NOWADAYS, many people suffer from dengue and dengue fever. Dengue and dengue fever are caused by either one of the four virus serotypes: DEN-1, DEN-2, DEN-3 and DEN-4.
The four viruses are closely related to each other but, however, they are antigenically distinct.
It is one of the most common mosquito-borne infections with flu-like symptoms and can sometimes cause a potentially lethal complication called dengue haemorrhagic fever.
Symptoms of the complication may include fever, joint pain, rash, severe headache, pain behind the eyes and nausea.
People with the more severe form of the disease, i.e. dengue hemorrhagic fever, may experience breathing problems, bruising, bleeding from the nose or gums, and circulatory system breakdown.
This disease used to be called break-bone fever because it sometimes causes severe joint and muscle pain.
It is transmitted by the Aedes aegypti mosquito, which also transmits diseases as yellow fever.
The origins of the word ‘dengue’ are not clear, but one theory is that it is derived from the Swahili phrase ‘Ka-dinga pepo’, meaning ‘cramp-like seizure caused by an evil spirit’.
The Swahili word ‘dinga’ may possibly have its origin in the Spanish word ‘dengue’, meaning fastidious or careful, which would describe the gait of a person suffering the bone pain of dengue fever.
Alternatively, the use of the Spanish word may have derived from the similar-sounding Swahili.
Slaves in the West Indies who contracted dengue were said to have the posture and gait of a dandy, and the disease was thus known as ‘Dandy fever’.
The symptoms of dengue are severe headache, pain in the muscles and joints, and rashes that can be described as small red spots.
Some patients experience gastritis, diarrhoea, vomiting and abdominal pain too. Dengue usually starts suddenly with a high fever, headache, pain behind the eyes, and pain in the muscles and joints.
A rash usually appears 3 to 4 days after the start of the fever. Nausea, vomiting and loss of appetite are common symptoms.
Each type of the dengue virus is re-emerging worldwide, especially in the western hemisphere.
Researches have shown that several factors are contributing to the resurgence of dengue fever such as uncontrolled urbanisation, increased international travel, substandard socio-economic conditions and finally global warming.
Global warming has shown to be a major contributor to the spread of dengue fever. Global warming can cause dry spells in some countries and increased rainfall and humidity in others.
The dry spells reduce small medium bodies of water like springs and ponds to small puddles that become potential breeding ground for mosquitoes.
Likewise, increased rainfall and humidity also leads to collection of water that affords possible breeding grounds for mosquitoes.
Dengue is spread by the Aedes aegypti, a domestic, day-biting mosquito that prefers to bite humans.
They breed in clean water. Currently there is no vaccine available to prevent this fever. But scientists are trying their level best to invent a vaccine against this disease.
The only treatment for dengue and dengue fever is complete bed rest and intake of plenty of fluids like water, fruit juices and milk.
—The writer is contributing columnist, based in Mumbai, India