Sri Lanka is currently witnessing an alarming rise in dengue cases, with the National Dengue Control Unit (NDCU) reporting that 3,649 dengue patients have been recorded in the country within the first three weeks of the year.
The highest number of cases was recorded in the Western Province, with 1,576 cases. Colombo District reported 491 cases, Gampaha 558, and Kalutara 95 cases. The NDCU has also revealed that two deaths from dengue have been reported so far.
The NDCU further notes that 22 districts across the country have been identified as high-risk areas for dengue, with health officials actively monitoring the situation. Health officials urge people to keep their surroundings clean and destroy mosquito breeding places in order to keep dengue at bay.
The Clean Sri Lanka initiative, having identified this issue, has disclosed plans to build a holistic mechanism by solving mismanagement of waste disposal, strengthening inspections of breeding grounds, and fining, while also directing media outlets to conduct awareness programmes.
Brief history of dengue outbreaks in SL
The magnitude of Dengue Fever (DF) and Dengue Haemorrhagic Fever (DHF) epidemics in Sri Lanka increased during the early 2000s. Two of the largest epidemics occurred in 2002 and 2004, with 8,931 cases recorded according to the Quarterly Epidemiological Bulletin of the NDCU.
Dengue has a seasonal transmission in Sri Lanka, with two peaks occurring during the monsoon rains in June-July and October-December, respectively. Currently, almost all districts are reporting cases, with the Colombo, Gampaha, and Kalutara Districts in the Western Province having the highest rates.
Potential breeding sites
Dengue vectors, being container breeders, reproduce in artificial and natural wet containers, preferably with clear, unpolluted water. Breeding sites are found both inside and outside premises, at ground level and above, such as roof gutters, overhead tanks, and slabs.
These containers are found at any type of premises including houses, offices, hospitals, garages, commercial sites, yards containing automobile parts, schools, religious places, cemeteries, bare lands, construction sites, and plant nurseries. Furthermore, discarded containers along river and stream banks and railway lines are also possible breeding sites of Aedes aegypti and Aedes albopictus.
However, in some instances, the breeding sites are area specific, such as shallow cemented wells in Batticaloa and Jaffna. Aedes aegypti prefers to oviposit in artificial containers. Although Aedes albopictus is considered as a sylvatic species and breeds in natural containers such as leaf axils and tree holes, it also breeds in artificial containers in urban and peri-urban areas.
Aedes aegypti shares its habitat with other Aedes species including Aedes albopictus, non-Aedes species, and occasionally with some Anopheles species.
The NDCU classifies the most common breeding sites of Aedes aegypti and Aedes albopictus in Sri Lanka as follows: discarded receptacles (plastic containers, tins, clay pots, yoghurt and ice cream cups, bottles, cans, damaged ceramic items, coconut shells, etc.), water storage containers (water storage cement tanks, barrels, and other containers), automobile tyres and machinery parts, building structures (roof gutters, concrete slabs, etc.), household/institutional appliances (refrigerator trays, flower vases, ornamental ponds, non-functional cisterns, and squatting pans of wash rooms), other artificial breeding sites (abandoned boats, cemeteries, etc.), and natural breeding sites (leaf axils and tree holes).
Dengue cases during rainy season
Government Medical Officers’ Association (GMOA) Spokesperson Dr. Chamil Wijesinghe described the present situation as alarming, with thousands of cases reported within just three weeks into the year. He attributed the rise to multifactorial causes such as ongoing rains, lack of proper waste disposal mechanisms, inadequate drainage systems, and high population density.
Generally, most dengue cases were reported in high population density areas such as cities, especially Colombo and Gampaha, Dr. Wijesinghe told The Sunday Morning. “In Colombo, areas such as Pettah and its surroundings, Maharagama, Boralesgamuwa, Kolonnawa, Wellampitiya, and Angoda have been identified as the main pockets of dengue in recent years.”
A Govt. and public responsibility
Dr. Wijesinghe highlighted that dengue was preventable and advocated the need for the Government and the public to share equal responsibility to take necessary measures in tackling this matter.
He stressed the importance of cleaning, drainage management, and destroying mosquito breeding grounds. “The Ministry of Health and relevant Government officials should arrive at a decision and act on this as soon as possible given that we are witnessing a rise of cases,” he said.
The GMOA Spokesperson also stressed the need for inter-sectoral collaboration, including the Police, Local Government, and tri-forces, to expedite the process.
He emphasised that a failure in this regard would lead to continued high numbers of dengue cases, exacerbating the suffering of people.
No challenges in diagnosis and treatment
Dr. Wijesinghe noted that despite the rising number of dengue cases, there were no significant challenges in identification and treatment, citing that the high-risk numbers themselves demonstrated the effectiveness of the diagnostic system and that patients were not being missed.
“At present, the healthcare system is manageable. However, if this leads to a massive outbreak, it will become challenging to handle,” he said, referring to the experiences of 2017 and 2018. He also highlighted the current shortage of doctors and specialists, which could exacerbate the situation.
Therefore, he emphasised the importance of taking precautions and implementing necessary action to prevent a spike in cases.
Need to spread awareness
Dr. Wijesinghe said that while awareness programmes had already commenced, there was a need to see them being orchestrated at the ground level, including within municipal councils and through Medical Officers of Health (MOHs) in villages and towns.
However, he pointed out that such awareness programmes alone would not yield the desired results, as the public also needed to share responsibility by cleaning their gardens and surrounding areas, destroying mosquito breeding grounds.
Clean Sri Lanka and tackling dengue
Given that garbage dumping grounds managed by certain municipal councils often act as breeding grounds for dengue mosquitoes, Clean Sri Lanka member Chaminda Jayasuriya stressed the importance of resolving mismanagement issues and initiating a more effective garbage handling and disposal process to address this.
Jayasuriya highlighted the availability of sufficient locations for garbage burning and proposed utilising garbage to generate electricity, produce fertiliser, or feed animals, ensuring a proper mechanism for waste management.
He pointed to ongoing discussions and coordinating efforts with municipal councils and local authorities, as these entities are responsible for handling the cleaning process. Jayasuriya also noted that a concrete solution to tackle the garbage problem would be implemented within the next year or two, which in turn would help mitigate the dengue issue.
He explained that Public Health Inspector (PHI) house inspections were conducted regularly to identify mosquito breeding grounds under an established mechanism.
“The Ministry of Health has a proper system in place where, if an individual is infected with dengue and admitted to the hospital, the MOH contacts the patient to obtain their details. Following this, the grama niladhari, PHI, MOH, and Police visit the patient’s residence to inspect it and inform nearby houses,” he said.
However, he acknowledged that there were instances where this process did not function as intended and assured that efforts were underway to strengthen the mechanism further.
Jayasuriya also stressed that the enforcement of fines would be reinforced to encourage the public to clean their residences. Additionally, he revealed ongoing discussions with PHIs to initiate restaurant inspections as part of dengue prevention efforts.
He further noted that the current staff was sufficient to address the dengue issue and said that there were no plans to hire additional personnel.
Jayasuriya noted that discussions had been held with media institutions to spread awareness by conducting campaigns similar to Covid-19 awareness programmes, for which they had received a positive response.