The Environmental Interventions Unit of icddr,b and the Epidemiology, Disease Control and Research (IEDCR) Wednesday launched an initiative to undertake environmental surveillance of Covid-19 and enteric pathogens in Dhaka and the Rohingya camps. Under the initiative, wastewater samples will be collected from selected spots comprised of drains, canals, and pumping stations in selected areas of Dhaka city and the Rohingya camps to track and monitor four vaccine-preventable pathogens including Salmonella typhi, Vibrio cholerae, Rotavirus of enteric pathogen and Covid in the communities. The benefit of environmental surveillance is multifaceted – it is highly cost-effective and supplementary to the clinical surveillance system, it provides early warnings, and the data generated are free from bias by healthcare access or healthcare behaviour. Also, it is effective in both symptomatic and asymptomatic infections, and evidence from environmental surveillance can be helpful for planning public health emergency responses – including in health communications, health facility preparedness, and vaccination campaigns. Environmental surveillance relies on wastewater samples, and helps track pathogens in circulation in the population, including their presence or absence, trends in concentrations, and generates an early warning, among others. A few low- and middle-income countries, including Pakistan and India, have deployed environmental surveillance for different diseases and successfully detected silent outbreaks – meaning a disease that otherwise would have gone unnoticed. The environmental surveillance initiative in Bangladesh will be implemented in cooperation with the Dhaka North City Corporation, Dhaka South City Corporation, Dhaka Water Supply and Sewerage Authority in Dhaka, the Department of Public Health Engineering, Refugee, Relief and Repatriation Commissioner, and Cox's Bazar Civil Surgeon Office.