Dengue on the rise

Introducing any new vaccine r on the rise equires careful assessment :

By Carol Aloysius

Despite recent interventions by the Health Ministry resulting in a drastic drop in suspected dengue fever cases, the disease is still widely prevalent among all people.

The Sunday Observer asked experts from the National Dengue Control Board headed by Dr. Hasitha Tissera to explain why the Health Ministry is wary about introducing the WHO endorsed Dengvaxia said to be the world’s first dengue vaccine and already licensed in some countries to prevent the deadly disease.

Senior Consultant and Community Physician, National Dengue Control Board, Dr Preshila Samaraweera and Dr.Jayantha Weeraman-Consultant Paediatrician Epidemiology Unit,

responded to this question while stressing the importance of preventing the disease by keeping our environment free of breeding sites that attract the dengue vector.

Excerpts…

Q: The WHO has recently endorsed a vaccine – Dengvaxia , said to be the world’s first vaccine against dengue. Is Sri Lanka considering introducing this in the near future?

A: There is a National Expert Committee for vaccines .Those Experts of the Health Ministry is considering about the Dengue Vaccine. I think the Ministry will take the decision at the right time.

Q: Why are you wary about introducing it to the immunization programme? What are your concerns?

A: As you know vaccines are given to healthy people. Therefore, the most important thing is the safety of the vaccine. The other aspect is the effectiveness of the vaccine. That means the vaccine should have the ability to prevent the disease before it enters our body naturally .

Q: What considerations do you take into account before a new vaccine is introduced to the country?

A: Any decision about a vaccine introduction to our immunization programme, requires careful assessment at country level, including national and sub national dengue epidemiology, sero-prevalence rates, modal age of the affected group( i.e. most affected age group), predicted impact, cost effectiveness with country specific hospitalization rates affordability and budget impact. This criteria applies to all new vaccines.

Q: Health officials found several potential breeding sites for dengue carrying mosquitoes to lay their larvae, during the recent Dengue Control Week. Who were the biggest offenders? Schools? Government buildings? Private offices?

A: During the National Mosquito Control Week we have inspected 631,416 premises which includes 2017 schools,4288 government Institutes,3274 construction sites,2641 religious places etc. Of these, 33% of schools, 26% of government institutes, 42% of construction sites, and 34% of religious places were identified as having potential breeding places for the dengue mosquito. So, it is important that we must have a social responsibility to keep our premises free of mosquito breeding sites.

Q: The highest number of suspected and confirmed cases has for the past several years, been from the Colombo District. Why? Is it over population? Poor sanitation? Uncleared garbage? An antiquated drainage system?

A: Yes, all those factors contribute to the higher number of cases in the Colombo District. Improper urban planning, malfunctioning drainage system, shortage of waste management programmes, and the increase in internal migration, with more rural based workers migrating to Colombo for work, have collectively resulted in more breeding grounds for the mosquitoes.

Q: What are the symptoms of dengue fever?

A: Dengue fever can be suspected if you have acute onset of fever with 2 or more of the following symptoms; ,Headache, especially retro-orbital pain, Mayalgia/Athralgia , Rash (diffuse,erythematous,Macular,)Haemorrhagic manifestations(petechiae,positive tourniquet test etc.)

Q: How do you treat it? With home remedies?

A: If you live in a dengue endemic area and if you have fever for more than two days, you could be a suspect dengue fever patient. In that case, for the first two days make sure the patient gets adequate bed rest. Give plenty of fluids (rice cunjee,soup,fruit juices, water etc.) Give paracetamol (correct dose) 6 hourly with a maximum of 4 doses per day to bring down the temperature. Other home remedies would include : tepid sponging to control fever when it is high despite being given paracetamol. Make the patient rest under a bed net even during daytime to prevent mosquito bites.

Q: If the fever continues after two days?

A: Consult a qualified Medical Officer without delay.

Q: Are there any drugs that should not be taken in a suspected dengue fever case?

A: Do not take steroids and non-steroidal anti inflammatory drugs containing drugs to reduce fever, such as (Aspirin,Ibuprofen,Diclofenac, Sodium, Mefahnamic acid ) orally or by any other route.Do not give red or black coloured food or drink (eg.coffee,coca cola,etc.)

Q: What are the Do’s?

A: A full blood count should be done at least on the third day of the illness. But if you are pregnant a full blood count should be done on the first day of the fever.

Q: When is hospitalization required for dengue?

A: A qualified Medical Officer will decide when to admit the patient to the hospital. But if you have the following symptoms you have to be cautious and immediately go to hospital.

Abdominal pain or tenderness,

Persistent vomiting, Clinical signs of plasma leakage: pleural effusion and ascites, Mucosal bleeding, Lethargy, restlessness, Besides that, pregnant mothers, elderly patients, obese patients, patients with other chronic diseases and patients with adverse social circumstances may need admission even without the above criteria.

Q: Are flu shots the same as a vaccine to prevent dengue?

A: No, not at all. Flu shots are different and they have to be given every year as the strains differ from one year to the other. But dengue virus does not change like that.

It has only 4 sero-types.

Q: Some believe flu shots can also cure dengue, and that certain native herbs can cure dengue. Your comments?

A: I personally don’t believe in any other treatment for dengue, unless there is evidence based data after clinical trials.

Q: I understand there is a National Plan to control Dengue. Can you give us an outline of that plan and your goals?

A: The Health Ministry will be working to achieve and maintain a low mortality rate and bring down the current morbidity level.

To achieve that target the Ministry has adopted five strategies: namely, Vector Surveillance and Integrated Vector Management, Disease Surveillance, Disease management, Inter-sectoral Coordination and Social Mobilization with Outbreak response communication.

Q: Your advice to the public on what to do and what not to do, if they suspect they have dengue?

A: It is important to prevent mosquito breeding places as most patients’ homes have been infested with breeding sites. Eliminating all mosquito breeding sites in our neighbourhoods is the first step to preventing dengue fever.

(Dr Samaraweera wishes to acknowledge the input from Dr.Hasitha Tissera National Coordinator for Dengue Control and Prevention and Dr.Jayantha Weeraman-Consultant Paediatrician Epidemiology Unit for her interview with us.)

For more information contact the National Dengue Control Unit on T.P 2384291