La Nina may be the cause of a pandemic

US scientists on January 16 said La Nina weather phenomenon in the tropical Pacific region may be the main cause of dangerous pandemics in the world.

>>>La Nina weather phenomenon has reached its peak

Professor Jeffrey Shaman from Columbia University's School of Public Health and Professor Marc Lipsitch at Harvard School of Public Health, conducted a study on the relationship between weather patterns and pandemics. in 1918, 1957, 1968 and 2009, by examining reports on seawater temperature in the Pacific tropical region in the fall and winter before the four influenza pandemics appeared.

Scientists found that all four pandemics occurred after the surface temperature of the sea was below the average and coincided with the appearance of La Nina.

In addition, based on previous studies, scientists believe that La Nina weather phenomenon has changed migration habits, rest time, adaptation and mixing between different species of species. migratory birds.

These weather conditions facilitate the exchange of genes or the recombination of genes, thereby creating more variants of influenza viruses.

According to Professor Samen, pandemics often stem from major changes in the influenza virus genome. La Nina weather phenomenon has contributed to these changes by creating a mix of species of migratory birds, which are considered the main source of dangerous flu viruses.

Changes in the migratory habits of birds also change the way in which these species are exposed, as well as between birds and domestic animals such as pigs. The gene exchange between avian influenza virus and swine influenza virus is one of the main causes of the 2009 A / H1N1 pandemic.

The study is published in the report of the US National Academy of Sciences.