Sangchai Yingsakmongkon. Identification of dengue serotypes along the Thai-Laos border using the Nasba technique . Master's Degree(Tropical Medicine). Mahidol University. : Mahidol University, 2004.
Identification of dengue serotypes along the Thai-Laos border using the Nasba technique
Abstract:
In this study, the detection of dengue serotypes was determined by NASBA technique. The samples were 402 probable DF/DHF patients and 171 students, aged 2-15 years and living in Nhong Kai, Nakhorn Phanom, and Mukdahan provinces. Data were collected from June to September 2002. The samples were tested by Combo Q Check test kit, enzyme-linked immunosorbent assay (ELISA), polymerase chain reaction (PCR) and nucleic acid sequence-based amplification (NASBA). Statistical analyses used were descriptive statistics, Cochran’s Q test, McNemar test, and Kappa. Four serotypes of dengue virus were found in 2 provincial hospitals, except in Mukdahan Provincial Hospital, where only dengue virus serotype 2 was found. Mainly, dengue virus infections were due to dengue 2, by PCR and NASBA. There was excellent correlation in determination of dengue serotypes between PCR and NASBA (Cochran’s Q test, P = 0.065, N = 78), while the positive cases determined by ELISA were more than those determined by Combo Q Check test (McNemar test, P= 0.02, N=78).
When compared to the PCR method, the sensitivities of NASBA by dengue 1-4 were 100, 100, 88.89, and 100%, respectively, while the specificities of NASBA by dengue 1-4 were 100, 99.32, 100, and 100%, respectively. For serotyping, NASBA showed similar specificity and sensitivity to PCR (κ= 0.97), was also rapid and used only a heating block and water bath. Therefore, the NASBA technique was more suitable in the field than PCR.