Also known as dengue fever, breakbone fever, and dandy fever, dengue is endemic and epidemic in tropical and subtropical regions. It is an acute infection caused by a ﬂavivirus (family togaviridae) transmitted by mosquitoes – especially Aedes aegypti. Incubation period is 5–8 days, and is followed by abrupt onset of symptoms: fever, facial ERYTHEMA with intense itching (which spreads throughout the body), sore throat, running eyes, and painful muscles and joints are common accompaniments. The symptoms subside within a few days and are frequently succeeded by a relapse similar to the ﬁrst. Further relapses may occur, and joint pains continue for some months. In uncomplicated dengue the mortality rate is virtually zero. Diagnosis is by virus isolation or demonstration of a rising antibody-concentration in the acute phase of infection. There is no speciﬁc treatment, but mild analgesics can be used to relieve the pains, and calamine lotion the itching. Prevention can be achieved by reduction of the mosquito-vector population.
Dengue haemorrhagic fever This is a more severe form of the disease which usually occurs in young children; it is largely conﬁned to the indigenous population(s) of south-east Asia. It is accompanied by signiﬁcant complications and mortality. Immunological status of the host is considered important in pathogenesis.