Unveiling the Burden of Dengue in Sri Lanka

The Dengue update

For the year 2017, 186101 and in the month of September, 2018, 38565 suspected dengue cases were reported to the Epidemiology Units all over the island. Approximately 43% of the dengue fever cases were reported from the Western Province and the most affected area with the highest number of reported cases is Colombo District (18186) followed by Gampaha (12121), Kurunegala (4889), Kalutara (4589), Batticaloa (3946), Ratnapura (3898), and Kandy (3853). Preliminary laboratory results have identified Dengue virus serotype 2 (DENV-2) as the circulating strain in this outbreak. Although all four DENV have been co-circulating in Sri Lanka for more than 30 years and DENV-2 has been infrequently detected since 2009.The current dengue fever outbreak occurs in a context of massive heavy rains and flooding and is currently affecting 15 out of 25 districts in Sri Lanka where almost 600 000 people have been affected.

The deadly menace

Dengue fever is endemic in Sri Lanka, and usually occurs every year soon after rainfall when it is optimal for mosquito breeding. The viruses are spread by mosquitoes of the species Aedesaegypti and Aedesalbopictus, widely adapted to urban and suburban environments. The viral infection is caused by four dengue virus serotypes (DENV-1, DENV-2, DENV-3, and DENV-4). Infection with one serotype provides long-term immunity to the homologous serotype but not to the other serotypes; secondary infections put people at greater risk for severe dengue fever and dengue shock syndrome. However DENV-2 has been identified only in low numbers since 2009 and is reportedly over 50% of current specimens which have been serotyped.

Mild dengue fever (MDF)

Symptoms can appear up to 7 days after being bitten by the mosquito that carries the virus.They include:Aching muscles and joints
Body rash that can disappear and then reappear
High fever
Intense headache
Pain behind the eyes
Vomiting and feeling nauseous

Symptoms usually disappear after a week, and mild dengue rarely involves serious or fatal complications.

Dengue hemorrhagic fever (DHF)

At first, symptoms of DHF may be mild, but they gradually worsen within a few days. As well as mild dengue symptoms, there may be signs of internal bleeding.A person with Dengue hemorrhagic fever may experience:

Bleeding from the mouth, gums, or nose
Clammy skin
Damage to lymph and blood vessels
Internal bleeding, which can lead to black vomit and feces, or stools
A lower number of platelets in the blood
Sensitive stomach
Small blood spots under the skin
Weak pulse

Without prompt treatment, DHF can be fatal.

Dengue shock syndrome (DSS)

DSS is a severe form of dengue. It can be fatal. Apart from symptoms of mild dengue fever, the person may experience:

Intense stomach pain
Disorientation
Sudden hypotension, or a fast drop in blood pressure
Heavy bleeding
Regular vomiting
Blood vessels leaking fluid

Without treatment, this can result in death.

Treatments

Dengue is a virus, so there is no specific treatment or cure. However, intervention can help, depending on how severe the disease is.

For milder forms, treatment includes:

Preventing dehydration: A high fever and vomiting can dehydrate the body. The person should drink clean water, ideally bottled rather than tap water. Rehydration salts can also help replace fluids and minerals.
Painkillers, such as Tylenol or paracetamol: These can help lower fever and ease pain.
Non-steroidal anti-inflammatory drugs (NSAIDs), such as aspirin or ibuprofen, are not advised, as they can increase the risk of internal bleeding.

More severe forms of dengue fever may need: