Entomological surveillance of dengue vector Aedes aegypti in Delhi during COVID-19 pandemic

Abstract

Introduction: Dengue has become endemic in Delhi and incidences are alarmingly risen due to key factors similar as occurring globally i.e. large scale migration to Delhi for economic avenues has led to mushrooming of unauthorised areas and lack of 24 X 7 water supply has compelled citizens to store water in improper containers thus increasing breeding sites. In Delhi, staff of vector-borne disease control programme was dedicated to prevention and control of COVID-19 Pandemic thereby compromising the entomological surveillance and control measures for VBDs. Material and Methods: This is a descriptive study based on analysis of entomological data generated during surveillance by the entomological team of City SP Zone under North Delhi Municipal Corporation from January 2020 to Jun 2021. Peridomestic areas were checked for the presence of mosquito breeding. If the container was found positive either source reduction was done or was treated with Temephos Granules.Results: In Delhi, previously approx. 70% of dengue cases were reported from the age group 11 to 40 years. In 2020, due to lockdown, no mobility in the human population might have restricted the Dengue cases. High breeding was reported during unlock period and dengue cases from mid-July 2020 onwards were increased. During post-monsoon, the number of positive containers increased proportionately may be due to reduced surveillance.Conclusion: Vector surveillance and strategies of Integrated Vector Management (IVM) suffered during Lockdown of 2020 and 2021. Any neglected co-infection of dengue along with COVID may lead to diagnostic and case management challenges. Hence surveillance of VBDs can’t be ignored in such situations as COVID-19.