Syphilis testing practices in the Americas

• Authors: Thuy T. Trinh, Centers for Disease Control and Prevention; Mary Kamb, Emory University; Minh Luu, Emory University; D. Cal Ham, Centers for Disease Control and Prevention; Freddy Perez, Pan American Health Organization
• Journal Title: Tropical Medicine and International Health
• Volume: Volume 22, Number 9
• Publisher: Wiley | 2017-09-01, Pages 1196-1203
• Type of Work: Article | Post-print: After Peer Review
• Publisher DOI: http://doi.org/10.1111/tmi.12920
• Subjects: Health Sciences, Public Health; Health Sciences, Medicine and Surgery
• Keywords: Science & Technology; Life Sciences & Biomedicine; Public, Environmental & Occupational Health; Tropical Medicine; syphilis testing; Pan American Health Organization; Americas; laboratory quality assurance; congenital Syphilis; elimination of mother-to-child transmission of syphilis and HIV; DRIED TUBE SPECIMENS; METAANALYSIS; POPULATIONS

Abstract

Objective: To present the findings of the Pan American Health Organization's 2014 survey on syphilis testing policies and practices in the Americas. Methods: Representatives of national/regional reference and large, lower-level laboratories from 35 member states were invited to participate. A semi-structured, electronically administered questionnaire collected data on syphilis tests, algorithms, equipment/commodities, challenges faced and basic quality assurance (QA) strategies employed (i.e. daily controls, standard operating procedures, technician training, participating in external QA programmes, on-site evaluations). Results: The 69 participating laboratories from 30 (86%) member states included 41 (59%) national/regional reference and 28 (41%) lower-level laboratories. Common syphilis tests conducted were the rapid plasma reagin (RPR) (62% of surveyed laboratories), venereal disease research laboratory (VDRL) (54%), fluorescent treponemal antibody absorption (FTA-ABS) (41%) and Treponema pallidum haemagglutination assay (TPHA) (32%). Only three facilities reported using direct detection methods, and 28 (41% overall, 32% of lower-level facilities) used rapid tests. Most laboratories (62%) used only traditional testing algorithms (non-treponemal screening and treponemal confirmatory testing); however, 12% used only a reverse sequence algorithm (treponemal test first), and 14% employed both algorithms. Another nine (12%) laboratories conducted only one type of serologic test. Although most reference (97%) and lower-level (89%) laboratories used at least one QA strategy, only 16% reported using all five basic strategies. Commonly reported challenges were stock-outs of essential reagents or commodities (46%), limited staff training (73%) and insufficient equipment (39%). Conclusions: Many reference and clinical laboratories in the Americas face challenges in conducting appropriate syphilis testing and in ensuring quality of testing.