Syphilis testing practices in the Americas

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.

Keywords: Americas; Américas; Amériques; Organisation Panaméricaine de la Santé (OPS); Organización Panamericana de la Salud (OPS); Pan American Health Organization; Sífilis congénita; assurance qualité de laboratoire; congenital Syphilis; dépistage de la syphilis; eliminación de la transmisión vertical de la sífilis y el VIH; elimination of mother-to-child transmission of syphilis and HIV; garantía de calidad de laboratorio; laboratory quality assurance; prueba de sífilis; syphilis congénitale; syphilis testing; élimination de la transmission mère-enfant de la syphilis et du VIH.

Figure 1

Syphilis serology tests reportedly used among laboratories in the Americas regions(N = 69)*. *Multiple choices possible, thus total does not add to 100%.

Figure 2

Syphilis testing algorithms reported by participating laboratories(N = 69)*. *Multiple choices possible, thus total does not add to 100%.