Dengue is on the rise – what to look out for

By: Osler Health International

Star Vista clinic
Posted on: 14 Mar 2022

What is Dengue?

Dengue is a mosquito-borne viral disease, transmitted by the Aedes genus family of mosquitoes. These insects are found mostly in tropical and subtropical regions, which is what puts those of us living in Singapore at risk.

Dengue remains endemic in Singapore with cyclical peaks occurring every few years.  We usually see a rise in dengue cases during the warmer months – typically April to August.

There are four different serotypes of the dengue virus, all of which can cause severe disease. Although infection with any one serotype of the virus confers lifelong immunity for that particular serotype, reinfection is possible with a different serotype of the virus.  This is important for us to understand as a community to continue our efforts for prevention of dengue and keep our vigilance to look out for possible new dengue infections.

Dengue is a legally notifiable disease in Singapore. Your doctor will submit details of your infection to Ministry of Health (MOH).

What are the symptoms?

The usual symptoms include:

  • Fever, often an abrupt high-grade fever with spikes 39 – 5°C. This may last 2 – 7 days.
  • Headache
  • Body aches
  • Joint pains
  • Facial flushing
  • Skin redness or rash

Some individuals also experience sore throat, sore or red eyes, loss of appetite, nausea and vomiting, abdominal pain, lethargy and / or dizziness.

In severe cases of dengue, bleeding may occur and present itself in the form of nose bleeds, bleeding gums, blood in stools, vaginal bleeding or bleeding from a blood-taking site.

In young children, the high-grade fever can cause febrile seizures and/or a change in their general behaviour.

When should I see a Doctor?

Dengue can lead to a severe illness in some patients with complications of bleeding and shock, leading to significant deterioration in the health of an individual and can be life-threatening.

If you have persistently high fever for 1 – 2 days, with some or all of the above-mentioned symptoms, please consult a doctor.

Your doctor will review your symptoms and examine you to look for any potential evidence of complications. They may also suggest doing some blood tests to assess your blood count levels and liver function. A blood test to test for dengue may also be undertaken.

If you are suspected of dengue, your doctor will advise you to repeat some blood tests over the next few days to monitor your condition, and if required, refer you for in-patient hospital treatment if your condition appears to be deteriorating.

What is the treatment for dengue?

Although dengue infection is complicated, the management of dengue remains quite straightforward. The treatment for dengue is focused on maintaining adequate hydration, reducing high-grade fever with anti-pyretics and monitoring for development of severe illness with regular assessment of the patient and early, regular (even daily) blood tests.

Are there long-term complications of dengue?

After recovering from dengue, there are usually no long-term complications. Some patients, as expected after a viral illness, may develop post-viral fatigue. The blood count levels and changes in liver function tend to return to normal within four weeks.

We advise our patients to resume their normal activities as they feel physically capable. Alcohol and strenuous exercise should be avoided for 3 – 4 weeks as the changes in liver can take up to three weeks to return to normal.

Repeat blood tests to monitor blood count levels and liver function is recommended four weeks after illness. 

Dengue vaccine

Vaccination is an important way to prevent viral illnesses. However, when it comes to dengue the only vaccine currently available is Dengvaxia. This vaccine does not offer complete protection and those vaccinated can still catch dengue. Furthermore, clinical trials have shown that individuals who never had dengue before and were vaccinated with Dengvaxia were at a higher risk of getting more severe dengue infections.

Currently, Dengvaxia is only recommended for patients who have had a previous dengue infection and live in highly endemic areas, where at least 80% of the population has had dengue before. As this is not the case in Singapore, Dengvaxia is only recommended for those who have had previous dengue infections after a thorough discussion with your family doctor.

Keep an eye on the NEA website to understand where the latest clusters are located and please contact your doctor if you are showing symptoms. If you are new to Singapore, please read our New to Singapore Health Brochure which includes information on dengue.

For appointments call: T: 63392727



  1. Dengue: Guidelines for diagnosis, treatment, prevention and control. Geneva, WHO 2009.
  2. Dengue. National Centre for Infectious Diseases Singapore, updated March 2022.
  3. Kularatne S A M. Dengue fever BMJ 2015; 351 :h4661 doi:10.1136/bmj.h4661
  4. M Chan and Prof Leo YS. Rish in Dengue cases underscores need for constant vigilance. National Centre for Infectious Diseases Singapore, updated March 2022.
Raffles Hotel Arcade Star Vista