Causes of Dengue Hemorrhagic Fever (DHF)
Dengue hemorrhagic fever (DHF) is a severe form of dengue fever primarily caused by infection with a different dengue virus serotype from a previous infection. Factors increasing the risk of DHF include:
- Caucasians: For unknown reasons, Caucasians are more susceptible to developing DHF.
- Children under 12: Children in this age group have an increased risk due to their developing immune systems.
- Females: Females tend to experience more severe dengue infections than males.
Immune Response: DHF typically occurs when an individual who has been previously infected with one dengue virus serotype is infected with a different serotype. The antibodies developed during the initial infection can enhance the immune response to the second infection, leading to a more severe illness.
Geographical Distribution: Individuals living in or traveling to tropical regions where dengue is endemic are at an increased risk of contracting DHF. The Aedes mosquito, which carries the dengue virus, is prevalent in these areas.