tropics, with no winter, peak timings are irregular.</p> <h4>Methods</h4> <p>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 6000 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.</p> <h4>Results</h4> <p>From August 2009 to December 2015, 63 clinics were enrolled and 36 920 SMS reports were received, covering approximately 1.7M outpatient visits. Approximately 10.6% of outpatients met the ILI case definition. ILI activity in HCMC exhibited strong nonannual dynamics with a dominant periodicity of 206 days. This was confirmed by time series decomposition, stepwise 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 nasopharyngeal 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).</p> <h4>Conclusion</h4> <p>This suggests, for the first time, that a nonannual cycle may be an essential driver of respiratory disease dynamics in the tropics. An immunological interference hypothesis is discussed as a potential underlying mechanism.</p> |
| spellingShingle | Lam, H Wesolowski, A Hung, N Nguyen, T Nhat, N Todd, S Vinh, D Vy, N Thao, T Thanh, N Tin, P Minh, N Bryant, J Buckee, C Ngoc, T Chau, N Thwaites, G Farrar, J Tam, D Vinh, H Boni, M Nonannual seasonality of influenza-like illness in a tropical urban setting |
| title | Nonannual seasonality of influenza-like illness in a tropical urban setting |
| title_full | Nonannual seasonality of influenza-like illness in a tropical urban setting |
| title_fullStr | Nonannual seasonality of influenza-like illness in a tropical urban setting |
| title_full_unstemmed | Nonannual seasonality of influenza-like illness in a tropical urban setting |
| title_short | Nonannual seasonality of influenza-like illness in a tropical urban setting |
| title_sort | nonannual seasonality of influenza like illness in a tropical urban setting |
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