Health
DENGUE FEVER
Dengue fever 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. It is also known as breakbone fever. The geographical spread includes northern Australia, Singapore, Malaysia, Taiwan, Thailand, Vietnam, Indonesia, Honduras, Costa Rica, Philippines, Pakistan, India, Bangladesh, Puerto Rico, Bolivia, Brazil, Guyana, Venezuela, Trinidad and Samoa. Unlike malaria, dengue is just as prevalent in the urban districts of its range as in rural areas. 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.The WHO says some 2.5 billion people, two fifths of the world's population, are now at risk from dengue and estimates that there may be 50 million cases of dengue infection worldwide every year. The disease is now epidemic in more than 100 countries.
SIGNS AND SYMPTOMS
The disease manifests as a sudden onset of severe headache, muscle and joint pains (myalgias and arthralgiasę¢„evere pain that gives it the nick-name break-bone fever or bonecrusher disease), fever, and rash. 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. DHF combined with a cirrhotic liver has been suspected in rapid development of Hepatocellular Carcinoma. Given the DEN virus is related to the Hepatitis C virus this is an avenue for further research as HCC is among the top five leading cancerous causes of death outside of Europe and North America . Normally HCC does not occur in a cirrhotic liver for ten or more years after the cessation of the poisoning agent. DHF patients can develop HCC within one year of cessation of abuse.Treatment>>