Experts warn of a spike in dengue cases

Intermittent rain and warmer temperature may lead to higher cases of dengue, experts warn, especially as more Malaysians are staying indoors.

Institute of Ocean and Earth Sciences senior research fellow Prof Datuk Dr Azizan Abu Samah said while the current weather pattern was not out of the ordinary, the frequent shifts between rain and sunshine could contribute to a rise in dengue cases.

“Now we have intermittent rain combined with high temperature, the chances of (having Aedes mosquitoes) breeding are higher.

“During such intermittent showers, it will rain followed by one or two days where there is no rain, leaving pools of water where Aedes mosquitoes can breed,” he said, adding the highest rainfall for the Kuala Lumpur region would be around April before it tapers off in later months.

He added that the higher temperature could also lead to a spike in dengue cases.

World Health Organisation Collaborating Centre for Arbovirus Reference and Research director Prof Dr Sazaly Abu Bakar said the trend for dengue cases this year was similar to last year’s trend.

When asked whether the movement control order (MCO) would have affected the number of dengue cases, he said it was unlikely.

“After the MCO was eased, the number of dengue cases started going up. However, last year, we saw the trend for the month was also about the same,” he said.

He said while the yearly weather pattern might have a bearing on the number of dengue cases, more funding needs to be devoted to research to better understand what caused a spike in dengue cases.

He added that while previous research in Singapore proposed that dengue cases were linked to outdoors mobility, the rising number of dengue cases during the country’s circuit breaker appeared to suggest otherwise.

Singapore recorded 1,158 new dengue cases in the week ending June 13, the highest ever recorded in Singapore since 2014.

“Some researchers in India suggested that when we stay indoors, especially when it is hot and humid, outbreaks tend to increase and to be more sustained. When we stay indoors, people are more concentrated in those (residential) areas, so mosquitoes have more ‘targets’ to bite,” he said.

Prof Sazaly also suggested that authorities could consider “clearing” people away from areas which report dengue clusters for a certain period of time.

“For Covid-19 clusters, we introduced enhanced MCO in selected areas. So for dengue, we could instead instruct everyone to leave the area and conduct fogging in that area,” he said.

Health Minister Datuk Seri Dr Adham Baba said from January to June 13, there were 50,511 cases of dengue fever and 88 deaths.

The same period last year recorded 56,819 cases and 88 deaths.