Washington: India has nearly 6 million more dengue cases than the official annual tally and costs the nation $1.11 billion, roughly the same India spends on its national space programme, according to a new study.

American and Indian researchers have calculated that the number of those suffering from the mosquito-borne disease is about 282 times higher than officially reported, according to the study published online Tuesday in the American Journal of Tropical Medicine and Hygiene.