Abstract:

To analyze the deletion and polymorphism of exon 2 region of Plasmodium falciparum histidine rich protein 2 (Pfhrp2) gene from the blood samples of the imported falciparum malaria cases in Henan Province in 2020. The information and blood samples of the imported falciparum malaria cases confirmed by Henan Provincial Malaria Diagnosis Reference Laboratory in 2020 were collected. Nested PCR was performed to amplify Pfhrp2 exon 2 used DNA extracted from blood samples, and the positive amplification products were sequenced. A total of 37 blood samples of confirmed imported falciparum malaria cases were collected. 35 sequences of Pfhrp2 exon 2 were amplified successfully by nested PCR and the positive rates was 94.59% (35/37). 28 of 35 positive amplification products were sequenced successfully, with an average length of 822 bp. Twelve kinds of repeat types were found in the amino acid chains encoded by Pfhrp2 exon 2. All the amino acid chains started with types 1 (AHHAHHVAD) and ended with types 12 (AHHAA), and contained type 1, 2, 4, 11 and 12. The proportion of other repeat types in descending order were type 13 (96.43%, 27/28), 3 (92.86%, 26/28), 7 (82.14%, 23/28), 8 (64.29%, 18/28), 6 (60.71%, 17/28), 5 (46.43%, 13/28) and 9 (32.14%, 9/28), respectively. The results of this study showed that there was a high diversity of Pfhrp2 exon 2 in imported Plasmodium falciparum from Henan Province in 2020, which might cause different results of rapid diagnostic tests.

Key words: Imported Plasmodium falciparum, Pfhrp2 gene, Polymorphism, Henan Province