What is Dengue fever (Breakbone fever)

Dengue fever is a mild viral illness transmitted by mosquitoes. It is characterized by fever, rash, and muscle and joint pains.

Statistics on Dengue fever (Breakbone fever)

This is the most common arthropod-borne viral infection in humans with 50-100 million cases every year and over 10 000 deaths. It is most prevalent in Asia, South America and Africa although it has been reported in the USA.

Risk Factors for Dengue fever (Breakbone fever)

The disease is transmitted by they Aedes Aegypti mosquito. Hence risk factors for infection include:

  • the presence of mosquito breeding grounds: pools of standing water, drainage dtches, and dumps in cities.
  • not using mosquito nets and insect repellants in endemic areas.
  • Having been infected with one type of a Dengue virus (there are four serotypes) puts one at risk of developing Dengue haemorrhagic fever with a subsequent infection from another serotype.

Progression of Dengue fever (Breakbone fever)

There are 4 different varieties of dengue virus transmitted by daytime biting A. aegypti.

Human are infective for the first 3 days of the illness (the viraemic stage). Mosquitoes remain infected after biting on an infected individual for the rest of their lives.

There are 2 clinical forms of the virus:

  • Classic dengue fever: milder febrile disease occurring after first ever infection with a dengue virus.
  • Dengue haemorrhagic fever: this is a severe form of dengue fever and is thought to result from 2 or more sequential infections with different dengue virus serotypes. The disease starts mildly, often with upper respiratory tract symptoms, followed by abrupt onset of shock and haemorrhage into the skin and ear, epistaxis, haematemesis and meleana (known as the dengue shock syndrome).

How is Dengue fever (Breakbone fever) Diagnosed?

Laboratory abnormalities may include:

  • FBP:
    anaemia and/or thrombocytopaenia.
  • Abnormalities on liver function tests, coagulopathy (abnormal clotting times).

Prognosis of Dengue fever (Breakbone fever)

Dengue fever itself is a mild viral illness, and full recovery is expected. Dengue haemorrhagic fever, on the other hand, can be severe, associated with a 1-2% mortality rate.

How is Dengue fever (Breakbone fever) Treated?

  • Treatment is supportive.
  • To prevent infection, travellers should be advised to sleep under impregnated nets and to use topical insect repellants. Adult mosquitoes should be destrroyed by sprays and breeding sites should be eradicated.
  • A vaccine against the dengue virus has not been developed because of a fear of immunologically enhancing the inflammatory response and thus worsening the symptoms.

Dengue fever (Breakbone fever) References

  1. Kumar P, Clark M. Clinical Medicine. Fourth Ed. WB Saunders, 2002.
  2. Murray PR, Rosenthal KS., Kobayashi GS., Pfaller MA., Medical Microbiology 3rd Ed Mosby 1998.