Dengue is transmitted by the bite of an Aedes mosquito infected with any one of the four dengue viruses. It occurs in tropical and sub-tropical areas of the world. Symptoms appear 3—14 days after the infective bite. Dengue fever is a febrile illness that affects infants, young children and adults.
Symptoms range from a mild fever, to incapacitating high fever, with severe headache, pain behind the eyes, muscle and joint pain, and rash. There are no specific antiviral medicines for dengue. It is important to maintain hydration. Use of acetylsalicylic acid (e.g. aspirin) and non steroidal anti-inflammatory drugs (e.g. Ibuprofen) is not recommended.
Dengue haemorrhagic fever (fever, abdominal pain, vomiting, bleeding) is a potentially lethal complication, affecting mainly children. Early clinical diagnosis and careful clinical management by experienced physicians and nurses increase survival of patients.

By World Health Organization


The population of Sri Lanka is 20.97 million (2015) people. Some 1.84 million are migrant workers. The number of Dengue Fever affected individuals in 2015 was 29, 777. In 2016 it was 55, 154. Statistics for the first 5 months of 2017 show affected individuals to be 56,887! And the total number of dengue affected individuals is expected to rise to more than 136, 528. Following the above mentioned statistics, the simple mathematical calculation gives an alarming figure of the percentage of dengue affected individuals to date. It is approximately 1% of the entire population for the period of three years, 2015-2017. [2] Local Government Institutions play a major role in the Dengue Prevention Scheme. The Government’s failure to hold local elections means that the country is running without functioning local government institutions. There is a severe outcry by the people about the total collapse of the State’s mechanism on Dengue Fever Prevention.


The female Aedes aegypti mosquito is the vector for the VIRAL infection of Dengue. This is how it happens. The female mosquito bites a person with the dengue virus in his/her blood. With this human bite a mosquito is then infected with the dengue virus. After about one week, the next bites of the mosquito, inject and spread the virus into healthy human beings. There is no transmission of Dengue Fever from human to human. But, theoretically it is speculated that blood transfusions, organ transplants and transmission to the baby from the mother are possible [3]. Dengue mosquitoes are unable to survive easily in cold climates thus confining the disease to tropical and sub-tropical areas. Interestingly, the dengue mosquito is usually associated with human habitats making infection easier. In other words, wherever human beings live, dengue mosquitoes are also there as long as the other circumstances are favorable for them. Female mosquitoes need additional human blood to produce eggs. Both male and female mosquitoes consume plant nectar for their sugar requirements. Female mosquitoes feed on humans both indoors and outdoors during the daytime (from dawn to dusk) but more in the early morning and before dusk. The more vulnerable populations reside in urban and suburban areas. Infected persons can spread the disease from one country to another or from one area to another through travel.

The first confirmed dengue patient in Sri Lanka was diagnosed in 1962. The first outbreak was reported in 1965- 1966. After that dengue was not that great a threat in Sri Lanka, though isolated cases were reported from time to time. Sri Lanka experienced its first Dengue Fever EPIDEMIC in 1989 – 1990. After that, studies revealed that more progressive and devastating epidemics are surfacing at regular intervals [4].

During the last 6 months of 2017, 56,887 suspected dengue cases have been reported to the Epidemiology Unit from all over the island. Approximately 42.55% of dengue cases were reported from the Western Province [5]. Other districts more vulnerable are Gampaha, Kalutara, Galle, Kandy, Ratnapura, Jaffna and Trincolmalee [6].

Let us consider figures related to dengue during the recent past. The number of cases reported over the years is fluctuating but the overall TREND IS RISING. In 2015, the number was under 30,000. (2015: 29,777). In 2016 it was 55,150. In 2017, during the last 5 months, the reported number of cases is 56,887. This figure is more than the total number in 2016 which was the highest number recorded in our history [6].

To minimize Dengue Fever morbidity much effort has been expended from 2005-2014. As described earlier, although the number of cases reported fluctuated, the overall trend is increasing with a maximum in 2017. It indirectly tells a hidden story. Measures adopted so far are not efficient enough to address this burning issue in Sri Lanka. There may be several excuses for this allegation and I will name two. The first is the type of virus which is active when a person is first bitten. It is more virulent, causing more casualties than in earlier years. The second is climate change including rising temperatures which favor the survival of the virus through globalization and travel.

Whatever the highlighted facts, the seriousness of the problem in Sri Lanka is getting worse, warranting urgent intervention. Can the State alone eradicate dengue from our country? No again.

Individual responsibility is very much higher than the State’s. But the State’s responsibility is considerable nevertheless. There are specific aspects that the State should take care of in order to control this scourge.

The dengue mosquito can fly an average of 200 meters in order to find water to lay eggs. This is a long way. To reduce the risks of infection, a responsible citizen is responsible for the cleanliness of his own house and surroundings. An irresponsible citizen, far from the first house, but with mosquitoes in his premises, will up the risk to the responsible person’s home area. The State has the major responsibility to look after the vulnerable areas effectively. In the past there was a successful and excellent HomeVisiting Program initiated by the Municipal Councils with the help of the armed forces. A fine was imposed for not following official requirements and an additional fine of Rs. 50,000 if a person continued to offend. With such strict regulations, one would think that people would tend to be afraid of the fine and the Courts, making them careful to maintain their environment up to standard. But this is not the case. CLEAN UPS are hardly seen today.

