สถาบันวิจัยวิทยาศาสตร์สาธารณสุข

National Institute of Health of Thailand

Screening tests for diagnosis of HIV-1 infection: problems and selection of the tests

Authors : Suthon Vongsheree*, Nuanjun Ruchusatsawat*, Hunsa Thaisri*, Pongnuwat Srignam*


Affililations:       *Health Sciences Research Institute, Department of Medical Sciences

                            Ministry of Public Health

 

Source:               Communicable Disease Journal 1997; 23(4): 577-582

           

Language:         Thai with English abstract

 

Abstract

 

The main objectives of the study were to evaluate 4 screening tests for the diagnosis of HIV-1 infection, to find supportive data on National Guideline for HIV-1 Testing which recommended by the Thai Ministry of Public Health (MOPH) in 1996 and to reveal problems encounter with HIV testing using multiscreening tests. The guideline encourage the laboratory to finish final report herself, with minimal confirmatory tests. Initial reactive sera of 663 cases, with prior positive by particle agglutination (PA), were tested by additional enzyme-linked immunoassay (EIA), repeat PA and were confirmed by immunofluorescent assay or Western blot (WB). The result showed that 2 screening tests, with different principle of analyses, reported concordant positive results of 645-647 WB positive cases (97.38%-97.60%). Such these specimens were not necessary to refer for HIV confirmatory test. Only 3-12 cases were discordant by 2 screening tests which were required to confirm. Of 25 problem specimens with WB indeterminate occupied discordant 2 screening tests 16 cases (64%) and showed gp160 and/or p24 more frequently than other bands (17/33; 54.8%). By using 2 different screening tests, e.g. EIA and PA as suggested by Thai MOPH 1996, such common errors could be avoided and the report data was valid enough besides of confirmatory tests.