An assessment of laboratories performance for anti HIV testing in the Northern Thailand, during 2009–2011

Abstract

     Antibody testing is the most common way to diagnose HIV infection in laboratories which need good quality. The objective of this retrospective study is to assess the HIV diagnosis performances of 216 government and private laboratories from 17 provinces in the Northern Thailand participated in Proficiency Testing for HIV Serology in Northern Scheme during 2009–2011 that tested nine trial samples. Testing algorithms, serology assays, the accuracy and precision rates were compared among nine trials. The results showed that the trend of HIV testing algorithm by three methods was significantly increased (p<0.001) while one method was significantly reduced (p<0.0001). The serological method performed were classified into four assay including machine-based assay (MBA), microplate Enzyme immunoassay (EIA), rapid assay and Particle agglutination (PA). Rapid assay was the most popular assay (57.19 %) followed by PA, MBA and EIA (31.30 %, 10.63 % and 0.88 % respectively). The using rate of EIA was significantly reduced (p<0.0001) but rapid test, PA and MBA were not significantly changed throughout the period time. However, the trend of using MBA was slightly increased. The accuracy and precision rates of all assays were significantly different. (p=0.02) EIA had the best accuracy rate at 100 %, followed by rapid test, MBA and PA at 99.86 %, 99.83 % and 97.79% respectively. In addition, EIA had the best precision rate at 100%, followed by rapid test, MBA and PA at 99.85 %, 99.42% and 98.07% respectively. The average of accuracy and precision rates of result interpretation were 99.66% and 99.45% respectively that were not significantly throughout the period time. (p=0.08 and p=0.10 respectively) The result showed that laboratories in the Northern Thailand have had the good performance and high quality for HIV testing.