The local authority of an area is responsible to clean the area in order to control the epidemic. According to Dr. Pradeep Kariyawasam, Former Chief Medical Officer of Health, Colombo in an article in “The Island” newspaper (May 2nd) was of the following opinion. “Dengue control and prevention is a duty of the local authority. The Public Health Department of the Colombo Municipal Council has a cadre of 1200: it should have around 55 Public Health Inspectors, 150 Midwives, 185 Health instructors, 55 Mosquito control Field Assistants, who could have been used to inspect all the premises and land parcels in the city which number around 80,000. Unfortunately, instead of these 450 Field Officers, we had only around 180 to do this work.” [7]. This data points out the inefficient work that a person is able to deliver because of the tremendous workload taken on. It is the sole responsibility of the State to employ people, even on a temporary basis, to get the clean-up and inspection done during peak times of the monsoon of the epidemic.

During the past there were organized control programs of fogging and spraying to disrupt potential mosquito nesting sites. But, this is no more to be seen. Why it cannot be implemented in an efficient and organized way, in order to cover both internal and external environments where mosquitoes can breed, is the basic question, needing an answer.

The inspection for mosquitoes should not be restricted to the Dengue control week. It should be carried on regularly, routinely in an organized scheduled manner. Dedicated Ministers and Authorities should periodically inspect the work. Relevant Ministers or responsible Ministries are the people who can address the problem facing the entire populace. They should develop sensitivity to this on-going Public Health DANGER. A target/goal must emerge from the Government to minimize mosquito breeding places.

Education on the disease is PRIMARY and the huge cost would be notable. According to Dr. Pradeep Kariyawasam, Former Chief Medical Officer of Health, Colombo, “Our budget, does not allow us to communicate our educative messages via electronic media and the press. TV companies charge Rs.20,000 per 15 seconds. A one-page newspaper advertisement costs Rs.100,000. Even in the State-owned media we do not get a chance[8].”

The privatization of the Cleaning Services by some local Councils is said to be a strong factor negatively affecting the problem. These restricted Cleaning Services come with many rules and regulations. Since there are no more functioning local Councils and as elections are being postponed indefinitely, the situation has gone from bad to worse. Now, no one is responsible for the routine, scheduled, clean up functions in local areas.

The State should be directly responsible for the ever-increasing numbers and for the variety of mosquito-breeding habitats. These are the results of rapid and poorly planned urbanization, globalization, consumerism, poor solid waste and water management and increasing population movements without adequate measures to prevent vector breeding. Climate changes influence the eco-system. It encourages vector breeding for which mankind is directly responsible.
It has to be mentioned that poverty, reduced access to health services, housing, sanitation and clean water, should be considered by the State in order to address this serious issue facing everyone [9].

The mass media highlighted how the recent flood was due to unplanned constructions and land fillings–all politically biased. Is the State responsible for these unplanned activities which are at times illegal?

There is no efficient method of waste disposal in Sri Lanka today. Such mundane, yet common issues are not addressed with enough strength and attention. Needed are strong leaders, to implement sustainable programs to implement effective ways of waste disposal. Non bio-degradable tires, plastic containers and tins are some of the most accessible objects where mosquitoes breed. However, up to now, there is no OPERATIVE, effective way to dispose of them so they do not pose a threat to the environment.

Following are international statistics that have to be considered: “an estimated 50–100 million Dengue infections occur annually in over 100 endemic countries. Almost half of the world’s population is currently considered at risk of contracting dengue. The South-East Asia Region contributes to more than half of the global burden of dengue. About 52% of the world’s population is at risk as they are residing in this Region” [10].

To conclude, Dengue is a lethal disease which does not have a specific vaccination or treatment protocol. The most important point that should be highlighted is that Dengue Fever is a disease that can be controlled. Hong Kong has achieved Dengue Fever control, so it is achievable goal. The individual and the State’s responsibility is a two-pronged effort. It is urgent that the State put more emphasis on the subject. They need to issue strategic, effective and sustainable plans for the near future. Dengue is not a disease like AIDS where the individual’s responsibility is the answer. Dengue is a disease that can be controlled with diligent mosquito control. To achieve this, State support is KEY as it is impossible for individual’s to do this alone. An individual can clean his home/garden environs, but the threat remains unless the State takes overall responsibility for all vulnerable areas in the entire country.


