We use cookies to understand how you use our site and to improve your experience. This includes personalizing content and advertising. To learn more, click here. By continuing to use our site, you accept our use of cookies. Cookie Policy.

Features Partner Sites Information LinkXpress
Sign In
Advertise with Us
Abbott Diagnostics- Hematology Division

Download Mobile App




Events

ATTENTION: Due to the COVID-19 PANDEMIC, many events are being rescheduled for a later date, converted into virtual venues, or altogether cancelled. Please check with the event organizer or website prior to planning for any forthcoming event.
20 Oct 2021 - 22 Oct 2021
21 Oct 2021 - 24 Oct 2021
Virtual Venue

WHO Warning: Rapid Tests Misdiagnose Many Cases of P. falciparum Malaria in Africa

By LabMedica International staff writers
Posted on 05 Oct 2021
Print article
Image: Blood smear from a P. falciparum culture. Several red blood cells have ring stages inside them. Close to the center is a schizont and on the left a trophozoite (Photo courtesy of Wikimedia Commons)
Image: Blood smear from a P. falciparum culture. Several red blood cells have ring stages inside them. Close to the center is a schizont and on the left a trophozoite (Photo courtesy of Wikimedia Commons)
A pair of mutations, which result in deletion of the Plasmodium falciparum histidine-rich protein 2 (HRP2), render the malaria parasite invisible to the most commonly used rapid diagnostic tests.

In Africa, most rapid diagnostic tests (RDTs) for falciparum malaria recognize histidine-rich protein 2 antigen. Plasmodium falciparum parasites lacking histidine-rich protein 2 (pfhrp2) and 3 (pfhrp3) genes escape detection by these RDTs.

HRP2 is a histidine- and alanine-rich, water-soluble protein, which is localized in several cell compartments including the parasite cytoplasm. The antigen is expressed only by P. falciparum trophozoites. A substantial amount of the HRP2 is secreted by the parasite into the host bloodstream, and the antigen can be detected in erythrocytes, serum, plasma, cerebrospinal fluid, and even urine as a secreted water-soluble protein.

Investigators at the University of North Carolina School of Medicine (Chapel Hill, USA) used several advanced genomic tools to determine the extent of HRP2 deletions expressed by P. falciparum in Africa. Specifically, they analyzed blood samples from a cohort of 12,572 participants enrolled in a prospective, cross-sectional survey along Ethiopia’s borders with Eritrea, Sudan, and South Sudan using RDTs, multiple PCR assays, an ultrasensitive bead-based immunoassay for antigen detection, whole-genome sequencing (WGS) and/or molecular inversion probe (MIP) deep sequencing.

Results indicated that histidine-rich protein 2-based RDTs would miss approximately 9.7% of P. falciparum malaria cases owing to deletion of the pfhrp2 gene.

“This is a serious problem for malaria control efforts and a reminder that pathogens are very capable of adapting to survive,” said senior author Dr. Jonathan B. Parr, assistant professor of infectious diseases at the University of North Carolina School of Medicine. “Surveillance across the Horn of Africa and alternative malaria diagnostic approaches in affected regions are urgently needed. Our work indicates that prhrp3 deletions have arisen independently multiple times over the course of years. “We also found signs that RDT-based testing and treatment are driving a recent rise in pfhrp2 deletion mutation prevalence, allowing parasites to escape detection.”

The World Health Organization (WHO) now recommends that all malaria endemic countries start and maintain surveillance for pfhrp2/3 deletions and respond appropriately when they are confirmed, in order to prevent unnecessary morbidity and deaths and to safeguard inroads that have been made towards malaria elimination, particularly in sub-Saharan Africa.

The malaria RDT paper was published in the September 27, 2021, online edition of the journal Nature Microbiology.

Related Links:
University of North Carolina School of Medicine

New
Gold Supplier
Lactate Dehydrogenase (LDH) Assay
LDH 21 FS
New
ELISA Mini Workstation
Crocodile 5-in-one
New
Laboratory Automation System
UniVerse
New
Silver Supplier
Quality Control Material
Multichem U

Print article

Channels

Clinical Chem.

view channel
Image: Simoa is an ultra-sensitive immunoassay technology that allow detection of proteins and nucleic acids at lowest possible levels (Photo courtesy of Quanterix)

Plasma Amyloid-β 42/40 Assays Compared in Alzheimer Disease

Blood-based tests for brain amyloid-β (Aβ) pathology are needed for widespread implementation of Alzheimer disease (AD) biomarkers in clinical care and to facilitate patient screening and monitoring of... Read more

Hematology

view channel
Image: Bone marrow aspirate from a patient with peripheral T-cell lymphoma (Photo courtesy of Peter Maslak, MD)

Mutation Analysis Links Angioimmunoblastic T-Cell Lymphoma to Clonal Hematopoiesis

Peripheral T-cell lymphoma (PTCL) is a heterogeneous group of lymphoid tumors and encompass peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS), angioimmunoblastic T-cell lymphoma (AITL), and... Read more

Immunology

view channel
Image: The BD LSRFortessa X-20 Cell Analyzer can be configured with up to five lasers to detect up to 20 parameters simultaneously to support ever increasing demands in multicolor flow cytometry (Photo courtesy of BD Biosciences)

Highly Multiplexed Cell Surface Protein Analyzed Via Flow Cytometry

Modern immunologic studies increasingly requires high-dimensional analyses to understand the complex milieu of cell types that comprise the tissue microenvironments of disease. One of the cornerstones... Read more

Pathology

view channel
Image: Characteristic bronchoalveolar lavage findings of diffuse alveolar hemorrhage (Photo courtesy of Peter C. Bauer, MD)

Bronchoalveolar Lavage Cell Pattern Determined for Diffuse Alveolar Hemorrhage

Diffuse alveolar hemorrhage (DAH) is a clinicopathological syndrome that describes the accumulation of intra-alveolar red blood cells originating from the alveolar capillaries. DAH can induce severe respiratory... Read more

Industry

view channel
Image: GastroPanel Quick Test (Photo courtesy of Biohit Healthcare)

Biohit’s Innovative GastroPanel Quick Test Receives CE Mark

Biohit Healthcare’s (Helsinki, Finland) GastroPanel Quick Test, the latest innovation in its unique GastroPanel product family, is now CE marked. The GastroPanel Quick Test is intended for diagnosing... Read more
Copyright © 2000-2021 Globetech Media. All rights reserved.