The information presented in this update is based on data provided by Ministries of Health and National Influenza Centers of Member States to the Pan American Health Organization (PAHO) or from updates on the Member States’ Ministry of Health web pages.
Regional Update EW 06, 2015
- North America: All influenza activity indicators decreased or remained the same, although they remained elevated. In Canada, ILI activity decreased this week but remained slightly above expected levels. Influenza detections continued to decrease (16.3% positivity). Amongst subtyped strains, influenza A(H3N2) predominated, of which 94% differ from the current Northern Hemisphere vaccine strain. Detections of RSV remained high but continued to decrease this week. In the United States, ILI activity (3.2%) continued to decreased but remained above the national baseline of 2%. Influenza detections (13% positivity) continued to decrease, and influenza A (not subtyped) and influenza A(H3) predominated. Sixty-nine percent of influenza A(H3N1) strains characterized differ from the current Northern Hemisphere vaccine strain. Influenza-associated hospitalization rates among adults aged ≥65 years are higher this season in comparison to previous influenza seasons and the percentage of deaths due to pneumonia and influenza (7.2%) remained above the epidemic threshold. RSV activity continued at a high level, although this week it decreased. In Mexico, ARI and pneumonia activity continued to decrease. Influenza detections decreased in the last two EW, with influenza A(H3N2) predominated among circulating influenza viruses and 11.6% influenza positivity reported during EW 6.
- Caribbean: Respiratory virus activity remained low with the exception of Puerto Rico and Jamaica, where influenza detections continue to increase.
- Central America: Respiratory virus activity remained low and SARI activity was within expected levels. Few influenza A detections, mainly influenza A(H3N2) in El Salvador. RSV continued to decrease and is at low levels.
- Andean Sub-region: Respiratory virus activity remained low or within expected levels, although an increase in RSV has been observed in Ecuador and light circulation in Colombia. Little or no influenza circulation in recent weeks.
- Southern Cone: Influenza activity remains at inter-seasonal levels. Acute respiratory infection and other respiratory virus activity remains low and within expected levels.