Clinical manifestations of dengue, Zika and chikungunya in the Pacific Islands: A systematic review and meta-analysis.

Dengue, Zika and chikungunya outbreaks pose a significant public health risk to Pacific Island communities. Differential diagnosis is challenging due to overlapping clinical features and limited availability of laboratory diagnostic facilities. There is also insufficient information regarding the complications of these arboviruses, particularly for Zika and chikungunya. We conducted a systematic review and meta-analysis to calculate pooled prevalence estimates with 95% confidence intervals (CI) for the clinical manifestations of dengue, Zika and chikungunya in the Pacific Islands. Based on pooled prevalence estimates, clinical features that may help to differentiate between the arboviruses include headache, haemorrhage and hepatomegaly in dengue; rash, conjunctivitis and peripheral oedema in Zika; and the combination of fever and arthralgia in chikungunya infections. We estimated that the hospitalisation and mortality rates in dengue were 9.90% (95% CI 7.67-12.37) and 0.23% (95% CI 0.16-0.31), respectively. Severe forms of dengue occurred in 1.92% (95% CI 0.72-3.63) of reported cases and 23.23% (95% CI 13.58-34.53) of hospitalised patients. Complications associated with Zika virus included Guillain-Barré syndrome (GBS), estimated to occur in 14.08 (95% CI 11.71-16.66) per 10,000 reported cases, and congenital brain malformations such as microcephaly, particularly with first trimester maternal infection. For chikungunya, the hospitalisation rate was 2.57% (95% CI 1.30-4.25) and the risk of GBS was estimated at 1.70 (95% CI 1.06-2.48) per 10,000 reported cases. Whilst ongoing research is required, this systematic review enhances existing knowledge on the clinical manifestations of dengue, Zika and chikungunya infections and will assist Pacific Island clinicians during future arbovirus outbreaks.