Plasmodium falciparum isolate with histidine-rich protein 2 gene deletion from Nyala City, Western Sudan

Mohammed A Boush,Khalid Hajissa,A Maki,Mustafa Talib,Moussa A Djibrine,Abdulrahman Mohammed,Zeehaida Mohamed,Khalid B Beshir,Ali Mussa

doi:10.1038/s41598-020-69756-8

Abstract

In remote areas of malaria-endemic countries, rapid diagnostic tests (RDTs) have dramatically improved parasitological confirmation of suspected malaria cases, especially when skilled microscopists are not available. This study was designed to determine the frequency of Plasmodium falciparum isolates with histidine-rich protein 2 (pfhrp2) gene deletion as one of the possible factors contributing to the failure of PfHRP2-based RDTs in detecting malaria. A total of 300 blood samples were collected from several health centres in Nyala City, Western Sudan. The performance of PfHRP2-based RDTs in relation to microscopy was examined and the PCR-confirmed samples were investigated for the presence of pfhrp2 gene. A total of 113 out of 300 patients were P. falciparum positive by microscopy. Among them, 93.81% (106 out of 113) were positives by the PfHRP2 RDTs. Seven isolates were identified as false negative on the basis of the RDTs results. Only one isolate (0.9%; 1/113) potentially has pfhrp2 gene deletion. The sensitivity and specificity of PfHRP2-based RDTs were 93.81% and 100%, respectively. The results provide insights into the pfhrp2 gene deletion amongst P. falciparum population from Sudan. However, further studies with a large and systematic collection from different geographical settings across the country are needed.

Highlights

Malaria remains a major public health problem in sub Saharan Africa in which majority of the populations are at risk[1]
Despite the diagnostic threat posed by P. falciparum parasites lacking the pfhrp[2] gene, sporadic data is available about the existence of P. falciparum parasites with pfhrp[2] deletion in Sudan, which has high burden of malaria in the region
Evidence from many African countries revealed that histidine-rich protein-2 (HRP2)-based rapid diagnostic tests (RDTs) failed to detect P. falciparum parasites[19]

Summary

Introduction

Malaria remains a major public health problem in sub Saharan Africa in which majority of the populations are at risk[1]. Late diagnosis and treatment of the disease can lead to life threatening conditions[2]. The World Health Organization (WHO) implements vector control, early diagnosis and prompt treatment strategies to eliminate m alaria[3]. The early, rapid and accurate diagnosis is an essential component in malaria control and elimination programs. Microscopic detection of malaria parasites is still considered the gold standard for diagnosis of the disease; this method is relatively sensitive and allows parasitic quantitatification and species identification[4,5]. RDTs were implemented as part of malaria case management along with microscopy for diagnosing malaria among suspected cases in Sudan[8]. Recent reports indicate that PfHRP2-based RDTs may provide false negative results[10]. Though among the causes of false negative results are product quality, transportation, storage

Methods

Results

Conclusion