Background
Previous studies in the Bono Region (middle belt) of Ghana have reported persistent Onchocerca volvulus infection and associated morbidities after nearly three decades of ivermectin treatment. This study aimed to assess the usability, acceptability, and cost of the Ov16 SD BIOLINE rapid diagnostic test (Ov16 RDT) in onchocerciasis surveillance activities in the middle belt of Ghana.

Methodology
A cross-sectional study was conducted in 6 endemic communities in the Tain District and Wenchi Municipality. A total of 254 individuals (54% females; median age (range)=31 (5–83) years), agreed to participate in Ov16 RDT (100%), skin-snip microscopy (37%) and nodule palpation (100%). A total of 94 individuals participated in all three diagnostic tests, and post-test interviews were conducted with them, as well as with nine technicians. A cost analysis was also performed based on testing a hypothetical cohort of 400 individuals.

Principal findings
Seropositivity of IgG4 antibodies against the Ov16 O. volvulus antigen was 23.6% (60/254, 95%CI = 18.8%–29.2%); microfilarial positivity 11.7% (11/94, 95%CI = 6.7%–19.8%) and nodule positivity 5.5% (14/254, 95%CI = 3.3%–9.0%). Female sex, age over 30 years, and farming occupation were all associated with higher odds of anti-Ov16 seropositivity. Among 5–9-year-olds, anti-Ov16 seropositivity was 11.1% (3/27), microfilarial positivity 23.1% (3/13) and nodule positivity 3.7% (1/27). Most participants and technicians preferred Ov16 RDT because of being less painful and invasive, easier to use and faster. Had 400 participants been tested, the total cost per individual would be US$24 (Ov16 RDT) and US$74 (skin-snip microscopy).

Conclusions
Ov16 RDT is more acceptable and affordable (a third of the cost) compared to skin-snipping for surveillance activities in transmission hotspots in Ghana.