KUALA LUMPUR: With the country's attention and resources geared towards battling the Covid-19 pandemic, medical experts warn of the looming risk of dengue amid the rainy season in Malaysia.
According to the World Health Organisation (WHO), despite a risk of dengue infection existing in 129 countries, 70 per cent of the actual burden is in Asia with Malaysia having one of the highest number of cases.
Over the last two years, dengue has been on the rise in Malaysia, registering 80,615 cases (147 deaths) in 2018 and 130,101 cases (182 deaths) last year.
Based on annual data released by the Health Ministry's Crisis Preparedness and Response Centre (CPRC), dengue cases usually start increasing from May and spike after the monsoon during July and August.
With the Movement Control Order (MCO) in place and most of the premises closed, experts have cautioned that heavy rain could lead to pooling of water and contribute to an increase in mosquito breeding sites.
The warmer temperature could accelerate transmission rates of dengue fever and the humid weather creates favourable conditions for the vectors to flourish.
Universiti Selangor Visiting Professor of Environmental Health Prof Dr Jamal Hisham Hashim said while the nation is in full force combating Covid-19, authorities should be wary of the impending outbreaks of other communicable diseases that are endemic in the country like dengue fever.
"Dengue is the world's fastest-growing vector-borne disease and is a serious concern wherever it is found within the world's expanding dengue belt. There is no cure for it, and its vaccine has some effectiveness issues.
"We should be continuously vigilant of the disease as dengue cases may spike at any time. Studies indicate that cases tend to increase during warmer temperatures with moderate rain like what Malaysia is experiencing now," he told the New Straits Times.
Jamal said while construction sites are an important driver of dengue transmission, they are only one of the Aedes mosquitoe breeding grounds.
"Aedes breeds in discarded containers, rain gutters, clogged drains, plant pots, water storage containers and uncovered water tanks.
"Dengue hotspots also include open and abandoned spaces around residential areas, which may be used as illegal dumping grounds.
"If people come across such areas, they should notify the local authorities or the district health office."
Jamal said the Health Ministry is well-equipped and prepared to handle dengue outbreaks as the Standard Operating Procedure (SOP) is well-established in Malaysia.
"I do not think dengue cases will get out of control amidst the current Covid-19 outbreak, unless the situation worsens. This is quite unlikely to happen as we are now over the peak for the Covid-19 epidemic in the country.
"Fortunately, the Health Ministry has a good surveillance system for foodborne, waterborne, vector-borne and zoonotic diseases, which can flare up in our communities."
Former deputy director-general of public health Professor Datuk Dr Lokman Hakim Sulaiman said dengue "could be a silent killer" amid the attention over Covid-19.
"Last year, cases started to increase in Week 19 (now we are in Week 17). In terms of more severe dengue, the number of dengue deaths to date this year is 60, not much different from 64 in the same period last year."
According to the latest statistics from the CPRC's Dengue Operations Centre (http://idengue.arsm.gov.my/), 38,464 dengue cases were reported in Malaysia between Dec 29 last year and April 22 this year.
A total of 63 deaths from dengue were reported between January and April 18 this year.
The six states with the highest number of dengue cases were Selangor with 23,140 cases, Johor (3,181), Kuala Lumpur (2,932), Sabah (2,056), Kelantan (1,441) and Perak (1,255).
Dr Lokman said while Covid-19 was more serious with higher case fatality rates (CFR) of 1.6 per cent (89/5,425) as compared with dengue with CFR of only 0.16 per cent (60/36,529), preventive measures should be in place as dengue is lethal.
The director of the Institute for Research, Development and Innovation at the International Medical University said, fortunately, anti-dengue activity — maintenance, cleaning and drying of stagnant water, spraying of pesticides — at construction sites was listed as essential services, allowed and required to be continued during the MCO.
"Schools, universities and most office buildings are closed, which means there could be lots of stagnant water such as at the toilet and cistern that are great for Aedes breeding."
Malaysian Public Health Medicine Specialist Association president Datuk Dr Zainal Ariffin Omar said the upsurge in dengue cases and deaths pose an economic burden and loss of productivity cost to the nation.
He expressed concern that despite the high number of cases, dengue may be overlooked by the government and people because of Covid-19.
"In resource-limited settings, such as now where the attention is on Covid-19, this might put additional pressure on an already overburdened healthcare system, especially during the annual dengue epidemic.
"Abandoned construction sites, closure of public and private premises, neglected maintenance by local authorities, and people staying at home could lead to more Aedes breeding."
It was reported that in 2010, Malaysia spent a total of US$73.5 million (0.03 per cent of Malaysia's GDP) on its National Dengue Vector Control Programme.
About 92 per cent of the amount was used for fogging.
Dr Zainal said the public should carry out regular search and destroy breeding places at home and its vicinity, while local authorities should conduct public fogging and intensify control measures.