Influenza season is quite variable across the Northern Hemisphere, with some regions seeing much earlier onsets than others - and quite often - a different mix of viruses as well.
Last year, while North America struggled with an unusually severe H3N2 season, Asia was hit by a strong wave of Influenza B, and Europe by a combination of both Influenza B & A, with A/H1N1 outnumbering A/H3N2 by 2 to 1.Last January, in Eurosurveillance: Changes In Timing Of Influenza Epidemics - WHO European Region 1996-2016, we saw a study that found Western European countries have seen a discernible shift towards later flu season peaks, while the opposite was true in Eastern Europe and Russia.
Our global flu season has a lot of moving pieces, and in our highly mobile and interconnected world, they can alter the trajectory of our current flu season in unpredictable ways.WHO EMRO has published the following summary of influenza activity reported during the month of October in the Eastern Mediterranean region, which shows a decided uptick in (primarily) Influenza A/H1N1 activity.
Influenza monthly update, October 2018
In the WHO Eastern Mediterranean Region, influenza activity is increasing in the month of October in many countries reporting data to FluNet and EMFLU namely, Afghanistan, Bahrain, Egypt, Iran (Islamic Republic of), Iraq, Jordan, Kuwait, Lebanon, Morocco, occupied Palestinian territory, Oman, Qatar and Saudi Arabia.
Influenza activity by subtype
• In October 2018, no new cases of human influenza A(H5N1) were reported in Egypt.
• In the northern Africa influenza transmission zone, A(H3) virus was detected predominantly in Egypt while Morocco reported no activity.
• In the western Asia influenza transmission zone, Qatar and Saudi Arabia reported co-circulation of all seasonal influenza viruses, while in Oman and Bahrain influenza A(H1N1)pdm09 and A(H3) virus were detected. Lebanon reported circulation of sporadic cases of the influenza A(H3) and Jordan, Iraq and oPt reported no activity.
• In southern Asia transmission zone, Iran (Islamic Republic of) reported circulation of sporadic influenza A(H1N1)pdm09 cases, while Afghanistan reported no activity.
Circulating influenza viruses by subtype
• During October 2018, national influenza centres and influenza laboratories in the Region tested a total of 5136 specimens for influenza viruses of which 1229 tested positive (24%).
• The average percentage of positivity rates is 24 %, with highest positivity rate recorded in Bahrain, Kuwait, Oman, Qatar and Saudi Arabia.
• Of the viruses tested; 1088 (89%) were influenza A viruses, including 673 (55%) influenza A(H1N1)pdm09 virus and 306 (25%) were influenza A(H3) virus. Influenza B (Lineage Not determined) virus accounted for 141 (11%) (Figure 3).