Indian Ocean basin-wide (IOBW) Index

Indian Ocean basin-wide (IOBW) Index

Context: The close association between dengue outbreaks in both the Northern and Southern hemispheres and the Indian Ocean basin-wide (IOBW) index has been demonstrated by the study.

About:

• The average sea-surface temperature variations across the tropical Indian Ocean are represented by the Indian Ocean basin-wide (IOBW) index.
• This index has emerged as a key predictor for estimating the magnitude and timing of dengue epidemics in each country.
• The association of the IOBW index with the Southern Hemisphere is stronger than its association with the Northern Hemisphere.
• The index exerts a more significant impact on temperatures in tropical regions. For instance, Brazil, situated in the Southern Hemisphere, experiences a higher burden of dengue.
• Dengue epidemics peak in the Northern Hemisphere between July and October and in the Southern Hemisphere between February and April, aligning with the respective summer seasons.
• The amplitude of dengue incidence tends to be higher when the IOBW index is positive and lower when it is negative.
• The link between Indian Ocean temperature and dengue incidence is likely attributable to its influence on regional temperatures through teleconnections, which are large-scale atmospheric patterns capable of transferring heat and moisture across vast distances.

Key Facts about Dengue