Dengue fever

Dengue fever

From Wikipedia, the free encyclopedia

Jump to: navigation, search"Dengue Fever" redirects here. For the band of the same name, see Dengue Fever (band).

Dengue virus

A TEM micrograph showing Dengue virus virions (the cluster of dark dots near the center).

Virus classification

Group:

Group IV ((+)ssRNA)Family:

FlaviviridaeGenus:

FlavivirusSpecies:

Dengue virus

Dengue feverClassification and external resources

ICD-10A

HYPERLINK "http://www.who.int/classifications/apps/icd/icd10online/?ga00.htm+a90" \o "http://www.who.int/classifications/apps/icd/icd10online/?ga00.htm+a90" 90.

ICD-9061

DiseasesDB3564

MedlinePlus001374

eMedicinemed/528

MeSHC02.782.417.214

Dengue fever (pronounced /dge/ (BrE), /dgi/ (AmE)) and dengue hemorrhagic fever (DHF) are acute febrile diseases, found in the tropics and Africa, and caused by four closely related virus serotypes of the genus Flavivirus, family Flaviviridae.[1] It is also known as breakbone fever. The geographical spread is similar to malaria, but unlike malaria, dengue is often found in urban areas of tropical nations, including Trinidad, Puerto Rico, Singapore, Malaysia, Taiwan, Thailand, Indonesia, Philippines, Pakistan, India, Brazil, Vietnam, Guyana, Venezuela, Bangladesh and now Samoa[2]. Each serotype is sufficiently different that there is no cross-protection and epidemics caused by multiple serotypes (hyperendemicity) can occur. Dengue is transmitted to humans by the Aedes aegypti or more rarely the Aedes albopictus mosquito, which feed during the day.[3] There was a reported outbreak of the disease in Barbados and several adjoining islands in December 2008.

Contents

[hide] 1 Signs and symptoms

2 Diagnosis

3 Treatment

3.1 Emerging treatments

4 Epidemiology

5 Prevention

5.1 Vaccine development

5.2 Mosquito control

5.3 Potential antiviral approaches

6 Etymology

7 History

8 Use as a biological weapon

9 References

10 External links

[edit] Signs and symptomsThis is manifested by a sudden onset of severe headache, muscle and joint pains (myalgias and arthralgiassevere pain gives it the name break-bone fever or bonecrusher disease), fever, and rash.[4] The dengue rash is characteristically bright red petechiae and usually appears first on the lower limbs and the chest; in some patients, it spreads to cover most of the body. There may also be gastritis with some combination of associated abdominal pain, nausea, vomiting, or diarrhea.

Some cases develop much milder symptoms which can be misdiagnosed as influenza or other viral infection when no rash is present. Thus travelers from tropical areas may pass on dengue in their home countries inadvertently, having not been properly diagnosed at the height of their illness. Patients with dengue can pass on the infection only through mosquitoes or blood products and only while they are still febrile.

The classic dengue fever lasts about six to seven days, with a smaller peak of fever at the trailing end of the disease (the so-called biphasic pattern). Clinically, the platelet count will drop until the patient's temperature is normal.

Cases of DHF also show higher fever, variable haemorrhagic phenomena, thrombocytopenia, and haemoconcentration. A small proportion of cases lead to dengue shock syndrome (DSS) which has a high mortality rate.

[edit] DiagnosisThe diagnosis of dengue is usually made clinically. The classic picture is high fever with no localising source of infection, a petechial rash with thrombocytopenia and relative leukopenia - low platelet and white blood cell count.

The WHO definition of dengue haemorrhagic fever has been in use since 1975; all four criteria must be fulfilled:[5]1. Fever, bladder problem, constant headaches, severe dizziness and loss of appetite.

2. Hemorrhagic tendency (positive tourniquet test, spontaneous bruising, bleeding from mucosa, gingiva, injection sites, etc.; vomiting blood, or bloody diarrhea)

3. Thrombocytopenia (100)Normocytic anemia (80