Dengue fever is caused by RNA containing arbo viruses (Arthropod born viruses) of flavi virus group. The four distinct, but closely related viruses which cause dengue fever are mosquito borne flavi-ribo viruses of family Flaviviridae. Dengue fever is also known as the Break bone Fever. Mode of transmission The viruses of dengue fever are transmitted to humans through the bites of infective female Aedes aegypti (mosquito). Mosquitoes generally acquire the virus while feeding on the blood of an infected person. After virus incubation for 8-10days, an infected mosquito is capable of transmitting the virus.
Symptoms Two types of dengue fever are found: classical dengue fever and dengue haemorrhagic fever. Symptoms of Classical Dengue Fever: • Abrupt onset of high fever • Severe frontal headache • Pain behind the eyes which worsens with eye movement • Muscles and joint pains • Loss of sense of taste and appetite • Measles like rash over chest and upper limbs • Nausea and vomiting Symptoms of Dengue Haemorrhagic Fever: • Bleeding from the nose, mouth, gums, and skin bruising. • Severe and continuous stomach pains • Frequent vomiting with or without blood • Pale cold or clammy skin
• Excessive thirst ( dry mouth) • Rapid weak pulse • Difficulty in breathing • Restlessness and constant crying Treatment If there is fever, one should consult the doctor at once and take Paracetamol tablets on the advice of the doctor. Acetaminophen (Tylenol) is used to treat a high fever. Taking Aspirin and Dispirin should be avoided. Cold sponging should be done if fever is high. Plenty of liquids should be given to the patient if there are signs of dehydration. The patient should be rushed to the hospital if there is bleeding from any part of the body or if the patient becomes unconscious.
Detection and Diagnosis Tests that may be done to diagnose this condition include: * Antibody titer for dengue virus types * Complete blood count * Serology studies to look for antibodies to dengue virus Prevention No vaccine for Dengue fever is available. Eliminating mosquito breeding places is a key preventive measure. This can be done by covering small water containers, water tanks, changing the water of cooler and outdoor bird-baths every week, and discarding items that can collect rain or run-off water, especially old tires. One should wear clothes which cover arms and legs.
Children should not be allowed to play in shorts and half-sleeved clothes. Mosquito repellents, repellent creams should be used and one should sleep in mosquito-net. Mosquito abetment programs may reduce the risk of infection. Epidemiology Dengue fever occurs mostly in tropic and sub tropic regions, mostly in urban and semi-urban areas. This includes parts of Indonesian archipelago into northeastern Australia, south and Central America, Southeast Asia, sub-Saharan Africa. Dengue fever is being seen more in world travelers. Current impact The incidence of Dengue has grown dramatically around the world in recent decade.
Some 2. 5 billion people i. e. two fifth of the world population are now at the risk of Dengue. WHO currently estimates that there may be 50 million Dengue infections worldwide every year. In 2007, there were more than 8, 90,000 reported cases of Dengue in America of which 26000 cases were Dengue Haemorrhagic fever. Sources 1. Bhatia&Tyagi (2008) Trueman’s elementary Biology, Trueman Book Company, New Delhi. 2. Dengue and Dengue Hemorrhagic Fever, Edited by D. J. Gubler and G. Kuno, CAB International, Wallingford OX10 8DE, United Kingdom.