Singapore has just begun to get its second wave of coronavirus under control. Now, it's on track to face its worst-ever outbreak of another viral infection: dengue.
More than 14,000 dengue cases have been reported in the city-state since the start of the year, according to the National Environment Agency (NEA), reports the CNN.
The total number for the whole year is expected to exceed the 22,170 cases reported in 2013 -- the largest dengue outbreak in Singapore's history, the agency said.
Dengue is a viral infection transmitted by the Aedes mosquito, the same insect responsible for spreading Zika, chikungunya and yellow fever. It is commonly found in hot, wet regions of the tropics and subtropics during the rainy months.
Only about 25% of those infected show symptoms, which include high fever, severe headaches, muscle and joint pains. Extreme cases can bring bleeding, breathing difficulties, organ failure, and potentially death.
Dengue cases have grown dramatically worldwide, increasing 30-fold in the past 50 years. There are an estimated 100-400 million infections each year, and about half of the world's population is now at risk, according to the World Health Organization.
Scientists say hotter, wetter weather brought on by climate change has created ideal conditions for female mosquitoes to lay their eggs. Not only are there more mosquitoes, but the rapid urbanization occurring in many Asian nations means that susceptible populations are living in closer contact with disease-carrying insects.
Another potential factor that worsened the dengue outbreak this year could be the lockdown measures imposed for coronavirus, according to Luo Dahai, associate professor of Infection and Immunity at Nanyang Technological University.
In April, a second wave of infections broke out in Singapore among migrant workers living in packed dormitories, sending daily new infections from below 100 to above 1000 at its peak.
To contain its spread, the government issued a stay-at-home order and closed down non-essential workplaces and schools. These restrictive measures, known as the "circuit breaker," lasted from April 7 to June 1.
"When more people stay at home all the days, there could be more residential mosquito breeding and more opportunities for 'blood meals'," Luo said.