POST TIME: 22 July, 2019 00:00 00 AM
Dengue --- a bird's eye view

Dengue --- a bird's eye view


Dengue (pronounced as Dengee) is a Spanish word. It probably originated fro the word Dinga in the Swahili phrase Ka-dinga pepo means disease spread by evil spirit. The disease also known as Break bone fever is a tropical disease transmitted by the daytime biting of the female Aedes aegypti mosquito that breeds in standing water. This mosquito also causes Chikungunya. It is a single stranded RNA Flavivirus disease.

There are 60 flaviviruses. Diseases caused by these viruses include Yellow fever, Japanese encephalitis, Tick-borne encephalitis, West Nile encephalitis, Zika fever etc. Mosquito becomes infected about two weeks after feeding on an infected person and remains so throughout their life.


First recorded case is in Chinese Medical Encyclopedia from Jin Dynasty (266-420) A.D where it is described as water poison with flying insects. Marked spread of Dengue occurred after World War ll. Severe Dengue was first recognized in 1950 during Dengue epidemics in Philippines and Thailand.

Incubation Period

Incubation period is 5-6 days. One attack gives immunity for about 9 months only.

Local Statistics

In July 2019 in Bangladesh 84 Dengue patients were admitted in the hospitals. In June 1699 patients were identified as having Dengue. One lady doctor recently died in Square Hospital, Dhaka suffering from Dengue .It usually affects people between May-October.

Clinical feature

There are 4 serotypes of Dengue: DENV-1, - 2,-3 and -4. According to clinical features of the disease there are of 2 types.

a) Classical Dengue

b) Haemorrhagic Dengue

Classical Dengue

Dengue Triad consists of fever, rash and headache. Other sign -symptoms are: facial flushing, retro-bulbar pain increasing on eye movements, lacrimation, lymphadenopathy, patechiae on soft palat, anorexia, nausea, vomiting, bradycardia, severe muscle and joint pain, depression etc. Fever rises upto 40°C (104°F). It subsides after 3-4 days. After a gap of few days it returns again. Therefore the pyrexia is continuous or saddle back. type.

Hemorrhagic Dengue

Mainly occurs in South East Asia. There occurs thrombocytopenia, leucopenia, There is capillary leak syndrome leading to collection of fluid in chest and abdominal cavity. Other features are Epistaxis, Haematemesis, Malaena, Hypotension and Shock. Rashes appear, on limbs and then spread to trunk. Even with treatment 10% patients die.


Miscarriage, Premature birth, Bleeding gums .Vertical transmission from mother to child is possible.


Easy in endemic area by characteristic clinical features. Leucopenia, Thrombocytopenia, isolation of dengue virus by tissue culture in first few days, test for virus antibody types IgG and IgM with rising titre. Haemagglutination inhibition ELISA, +ve tourniquet test

Differential Diagnosis

One should remember the other haemorrhagic fevers while diagnosing Dengue e.g. Lassa fever, Marburg/Ebola virus disease, Yellow fever, Crimean-Congo fever etc.


Supportive treatment. No specific antibiotic is needed. Analgesic (Paracetamol) should be given but no Asprin or NSAID. Oral rehydration, Blood specially platelets transfusion and corticosteroid when necessary. Invasive procedures e.g. Nasogastric intubation, I.M injections and I.V drips etc should be avoided as far as possible.


Use of full sleeves dress and trousers, impregnated mosquito net, insect repellents, insecticides are useful, Small stagnant water pools should be abolished. There should no stagnant water in flower tubs, broken jars etc where mosquitoes can breed. Bushes should be cleared. Some one who had Dengue infection cannot donate blood for next 6 months. To prevent Dengue some of the countries in the world use vaccine against it. The vaccine is produced by Sanofi and the brand name is Dengvaxia.


Dengue is a mosquito borne viral disease which causes flue like illness but it may become potentially lethal. Instead of Aedes aegypti, few cases are transmitted by Aedes albopictus. About half of the world population is at risk. There is no specific treatment.

Early detection and proper supportive treatment lessens fatality. Prevention and control depends on effective vector control measures. It can also be transmitted by infected blood products, organ donation, so we should be cautious. India observes 16 June as World Dengue Day. To increase public awareness we should also observe Dengue Day. n