1. Rasika Sanjeewa Weerawickrama, LLB (Col), LLM (HK)), (Attorney-at-Law) is a Legal Practitioner in the Supreme Court of Sri Lanka
2. Stop Press: Dengue Cases 2017: January – May: 56,887, Dengue cases 2016: 54,945 (2015: 29,777) Click here to Read 
3. Dengue, Dengue Fact Sheet. Click here to Read
4. Dengue Transmission. Click here to Read 
5. Sri Lankan Situation. Click here to Read 
6. Dengu update Click here to Read
7. Dengue Epidemic: Back to basics to prevent spread, ‘The Island’ News Paper, May 2, 2017, Internet link: Click here to read

8. General Health Risks: Dengue.Click here to Read
9. Dengue count Sri Lanka: 2017; the worst year on record? Click here to Read
10. Who spreads dengue and severe dengue? Click here to Read
Stop Press: Dengue Cases 2017: January – May: 56,887

Image: Anti- dengue campaign by school children.

by Sanjeewa Weerawickwama.

Article source- http://srilankabrief.org/

Dengue Fever Symptoms

Dengue Haemorrhagic Fever is a mosquito-borne viral infection endemic in the tropical and sub-tropical regions. The female Ae.aegypti (the most important vector) mosquito is semi-domesticated, preferring to lay its eggs in man-made water containers, resting indoors and feeding in the early morning or late afternoon. There are 4 serotypes of Dengue virus. Dengue usually occurs as epidemics in Sri Lanka following monsoon seasons.
According to data from epidemiology unit of Sri Lanka, the number of total cases recorded for year 2009 is 32713. Most affected district was Kandy. Colombo, Gampaha and Kaluthara districts which have been susceptible in the past have also recorded a high rate of infection and deaths.
Dengue virus; There are 4 serotypes of the single-stranded RNA virus (flaviviridae).
Patients become infected once bitten by mosquitos. The virus passes to lymph nodes and replicates which is followed by spread to the circulation and other tissues. It is thought that infection with a secondary serotype is what leads to severe haemorrhagic disease.
Disease varies in severity
- Incubation period is 2-7 days.
- All haemorrhagic fever syndromes begin with abrupt onset of fever (39.5–41ºC) and myalgia.
- Fever is often biphasic with two peaks.
- Fever is associated with frontal or retro-orbital headache lasting 1–7 days, accompanied by generalised macular, blanching rash.
- Initial rash usually fades after 1–2 days.
- Symptoms regress for a day or two then rash reappears in maculopapular, morbilliform pattern, sparing palms and soles of feet. Fever recurs but not as high. There may be desquamation.
- DF cases experience severe bony and myalgic pain in legs, joints and lower back which may last for weeks (hence breakbone fever).
- Nausea, vomiting, cutaneous hyperaesthesia, taste disturbance and anorexia are common.
- Abdominal pain may occur and if severe suggests DHF pattern.The signs of dengue fever/ Dengue haemorrhagic fever are- High fever, rash, hypotension and narrow pulse pressure, poor capillary refill.
- There may be hepatomegaly and lymphadenopathy.
- A tourniquet placed on an arm may induce petechiae in early DHF cases. DHF sufferers exhibit a bleeding tendency as evidenced by petechiae, purpura, epistaxis, gum bleeding, GI haemorrhage and menorrhagia. There may be pleural effusion, ascites and pericarditis due to plasma leakage.
- Petechiae are best visualised in the axillae.
- Flushing of head and neck.
- Tender muscles on palpation.
- Periorbital oedema and proteinuria may be present.
- Maculopathy and retinal haemorrhages may also occur.
- DSS pattern cases progress through DHF until profound shock due to severe hypotension is present.
- CNS involvement e.g. encephalopathy, coma, convulsions.

- Hepatic failure: Means failure of the liver
- Encephalopathy: Means damage to the brain causing fits, loss of consciousness and confusion- Myocarditis – Inflamation of heart muscles
- Disseminated intravascular coagulation - Damage to blood vessels and blood cells causing problematic bleeding and clottingDengue can cause death
- FBC - low platelets and high packed cell volume if haemoconcentrated. Usually white cell count will fall
- Infection may be confirmed by isolation of virus in serum and detection of IgM and IgG antibodies for Dengue by ELISA, monoclonal antibody or haemagglutination
- Molecular diagnostic methods such as reverse-transcriptase-PCR are increasingly being used.
- Chest X-ray may show pleural effusion.
- Bed rest
- Nutritious diet and lot of liquids, But avoid red and brown foods and drinks like coffee, chocolate, grapes etc as it may misinterpret vomiting as blood stained vomitus.
- Fever control with paracetamol, tepid sponging and fans. Aspirin should be avoided.
- Need to seek advice from a qualified medical practitioner if fever lasts for more than 2 days
- Hospital managemnt includes intravenous fluid resuscitation with close monitoring. Haemorrhage and shock will require Fresh Frozen Plasma, platelets and blood. Intensive management with inotropes of the shock syndrome may be required in severe DHF/DSS cases.
- Vaccines are being researched
- Anti-mosquito public health measures such as reducing breeding sites ( flower pots, fish tanks,tires, coconut shells, tins, water collecting plants, gutters which can collect water) and good sewage management
- Insecticides to destroy the larvae
- Mosquito nets can be used during day time as the Aedes mosquitoes is day-biting.
- Mosquita repellents
- There is a bacteria called Bacillus thuringiensis which destroy the mosquito larvea

Featured Posts

Recent Posts

Show Panel