தொற்று நோய் மற்றும் நோயியல் இதழ்

சுருக்கம்

Paradigm Shift in Transmission of Vector Borne Diseases

Upasana Shyamsunder Singh, Monali Praharaj, Chayan Sharma and Aparup Das

Infectious diseases transmitted by insect vectors, otherwise known as Vector Borne Disease (VBDs) are causing havoc in the tropical and sub-tropical regions of the globe. Diseases like malaria, dengue, chikungunya, and zika are endemic to many of the countries. These VBDs not only cause mortalities, but some of them also cause high morbidity. Under a traditional model of disease transmission, symptomatic human hosts (patients) are considered to be the reservoir of pathogens which are then taken by the insect vectors and infect a new uninfected human host. This model therefore, assumes that the rate of transmission of VBDs is dependent on the number of symptomatic hosts in the population. However, in recent years this model seems not to hold true. In turn, recent research works have indicated that disease transmission is majorly contributed by otherwise underestimated high number of asymptomatic individuals in the population. In this communication, we have brought about the cases of high number of asymptomatic individuals infected with malaria, dengue and chikungunya in synthesizing and bringing into notice the importance of asymptomatic infection and the future direction to control VBDs through appropriate surveillance. We have also proposed a model to understand the relationship between symptomatic/asymptomatic infections and outbreak of epidemic/ inter-epidemic periods.