Outbreak of dengue fever in Karachi 2006: a clinical perspective.

OBJECTIVE This study reports clinical manifestations and spectrum of severity of dengue fever (DF), dengue haemorrhagic fever (DHF) and dengue shock syndrome (DSS) in adult patients admitted during 2006 outbreak in Karachi. A rough estimation of cost of care was also calculated. METHODS A cross-sectional study was done at a tertiary care hospital in Karachi from January to December 2006. Patients suspected of having DF with positive dengue IgM antibodies were included and records were reviewed. Patients were divided into DF, DHF and DSS as per WHO classification, and the severity of clinical manifestations was determined. RESULTS A total of 278 (65.72%) of 423 patients admitted with suspected dengue illness had positive IgM titer. Mean age was 31 +/- 12.9 years, with 168 (60%) males and 110 (40%) females. Common presenting symptoms were fever (100%), vomiting (78%), epigastric pain (52%), bleeding tendencies (34%), and erythematous rash (33%). Thrombocytopenia (60%), Leucopenia (45%), elevated transaminases (ALT 71%; AST 88%), and deranged PT (22%) and aPTT (75%) were the predominant. Laboratory parameters: DF was diagnosed in 169 (61%) patients, 82 (29%) were classified as DHF, and 27 (10%) as DSS. Patients with DHF/DSS were younger <30 years (n=60, 55%) and had longer hospital stay (p=0.001). Case fatality rate for DHF/DSS group was 4.6%. CONCLUSION It was estimated that endemicity of DF is on the rise in Karachi and a significant proportion of patients had DHF and DSS. Younger patients develop DHF and DSS and have high case fatality rate.