Dengue

May 28
11:28

2005

Wong Lai Teng

Wong Lai Teng

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Dengue fever, a disease caused by mosquitos, was reported in Malaysia since 1902 but it was only known as haemorrhagic dengue when the first severe dengue outbreak occurred in Penang in 1962. Since then, dengue fever has been spreading across the country mainly in the cities and suburban areas.

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The overview of dengue fever in Malaysia is much clearer from the distribution of cases according to states,Dengue Articles areas, age and gender. The number of dengue fever is relatively high in the more developed and densely populated states like Selangor, Kuala Lumpur and Johor. Actually, dengue fever can be found wherever the mosquito vector is present and introduced, whether in the rural or urban areas, with the risk generally higher in the latter.

Dengue virus is categorized under the Flaviviridae family and it has four cerotypes including DEN-1, DEN-2, DEN-3 and DEN-4. The important vectors for dengue viruses are Aedes aegypti and Aedes albopictus. The transmission of the disease starts when the vector bites the individual who has been infected with the virus. These vectors like to bite early in the morning and late evening. It multiplies in clear and stagnant water indoor or outdoor. Dengue virus needs about eight to ten days ( the incubation period for the virus) to replicate in the vector’s saliva gland. When the vector bites and sucks the blood of any new and healthy individual, this individual will get infected with the virus. Virus can be found in the blood stream about four to six days after the incubation period.

Dengue Haemorrhagic fever (DHF) is a severe and sometimes fatal form of dengue. Typical cases of DHF are characterized by four major clinical manifestations: high fever, haemorrhagic phenomena, hepatomegaly and circulatory failure. Moderate to marked thrombocytopenia with concurrent haemoconcentration is a distinctive clinical laboratory finding of DHF. The major pathophysiological change that determines the severity of disease in DHF is the leakage of plasma, as manifested by an elevated haematocrit (haemoconcentration), a serous effusion or hypoproteinaemia.

Children with DHF commonly present with a sudden rise in temperature accompanied by facial flush and other non-specific constitutional symptoms resembling dengue fever, such as anorexia, vomiting, headache, muscle, bone or joint pain.

Hepatomegaly - enlargement of the liver.

Haemorrhagic – bleeding

Haematocrit – the volume percentage of erythrocytes (red blood cells) in whole blood.

Hypoproteinaemia – deficiency of proteins in the blood.