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Dynamics of influenza in tropical Africa: Temperature, humidity, and co‐circulating (sub)types

BACKGROUND: The association of influenza with meteorological variables in tropical climates remains controversial. Here, we investigate the impact of weather conditions on influenza in the tropics and factors that may contribute to this uncertainty. METHODS: We computed the monthly viral positive ra...

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Autores principales: Yang, Wan, Cummings, Matthew J., Bakamutumaho, Barnabas, Kayiwa, John, Owor, Nicholas, Namagambo, Barbara, Byaruhanga, Timothy, Lutwama, Julius J., O'Donnell, Max R., Shaman, Jeffrey
Formato: Online Artículo Texto
Lenguaje:English
Publicado: John Wiley and Sons Inc. 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6005592/
https://www.ncbi.nlm.nih.gov/pubmed/29573157
http://dx.doi.org/10.1111/irv.12556
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author Yang, Wan
Cummings, Matthew J.
Bakamutumaho, Barnabas
Kayiwa, John
Owor, Nicholas
Namagambo, Barbara
Byaruhanga, Timothy
Lutwama, Julius J.
O'Donnell, Max R.
Shaman, Jeffrey
author_facet Yang, Wan
Cummings, Matthew J.
Bakamutumaho, Barnabas
Kayiwa, John
Owor, Nicholas
Namagambo, Barbara
Byaruhanga, Timothy
Lutwama, Julius J.
O'Donnell, Max R.
Shaman, Jeffrey
author_sort Yang, Wan
collection PubMed
description BACKGROUND: The association of influenza with meteorological variables in tropical climates remains controversial. Here, we investigate the impact of weather conditions on influenza in the tropics and factors that may contribute to this uncertainty. METHODS: We computed the monthly viral positive rate for each of the 3 circulating influenza (sub)types (ie, A/H1N1, A/H3N2, and B) among patients presenting with influenza‐like illness (ILI) or severe acute respiratory infections (SARI) in 2 Ugandan cities (Entebbe and Kampala). Using this measure as a proxy for influenza activity, we applied regression models to examine the impact of temperature, relative humidity, absolute humidity, and precipitation, as well as interactions among the 3 influenza viruses on the epidemic dynamics of each influenza (sub)type. A full analysis including all 4 weather variables was done for Entebbe during 2007‐2015, and a partial analysis including only temperature and precipitation was done for both cities during 2008‐2014. RESULTS: For Entebbe, the associations with weather variables differed by influenza (sub)type; with adjustment for viral interactions, the models showed that precipitation and temperature were negatively correlated with A/H1N1 activity, but not for A/H3N2 or B. A mutually negative association between A/H3N2 and B activity was identified in both Entebbe and Kampala. CONCLUSION: Our findings suggest that key interactions exist among influenza (sub)types at the population level in the tropics and that such interactions can modify the association of influenza activity with weather variables. Studies of the relationship between influenza and weather conditions should therefore determine and account for co‐circulating influenza (sub)types.
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spelling pubmed-60055922018-07-01 Dynamics of influenza in tropical Africa: Temperature, humidity, and co‐circulating (sub)types Yang, Wan Cummings, Matthew J. Bakamutumaho, Barnabas Kayiwa, John Owor, Nicholas Namagambo, Barbara Byaruhanga, Timothy Lutwama, Julius J. O'Donnell, Max R. Shaman, Jeffrey Influenza Other Respir Viruses Original Articles BACKGROUND: The association of influenza with meteorological variables in tropical climates remains controversial. Here, we investigate the impact of weather conditions on influenza in the tropics and factors that may contribute to this uncertainty. METHODS: We computed the monthly viral positive rate for each of the 3 circulating influenza (sub)types (ie, A/H1N1, A/H3N2, and B) among patients presenting with influenza‐like illness (ILI) or severe acute respiratory infections (SARI) in 2 Ugandan cities (Entebbe and Kampala). Using this measure as a proxy for influenza activity, we applied regression models to examine the impact of temperature, relative humidity, absolute humidity, and precipitation, as well as interactions among the 3 influenza viruses on the epidemic dynamics of each influenza (sub)type. A full analysis including all 4 weather variables was done for Entebbe during 2007‐2015, and a partial analysis including only temperature and precipitation was done for both cities during 2008‐2014. RESULTS: For Entebbe, the associations with weather variables differed by influenza (sub)type; with adjustment for viral interactions, the models showed that precipitation and temperature were negatively correlated with A/H1N1 activity, but not for A/H3N2 or B. A mutually negative association between A/H3N2 and B activity was identified in both Entebbe and Kampala. CONCLUSION: Our findings suggest that key interactions exist among influenza (sub)types at the population level in the tropics and that such interactions can modify the association of influenza activity with weather variables. Studies of the relationship between influenza and weather conditions should therefore determine and account for co‐circulating influenza (sub)types. John Wiley and Sons Inc. 2018-04-17 2018-07 /pmc/articles/PMC6005592/ /pubmed/29573157 http://dx.doi.org/10.1111/irv.12556 Text en © 2018 The Authors. Influenza and Other Respiratory Viruses Published by John Wiley & Sons Ltd. This is an open access article under the terms of the http://creativecommons.org/licenses/by/4.0/ License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
spellingShingle Original Articles
Yang, Wan
Cummings, Matthew J.
Bakamutumaho, Barnabas
Kayiwa, John
Owor, Nicholas
Namagambo, Barbara
Byaruhanga, Timothy
Lutwama, Julius J.
O'Donnell, Max R.
Shaman, Jeffrey
Dynamics of influenza in tropical Africa: Temperature, humidity, and co‐circulating (sub)types
title Dynamics of influenza in tropical Africa: Temperature, humidity, and co‐circulating (sub)types
title_full Dynamics of influenza in tropical Africa: Temperature, humidity, and co‐circulating (sub)types
title_fullStr Dynamics of influenza in tropical Africa: Temperature, humidity, and co‐circulating (sub)types
title_full_unstemmed Dynamics of influenza in tropical Africa: Temperature, humidity, and co‐circulating (sub)types
title_short Dynamics of influenza in tropical Africa: Temperature, humidity, and co‐circulating (sub)types
title_sort dynamics of influenza in tropical africa: temperature, humidity, and co‐circulating (sub)types
topic Original Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6005592/
https://www.ncbi.nlm.nih.gov/pubmed/29573157
http://dx.doi.org/10.1111/irv.12556
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