Transmission dynamics, clinical characteristics and sero-surveillance in the COVID-19 outbreak in a population dense area of Colombo, Sri Lanka April- May 2020 ανά Jeewandara, C, Guruge, D, Jayathilaka, D, Deshan Madhusanka, PA, Pushpakumara, PD, Tanussiya Ramu, S, Sepali Aberathna, I, Saubhagya Rasikangani Danasekara, DR, Pathmanathan, T, Gunatilaka, B, Malavige, S, Dias, Y, Wijayamuni, R, Ogg, GS, Malavige, GN