Dengue fever is a disease which is caused by a family of viruses transmitted by mosquitoes. It is an acute illness of sudden inception followed by the symptoms such as headache, fever, exhaustion, severe muscle and joint pain, swollen lymph nodes (lymphadenopathy), and rash. The occurrence of fever itchy rash, and headache (the “dengue triad”) is characteristic of dengue. Some other symptoms of dengue fever include bleeding gums, severe pain behind the eyes, and red palms and soles.
Dengue can affect anyone but tends to get more severe in people with fragile immune systems. It is caused by one of the five serotypes of the dengue virus and so it is possible to get dengue fever multiple times. though, an attack of dengue produces life long immunity to that particular viral serotype which the patient was exposed to. Dengue is also known by other names, like “breakbone fever” or “dandy fever. The name “breakbone fever” was given to it because the victims of dengue often have contortions due to the intense pain in the joints, muscles, and bones. Slaves in the West Indies who brawled dengue were said to have “dandy fever” because of their postures and gait.
Dengue hemorrhagic fever is a more hazardous form of the customary viral illness. The symptoms are headache, fever, rash, and evidence of bleeding (hemorrhage) in the body. Petechiae (small red spots or purple splotches or blisters under the skin), bleeding in the nose or gums, black stools, or easy bruising are all likely to be the signs of hemorrhage. This type of dengue fever can be life-threatening and can develop into to the most severe form of the illness, dengue shock syndrome. The virus injects our body from the bite of a striped Aedes aegypti mosquito that has previously bitten an infected person. The breeding season for these mosquitoes is during the rains but can breed in water-filled flower pots, plastic bags, and cans year-round. One mosquito bite is sufficient to cause the disease.
The virus is not transmissible and cannot be spread directly from person to person. It is mosquito-borne, so there has to be a person-to-mosquito-to-another-person pathway. The full life cycle of the virus involves the mosquito as the vector (transmitter) and the human as the source of infection. It takes 3 to 15 day(usually 5 to 8) after being bitten by a mosquito carrying the virus for the symptoms to show up. Dengue fever starts with symptoms like chills, headache, pain in the back of the eyes, appetite loss, feeling unwell (malaise), and low backache. Aching in the legs and joints occurs during the initial hours of illness. The body temperature rises quickly as high as 104 F (40 C), with relatively low heart rate (bradycardia) and low blood pressure (hypotension). The eyes turn reddish. A flushing or pale pink rash appear over the face and body and then disappear. The lymph nodes in the neck and groin are often swollen.
High fever and other symptoms of dengue lasts upto two to four days, followed by a rapid drop in body temperature with plentiful sweating. This brings a sense of well-being with normal temperature that lasts about a day. A second rapid rise in temperature follows and a characteristic itchy rash (small red spots, called petechiae) appears along with the fever and spreads from the extremities to cover the entire body except the face. The palms and soles may get bright red and swollen.