Doctor's Notes on Dengue Fever
Dengue fever is a disease caused by a family of viruses transmitted by mosquitoes. It can affect anyone but tends to be more severe in people with compromised immune systems. Dengue fever can be caused by any of five serotypes of the dengue virus, so it is possible to get dengue fever multiple times. Other names for dengue fever include "breakbone fever" or "dandy fever."
Characteristic symptoms of dengue virus infection include fever, headache, and an itchy rash. Other symptoms associated with dengue fever include Other signs of dengue fever include bleeding gums, severe pain behind the eyes (retro-orbital pain), and red palms and soles. People with the condition also have contortions due to intense pain in the joints, muscles, and bones.
Dengue Fever Symptoms
The symptoms and signs for dengue begin about three to 15 days (incubation period) after a mosquito bite transfers a virus (dengue virus serotypes 1-4) to a person previously unexposed to the viruses. Fever and painful muscle, bone, and joint aches can occur during the first few hours of symptoms when headache, chills (shivering and/or sweating), rash (may be itchy) and/or red spots or flushing, and swollen lymph nodes first appear. Pain behind or in back of the eyes is also a common symptom. Some individuals may develop a sore throat, vomiting, nausea, abdominal and/or back pain, and loss of appetite. These symptoms usually last about two to four days and then diminish, only to reappear again with a rash that covers the body and spares the face. The rash also may occur on the palms of the hands and the bottom of the feet, areas frequently spared in many viral and bacterial infections. The symptoms may last about one to two weeks with complete recovery, in most cases, in a few weeks. However, some people can develop more severe symptoms and complications, such as hemorrhagic areas in the skin (easy bruising), gums, and the gastrointestinal tract. This condition is termed dengue hemorrhagic fever (DHF). The majority of DHF is seen in children under 15 years of age, but it can occur in adults. Another clinical variation of dengue fever is termed dengue shock syndrome (DSS); DHF usually precedes DSS. The patients eventually develop severe abdominal pain, heavy bleeding, and blood pressure drops; this syndrome, if not treated quickly, may cause death.
Dengue Fever Causes
Four closely related viruses cause dengue fever. The viruses are transmitted from Aedes aegypti and Aedes albopictus mosquitoes to humans in a viral life cycle that requires both humans and these mosquitoes. There is no human-to-human dengue fever transmission. Once a mosquito is infected, it remains infected for its life span. A human can infect mosquitoes when the human has a high number of viruses in the blood (right before symptoms develop). The viruses belong to the Flaviviridae family and have an RNA strand as its genetic makeup. Virologists term them dengue virus types 1-4 (DENV 1-4). All four serotypes are closely related. However, there are enough antigenic differences between them that if a person becomes immune to one serotype, the person can still be infected by the other three serotypes.
Viruses are small particles of genetic material (either DNA or RNA) that are surrounded by a protein coat. Some viruses also have a fatty "envelope" covering. They are incapable of reproducing on their own. Viruses depend on the organisms they infect (hosts) for their very survival. Viruses get a bad rap, but they also perform many important functions for humans, plants, animals, and the environment. For example, some viruses protect the host against other infections. Viruses also participate in the process of evolution by transferring genes among different species. In biomedical research, scientists use viruses to insert new genes into cells.
When most people hear the word "virus," they think of disease-causing (pathogenic) viruses such as the common cold, influenza, chickenpox, human immunodeficiency virus (HIV), and others. Viruses can affect many areas in the body, including the reproductive, respiratory, and gastrointestinal systems. They can also affect the liver, brain, and skin. Research reveals that that viruses are implicated in many cancers as well.
Stomach Pain : Nausea & Other Causes QuizQuestion
Bowel regularity means a bowel movement every day.See Answer
Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.