Influenza in the tropics shows variable seasonality

April 27, 2016

Whilst countries in the tropics and subtropics exhibit diverse patterns of seasonal flu activity, they can be grouped into eight geographical zones to optimise vaccine formulation and delivery timing, according to a study published April 27, 2016 in the open-access journal PLOS ONE by Siddhivinayak Hirve from the World Health Organization, Geneva, Switzerland, and colleagues.

Historically, flu vaccine programs have been designed around predictable peaks in infection seasonally observed in temperate climates. However, vaccine programs based on seasonality in temperate regions may not apply to the tropics where patterns in influenza activity are less well understood. The authors of the present study used FluNet, a global tool for influenza surveillance, to analyse national flu data from 138 countries in the tropics and subtropics, examining flu seasonality and identifying annual peaks in flu cases.

The authors found that flu activity patterns in the tropics and subtropics were much more complex than in the temperate northern and southern hemispheres. They were able to discern patterns in influenza activity for 70 countries and found most of these had one or two distinct peaks per year. Countries nearest to the equator often had year-round flu activity. Based on their findings, the researchers constructed eight zones of countries sharing similar flu patterns: two zones in America, two in Asia and four zones in Africa and the Middle East.

While the researchers were able to discern national trends, the high-level data used did not allow resolution of regional trends within countries. Nonetheless, the authors state that the study may provide helpful insight into flu trends in the tropics and subtropics, suggesting novel geographical zones to help time flu vaccination programmes.
-end-
In your coverage please use this URL to provide access to the freely available paper: http://dx.plos.org/10.1371/journal.pone.0153003

Funding: The work was supported by the following: WZ--Grant no. OPP1084574 to the World Health Organization, Geneva from the Bill and Melinda Gates Foundation, USA; JP--Two grants to Netherlands Institute for Health Services Research (WHO grant 2014/430731-0 and an unrestricted Sanofi Pasteur grant GIBS-FLU37-EXT); NB--Grant OPP1084288 to the Program for Appropriate Technology in Health, Seattle, US from the Bill and Melinda Gates Foundation, US; and EAB--grant 1U51GH001191-01 to the Centers for Disease Control and Prevention, Atlanta.

Competing Interests: The authors have declared that no competing interests exist.

Citation: Hirve S, Newman LP, Paget J, Azziz-Baumgartner E, Fitzner J, Bhat N, et al. (2016) Influenza Seasonality in the Tropics and Subtropics - When to Vaccinate? PLoS ONE 11(4): e0153003. doi:10.1371/journal.pone.0153003

PLOS

Related Patterns Articles from Brightsurf:

New malaria transmission patterns emerge in Africa
An international study reveals how future climate change could affect malaria transmission in Africa over the next century.

Lung injuries from vaping have characteristic patterns on CT
Injuries to the lungs from vaping have suggestive patterns on CT scans that could help physicians make accurate diagnoses and reduce unnecessary biopsies, according to a new study.

New technique for engineering living materials and patterns
A new method for engineering living materials called 'MeniFluidics', made by researchers at the University of Warwick could see a transformation in tissue engineering and bio-art, as well as new ways to research cellular interactions.

Separations between earthquakes reveal clear patterns
So far, few studies have explored how the similarity between inter-earthquake times and distances is related to their separation from initial events.

Psychiatry: Five clearly defined patterns
Psychiatrists led by Nikolaos Koutsouleris from Ludwig-Maximilians-Universitaet (LMU) in Munich have used a computer-based approach to assign psychotic patients diagnosed as bipolar or schizophrenic to five different subgroups.

Biophysics: Orientation of protein patterns
During embryogenesis in the nematode Caenorhabditis elegans, the first cell division occurs transverse to the long axis of the fertilized egg.

Patterns in the brain shed new light on how we function
Patterns of brain connectivity take us a step closer to understanding the key principles of cognition.

Imprinted color patterns
Structural colors appear because the imprinted pattern on a surface changes the wavelengths of light.

From firearms to fish -- following patterns to discover causality
Mathematicians have successfully applied a new, pictorial approach to answer complex questions that puzzle analysts, such as, do media stories on firearm legislation influence gun sales?

Screen time patterns of kids
Screen time data for nearly 3,900 children were used to examine patterns of screen time use and the association with sociodemographic characteristics such as parental education levels and sex of the child.

Read More: Patterns News and Patterns Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.