Real-Time Polymerase Chain Reaction Method for the Detection of Onchocerca volvulus in Post-Elimination Surveillance of Onchocerciasis in Ecuador

Am J Trop Med Hyg. 2023 Nov 6;109(6):1368-1371. doi: 10.4269/ajtmh.23-0435. Print 2023 Dec 6.

Abstract

Onchocerciasis has been declared eliminated in Ecuador and surveillance measures are of great interest. In this study, we examined the infectivity rates of Simulium exiguum by Onchocerca volvulus in previously hyperendemic areas in Esmeraldas province of Ecuador. These areas had previously undergone mass administration of ivermectin, which led to the interruption of transmission in 2009 and the certification of elimination in 2014. The study included three communities in Río Cayapas and one in Río Canandé, and a total of 2,950 adult S. exiguum were collected in 2018. We used quantitative polymerase chain reaction with O. volvulus O-150 plasmid control DNA to analyze 59 pools. Our findings revealed that the infectivity rates were zero, indicating that the transmission of O. volvulus remained suspended in the area.

MeSH terms

  • Adult
  • Animals
  • Ecuador / epidemiology
  • Humans
  • Intestinal Volvulus*
  • Ivermectin / therapeutic use
  • Onchocerca / genetics
  • Onchocerca volvulus* / genetics
  • Onchocerciasis* / diagnosis
  • Onchocerciasis* / epidemiology
  • Onchocerciasis* / prevention & control
  • Real-Time Polymerase Chain Reaction
  • Simuliidae*

Substances

  • Ivermectin