Changing pattern of symptoms in dengue patients over the years:A review and meta-analysis

Objective:To describe the pattern of vomiting,diarrhoea and abdominal pain among dengue patients over the years in different age groups.Methods:Electronic databases were used to include studies that reported symptoms of vomiting,diarrhoea or/and abdominal pain.Confirmation of dengue was conducted by laboratory diagnosis.The exclusion criteria were case reports and studies which only described specific settings,focused only on dengue haemorrhagic fever or severe dengue and co-infection.Meta-analysis was performed on the overall prevalence of vomiting,diarrhoea and abdominal pain which was then stratified according to years and different age groups.Results:Out of the 2002 studies,32 studies were included.All studies were conducted between 1995 and 2014.The studies were conducted in 18 countries with a total sample size of 69466.The predominant symptom was abdominal pain before 2004 but became vomiting thereafter.The prevalence of vomiting was constant throughout the years(20%-40%),but the prevalence of abdominal pain reduced from 30%-50%to 20%-30%.The prevalence of diarrhoea increased steadily from 5%to 30%.Abdominal pain was the predominant symptom in children(75.03%)[95%confidence interval(CI):64.89%-85.17%],while diarrhoea was predominant in adults(32.42%)(95%CI:23.96%-40.88%).For studies which included all ages,the predominant symptom was vomiting(45.18%)(95%CI:33.87%-56.49%).Conclusions:The knowledge of symptomatic pattern change could assist clinicians in diagnosing and managing dengue patients.Future studies could address the occurrence of this change and the difference in symptoms between children and adults.