Extensive multiple test centre evaluation of the VecTest^TM malaria antigen panel assay

Abstract

Abstract. To determine which species and populations of Anopheles transmit malaria in any given situation, immunological assays for malaria sporozoite antigen can replace traditional microscopical examination of freshly dissected Anopheles. We developed a wicking assay for use with mosquitoes that identifies the presence or absence of specific peptide epitopes of circumsporozoite (CS) protein of Plasmodium falciparum and two strains of Plasmodium vivax (variants 210 and 247). The resulting assay (VecTest TM Malaria) is a rapid, one-step procedure using a`dipstick' test strip capable of detecting and distinguishing between P. falciparum and P. vivax infections in mosquitoes. The objective of the present study was to test the efficacy, sensitivity, stability and field-user acceptability of this wicking dipstick assay. In collaboration with 16 test centres world-wide, we evaluated more than 40 000 units of this assay, comparing it to the standard CS ELISA. The`VecTest TM Malaria' was found to show 92% sensitivity and 98.1% specificity, with 97.8% accuracy overall. In accelerated storage tests, the dipsticks remained stable for >15 weeks in dry conditions up to 45 C and in humid conditions up to 37 C. Evidently, this quick and easy dipstick test performs at an acceptable level of reliability and offers practical advantages for field workers needing to make rapid surveys of malaria vectors.

Mosquito Anthropophily: implications on malaria transmission in the northern Brazilian Amazon

“…This test has been extensively evaluated and presents an overall 92% sensitivity and 98.1% specifi city as compared to standard CS enzyme-linked immunosorbent assay (ELISA) (Ryan et al 2002).…”

Evidence for Transmission of Plasmodium Vivax Among a Duffy Antigen Negative Population in Western Kenya

“…6,7 We report here, however, evidence that a parasite having molecular and antigenic characteristics specific for P. vivax is being transmitted among Fy a−b− indigenes of western Kenya. We were first alerted to this possibility when four wild Anopheles, among a group being used to validate a new dipstick assay, 8 consistently gave positive results for P. vivax circumsporozoite protein, phenotype VK 247. 9 …”

Evaluation of the VecTest Malaria Antigen Panel Assay for the Detection ofPlasmodium falciparumandP. vivaxCircumsporozoite Protein in Anopheline Mosquitoes in Thailand

“…Bangs et al (2002) reported that the performance of the V-MAP assay was comparable to that of the CS ELISA in Indonesia and Papua New Guinea. More recently, Ryan et al (2002) analyzed data from over 40,000 assays conducted at 16 different test centers from around the world and found that performance of the V-MAP was comparable to the CS ELISA. Although the data from this study was incorporated into that of Ryan et al (2002), we provide additional details and analysis of V-MAP performance that are not found in the previous paper.…”

“…More recently, Ryan et al (2002) analyzed data from over 40,000 assays conducted at 16 different test centers from around the world and found that performance of the V-MAP was comparable to the CS ELISA. Although the data from this study was incorporated into that of Ryan et al (2002), we provide additional details and analysis of V-MAP performance that are not found in the previous paper. Therefore, the objective of this study was to evaluate the performance of a lot of 5,000 V-MAP assays produced under GMP (ISO 9001) standards.…”