Aside from the COVID-19 virus outbreak, Singapore is also dealing with a surge in dengue cases as over 4,000 people were reportedly infected with dengue fever since the beginning of the year, which double the number of cases reported within the same period in 2019.
Earlier on 20 February, Singapore confirmed the first patient to be co-infected with both the coronavirus (COVID-19) and dengue fever. The patient is the 82nd confirmed COVID-19 case in the country, and the Ministry of Health (MOH) remarked it as “an extremely unique occurrence”.
According to Environment and Water Resources Minister Masagos Zulkifli, about 300 to 400 new cases have been reported since January, adding that there could be more instances of transmission during the warmer months of the year, the Straits Times reported earlier today (23 March).
He noted the three factors that caused the surge in dengue cases between June and October, including the emergence of less common dengue virus serotype – dengue virus serotype 1 and 2 (DENV-1 and DENV-2) –warmer temperatures, and rain which caused the increase in the population of the Aedes aegypti mosquito.
“If the three factors I mentioned persist, this number could rise beyond the historical weekly peak of 891 cases recorded in July 2014, during the peak season,” Mr Masagos said during the launch of the National Dengue Prevention Campaign in Ang Mo Kio yesterday (22 March).
The National Environment Agency (NEA) released a statement on the same day, stating that additional proactive steps are needed to handle the mosquito population else the country may experience an increasing trend of dengue cases in the second half of this year, Channel News Asia reported on Sunday.
“The warmer months from June to October usually see higher transmission of dengue in Singapore, due to accelerated development of the Aedes mosquito and shorter incubation period of the dengue virus,” NEA stated.
NEA also noted that there has been a surge in dengue virus serotype 3 (DENV-3) cases in the past four months, indicating the rise of DENV-3 is worrying “as we have not had dengue outbreaks driven by DENV-3 in Singapore for almost three decades”.
“The monthly proportion of DENV-3 cases in February was approximately 48 per cent, almost double the proportion of DENV-2 cases at 26 per cent, NEA noted.
This means that the people have lower immunity to DENV-3, and consequently a large proportion of the population will be susceptible to DENV-3 infection, according to NEA.
“The combination of a potential sustained change in the predominant dengue virus serotype, coupled with the high Aedes aegypti mosquito population in some areas, and the unusually high number of dengue cases seen currently, could create a momentum of transmission that may drive even more dengue cases when we enter the warmer months ahead,” NEA stated.
Mr Masagos, on the other hand, remarked that it is “still too early” to tell if there has been a switch of predominant dengue virus type, and assured that the NEA is monitoring the situation closely.
Following this year’s dengue outlook, the NEA has decided to launch the annual National Dengue Prevention Campaign in March, which aimed to raise residents’ awareness of the importance of clean water in preventing dengue disease.
Mr Masagos also called for a collective effort and urged everyone to do their part in preventing mosquito breeding.