Caini, S., El-Guerche Séblain, C., Ciblak, M.A., Paget, J.
Epidemiology of seasonal influenza in the Middle East and North Africa, 2010-2016: circulating 20 influenza A and B viruses and spatial spread of epidemics.
Influenza and Other Respiratory Viruses, 12 (2018) 3, p. 344-352.
Background:
There is limited knowledge regarding the epidemiology of influenza in Middle East and North Africa.
Objectives: We described the patterns of influenza circulation and the timing of seasonal epidemics in countries of Middle East and North Africa.
Methods: We used virological surveillance data for 2010-2016 from the WHO-FluNet database. In each country, we calculated the median proportion of cases that were caused by each virus
type and subtype; determined the timing and amplitude of the primary and secondary peaks
; and used linear regression models to test for spatial trends in the timing of epidemics.
Results: We included 70,532 influenza cases from seventeen countries. Influenza A and B accounted for a median 76.5% and 23.5% of cases in a season, and were the dominant type in 86.8% and 13.2% of seasons. The proportion of influenza A cases that were subtyped was 85.9%, while only 4.4% of influenza B cases were characterized. For most countries, i
nfluenza seasonality was similar to the Northern Hemisphere, with a single large peak between January and March; exceptions were the countries in the Arabian Peninsula and Jordan, all of which showed clear secondary peaks, and some countries had an earlier primary peak (in November-December in Bahrain and Qatar).
The direction of the timing of influenza activity was east-to-west and south-to-north in 2012-
2013 and 2015-2016, and west-to-east in 2014-2015.
Conclusions: The epidemiology of influenza is generally uniform in countries of Middle East and North Africa, with influenza B playing an important role in the seasonal disease burden.