Mohanty Stuti, Jones Abbey M, Dash Swagatika, Chhatria Satya Ranjan, Padhan Timir Kanta, Mohanty Sanjib, Carlton Jane M, Ompad Danielle C, Kessler Anne, Sahu Praveen Kishore
Department of Molecular Biology and Infectious Diseases, Community Welfare Society Hospital, Rourkela, Odisha, India.
Department of Epidemiology, School of Global Public Health, New York University, New York, New York.
Am J Trop Med Hyg. 2024 Dec 17;112(3):601-609. doi: 10.4269/ajtmh.24-0330. Print 2025 Mar 5.
Diagnostic escape via Plasmodium falciparum (P. falciparum) histidine-rich protein 2 (pfhrp2) gene deletions is a major potential hurdle for global malaria elimination efforts. We investigated the prevalence of pfhrp2 gene deletions in 15 malaria-endemic villages in the state of Odisha, India, and modeled their impact on an ongoing in-country malaria intervention program. We found that 61.6% of subpatent P. falciparum infections (i.e., rapid diagnostic test [RDT]-negative and positive by polymerase chain reaction [PCR]) had pfhrp2 gene deletions, which were predominantly located in the exon 2 region (96.2%) and largely identified in samples from febrile individuals (82.6%). DNA sequencing and protein diversity features were characterized in a subset of samples from individuals with subpatent infections carrying intact pfhrp2 exon 2 loci. Our analyses revealed novel amino acid repeat motifs (231-293 amino acids), and these variant repeat sequences differed from those of RDT+/PCR+ samples. We also evaluated the state-sponsored mass screening and treatment intervention in the context of pfhrp2 gene deletions. We found that mass screening and treatment conducted alongside additional interventions (e.g., long-lasting insecticidal net distribution, indoor residual spraying) reduced the relative risk of infection for both P. falciparum parasites harboring a pfhrp2 deletion (adjusted relative risk ratio [aRRR] = 0.3; 95% CI = 0.1-1.0) and P. falciparum parasites with intact pfhrp2 genes (aRRR = 0.4; 95% CI = 0.2-1.1) when compared with the use of mass screening and treatment by RDT alone. Combined, our findings highlight the need for alternative diagnostic targets and tools as India moves toward its goal of malaria elimination by 2030.
通过恶性疟原虫(P. falciparum)富含组氨酸蛋白2(pfhrp2)基因缺失实现的诊断逃逸,是全球疟疾消除工作的一个主要潜在障碍。我们调查了印度奥里萨邦15个疟疾流行村庄中pfhrp2基因缺失的流行情况,并模拟了它们对正在进行的国内疟疾干预项目的影响。我们发现,61.6%的亚临床恶性疟原虫感染(即快速诊断检测[RDT]阴性但聚合酶链反应[PCR]阳性)存在pfhrp2基因缺失,这些缺失主要位于外显子2区域(96.2%),并且大多在发热个体的样本中被发现(82.6%)。对携带完整pfhrp2外显子2位点的亚临床感染个体的一部分样本进行了DNA测序和蛋白质多样性特征分析。我们的分析揭示了新的氨基酸重复基序(231 - 293个氨基酸),这些变异重复序列与RDT+/PCR+样本的不同。我们还在pfhrp2基因缺失的背景下评估了国家资助的大规模筛查和治疗干预措施。我们发现,与仅使用RDT进行大规模筛查和治疗相比,在进行额外干预措施(如分发长效驱虫蚊帐、室内滞留喷洒)的同时开展大规模筛查和治疗,降低了携带pfhrp2缺失的恶性疟原虫寄生虫(调整后相对风险比[aRRR] = 0.3;95%置信区间[CI] = 0.1 - 1.0)和具有完整pfhrp2基因的恶性疟原虫寄生虫(aRRR = 0.4;95% CI = 0.2 - 1.1)的相对感染风险。综合来看,我们的研究结果凸显了在印度朝着2030年消除疟疾目标迈进时,需要替代诊断靶点和工具。