tetano
Editor, Senior Moderator
The death toll of the 2009 influenza pandemic in equatorial climates may have been much lower than originally thought, according to a study supported by the National Institutes of Health's Fogarty International Center. The paper, published in PLoS ONE, challenges the idea that the pandemic was deadlier in the tropics, which harbor nearly half of the world's population and which have the highest burden of infectious disease.
The study may have a direct bearing on global estimates of pandemic burden and on the assessment of immunological, socioeconomic and environmental drivers of the outbreak, according to Fogarty researcher Dr. Wladimir J. Alonso, who led the study. The authors stressed that comparing disease burden as reliably as possible is critical in areas with competing health priorities and limited resources, as is the case for Brazil and other countries in the equatorial region.
Alonso's group of epidemiologists found evidence of far milder and delayed influenza pandemic mortality towards areas of Brazil closer to the equator. "We found that respiratory mortality was substantially higher during the pandemic in the southern and richer half of Brazil, where its circulation coincided with the colder winter months," said Alonso. "But even more puzzling, little or no difference from pre-pandemic mortality levels was identified in equatorial regions."
To arrive at these estimates, the researchers investigated laboratory-confirmed pandemic deaths in each Brazilian state and estimated the mortality burden caused by the pandemic that was above what would be expected in an average year. The analytical approach they employed determined baseline mortality in pre-pandemic years by considering the usual variability—including that of seasonal epidemics—in each location, and let them compare the impact of the pandemic across areas with different climatic and epidemiological profiles.
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Source: NIH/Fogarty International Center
http://www.sciencecodex.com/nih_stu...ess_affected_by_2009_influenza_pandemic-95926
The study may have a direct bearing on global estimates of pandemic burden and on the assessment of immunological, socioeconomic and environmental drivers of the outbreak, according to Fogarty researcher Dr. Wladimir J. Alonso, who led the study. The authors stressed that comparing disease burden as reliably as possible is critical in areas with competing health priorities and limited resources, as is the case for Brazil and other countries in the equatorial region.
Alonso's group of epidemiologists found evidence of far milder and delayed influenza pandemic mortality towards areas of Brazil closer to the equator. "We found that respiratory mortality was substantially higher during the pandemic in the southern and richer half of Brazil, where its circulation coincided with the colder winter months," said Alonso. "But even more puzzling, little or no difference from pre-pandemic mortality levels was identified in equatorial regions."
To arrive at these estimates, the researchers investigated laboratory-confirmed pandemic deaths in each Brazilian state and estimated the mortality burden caused by the pandemic that was above what would be expected in an average year. The analytical approach they employed determined baseline mortality in pre-pandemic years by considering the usual variability—including that of seasonal epidemics—in each location, and let them compare the impact of the pandemic across areas with different climatic and epidemiological profiles.
...
Source: NIH/Fogarty International Center
http://www.sciencecodex.com/nih_stu...ess_affected_by_2009_influenza_pandemic-95926