Pandemic (H1N1) 2009 regional update 26 Oct 2009
I- Evolution of the pandemic
In Canada and the United States, spread of influenza continues to be widespread and trends of acute respiratory disease continue to increase.
In the United States, in EW 41, outpatient influenza-like-illness (ILI) activity continued to increase, remaining above the national baseline for the eighth consecutive week. Emerging Infections Program(EIP) laboratory-confirmed influenza hospitalizations rates remained high, especially in persons 5-49 years of age. The proportion of deaths attributed to pneumonia and influenza crossed the epidemic threshold for the first time in this influenza season in EW 40 and remained above this threshold.
A total of 95 pediatric deaths associated with pandemic (H1N1) 2009 have been reported to the Centers for Disease Control (CDC) since the emergence of the virus. Since August 30, 2009, CDC has received 53 reports of influenza-associated pediatric deaths; 47 of the 53 deaths were due to 2009 influenza A (H1N1) virus infections, and the remaining six were associated with influenza A virus for which the subtype is undetermined. This week, 11 influenza-associated pediatric deaths were reported to CDC-nine were associated with pandemic (H1N1) 2009 and two were associated with an influenza A virus for which the subtype is undetermined. Reports of pediatric influenza-associated deaths during the early fall are uncommon, but have occurred in the setting of geographically widespread high levels of pandemic influenza A (H1N1) in the United States. Seven of the 32 pediatric deaths (22%) had positive bacterial cultures; five of these were positive Staphylococcus aureus, of which three were methicillin-resistant. On Saturday, September 24, 2009, the United States declared a national emergency due to the pandemic.
Based on information available from Mexico's webpage1, the greatest number of laboratory-confirmed cases was seen in the Federal District, Chiapas, Yucatan, Nueva Leon, San Luis Potosi, and Jalisco. As compared to the previous week (October 12), the greatest increases in confirmed cases were observed in Aguascalientes, Mexico, Durango, San Luis Potosi, and Jalisco. Of note, the states of Aguascalientes, Durango and Baja California Sur have experienced increases of more than 20% per week for at least the last three weeks.
In the Caribbean, acute respiratory disease activity has been variable with some countries reporting increasing trends in acute respiratory disease while others are reporting decreasing or unchanged trends. Overall, the intensity of acute respiratory disease and impact of acute respiratory disease on health care services is remaining low to moderate, with the exception of Belize which reported very high intensity of acute respiratory disease but a moderate impact of acute respiratory disease on health care services.
Cuba continues to report widespread influenza activity and increasing trends and high intensity of acute respiratory disease. Trinidad and Tobago reported their first pandemic-associated deaths last week (EW 40); in total, there have been 43 deaths in this region, including 22 in the Dominican Republic, and seven in Cuba.
In relation to the geographic spread of influenza, all countries except El Salvador reported widespread activity. The trend of acute respiratory disease is decreasing or unchanged in much of this region, with the exception of Guatemala, which reported an increasing trend. All countries are reporting low/moderate intensity of acute respiratory disease except Guatemala, which is reporting high intensity. The overall impact of acute respiratory disease on health care services was low or moderate in these countries. Several countries are reporting simultaneous outbreaks of dengue and cases of co-infection of both viruses are being investigated
All the countries providing an update this week reported widespread geographic spread of influenza. This week, Colombia reported a continued increasing trend of acute respiratory disease, while Ecuador reported a new increasing trend in acute respiratory disease. All reporting countries had a low or moderate intensity of acute respiratory disease and a low impact on health care services due to acute respiratory disease.
Most of these countries continued to experience a decreasing or unchanged trend of acute respiratory disease, with low/moderate intensity of acute respiratory disease, and low impact on health care services. Paraguay, however, reported a new increasing trend and high intensity of acute respiratory disease. Brazil reported an overall decreasing trend in acute respiratory disease and in severe acute respiratory illness (SARI) (97.3% decrease between EW 31 and 40) but also reported school outbreaks in the southern part of the country (Paraná). Since EW 36, Brazil reported an additional 469 pandemic-influenza associated deaths.
- The intensity of acute respiratory diseases in North America was high in Canada, Mexico, and the U.S.
- In Central America had a low or moderate intensity of acute respiratory disease; with the exception of El Salvador, which had a high intensity of acute respiratory disease and an increasing trend of acute respiratory disease
- Caribbean countries reported increasing or unchanged trends in acute respiratory disease, with outbreaks in schools.
- Most of South America had a decreasing trend and low or moderate intensity of acute respiratory disease; Colombia, however, had an increasing trend in acute respiratory disease
- 81.95% of subtyped influenza A viruses were pandemic (H1N1) 2009
- 133 new confirmed deaths in 10 countries (3539 cumulative deaths)