Post-pandemic influenza-associated mortality in Mexico

Area of Science:

• Epidemiology
• Infectious Diseases
• Public Health

Background:

• Influenza poses a significant global respiratory infection burden.
• Limited data exists on influenza A(H1N1)pdm09 virus impact on mortality post-2009 pandemic.
• Understanding demographic shifts in influenza mortality is crucial for public health interventions.

Purpose of the Study:

• To estimate influenza-associated mortality for respiratory, cardiovascular, and all-cause events in Mexico from 1998-2015.
• To compare the proportion of influenza-associated deaths across different age groups.
• To analyze the demographic impact of influenza A(H1N1)pdm09 virus on mortality patterns.

Main Methods:

• Utilized national mortality register data from Mexico (1998-2015).
• Calculated average influenza-associated mortality rates per 100,000 population.
• Compared death proportions in various age strata, focusing on key winter seasons.

Main Results:

• Average annual rates: 5.2 (respiratory), 6.3 (cardiovascular), 19.6 (all-cause) deaths/100,000 population.
• Highest respiratory deaths in adults ≥60 years; children <5 also affected.
• Shift observed post-2009, with increased deaths in 20-59 age group during specific pandemic/winter seasons (2009, 2011-12, 2013-14).
• Consistent reduction in mortality rates for children <5 years.
• Influenza A(H1N1)pdm09 virus demonstrated a persistent change in demographic mortality patterns, especially in 2013-2014.

Conclusions:

• Influenza A(H1N1)pdm09 virus altered mortality demographics in Mexico post-2009.
• Mortality rates decreased in young children but remain elevated in adults >60.
• Persistent changes in influenza-associated mortality patterns highlight the need for ongoing surveillance and targeted interventions.