Dengue and chikungunya in India

Sanjit Bagchi recently highlighted the surge in cases of dengue in India. 1 It is worth noting that chikungunya, another disease borne by the Aedes egypti mosquito, also poses a major health threat to large populations. 2 The 2 diseases have similar symptoms, although hemorrhagic manifestations are relatively rare with chikungunya. Therefore, care should be taken when caring for patients suffering from either of these diseases as the diagnosis could be incorrect. Although cases of dengue are mostly seen in the northern parts of India, chikungunya is more prevalent in India’s southern states.

The control of mosquito-borne diseases in India usually involves a strategy based on that used to control the spread of malaria by Anopheles mosquitoes. However, unlike Anopheles mosquitoes, the Aedes mosquitoes that spread dengue and chikungunya can breed in clean as well as in dirty water, and they usually bite during the daytime.

These mosquito-borne diseases have a socio-economic impact as well. A few foreign tourists have reported symptoms of chikungunya upon their return home from tropical areas. 3 Assuming that the number of tourists visiting tropical countries from non-endemic countries would decline owing to epidemics of these diseases, Mavalankar and colleagues reported that the loss of tourism revenue would be comparable to the estimated annual cost of preventing or treating chikungunya and dengue in these countries. 4 Such a decline in tourism revenue would be a major setback for a country like India, which is a hotspot for tourism and where almost 80% of patients with chikungunya live below the poverty line. 5