First Round of External Quality Assessment Scheme for SARS-CoV-2 Laboratories During the COVID-19 Pandemic in Thailand.

The emergence of SARS-CoV-2 necessitated the rapid deployment of tests to diagnose COVID-19. To monitor the accuracy of testing across the COVID-19 laboratory network in Thailand, the Department of Medical Sciences under the Ministry of Public Health launched a national external quality assessment (EQA) scheme using samples containing inactivated SARS-CoV-2 culture supernatant from a predominant strain in the early phase of the Thailand outbreak. All 197 laboratories in the network participated; 93% (n=183) of which reported correct results for all 6 EQA samples. Ten laboratories reported false-negative results, mostly for samples with low viral concentrations, and 5 laboratories reported false-positive results (1 laboratory reported false positives and false negatives). An intralaboratory investigation of 14 laboratories reporting incorrect results revealed 2 main causes of error: (1) RNA contamination of the rRT-PCR reaction and (2) poor-quality RNA extraction. Specific reagent combinations were significantly associated with false-negative reports. Thailand's approach to national EQA for SARS-CoV-2 can serve as a roadmap for other countries interested in implementing a national EQA program to ensure laboratories provide accurate testing results, which is crucial in diagnosis, prevention, and control strategies. A national EQA program can be less costly and thus more sustainable than commercial EQA programs. National EQA is recommended to detect and correct testing errors and provide postmarket surveillance for diagnostic test performance.

Frequencies and specificities of red cell alloantibodies in the Southern Thai population.

CONTEXT: Detailed reports of red cell alloantibody frequencies and specificities in the Thai population are limited. The aims of this study were to determine the specificity and compare the frequency of alloantibodies detected using column agglutination technology (CAT) and conventional tube techniques in blood donors and previously transfused patients. SETTINGS AND DESIGN: WE RETROSPECTIVELY REVIEWED ANTIBODY SCREENING AND IDENTIFICATION RECORDS FOR TWO TIME PERIODS: January-December 2006 during which conventional tube techniques were used and January 2008-December 2009 when CAT was used. RESULTS: The overall prevalence of alloantibodies in both patients and donors when using conventional tube techniques was 0.7%, for patients only was 0.9% and donors 0.6%. The most frequent antibodies detected in both groups were anti-Le(a), anti-Mi(a), anti-Le(b), anti-P1 and anti-E. When using CAT, alloantibodies were found in 0.8% of patients and 0.13% of donors with the five most common alloantibodies found in patients were anti-Mi(a), anti-E, anti-Le(a), anti-c and anti-Le(b) respectively. Similarly the common alloantibody specificities in donors were anti-Le(a), anti-Mi(a), anti-Le(b), anti-M and anti-D. CONCLUSIONS: One of the most commonly identified alloantibodies in the Thai population studied was anti-Mi(a) suggesting that Mia positive red cells should routinely be included in antibody screening and identification in this population. For antibody screening and identification, CAT method detected immune and warm alloantibody (ies) more frequently than that associated with conventional tube techniques.

External quality assessment in blood group serology in the World Health Organization South-East Asia Region.

BACKGROUND: The quality of blood transfusion services (BTS) is essential for the treatment of patients who need blood or blood products. BTS involve several steps, including the acquisition of the donor's blood, blood grouping, unexpected antibody screening, blood storage, transfusion, etc. There is a need to check the effectiveness of all elements in the BTS can be assessed and monitored by an external quality assessment. AIM: To assess and evaluate the performance of ABO and Rh(D) blood grouping and unexpected antibody screening of the selected World Health Organization (WHO) South-East Asia Region Member country laboratories. METHODS: WHO Collaborating Centre on Strengthening Quality of Health Laboratories (Thailand) organized a regional external quality assessment scheme for blood group serology (REQAS-BGS) between 2002 and 2008 for laboratories in countries of the WHO South-East Asia Region. Test items for ABO and Rh(D) blood groupings and unexpected antibody screening and identification were distributed three cycles per year to BTS laboratories in Bangladesh, Bhutan, India, Indonesia, Maldives, Myanmar, Nepal, Sri Lanka and Thailand. By the end of the project, a total of 20 BTS laboratories had participated for differing lengths of time. RESULTS: It was found that 87.5%, 93.3%, 81.3%, 92.3%, 100% and 87.5% of laboratories returned the test results in 2002, 2003, 2004, 2006, 2007 and 2008, respectively. Laboratories with excellent quality or a trend of quality improvement for ABO and Rh(D) blood grouping, unexpected antibody screening and identification during the six years were 60% (12/20), 50% (10/20), 52.9% (9/17) and 81.8% (9/11), respectively. At the initiation of the scheme, most laboratories were using substandard methods for ABO and Rh blood groupings, i.e. performing only direct blood grouping alone but subsequently adopted the standard methods, i.e. performing both direct and reverse blood groupings. CONCLUSION: REQAS-BGS in South-East Asia countries has been useful for assessing, monitoring and improving the quality of testing. Challenges such as high costs and regulatory requirements for international shipment of blood samples could be solved by amending the regulation(s) for shipment, or establishing a national EQAS.