Ranjan Ramasamy

Title : Dengue transmission and aedes vector dynamics before, during and after COVID-19 travel restrictions

Abstract:

Contrary to expectation, dengue incidence decreased in many countries during the period when stringent population movement restrictions were imposed to combat COVID-19. Using a Seasonal Autoregressive Integrated Moving Average model, we previously reported a 74% reduction in the predicted number of dengue cases from March 2020 to April 2021 in the whole of Sri Lanka, with reductions occurring in all 25 districts in the country. The fall in dengue incidence was accompanied by an 87% reduction in larval collections of Aedes vectors in the northern Jaffna city. It was proposed that movement restrictions led to reduced human contact and blood feeding by Aedes vectors accompanied by decreased oviposition and vector densities that were responsible for diminished dengue transmission. These findings are extended here by investigating the relationship between dengue incidence, people movement restrictions and vector larval collections, between May 2021 and July 2022 when movement restrictions began to be lifted, with their complete removal in November 2021. The new findings further support our previous proposal that
population movement restrictions imposed during the COVID-19 pandemic reduced dengue transmission primarily by influencing human-Aedes vector interaction dynamics.

Audience Take Away 
• Appreciation of dengue virus transmission in relation to Aedes mosquito vector dynamics
• Assist teaching of public health, epidemiology and virology
• Help further research to advance knowledge on dengue virus epidemiology
• Understand neglected aspects of population exposure to mosquito disease vectors
• Appreciate epidemiological aspects of dengue and other mosquito-borne diseases

Biography:

Ranjan Ramasamy graduated from the University of Cambridge, UK and then obtained a PhD also from the University of Cambridge. He has since held academic appointments in the UK and abroad including Australia, Sri Lanka and the USA. He was the Chairman of the National Science Foundation of Sri Lanka, Professor of Life Sciences at the Institute of Fundamental Studies in Kandy in Sri Lanka, Professor of Biochemistry in the University of Jaffna in Jaffna Sri Lanka, Professor of Immunology in the University Brunei Darussalam Medical School and held institute appointments at the Babraham Institute in Cambridge in the UK & Scripps Clinic and Research Foundation in La Jolla in the USA. He has more 250 publications in fields pertaining to Medical Sciences. He was on the Committee on Scientific Planning and Review of the International Council for Science, and the Board of Governors of the International Centre for Genetic Engineering and Biotechnology.