Molecular detection of sub-microscopic infections and Plasmodium falciparum histidine-rich protein-2 and 3 gene deletions in pre-elimination settings of South Africa

• Published in: Scientific reports Vol. 14; no. 1; pp. 16024 - 9
• Main Authors: Oyegoke, Olukunle O., Akoniyon, Olusegun P., Maharaj, Leah, Adewumi, Taiye S., Malgwi, Samson A., Aderoju, Samuel A., Fatoba, Abiodun J., Adeleke, Matthew A., Maharaj, Rajendra, Okpeku, Moses
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 11-07-2024; Nature Publishing Group; Nature Portfolio
• Subjects: 631/208; 631/326; Antigens, Protozoan - genetics; Disease transmission; Gene Deletion; Histidine; Humanities and Social Sciences; Humans; Malaria; Malaria, Falciparum - diagnosis; Malaria, Falciparum - epidemiology; Malaria, Falciparum - genetics; Malaria, Falciparum - parasitology; Malaria, Falciparum - prevention & control; multidisciplinary; Phylogenetics; Phylogeny; Plasmodium falciparum; Plasmodium falciparum - genetics; Protozoan Proteins - genetics; rRNA 18S; Science; Science (multidisciplinary); South Africa - epidemiology; Surveillance; Vector-borne diseases; South Africa
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-024-60007-8

South Africa’s efforts toward eliminating malaria have positioned the country in the pre-elimination stage. Imported and sub-microscopic cases still contribute to the persistence of malaria in regions of low transmission as identified in this study where diagnostics is built largely on the use of Rapid Diagnostic Test (RDT). However, the presence of
Pfhrp2/3
gene deletion is known to interfere with the accuracy of diagnosis with the use of RDT. Malaria elimination and detection of
Pfhrp2/3
gene deletion in the pre-elimination setting requires accurate molecular surveillance. With the core objective of this study being the determination of the presence sub-microscopic malaria cases and deleted
Pfhrp2/3
gene markers, a total of 354 samples were collected from five districts of KwaZulu Natal, South Africa. These samples were prepared for molecular analysis using primers and PCR conditions specific for amplification of
18S rRNA
and
msp-1
gene. Positive amplicons were analysed for the presence of
Pfhrp2/3
and flanking genes, along with Sanger sequencing and phylogenetic studies. Out of 354 samples collected 339 were tested negative with PfHRP2 based RDTs. Of these
Pfhrp2
and
Pfhrp3
gene deletions were confirmed in 94.7% (18/19) and 100% (19/19) respectively. High migration rate (75%) among the study participants was noted and phylogenetic analysis of sequenced isolates showed close evolutionary relatedness with India, United Kingdom, Iran, and Myanmar and China isolates. Molecular-based test is recommended as an essential surveillance tool for malaria management programs as the target focuses on elimination.