Dengue

Dengue fever, also known as "breakbone fever", due to intense musculoskeletal pain, is a viral disease. It is an imported disease, so not endemic in our country, nonetheless, it can give rise to native cases thanks to the spread of one of its vectors (Asian tiger mosquito).

CAUSATIVE AGENT AND INFECTIVE CYCLE

A Flavivirus is the culprit of this disease and is transmitted by the same mosquitoes that can transmit chikungunya and Zika. It is particularly spread by the Aedes aegypti and to a lesser extent, by Aedes albopictus.

Four different virus serotypes are known (DENV-1, DENV-2, DENV-3 e DENV-4). A patient affected by a serotype and subsequently cured will remain immune to the serotype forever. However, immunity to other serotypes is only partial and temporary; subsequent infections from other serotypes will increase the risk of developing a more severe form of the disease.

SYMPTOMS AND COURSE OF THE DISEASE

The spectrum of the disease can range from a mild flu-like form (classic form) to a sever hemorrhagic form that can progress to shock syndrome.

The disease occurs after an incubation of 2 to 15 days (on average 4-7 days) and has a sudden onset of hemorrhaging.

In its mild form, the symptoms are high fever, arthralgia, a severe headache, and a skin rash.

In the hemorrhagic form and usually after a short period of defervescence, a worsening of symptoms follows (3 to 7 days after the onset of the fever). Frequent, yet non-essential warning symptoms are abdominal pain, vomiting, lethargy, bleeding, hepatomegaly, fluid accumulation, increased hematocrit, and decreased platelets.

Hemorrhagic fever and shock occur in less than 1% of patients and are associated with more "virulent" viral genotypes, age, genetic factors and, most importantly, previous exposure. The mild form is generally benign and is self-limited with symptom remission after about 4 weeks. A fatigue condition can persist for weeks after the clinical remission of the disease. The lethality rate is less than 1%.

If the patient is hemorrhaging and is consequently hospitalized, then there may be a decrease in symptoms. However, if the disease is not treated, the patient can suffer shock followed by a circulatory collapse. Without proper treatment, the patient can die within 12 to 24 hours; the average mortality rate is 10-20%.

As a tropical disease, dengue is second in importance only to malaria!

TREATMENT AND PREVENTION

There is currently no vaccine or specific medical treatment. Once the disease is contracted, the therapy is then based on the administration of symptomatic drugs (antipyretics, anti-inflammatories), bed rest, fluid replenishment, and exercises to relieve stiffness and joint pain. It is necessary to avoid salicylates (for hemorrhagic tendency), antibiotics, and corticosteroids (should be avoided during the acute phase of the disease).

Prevention is primarily about avoiding or minimizing mosquito bites; surveillance is key when the virus has been introduced.

Last modified: Jan 2021