The presence of water and dengue is strongly related. Since it is raining heavily, water remains accumulated in many places, it becomes a breeding ground for mosquitoes. We need to ensure that every corner of our house and immediate surroundings is free from mosquito breeding. There should be no scope for stagnation of water.
What is dengue fever?
Dengue fever is a disease caused by a family of viruses that are transmitted by mosquitoes. It is an acute illness of sudden onset that usually follows a benign course with symptoms such as headache, fever, exhaustion, severe muscle and joint pain, swollen glands (lymphadenopathy), and rash.
The presence (the "dengue triad") of fever, rash, and headache (and other pains) is particularly characteristic of dengue. Other signs of dengue fever include bleeding gums, severe pain behind the eyes, and red palms and soles.
Dengue (pronounced DENG-gay) strikes people with low levels of immunity. Because it is caused by one of four serotypes of virus, it is possible to get dengue fever multiple times. However, an attack of dengue produces immunity for a lifetime to that particular serotype to which the patient was exposed.
Dengue goes by other names, including "breakbone" or "dandy fever." Victims of dengue often have contortions due to the intense joint and muscle pain, hence the name breakbone fever.
How is dengue fever contracted?
The virus is contracted from the bite of a striped Aedes aegypti mosquito that has previously bitten an infected person. The mosquito flourishes during rainy seasons but can breed in water-filled flower pots, plastic bags, and cans year-round. One mosquito bite can inflict the disease.
The virus is not contagious and cannot be spread directly from person to person. There must be a person-to-mosquito-to-another-person pathway.
After being bitten by a mosquito carrying the virus, the incubation period ranges from 3 to 15 (usually five to eight) days before the signs and symptoms of dengue appear.
Dengue starts with chills, headache, pain upon moving the eyes, and low backache.
Painful aching in the legs and joints occurs during the first hours of illness.
The temperature rises quickly as high as 104 F (40 C), with relative low heart rate (bradycardia) and low blood pressure (hypotension).
The eyes become reddened.
A flushing or pale pink rash comes over the face and then disappears.
The glands (lymph nodes) in the neck and groin are often swollen.
Some patients may have a sore throat, congested pharynx and red eyes. Nausea and vomiting are common.
Fever and other signs of dengue last for two to four days, followed by a rapid drop in body temperature (defervescence) with profuse sweating. This precedes a period with normal temperature and a sense of well-being that lasts about a day. A second rapid rise in temperature follows. A characteristic rash appears along with the fever and spreads from the extremities to cover the entire body except the face. The palms and soles may be bright red and swollen.
What is the treatment for dengue fever?
Because dengue fever is caused by a virus, there is no specific medicine or antibiotic to treat it. For typical dengue, the treatment is purely concerned with relief of the symptoms (symptomatic).
Rest and fluid intake for adequate hydration is important.
Aspirin and nonsteroidal anti-inflammatory drugs like ibuprofen (Brufen/Mortin) should not be taken because of the possibility of worsening hemorrhagic complications.
Acetaminophen commonly known as paracetamol or crocin (Tylenol/Panadol) and codeine may be given for severe headache and for the joint and muscle pain (myalgia).
What is the prognosis for typical dengue fever?
The acute phase of the illness with fever and myalgias lasts about one to two weeks. Convalescence is accompanied by a feeling of weakness (asthenia), and full recovery often takes several weeks. Typical dengue is fatal in less than 1% of cases.
What is dengue hemorrhagic fever?
Dengue hemorrhagic fever is a more severe form of the viral illness. Manifestations include headache, fever, rash, and evidence of hemorrhage in the body. Petechiae (small red or purple blisters under the skin), bleeding in the nose or gums, black stools, or easy bruising are all possible signs of hemorrhage. This form of dengue fever can be life-threatening and can progress to the most severe form of the illness, dengue shock syndrome.
Dengue hemorrhagic fever (DHF) is a specific syndrome that tends to affect children under 10 years of age. It causes abdominal pain, hemorrhage (bleeding), and circulatory collapse (shock). DHF is also called dengue shock syndrome.
Patients with DHF must be monitored closely for the first few days since shock may occur or recur precipitously (dengue shock syndrome). Blood transfusions may be needed to control bleeding.
The mortality (death) rate with DHF is significant. It ranges from 6%-30%. Most deaths occur in children. Infants under a year of age are especially at risk of dying from DHF.
Recognition of the high risk patient
Fever patients have red spots on skin (petechiae), bleeding from gums or nose, vomiting of blood.
Patients who remain ill (despite drop in temperature) and whose general condition deteriorates.
Clammy skin, cold and sweaty extremities, drowsiness, and/or restlessness.
High fever with bleeding symptoms - rush to hospital
Blood spots under the skin (petechiae).
Bleeding from gums.
Nose bleeds (epistaxis).
Early, efficient and accurate diagnosis of dengue is of primary importance for clinical care. Routine tests like complete blood counts, liver function tests, etc, should be done in each suspected case of dengue fever.
A pattern of increasing hematocrit (marker of blood viscosity), decreasing leucocyte counts and a fall in platelets is highly suggestive of dengue.
Recently a breakthrough has been achieved in this regard with discovery of the Dengue NS1antigen detection test as a diagnostic tool in the early detection of dengue infection. It becomes positive by the 2nd day of illness and is detectable up to the 9th day. It has been highly successful across the world in timely diagnosis of dengue and its correlation with antibody levels is excellent.
How can dengue fever be prevented?
The transmission of the virus to mosquitoes must be interrupted to prevent the illness. To this end, patients are kept under mosquito netting until the second bout of fever is over and they are no longer contagious.
To prevent mosquito bites, wear long pants and long sleeves.
For personal protection, use mosquito repellant sprays that contain DEET when visiting places where dengue is endemic.
Limiting exposure to mosquitoes by avoiding standing water and staying indoors two hours after sunrise and before sunset will help.
The Aedes aegypti mosquito is a daytime biter with peak periods of biting around sunrise and sunset. It may bite at any time of the day and is often hidden inside homes or other dwellings, especially in urban areas.
There is currently no vaccine available for dengue fever. There is a vaccine undergoing clinical trials, but it is too early to tell if it will be safe or effective.