Introduction:
Dengue Infections are endemic in Indonesia. Infants are at risk of developing dengue fever (DF) and dengue hemorrhagic fever (DHF). Many infants have severe DHF with unusual manifestations and may suffer from complications and even death because of difficulties in early diagnosis and improper management. Many inter-related factors such as environmental, biological and demographic issues influence dengue epidemiology and transmission.

Objective:
Nowdays, All The Primary Health Care in Jakarta has already used simple test laboratorium complete blood, IgM IgG antibody serum, especially NS1 antigen serum to prove clinical diagnostic for dengue infection. 

Case Illustration:
An – 4 months old male infants came to emergency departement with chief complaint fever for 3 days ago, unusual fussiness and refusing to eat. There weren’t any symptoms like spontaneous bleeding (nose bleeding, melena). On the admission, the baby is awake and crying, the vital sign heart rate 126  beats/min with reguler rhythm, temperature 37, 7o C, respiratory 42 rate. Initial complete blood counts showed thrombocytopenia, and the blood sample ware negative for IgM and IgG antibody serum of dengue. On examination, there were some petechiaes in both lower limbs. Other systems were completely normal. Serologic testing for NS1 antigen serum was positive. And at last, the patient was transferred to hospital.
Discussion:
Accurate and timely diagnosis of dengue virus is important for early detection of dengue virus infection. NS1 antigen test is a test for dengue. It allows rapid detection on the first day of fever, before antibodies appear some 5 or more days later. NS1 is present in the serum of infected persons directly at the onset of clinical symptoms in primary dengue infection and produces a strong humoral response. It is detectable before the appearance of IgM antibodies. 
Conclusion:
Therefore, the dengue NS1 antigen test can be used to complement the current antibody test used in peripheral laboratories. Thus, the combination of the NS1 antigen and antibody tests could increase the diagnostic efficiency for early diagnosis of dengue infection. NS1 test is very easy, quckly, acurate, and low budget.