Malaria Panel Assay versus PCR: detection of naturally infected Anopheles melas in a coastal village of Equatorial Guinea

• Published in: Malaria Journal
• Main Authors: Micha Francisco, Ondo Melchor, Buatiche Jesús N, Bobuakasi Leonardo, Nzambo Sisinio, Cano Jorge, Moreno Marta, Benito Agustín
• Format: Article in Journal/Newspaper
• Language: English
• Published: BMC 2004
• Subjects: Arctic medicine. Tropical medicine; RC955-962; Infectious and parasitic diseases; RC109-216; Arctic
• Online Access: https://doi.org/10.1186/1475-2875-3-20; https://doaj.org/article/eb94c41106a846fa94449da30578e530

Abstract Background A study was carried out in a village of the mainland region of Equatorial Guinea in order to ascertain a) which members of Anopheles gambiae complex could be involved in malaria transmission and b) the rate of infectivity for Anopheles melas comparing two different methods, a PCR able to detect sporozoite-DNA and an immunochromatographic assay MPR (Malaria Rapid Dipstick Panel Assay). Methods Mosquitoes were sampled at night by indoor captures in two houses of a coastal village in Equatorial Guinea (Ayantang). Collected mosquitoes were identified as An. gambiae s.l. These were individually dried into silica-gel. The head-thorax of the An. gambiae s.l . mosquitoes were analysed by PCR to verify that the species was of the gambiae complex. Individual head-thorax and pools (5 pools) of homogenized mosquitoes employed in Malaria Rapid Panel assay (MRP assay) were lysed and DNA was extracted. PCR was designed from the 753 base pair insert of pBRKl-14 and DNA was amplified. The relationship between dipstick and PCR to detect Plasmodium falciparum sporozoites was measured in terms of sensitivity, specificity and test association (Cohen's kappa value). Results Two hundred and sixty-four An. gambiae s.l . females were studied (214 individually and five pools with 10 mosquitoes in each). PCR analysis showed that 207 mosquitoes were An. melas , 3 An. gambiae s.s . and 4 could not be identified. By using PCR as the gold standard method when dipstick assay was compared, matching results were obtained for 6 mosquitoes and, in one case MRP was positive while PCR was not reactive. MRP assay showed a low sensitivity (3.3%) when compared with falciparum -DNA detection (17,7% and 14,3%, series A and B respectively). Agreement between the two test formats was low (κ = 0,224). Conclusion It was determined that An. melas is the main anopheline vector involved in malaria transmission in Ayantang, a coastal village in mainland Equatorial Guinea. A comparison of PCR and Vec-Test Assay ® , concluded that the PCR ...