Study of the diagnostic accuracy of microbiological techniques in the diagnosis of malaria in the immigrant population in Madrid

Abstract

BackgroundMalaria is currently the most important human parasitic disease in the world responsible for high morbidity and mortality. Appropriate diagnostic methods are essential for early detection. Microscopy examination remains the gold standard, although molecular techniques have higher sensitivity and are very useful in cases of low parasitaemia and mixed infections. The objective of this study was to evaluate a new commercial molecular diagnostic technique.MethodsA prospective, observational, multicentre study was performed between January 2015 and April 2017. All participants were immigrants from malaria-endemic areas, who were divided into two groups: asymptomatic group and symptomatic. Samples from both groups were evaluated by a rapid diagnostic test (ImmunoQuick® Malaria + 4 RDT), microscopy examination, and two commercial molecular malaria tests (FTD Malaria and FTD Malaria Differentiation), then compared against an in-house reference PCR technique.ResultsIn all, 250 patients were included: 164 (65.6%) in the asymptomatic group, and 86 (34.4%) in the symptomatic group. There were seven cases of asymptomatic parasitaemia (prevalence = 2.8%) that were detected only by molecular methods. In the symptomatic group, there were seven cases of submicroscopic malaria. The main species detected was Plasmodium falciparum (96.6%). The commercial molecular technique had higher sensitivity than the other methods (S = 96%) and a high rate of concordance with the in-house reference PCR technique (Kappa score = 0.93).ConclusionsThe molecular techniques, although slower than microscopy, have adequate diagnostic accuracy and are very useful for the detection of P. falciparum in cases with low parasitaemia.

Diagnosis of malaria in a traveler 9 months after returning from West Africa by illumigene® LAMP assay: A case report

“…Current US and European guidelines recommend microscopy of thick and thin blood films combined with RDT as standard procedures for the diagnosis of malaria [13,14]. To rule out infection, febrile patients returning from malariaendemic regions have to be tested three times because microscopy cannot reliably identify parasite numbers <50/μl [1,2]. RDTs detect ≥100-200 parasites/μl and have a low sensitivity for identification of non-P. falciparum infections, especially for P. malariae and P. ovale as observed in this case [4,12,15,16].…”

“…Standard diagnosis is based on microscopy of thin and thick blood smears. Sensitivity and specificity of microscopy is influenced by the practical experience of the laboratory staff [2,3]. In addition, rapid diagnostic antigen tests (RDTs) are recommended by current guidelines [1,4].…”

Prevalence of submicroscopic malaria infection in immigrants living in Spain

“…ovale was performed (FTD Malaria Differentiation, Fast-Track Diagnostics). In addition to this, blood samples were sent to the National Centre of Microbiology (Insitituto de Salud Carlos III, Majadahonda, Spain) where a multiplex nested PCR detecting the four Plasmodium species was performed to validate the commercial PCR (results already published) [24].…”

Empirical Analysis of a Fine-Tuned Deep Convolutional Model in Classifying and Detecting Malaria Parasites from Blood Smears

“…The slides then pass through a light microscope for observation. However, this diagnostic method requires an advanced level of proficiency to attain accurate results [3]. Furthermore, additional complexity during diagnosis and treatment can lead to unreliable and slow outcomes due to insufficient specialized equipment and expertise in developing areas with many cases [4].…”