Bangladesh and Rwanda: a case for a high burden of influenza in tropical countries?

, ,
1 Laboratory for Human Evolutionary and Ecological Studies, Department of Genetics and Evolutionary Biology, Universidade de São Paulo, São Paulo, São Paulo, Brazil
2 Department of Epidemiology, Sao Leopoldo Mandic Medical School, Campinas, Sao Paulo, Brazil
3 Origem Scientifica, São Paulo, São Paulo, Brazil
DOI
10.7287/peerj.preprints.26705v1
Published
Accepted
Subject Areas
Epidemiology, Global Health, Infectious Diseases, Public Health, Translational Medicine
Keywords
Influenza, Burden of diseases, Equatorial countries, Mortality, Pandemic influenza, Hospitalization, Respiratory syncytial virus
Copyright
© 2018 Alonso et al.
Licence
This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ Preprints) and either DOI or URL of the article must be cited.
Cite this article
Alonso WJ, Freitas ARR, Schuck-Paim C. 2018. Bangladesh and Rwanda: a case for a high burden of influenza in tropical countries? PeerJ Preprints 6:e26705v1

Abstract

Several studies that analyzed the burden of influenza during the 2009 pandemic found that excess mortality tended to wane or even disappear in equatorial regions, adding to evidence that suggests that seasonal influenza may have a lower impact in tropical settings. We therefore analyzed with great interest the claims of two studies recently published in this journal of relatively high influenza-associated mortality burden in Bangladesh and hospitalization burden in Rwanda, two countries with mild winters. We detected a poor match between the temporal signature of influenza virus detection and ARI cases. The absence of respiratory syncytial virus (RSV) testing in these studies may have also contributed to distortions, especially in Rwanda where hospitalization rates were disproportionately high among younger children, usually the most affected by RSV. Additionally, many of the deaths attributed to influenza were of patients with severe previously existing conditions. We suggest that the issues discussed here are seriously considered in a putative recommendation of seasonal influenza vaccines in tropical settings.

Author Comment

This is a manuscript in which we discussed the evidence that influenza affects less equatorial regions than areas of higher latitude.