Dataset of the performance of RDTs for onchocerciasis, Gabon, 2015
Description
Skin snip biopsies remain the gold standard for the diagnosis of active infection with Onchocerca volvulus. However, in low-prevalence settings, such as after several rounds of community directed treatment with ivermectin (CDTI), the sensitivity of skin snipping is low, and the procedure is poorly tolerated. Detection of Ov16 IgG antibodies from dried blood spots (DBS) via enzyme linked immunosorbent assay (ELISA) or rapid diagnostic test (RDT) may therefore provide a more sensitive tool for the assessment of elimination of transmission (EoT). RDTs require little training and resources to deploy and are therefore favoured by policy makers in Lower-Middle Income Countries (LMICs). This dataset was compiled from individual-based surveys conducted across 67 villages in Gabon in 2015, aiming to compare the performance of skin snipping versus that of Ov16 RDTs and ELISA. Gabon had not received CDTI but features many implementation units (IU) with hypoendemic (<35% microfilarial prevalence) transmission. Local healthcare centres conducted the surveys. The initial participant pool totalled 5829 individuals, with a median age of 30 years (Interquartile Range (IQR): 11-55 years). Skin snips were obtained from 4350 individuals (sheet 1), and RDTs were performed on DBS collected from 4257 individuals. It's important to note that the individuals within these two groups do not always overlap. 337 individuals (7.7%) gave a positive skin snip, with 160 individuals (3.8%) recording a positive RDT. Of these, 110 individuals tested positive in both tests, giving the RDT an overall sensitivity of 69% and specificity of 39%. At the village level (sheet 2), the data illustrate the variability in sensitivity and specificity profiles of RDTs across varying endemicities, as assessed against the skin snipping results. These findings are juxtaposed with serological classifications determined via ELISA. High-specificity optimised onchocerciasis elimination program for the Americas (OEPA) ELISA was conducted in 58 (87%) of the 67 villages (sheet 3). A total of 2714 individuals underwent ELISA testing, producing 167 (6.2%) Ov16 positive results. These data highlight, that whilst broadly efficacious, there is a need for caution on the reliance of RDTs in determination of EoT and furthers calls for the development of novel RDT, with a target product profile (TPP) providing higher sensitivity and specificity values.