Major Threat to Malaria Control Programs by Plasmodium falciparum Lacking Histidine-Rich Protein 2, Eritrea

• Main Authors: Araia Berhane, Karen F. Anderson, Selam Mihreteab, Karryn Gresty, Eric Rogier, Salih Mohamed, Filmon Hagos, Ghirmay Embaye, Anderson Chinorumba, Assefash Zehaie, Simone Dowd, Norman C. Waters, Michelle L. Gatton, Venkatachalam Udhayakumar, Qin Cheng, Jane Cunningham
• Format: Article
• Language: English
• Published: Centers for Disease Control and Prevention 2018-03-01
• Series: Emerging Infectious Diseases
• Subjects: Plasmodium falciparum; parasites; malaria; histidine-rich protein 2 gene; HRP2; malaria control programs
• Online Access: https://wwwnc.cdc.gov/eid/article/24/3/17-1723_article

False-negative results for Plasmodium falciparum histidine-rich protein (HRP) 2–based rapid diagnostic tests (RDTs) are increasing in Eritrea. We investigated HRP gene 2/3 (pfhrp2/pfhrp3) status in 50 infected patients at 2 hospitals. We showed that 80.8% (21/26) of patients at Ghindae Hospital and 41.7% (10/24) at Massawa Hospital were infected with pfhrp2-negative parasites and 92.3% (24/26) of patients at Ghindae Hospital and 70.8% (17/24) at Massawa Hospital were infected with pfhrp3-negative parasites. Parasite densities between pfhrp2-positive and pfhrp2-negative patients were comparable. All pfhrp2-negative samples had no detectable HRP2/3 antigen and showed negative results for HRP2-based RDTs. pfhrp2-negative parasites were genetically less diverse and formed 2 clusters with no close relationships to parasites from Peru. These parasites probably emerged independently by selection in Eritrea. High prevalence of pfhrp2-negative parasites caused a high rate of false-negative results for RDTs. Determining prevalence of pfhrp2-negative parasites is urgently needed in neighboring countries to assist case management policies.