Dengue outbreaks follow a curious pattern. Once in five years, the case burden shifts to southern India. In 2022, Tamil Nadu, Karnataka and Andhra Pradesh formed 60% of India’s cases. Similar spikes in the south were recorded in 2012 and 2017. A month-wise breakup of cases reveals another interesting trend. The dengue infections mimic the progression of the south-west and northeast monsoons. The share of dengue deaths is disproportionately higher in Maharashtra and Kerala.
Back in the south
The table shows a State’s share of India’s total dengue cases. For instance, Tamil Nadu accounted for 32% of all cases reported in 2022 (till May). In 2022, the dengue burden shifted to the south as three States — Tamil Nadu, Karnataka and Andhra Pradesh — accounted for 60% of the dengue cases reported. The shift is part of a cycle in which cases in the south increase once in five years.
