Abstract

Background: Centre for HIV Testing, Lady Hardinge Medical College (CHT-LHMC) is working as a State Reference Laboratory (SRL) from 2007 and regularly performing External Quality Assurance Scheme (EQAS) activities of 24 Integrated Counselling and Testing Centres (ICTCs) and 16 blood banks (BBs) linked to it.

Objective: To evaluate and analyze data of 7 years (2007–2013) related to the EQAS activities of SRL (i.e., proficiency testing and retesting).

Materials and Method: It was a retrospective study. Proficiency tests were carried out twice a year from 2007–2013. The samples from BBs for EQAS retesting were tested using third-generation ELISA kits and samples from ICTCs by the kits provided by Delhi State AIDS Control Society.

Results: A total of 8194 (4992 samples from BBs and 3202 samples from ICTCs) samples were received over a period of 7 years for EQAS retesting. HIV-positive samples from BB and ICTCs were 163 (3.26%) and 646 (20.17%), respectively. Nineteen (0.38%) were tested as positive discordant and 3 (0.06%) were tested as negative discordant out of 4992 samples received from the BBs. No indeterminate result was found among the samples from ICTCs. Proficiency testing showed continuous improvement over the years with 100% participation in years 2012 and 2013. The various attributing factors affecting the test results as well as nonparticipation in proficiency testing were evaluated and discussed.

Conclusion: CHT-SRL-LHMC is a laboratory accredited by National Accreditation Board for Testing and Calibration Laboratories, and through EQAS activities the laboratory is providing constant support and opportunities for improvement of its linked centers.

Key words: State Reference Laboratory, HIV, External Quality Assurance Scheme, proficiency testing, retesting