Canadian Public Health Laboratory Research Articles

New anxiolitics in development

With emergence of pandemic COVID-19, rapid and accurate diagnostic testing is essential. This study compared laboratory-developed tests (LDTs) used for the detection of SARS-CoV-2 in Canadian hospital and public health laboratories, and some commercially available real-time RT-PCR assays. Overall, analytical sensitivities were equivalent between LDTs and most commercially available methods.

Quality Control Assessment of Canadian Laboratories Testing for Lyme Disease

In June 1990 a quality control assessment was undertaken of Canadian public health laboratories testing for antibodies to Borrelia burgdorferi, the etiological agent of Lyme disease. Twenty sera were distributed to nine laboratories, including 12 obtained from patients in Lyme endemic areas and presumed to be serological positives, and eight prescreened negative controls. Seventeen serological reports were submitted, comprising nine enzyme-linked immunosorbent assays (elisa), six immunofluorescent assays and two Western blot assessments. Antibodies were detected in 11 of the 12 sera which had been presumed to be positive. Assuming 11 positive sera had been submitted, the test sensitivities varied from 88.9 to 100% by elisa, and 54.5 to 90.1% by immunofluorescent assay. Specificities were 100% for all but one elisa and one immunofluorescent assay assessment. The results indicate a satisfactory performance by elisa but a need for upgrading or replacement of some immunofluorescent assay tests.

The use of T1 oligonucleotide mapping to determine that the emergence of Canadian 1973-like and 1974-like H3N2 strains in 1984 was the result of laboratory contamination.

Influenza undergoes extensive antigenic variation in nature. These new antigenic variants invariably supplant the preceding antigenic type that then disappears. In apparent contrast to this, two H3N2 strains that were forwarded to the Laboratory Centre for Disease Control, Ottawa, in 1984 from a Canadian public health laboratory for reference analysis were shown to be most closely related to 1973 and 1974 strains. Laboratory contamination on isolation by the regional public health laboratory was the most likely explanation for the occurrence of these strains, since one of the isolates (RV/76/84) was identical by T1 mapping to an A/Eng-like isolate being grown in the laboratory of isolation. The two isolates, RV/74/84 and RV/76/84, were shown to be distinct from each other and from prototype H3N2 strains by RNase T1 oligonucleotide mapping, SDS-PAGE, peptide mapping of hemagglutinin, and hemagglutination inhibition assay. RV/74 and RV/76 appeared to have been genetically stable for the 10 to 11 years preceding 1984; this is consistent with laboratory frozen storage for this period of time. This paper demonstrates the utility of RNase T1 mapping for the characterization of novel or spurious influenza isolates.