Failure of rapid diagnostic tests in Plasmodium falciparum malaria cases among travelers to the UK and Ireland: Identification and characterisation of the parasites.
Int J Infect Dis
; 108: 137-144, 2021 Jul.
Article
in English
| MEDLINE | ID: covidwho-1272471
ABSTRACT
OBJECTIVES:
Our objective was to systematically investigate false-negative histidine-rich protein 2 rapid diagnostic tests (HRP2-RDT) in imported Plasmodium falciparum malaria cases from travelers to the UK and the Republic of Ireland (RoI).METHODS:
Five imported malaria cases in travellers returning to the UK and RoI from East Africa were reported to the PHE Malaria Reference Laboratory as negative according to histidine-rich protein (HRP2)-RDT. The cases were systematically investigated using microscopic, RDT, molecular, genomic, and in in vitro approaches.RESULTS:
In each case, HRP2-RDT was negative, whereas microscopy confirmed the presence of P. falciparum. Further analysis revealed that the genes encoding HRP2 and HRP3 were deleted in three of the five cases. Whole-genome sequencing in one of these isolates confirmed deletions in P. falciparum chromosomes 8 and 13. Our study produced evidence that the fourth case, which had high parasitemia at clinical presentation, was a rare example of antigen saturation ('prozone-like effect'), leading to a false negative in the HRP2-RDT, while the fifth case was due to low parasitemia.CONCLUSIONS:
False-negative HRP2-RDT results with P. falciparum are concerning. Our findings emphasise the necessity of supporting the interpretation of RDT results with microscopy, in conjunction with clinical observations, and sets out a systematic approach to identifying parasites carrying pfhrp2 and pfhrp3 deletions.Keywords
Full text:
Available
Collection:
International databases
Database:
MEDLINE
Main subject:
Parasites
/
Malaria, Falciparum
Type of study:
Diagnostic study
/
Observational study
/
Prognostic study
/
Systematic review/Meta Analysis
Limits:
Animals
/
Humans
Country/Region as subject:
Europa
Language:
English
Journal:
Int J Infect Dis
Journal subject:
Communicable Diseases
Year:
2021
Document Type:
Article
Affiliation country:
J.ijid.2021.05.008
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