2020 dengue outbreak in singapore 2020 dengue outbreak in singapore in the 2020 dengue outbreak in singapore, a record-breaking number of dengue fever cases was reported in singapore. this was part of the wider 2019–2020 dengue fever epidemic which also affected several neighbouring countries in southeast asia. 2020 dengue outbreak in singaporediseasedengue fevervirus straindengue viruslocationsingaporedate2020confirmed cases35,315severe cases54deaths32fatality rate0.09%government websitenea dengue cases a locally uncommon strain of the dengue virus — one that the local populace would be more susceptible to – had begun to reemerge toward the end of 2019. this contributed to a four-year high in the number of people infected in the first six weeks of 2020, establishing a high baseline for disease incidence even before the onset of the peak dengue season in the middle of the year. there was a steep climb in the rate of infection beginning in may, and by early july the total number of cases for the year was projected to surpass the previous high of 22,170 recorded in the 2013 outbreak. the weekly disease incidence would reach a historic peak of 1,792 new cases during the week of 19–25 july. this surge of infections drove the cumulative number of cases to 22,403 on 5 august 2020, breaking the 2013 record. on 14 october, the number of deaths due to dengue reached 28, surpassing the previous record from the 2005 outbreak. the year ended with a total of 35,315 dengue fever cases, including 54 instances of dengue haemorrhagic fever, a more severe form of the disease. 32 deaths were attributed to the disease. timeline weekly incidence of dengue fever in singapore in 2020 chart based on information from weekly infectious diseases bulletins issued by ministry of health, singapore. data available under the terms of the singapore open data licence version 1.0. january 15 january: the national environment agency (nea) warned about the reemergence of the denv-3 strain of the dengue virus, which had not been common in singapore in the past three decades, meaning that the local population would be more susceptible to it. february 8 february: a four-year high in the number of people infected in the first six weeks of the year is reported, at 2,130 cases. may 11 may: senior parliamentary secretary at the ministry of education and ministry of trade and industry low yen ling contracted dengue. june 9 june: infection rates doubled in the span of five weeks, from 390 new cases a week to 872. the cumulative number of cases in the year crosses the milestone of 10,000 cases. 12 june: 895 infections are recorded in the first five and a half days of the epidemiological week, breaking the record for number of cases in a week. july 23 july: outgoing minister for transport khaw boon wan was hospitalised for dengue fever, just days ahead of his retirement following the 2020 general election. due to a high temperature, he had been admitted to an isolation ward as a precaution, but was later tested negative for covid-19. 25 july: the peak weekly disease incidence for the year occurs in the week of 19–25 july, which had a historic 1,792 infections, more than doubling the previous record of 891 cases in 2014. august 5 august: the previous record for number of cases in a year is surpassed when the number of cases reaches 22,403. october 14 october: the number of deaths due to dengue rises to 28, surpassing the previous high recorded in 2005. epidemiology distribution of dengue serotypes in singapore in 2020. denv-3 overtook denv-2 to become the dominant strain from january to april 2020. resurgence of less common denv-3 strain there are four strains of dengue virus, denv-1 to denv-4. infection with one serotype confers immunity against it, but not the others. since 2016, denv-2 had been the dominant strain in singapore, causing the majority of infections. there had not been an outbreak of the less common denv-3 in singapore for nearly three decades, so the local population had lower immunity against it and was more susceptible to infection when denv-3 returned as the dominant strain from january to april 2020. this contributed to an unusually high number of infections even before the start of the mid-year peak dengue season, which in turn increased the momentum of dengue transmission. concurrent covid-19 pandemic