A high-level media briefing was held on Wednesday at the Ministry of Health and Mass Media to raise public awareness ahead of the upcoming Mosquito Control Week, scheduled from tomorrow (June 30) to July 5. The initiative, spearheaded by Minister of Health and Mass Media Dr. Nalinda Jayatissa also addressed the current situation regarding dengue, chikungunya, malaria, and filaria in the country.
Senior health officials including Director General of Health Services Dr. Asela Gunawardena, National Dengue Control Unit Director Dr. Sudath Samaraweera, Community Medical Specialist Dr. Prashila Samaraweera, Anti-Filaria Campaign Director Dr. Prasanga Serasinghe, Malaria Control Campaign’s Dr. Indeevari Gunaratne, and Senior Assistant Secretary (Information and Publicity) Lakshmendra Damayantha Kumara Tennakoon were among the speakers.
Dengue cases continue to climb
Dr. Asela Gunawardena said that 27,932 dengue cases have been reported so far this year. The outbreak peaked in May, which recorded 6,034 cases, followed by 5,166 in April, and 4,372 in June. From January to June, 16 dengue-related deaths were recorded.
To combat the alarming spread of the virus, especially during the ongoing Southwest monsoon, the Ministry has declared a special Mosquito Control Week. The campaign will focus on 111 high-risk Regional Director of Health Services and MOH divisions, including the Colombo Municipal Council areas.
More than 1,100 inspection teams, supported by the Tri-Forces, Police, and Civil Defence Force, have been deployed. From January to June, 179,026 suspected mosquito breeding sites were inspected nationwide. This included 167,081 homes, 317 schools, 386 educational institutions, 927 Government offices, and other public and private premises.
Mosquito larvae were detected in 23 percent of homes, 28 percent of educational institutions, 40 percent of religious sites, and 50 percent in construction sites. Dengue larvae were also found in 46 schools and 13 percent of religious premises, prompting renewed calls for urgent cleanup and improved waste management.
No cure—only control
Dr. Sudath Samaraweera said that there is no vaccine or effective treatment for dengue, making mosquito control the only line of defence. He appealed for community support during the Mosquito Control Week, adding that efforts to control dengue would also reduce the transmission of other vector-borne diseases, such as chikungunya.
Chikungunya resurfaces
For the first time in over a decade, Sri Lanka is experiencing a resurgence of chikungunya, particularly in the Western Province. The health authorities have attributed the outbreak to a mutated strain of the virus that is more easily transmitted by Aedes aegypti mosquitoes, which thrive in monsoon conditions.
According to available data, 173 chikungunya cases were confirmed from sentinel hospitals in Colombo, Gampaha, and Kandy, with 22 cases reported in late 2024 and 151 more as of March 2025.
Hospitals such as the Lady Ridgeway Hospital for Children have also reported an increase in paediatric admissions due to chikungunya, dengue, and influenza, prompting warnings from medical professionals to closely monitor children and the elderly, who are more vulnerable to complications.
Health authorities reiterated the importance of eliminating mosquito breeding sites, using repellents, wearing long-sleeved clothing, and seeking timely medical attention. Public cooperation remains critical in breaking the cycle of transmission and protecting communities.
Filariasis
Director of the Anti-Filariasis Campaign, Dr. Prasanga Serasinghe, said that while filariasis is transmitted by mosquitoes, unlike some diseases, it does not typically cause sudden deaths. However, if left untreated, complications can lead to long-term conditions such as swelling of the limbs and legs.
Dr. Serasinghe called upon the public to support night-time blood and tissue tests conducted to identify infected persons. He said that filariasis is a treatable disease, and that vector mosquitoes can be controlled by maintaining clean surroundings and eliminating stagnant water sources.
He said the prevalence of filariasis in the country has been brought under effective control, and Sri Lanka had been certified by the World Health Organization (WHO) in 2016 as having eliminated lymphatic filariasis as a public health problem, after achieving microfilaria prevalence below one percent.
The WHO’s declaration does not mean filariasis has been eradicated, but that infection levels have been reduced to the point where the disease no longer poses a significant public health burden. Following the certification, Sri Lanka entered a post-validation surveillance phase to ensure infection levels remain low and to detect any signs of ongoing transmission.
Current situation
Dr. Serasinghe said that 27 patients were identified last year, and added that the disease could still spread via vector mosquitoes through infected persons arriving from overseas. Testing and surveillance efforts are continuing in at-risk areas.
The Anti-Filariasis Campaign remains active, with eight regional units. Its goals include completely interrupting transmission by 2030, strengthening vector control and surveillance, and managing morbidity and disability caused by the disease.
The Mass Drug Administration (MDA) ended in 2008, with mop-up rounds conducted from 2014 to 2016. Ongoing parasitological and entomological surveillance continues in previously endemic districts. Microfilaria prevalence has remained well below the one percent threshold, although small “hot-spots” persist. For instance, Galle recorded 0.03 percent in 2020 and 0.05 percent in 2021.
Clinics still report lymphoedema and hydrocele cases, though these are on the decline. In 2022, around 566 new lymphoedema visits were recorded, reflecting a 7.6 year year-on-year reduction in morbidity.
Lymphoedema is a chronic condition that causes swelling in the body’s tissues, commonly affecting the arms or legs, due to a poorly functioning lymphatic system. Hydrocele is a form of scrotal swelling that occurs when fluid collects in the sheath surrounding the testicle and can be congenital.
Malaria
Sri Lanka remains malaria-free, with strong public health vigilance still in place.
Consultant Community Physician of the Anti Malaria Campaign, Dr. Indeevari, said that although vector-borne malaria has been eradicated in Sri Lanka, the risk of reintroduction remains high due to the movement of returnees, migrant workers, and travellers from malaria-endemic countries such as India and nations in Africa.
Approximately 50 malaria patients are identified each year. In 2024, 38 cases were reported, 99 percent of them male returnees from abroad. About 75 percent of these patients were Sri Lankan nationals, and 15 cases have been reported so far this year.
Some patients reported in the Northern Province were persons who had travelled to endemic regions illegally and are now being treated to prevent further transmission upon their return.
Sri Lanka has maintained its malaria-free status since 2016, when it was officially certified by the WHO. The last indigenous case was reported in 2012, marking a significant milestone in the country’s public health history.
Since certification, Sri Lanka has been in the Prevention of Re-establishment (PoR) phase, focusing on keeping the country free from local transmission through rigorous monitoring of imported cases.
Although no local transmission has been reported since 2012, a few isolated incidents have occurred—including an introduced case in 2018 and a transfusion-transmitted case in 2021. These highlight the critical need for ongoing surveillance and rapid response.
Each year, small numbers of imported cases are identified, mostly among migrant workers, travellers, and pilgrims. 62 cases were reported in 2023, and 38 in 2024. As of April 2025, 14 cases have been detected and managed through prompt diagnosis and treatment.
Surveillance
To sustain its malaria-free status, Sri Lanka has adopted a comprehensive National Malaria Strategic Plan (2023–2027). It includes active surveillance at ports of entry, targeted prophylaxis for outbound travellers, mosquito vector monitoring, and rapid diagnostics. The plan also prioritises medical training, laboratory capacity-building, and awareness-raising in high-risk communities.
The authorities continue to collaborate with the military, fisheries, immigration services, and other sectors to prevent the re-establishment of the disease. Despite reduced public awareness and clinical familiarity with malaria, entomological receptivity—particularly due to the presence of Anopheles stephensi—remains a threat.
WHO and other international partners are supporting Sri Lanka’s efforts through technical expertise and funding, helping to safeguard the country’s malaria-free status amidst ongoing global health risks.
