Introduction A quality control system is crucial for ensuring the reliability of tests used to diagnose communicable diseases. Since 2005, Brazil has used rapid tests (RTs) for diagnosing HIV, which are regulated by a ministerial directive. RTs present challenging features because assays are often conducted by people without laboratory training, there may be no samples for repeating the test, and there is little availability of proficiency testing.
Methodology In 2012, Brazil began implementing a methodology for external quality control evaluation called DTS (dried tube specimen) due to its low cost, ease of execution in places lacking laboratory infrastructure, and ability to transport in ambient temperature by post, facilitating access to services that conduct RTs in a tropical country of vast geographic area. The DTS methodology is based on drying those serum or plasma samples with known reactivity to HIV, shipping them to institutions for rehydration, conducting of the tests, and interpretation of the results. Implementation began with production and validation of AEQ-DTS panels: fractionating, identification, and preparation of the panels with four samples each.
Results The selected service centres are part of the Counseling and Testing Centers Network, which provides assistance to vulnerable populations and comprises 518 centres of which 319 offer RTs for HIV. In 2012, 299 panels were shipped to these centres, 230 of which had received training in DTS methodology: 207 reported results in the Quali-TR computerised system. Of these, 190 sent the data correctly. The index of agreement of results with the characterization of the samples of the AEQ-DTS panel was 100% for these 190 institutions.
Conclusion The results obtained and ease of shipping demonstrate that DTS methodology is appropriate for external quality control assessments, and it will be expanded to include other centres that use RTs for diagnosing HIV.
- Rapid testing