Profile of National External Quality Assessment Scheme for HIV
Antibody Testing in Myanmar
HIV is one of the major infectious diseases in Myanmar and National AIDS Program of the country tries to prevent and control this infection. For this purpose, the diagnosis of HIV infection is very important, and the test results should be accurate and precise. To monitor the quality of HIV testing results, National Health Laboratory started the ‘National Exiternal Quality
Assessment Scheme for HIV Antibody Testing’ as an organizer as well as the distributer since
2005, with 65 participating laboratories & had increased the number yeasly.
National Health Laboratory Organize and hold the workshop for the new participants yearly, before distributing the panel samples to them. Panel samples are distributed twice a year and after that, analysed the returned results from the participants and give feedback report for corrective actions. For panal sample preparation, convert the plasma to serum using thrombin and ass Proclin as preservative. Positive sera are inactivated by 56? for 60 minutes to avoids the risk of
transmission during transportation by postal service. Homogeneity tests are done after aliquoting the samples and stability tests are also done to assess the quality of panel samples after transportation aliquoting the samples and stability tests are also done to assess the quality of panel samples after transportation to the participants. Five samples including HIV antibody positive, weak positive, weak positive and negative sera are distributed twice a year. Pane 15 and 16 samples were already distributed and analysed the returned results for 2012.
347 laboratories from 274 public hospitals, 41 AIDS/STD control teams and 6 INGOs are participating up to 2012. Out of these laboratories,8%(27/347) of the laboratories did not respond for panel 15 and panel 16 respectively. Nine%(30/320) of the laboratories for panel 15 and 5%(17/316) of the laboratories for panel 16 reported aberrant test results. Out of these aberrant test
results, 72%(28/39) and 92%(24/26) were false negative for panel 15 and panel 16 respectively.
For 2012, most of the non-responding laboratories were from remote area, and there was difficulty on sending the panel samples to them and returning their results to the organizer. Number of aberrant results decreased for panel 16 compared to the previous panel 15 after corrective actions. False negative results were reported more than false positive results. False negative results were due to using of test kits beyond the expiry date, inability to interpret the HIV Ab weak positive sample, not following the manufacturer’s instructions like testing with incorrect amount of
specimens and reagents, incorrect reading time of test results, using the test kit immediately after taken from refrigerator before reaching the room temperature etc. False positive test results were mainly due to result of contaminated pipette tips, reading the test results of ICT rapid test kits with reflected light, reading the test result after the correct reading time, sample mixed up and clerical error. For the corrective actions, the technicians who reported aberrant test results were given refresher training course and on site testing assessment were also done at the monitoring and supervisory visits. In the future, National Health Laboratory will allow the private hospital laboratories to participate in this scheme.