Introduction

00000000The first case of dengue haemorrhagic fever (DHF) in Thailand in 1950 was diagnosed as "influenza with bleeding", and the first DHF epidemic occurred in 1958 when it was limited only to Bangkok. There were 2,158 cases reported with 300 deaths, and with a morbidity rate (MR) of 8.87-100,000 population and case-fatality rate (CFR) of 13.9%(1).

00000000 Guidelines for the diagnosis and management of DHF were developed at the Children's Hospital by Dr Suchitra Nimmannitya.(2, 3, 4) The use of these guidelines brought down the CFR from 13.9% to 5% in the first 8 years. After this period, the CFR was reduced gradually from 5% to 1% in about 10 years due to the spread of DHF to most big cities in the country. Since 1971, the number of reported cases has been continuously on the increase. However, CFR has stayed <1% since 1979 and was below 0.5% in 1989(1).

Critical areas in efficient case management

00000000The clinical and laboratory criteria for the diagnosis of DHF developed at the Children's Hospital, Bangkok, during 1975(5) and which has been adopted by WHO, are based are based on the presence of major manifestations, in order of their appearance:
(1) High continuous fever for 2 - 7 days.
(2) Haemorrhagic manifestations, including at least a positive tourniquet test.
(3) Enlargement of liver.
(4) Circulatory disturbances (as shock in severe cases).
(5) Thrombocytopenia < 100,000 cells/cu.mm.
(6) Haemoconcentration: hematocrit (Hct) increased by 20% or other evidence of plasma leakage i.e. pleural effusion and/or ascites.

00000000These criteria meets 95% confidence level for making the diagnosis of DHF, but the diagnosis can be made only when a patient has completed his clinical course of illness.

00000000 DHF is classified into four grades according to the clinical hallmarks of bleeding and shock. Most patients of DHF grade I and II (non-shock) can recover spontaneously or shortly after a brief period of fluid therapy. In contrast, DHF grade III, and especially grade IV, patients need special attention and care from physicians and nurses with appropriate fluid resuscitation and judicious volume replacement. Correction of any metabolic and/or electrolytes abnormalities are critical in these patients. Concealed internal bleeding is likely in patients with prolonged shock.

00000000 Early detection of shock and proper management are the most important factors that determine the prognosis of DHF patients

00000000 The clinical course of DHF is divided into three phases:
(1)Febrile phase (2 - 7 days)
(2) Critical or leakage phase (24 - 48 hours)
(3) Convalescence phase (2 - 7 days)