Laboratory Diagnosis and Prognosis of Severe Dengue

• Sensitivity of the NS1 detection assays for diagnosis of laboratory-confirmed severe dengue. [ Time Frame: Within the first 72 hours of fever onset ] [ Designated as safety issue: No ]
  Percentage of detection assays which correctly predict laboratory-confirmed severe dengue.
• Specificity of the NS1 detection assays for diagnosis of laboratory-confirmed severe dengue. [ Time Frame: Within the first 72 hours of fever onset ] [ Designated as safety issue: No ]
  Percentage of detection assays which correctly predict different dengue serotypes.
• Positive predictive values of the NS1 detection assays for diagnosis of laboratory-confirmed severe dengue. [ Time Frame: Within the first 72 hours of fever onset ] [ Designated as safety issue: No ]
  Percentage of detection assays which correctly predict dengue infection.
• Negative predictive values of the NS1 detection assays for diagnosis of laboratory-confirmed severe dengue. [ Time Frame: Within the first 72 hours of fever onset ] [ Designated as safety issue: No ]
  Percentage of detection assays which correctly predict no dengue infection.

• Positive predictive values of the NS1 detection assays for children requiring hospitalization or parenteral fluid therapy. [ Time Frame: Estimated within 6 days of presentation ] [ Designated as safety issue: No ]
  Percentage of detection assays which correctly predict requirement of hospitalization and/or parenteral fluid therapy (dehydration, vomiting or signs of capillary permeability).
• Negative predictive values of the NS1 detection assays for children requiring hospitalization or parenteral fluid therapy. [ Time Frame: Estimated within 6 days of presentation ] [ Designated as safety issue: No ]
  Percentage of detection assays which correctly predict no requirement of hospitalization and/or parenteral fluid therapy (dehydration, vomiting or signs of capillary permeability).
• Sensitivity of the NS1 detection assays to predict the requirement of hospitalization or parenteral fluid therapy. [ Time Frame: Estimated within 6 days of presentation ] [ Designated as safety issue: No ]
  Percentage of detection assays which correctly predict the requirement of hospitalization and/or parenteral fluid therapy (dehydration, vomiting or signs of capillary permeability).
• Specificity of the NS1 detection assays to predict the dengue serotype which corresponds to the requirement of hospitalization or parenteral fluid therapy. [ Time Frame: Estimated within 6 days of presentation ] [ Designated as safety issue: No ]
  Percentage of detection assays which correctly predict the dengue serotype and it's correlation to a requirement of hospitalization and/or parenteral fluid therapy (dehydration, vomiting or signs of capillary permeability).

A study of dengue in children presenting to outpatient departments of 5 large hospitals in Ho Chi Minh City and Tien Giang province, Viet Nam.

Different blood tests are compared at the early stages of dengue fever onset in their ability to accurately and specifically detect children whose dengue will progress to severe disease.

In a prospective study in the outpatients department of three large hospitals in Ho Chi Minh City, Viet Nam, we will determine the early diagnostic sensitivity, specificity, positive and negative predictive values of two NS1 diagnostic tests in severe dengue cases.

The study is intended to develop a prognostic algorithm for the early identification of severe dengue cases.

Routine demographic, haematological and biochemical laboratory markers will be utilized to derive a prognostic algorithm that is clinically-useful for guiding patient triage and interventions.

We hope to discover and evaluate new early biomarkers of severe dengue and will evaluate candidate host response molecules and virological markers for their prognostic value.

We further plan to understand the phylogeography of DENV in the super-urban setting of HCMC.

We will use genome scale sequencing of DENV together with geospatial information on the residential addresses of patients to better understand transmission dynamics in space and time in a high transmission super-urban district of HCMC and thereby identify opportunities for public health interventions.

Patient presenting to outpatient department of participating hospitals with symptoms of dengue fever

Inclusion Criteria:

• Clinical suspicion of dengue
• Axillary temperature >=37.5C
• Less than 72hrs of fever
• Resident in Ho Chi Minh City
• 1-15 yrs of age
• Accompanying family member or guardian has a mobile phone
• Written informed consent

Exclusion Criteria:

• Any patient who the attending physician believes is unlikely to be able to attend follow-up
• Any patient in who the attending physician believes another diagnosis is more likely.

• Hospital for Tropical Diseases, Ho Chi Minh City, Viet Nam
• Children's Hospital No.1, Ho Chi Minh City, Viet Nam
• Children's Hospital No.2, Ho Chi Minh City, Viet Nam
• Tien Giang Provincial Hospital, Tien Giang, Viet Nam
• District 8 Hospital, Ho Chi Minh City, Viet Nam