Changing trends of vector-borne diseases after the COVID-19 pandemic in India

Although the unprecedented outbreak of coronavirus disease 2019 (COVID-19) and its deep-rooted consequences are visible in many areas, their impact on vector-borne diseases (VBDs) is only poorly understood. Therefore, the temporal trends of major VBDs such as malaria, dengue, chikungunya, Japanese encephalitis, and kala-azar in India were analyzed before and after the COVID-19 pandemic.

Data of annually reported VBD cases, such as malaria, dengue, chikungunya, Japanese encephalitis, and kala-azar, in India from 2014 to 2024 were collected and plotted on a bar graph using Microsoft Excel. Trend lines were drawn separately for all VBDs before and after 2020 and the R2 value was calculated. The Pearson correlation coefficient (r value) for each trend was calculated using Microsoft Excel to determine the strength of the trend before and after 2020 for each VBD.

The trend line of each VBD; including malaria, dengue, chikungunya, Japanese encephalitis, and kala-azar; showed a different pattern before and after 2020. The r value of the trend indicated that the COVID-19 pandemic has transformed the declining trend of malaria into a strongly increasing trend. The other trends affected by the pandemic were Japanese encephalitis, dengue, chikungunya, and kala-azar.

This study demonstrates a clear influence of the COVID-19 pandemic over the trend of VBDs ranging from mild changes to a total reversal of the trend.