Influenza Update

World Health Organisation
Jul 16, 2016
2 min read

Summary

In temperate countries in the southern hemisphere, influenza activity increased steadily in the last few weeks in South America and South Africa, but remained low overall in most of Oceania. Influenza activity in the temperate zone of the northern hemisphere was at inter-seasonal levels.

In temperate South America, influenza-like illness (ILI), acute respiratory infection (ARI) and severe acute respiratory infection (SARI) cases continued to increase. Of the respiratory viruses detected, respiratory syncytial virus (RSV) and influenza A(H1N1)pdm09 predominated.
In the temperate countries of Southern Africa, influenza detections continued to increase with predominantly influenza B viruses detected.
In Oceania, influenza virus activity remained low. ILI activity in Australia remains low for this time of the year.
In the Caribbean countries, respiratory virus activity remained generally low with decreasing influenza B activity reported in many countries over the past few weeks, except in Jamaica, where slight increases in SARI and pneumonia activities were observed.
In Central America, the number of hospitalizations due to pneumonia seemed to have peaked in El Salvador. In Panama, over the past few weeks, detections of influenza A(H1N1)pdm09 decreased slightly while detections of non-influenza respiratory viruses increased. RSV activity continued in Costa Rica and Guatemala.
In tropical South America, respiratory virus activities varied. In Colombia and the Plurinational State of Bolivia, influenza A(H1N1)pdm09 activity increased and RSV activity decreased or remained low. ARI and SARI activities were elevated compared to previous years in Colombia. Influenza A(H1N1)pdm09 detections seemed to have peaked and the proportion of SARI-related hospitalizations decreased to expected levels in Ecuador. In Peru, influenza A(H1N1)pdm09 activity decreased while RSV activity increased slightly. In Brazil, influenza detections and SARI indicators seemed to have peaked already.
In tropical countries of South Asia, influenza activity was generally low with influenza A and B co-circulating in the region.
In the northern temperate and central tropical regions of Africa, influenza activity was generally low with influenza A virus detections predominant in Western Africa and influenza B virus detections predominant in Eastern and Northern Africa.
In North America and Europe, influenza activity was low with influenza B predominant. ILI levels were below seasonal thresholds.
Influenza activity continued to decrease in temperate Asia with influenza B virus predominant.
National Influenza Centres (NICs) and other national influenza laboratories from 72 countries, areas or territories reported data to FluNet for the time period from 13 June 2016 to 26 June 2016* (data as of 2016-07-08 11:42:58 UTC).The WHO GISRS laboratories tested more than 50 149 specimens during that time period. 2207 were positive for influenza viruses, of which 1247 (56.5%) were typed as influenza A and 960 (43.5%) as influenza B. Of the sub-typed influenza A viruses, 808 (74%) were influenza A(H1N1)pdm09 and 284 (26%) were influenza A(H3N2). Of the characterized B viruses, 113 (25.7%) belonged to the B-Yamagata lineage and 327 (74.3%) to the B-Victoria lineage.