Anakinra in Dengue With Hyperinflammation ( AnaDen )

Inclusion Criteria: * Patients hospitalised with a clinical diagnosis of dengue and at least 1 warning sign(s) (see appendix) or severe dengue to Emergency department/inpatient wards/Intensive Care wards (ICU), * Ferritin levels \> 2000ng/mL * ≥ 12 years of age * Written informed consent or assent to participate in the study * Agree to come back for 2 follow up visits around day 30 of illness (maximum 5 weeks) and at 3 months Exclusion Criteria: * Pregnancy * Localizing features suggesting an alternative/additional diagnosis, e.g. pneumonia, sepsis * Patients taking immunosuppressive drugs or other biologics in last 1 month * Patients with underlying malignancy or immunosuppression * Children \<12 years * Have end-stage renal failure (baseline GFR \< 30ml/min) * Being treated for TB * Taking any drug with significant interaction with anakinra * The study physician judges that the patient is unlikely to attend follow up visit at around 3-4 weeks after fever onset - e.g. due to long travelling distance from the clinic