LABORATORY INVESTIGATION

IN DENGUE INFECTION

Dr Lai Jun YuanPegawai Perubatan Jabatan Patologi

Hospital Batu Pahat

LABORATORY INVESTIGATION

DISEASE MONITORING TESTS DIAGNOSTIC TESTS

DISEASE MONITORING TESTS(WBC, HCT, PLATELETS COUNT, LFT)

DIAGNOSTIC TESTS

DIAGNOSTIC TESTSC1. DENGUE SEROLOGY TESTS

• Haemagglutination Inhibition Test• Dengue IgM Test• Indirect IgG ELISA Test• Dengue Rapid Tests

2. VIRUS ISOLATION3. POLYMERASE CHAIN REACTION (PCR)4. NON STRUCTURAL PROTEIN – 1 (NS1 Antigen)

• Gold Standard for serological diagnosis

• Labour intensive & requires paired samples for interpretation

• Differentiate between 1° & 2 ° dengue infection

• Used mainly for research purpose

HAEMAGGLUTINATION INHIBITION TESTS

• Widely used serological test.

• Significantly higher in primary infections

DENGUE IgM TEST

• Detected after 7 days of onset of fever.

• Recommended if dengue IgM is still negative after day 7 in secondary dengue.

INDIRECT IgG ELISA TEST

• Qualitative detection of dengue IgM & IgG

• Possible of False Positive

• Need to confirm by dengue IgM ELISA tests

DENGUE RAPID TESTS

VIRUS ISOLATION

• Most definitive test for dengue infection• Performed in Lab equipped with tissue & virus

isolation facilities• Time consuming (2 weeks)• Expensive

POLYMERASE CHAIN REACTION (PCR)• Diagnosis of dengue infection in the early phase

(< 5 days of illness)

POLYMERASE CHAIN REACTION (PCR)

NON STRUCTURAL PROTEIN – 1(NS1 Antigen)• This antigen is present in high concentrations in

the sera of dengue infected patients during the early phase of the disease

AVAILABLE DENGUE INVESTIGATION IN JABATAN PATOLOGI HSNI

Dengue Rapid Test Possible of false positive Confirmation with ELISA Please call the lab prior to sending any samples TAT – 1hour

Dengue IgM ELISA method Done in batches TAT – 2 to 3 days

Dengue IgG (Special request) ELISA method TAT – 2 to 3 days

NS1 Antigen Rapid NS1Please call the lab prior to sending any

samplesTAT – 1hour

• NS1 Antigen (ELISA method) ELISA method Done in batches (twice a week) TAT – 2 to 3 days

REQUEST FORM FOR DENGUE SEROLOGY

Please write down the type of Tests:1) Dengue IgM2) Dengue IgG3) Rapid IgM/IgG4) NS1 Antigen5) Rapid NS1

DENGUE SEROTYPE SURVEILLANCE

• For NS1 Antigen Test only

• The form must be completely filled

Patient details Date of onset Clinical Finding

LASTLY

Dengue investigation is very costlyPlease plan carefully before you send

any investigation for dengue Investigation must base on clinical

presentation of the patient

REFERENCES

• Clinical Practice Guildlines “Management of Dengue Infection in Adults” 2nd Edition by MOH