High Prevalence of Plasmodium falciparum HRP2/3 Gene Deletions in Ethiopia: Implications for Malaria Diagnosis and Treatment—A Systematic Review and Meta-Analysis

TL;DR

This study finds that a significant number of malaria parasites in Ethiopia lack key genes used in diagnostic tests, which could lead to missed diagnoses and calls for updated testing methods.

Contribution

The study provides the first comprehensive meta-analysis on PfHRP2/3 gene deletions in Ethiopia, revealing high prevalence and implications for diagnostic accuracy.

Findings

The pooled prevalence of PfHRP2/3 gene deletions in Ethiopia is 35.64%.

PfHRP3 gene deletions are more common than PfHRP2 deletions.

Concurrent deletions of both PfHRP2 and PfHRP3 genes were found in 8.14% of cases.

Abstract

Plasmodium parasite species are the causative agents of malaria, which affects populations worldwide. Rapid diagnostic tests (RDTs), microscopy, and molecular methods have been used to diagnose the disease. HRP2 antigens are unique to P. falciparum, while RDTs can detect lactate dehydrogenase, aldolase, and HRP3. Nevertheless, PfHRP2-based RDTs may produce false-negative results if the parasite's PfHRP2/3 genes are deleted. This study is necessary because there is currently no compiled evidence-based information regarding PfHRP2/3 gene deletion in Ethiopia.

Primary research articles on PfHRP2/3 gene deletions (2000–2025) were retrieved from PubMed, Science Direct, and Google Scholar. Eligible studies were systematically searched between May 3 2025, and June 2, 2025. The quality of the included studies was assessed using the Newcastle–Ottawa Scale. Data analysis was performed using STATA Version 17, employing a random effects model. Heterogeneity among studies was evaluated using the I2 test. To assess publication bias, Begg's and Egger's tests were conducted along with funnel plot symmetry analysis.

A total of 932 studies were initially identified, among these 18 studies were selected for full-text review. After excluding 7 studies, 11 articles were included in the meta-analysis. The overall pooled prevalence of PfHRP2/3 gene deletions was 35.64% (95% CI: 21.43, 49.85). Specifically, the pooled prevalence of PfHRP2 and PfHRP3 gene deletions was 8.48% (95% CI: 0.96, 16.01) and 23.74% (95% CI: 12.16, 35.32), respectively, while concurrent deletions of both genes account for 8.14% (95% CI: 0.67, 15.61).

This systematic review and meta-analysis revealed a high prevalence of PfHRP2/3 gene deletions, highlighting significant challenges to the continued use of PfHRP2/3-based RDTs in malaria control programs in Ethiopia. Further nationwide surveillance using standardized methodologies is recommended to better understand the extent of these gene deletions and to guide the immediate phasing out of PfHRP2/3-based RDTs from the national malaria diagnostic algorithm. We also recommend that PCR be considered an essential diagnostic tool in in-vitro diagnosis (IVD).

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