Dengue fever is a viral infection transmitted from mosquitoes to humans. There are 4 distinct but closely related types of dengue virus: Dengue-1, Dengue-2, Dengue-3, and Dengue-4. The most common symptoms include high fever, headache, body aches, nausea, and rash.
The Dengue NS1 antigen, a glycoprotein synthesized in both membrane-bound and secreted forms, appears in the blood serum of infected individuals during the early stages of the disease. The NS1 test facilitates early diagnosis of dengue fever and typically provides rapid results.
When to get tested for dengue fever:
Rapid antigen testing can be performed from the first to the 7th day of fever. However, the first few days yield the most accurate results, as the positivity rate decreases significantly after the 5th day. Testing on the first day is effective because the presence of fever usually indicates the virus is circulating in the bloodstream, making it easier to detect.
Dengue testing requires a blood sample and should be conducted at a medical facility. After the sample is collected and processed, medical personnel place it on a test kit and wait for colored bands to appear. One band at the "C" mark indicates a negative result. Two bands at the "C" and "T" marks indicate a positive result for dengue fever.
Can dengue tests give false negatives?
False negatives are possible with this type of test, especially in individuals infected with the D2 strain during the initial days of illness. Therefore, even with a negative result, doctors won't rule out dengue fever if symptoms are present and will continue to closely monitor the patient, particularly on days 4 and 5.
Early dengue symptoms often resemble those of other viral infections, such as the flu. The initial phase can be particularly similar to Covid-19, making it easy to miss. Parental concern about taking children to the hospital can unfortunately lead to delayed diagnosis and treatment, increasing the risk of severe complications and even life-threatening situations.
Dengue fever progresses in various ways, ranging from mild to severe. Most patients recover fully. However, severe cases can be fatal if not monitored and treated promptly. Testing enables early detection, allowing doctors to track the disease's progression daily and implement appropriate interventions.
Signs requiring hospitalization include bleeding from mucous membranes (e.g., gums, nose, digestive tract), abdominal pain in the liver area, frequent vomiting, cold and clammy extremities, rapidly decreasing platelet count, blood thickening, reduced urine output, and fluid accumulation in the pleural or abdominal cavity.
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