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 49, 2014
- North America: Influenza activity continued to increase. In Canada, ILI activity has remained above expected levels since epidemiological week (EW) 35. Influenza detections (19.5% positivity) continued to increase and influenza A(H3N2) and influenza A (not subtyped) have predominated among circulating influenza viruses. During EW 49, widespread influenza activity was reported in British Columbia and Quebec. Eleven influenza A(H3N2) viruses have been characterized of which two (18%) were A/Texas/50/2012-like, component of the 2014-2015 northern hemisphere vaccine and nine (82%) showed reduced titers. The detections of RSV have continued to increase since EW 40. Influenza hospitalizations have continued to increase since EW 46 with the majority among those ≥65 years of age. In the United States, ILI activity (2.5%) is above the national baseline (2.2%) and during EW 49, widespread influenza activity was reported by 14 states (Colorado, Delaware, Florida, Georgia, Illinois, Kentucky, Louisiana, Maryland, Minnesota, New York, North Carolina, Ohio, Pennsylvania, and Texas). Influenza detections continued to increase (21% positivity) and influenza A (not subtyped) and influenza A(H3) have predominated among the circulating influenza viruses; 197 influenza A(H3N2) viruses have been characterized of which 64 (32.5%) were A/Texas/50/2012-like, the component of the 2014-2015 northern hemisphere vaccine and 133 (67.5%) showed reduced titers. Most viruses that showed reduced titers were antigenically similar to A/Switzerland/9715293/2013, the influenza A(H3N2) virus selected for the 2015 southern hemisphere vaccine. RSV detections have continued to increase since EW 39. Two influenza-associated pediatric deaths were reported this week and the overall hospitalization rate was 3.8 per 100,000 population with the highest rate among adults aged ≥65 years (13.4 per 100,000). The majority (95%) of hospitalized adults had at least one reported underlying medical condition. From mid-August to 11 December, 1,149 cases of Enterovirus D68 have been recorded in 48 states and the District of Columbia and reports from most states over the last months have indicated reduced Enterovirus D68-like illness activity. In Mexico, ARI activity remained within the endemic channel and the proportions of SARI/ILI consultations remained below 2%. The states with the highest ARI and pneumonia rate this week were Colima and Nuevo Leon and the proportion of positive samples for influenza this week was 38% with a predominance of influenza A(H3N2).
- Caribbean: Respiratory virus activity remained low with the exception of Cuba. In Cuba, influenza A(H3N2) detections have been increasing in the last four weeks. In Puerto Rico, ILI activity (as reported to CDC) was reported as high, and influenza detections remained low and decreasing during the last nine weeks. In Saint Lucia, the number of cases of fever and acute respiratory symptoms continued to decrease this week since peaking in EW 44. Among respiratory viruses, circulation of RSV and influenza A(H3N2) (Cuba) and parainfluenza (Dominican Republic) were observed.
- Central America: Respiratory virus activity remained low with the exception of Costa Rica. In Costa Rica, SARI activity and respiratory viruses detections decreased this week. In Nicaragua, ARI activity remained within expected levels and in Panama, respiratory viruses detections have been decreased since EW 46. Among respiratory viruses, circulation of RSV is decreasing, but still persisiting in Costa Rica and Panama and influenza A(H3N2) was detected in Costa Rica.
- Andean Sub-region: Respiratory virus activity remained low and ARI/SARI activity were within expected levels (Colombia, Ecuador). Among respiratory viruses, circulation of RSV (Colombia), influenza A(H3N2) (Colombia, Ecuador) and parainfluenza (Bolivia, Peru) was observed.
- Southern Cone: Respiratory virus activity and ARI/SARI activity have continued to decrease and were within expected levels. There have been very few influenza and other respiratory virus detections in the last weeks (Argentina, Chile, Paraguay, Uruguay).