The anti Dengue antibodies are antibodies directed towards the Dengue virus, useful for the diagnosis of Dengue hemorrhagic fever.
Dengue, more correctly defined Dengue fever, Dengue hemorrhagic fever or fever bone breaker, is an infectious disease caused by the Dengue virus of the same name.
There Dengue it is a tropical disease, and exists in four slightly different types, called Den-1, Den-2, Den-3 and Den-4. Dengue infection does not occur directly between people: the virus is transmitted via a vector, usually a mosquito of the type Aedes, which thus transmits the infected blood taken from a sick person to a healthy person.
The incubation time for Dengue is approximately 5-7 days. The main symptoms of Dengue are fever, even higher than 39 ° C, artalgia (pain in the joints, Myalgia (pain in the muscles).
There diagnosis Dengue fever clinic is not always easy, as it enters the differential diagnosis with typhus, with the Colorado tick fever, with yellow fever and other hemorrhagic-type fevers. Even the use of antibodies it does not always give a definitive answer as there are often false positives due to cross-reactions with other viruses of the Flavivirus type.
The WHO (World Health Organization, WHO) has thought of clinical criteria that can accompany the positivity of anti-Dengue antibodies in the diagnosis of Dengue hemorrhagic fever:
- acute onset of high fever (greater than 38 ° C) of a continuous type with a duration of at least 3-7 days,
- presence of hemorrhagic manifestations, with at least one of the following symptoms and signs: skin manifestations such as petechiae, purpura, ecchymosis, and bleeding such as bleeding gums, hematemesis (blood vomiting) or melaena (dark blooded stool);
- enlarged liver (hepatomegaly);
- decrease in platelets (thrombocytopenia) to less than 100,000 / ml);
- hemoconcentration (hematocrit increased by 20% compared to a previous control).
The anti Dengue antibodies they are detected by haemagglutinated inhibition (HI), complement fixation, enzyme immunoassays (ELISA), neutralization or immunocapture tests.
By means of an immunocapture test it is possible to distinguish between the IgM and IgG fractions: it is a highly specific test and is positivized within a week of illness.
Positive anti-Dengue antibodies
The positivization of anti-Dengue antibodies occurs as true positive for the following causes:
False positives from cross reactivity
The positivization of anti-Dengue antibodies occurs as false positive for the following causes:
- Flavivirus diseases (yellow fever, Japanese encephalitis and other viral encephalitis).
Tags: Laboratory medicine Blood