Clinical evaluation of BioFire® multiplex-PCR panel for acute undifferentiated febrile illnesses in travellers: a prospective multicentre study

Abstract

Background: Identifying the causes of Acute Undifferentiated Febrile Illness(AUFI) is key to improve the management of returning travellers with fever. We evaluated a BioFire®FilmArray® prototype panel of multiplex nucleic acid amplification tests(NAAT) targeting different relevant pathogens in travellers returning with fever. Methods: Prospective, multicenter study to evaluate a prototype panel in whole blood samples of adult international travellers presenting with AUFI in three European travel Clinics/Hospitals (November2017-November2019). We evaluated 15 target analytes: Plasmodium spp., P.falciparum, P.knowlesi, P.malariae, P.ovale, P.vivax, chikungunya virus, dengue virus, Zika virus, Anaplasma phagocytophilum, Borrelia spp., Leptospira spp., Orientia tsutsugamushi, Rickettsia spp., Salmonella spp. Results were compared with composite reference standards(CRS) for each target infection, including direct methods (smear microscopy, rapid diagnostic test(RDT), reference NAAT, blood cultures) and indirect methods(paired serology). Findings: Among 455 travellers with AUFI, 229 target infections were diagnosed; the prototype panel detected 143 (overall sensitivity and specificity of 62.5% and 99·8%, respectively). The panel identified all Plasmodium infections(n = 82). Sensitivity for dengue(n = 71) was 92·9%; 80·8% and 68·5% compared to RDT, NAAT and CRS. Compared to direct methods and CRS, respectively, the prototype panel detected 4/4 and 4/6 chikungunya, 2/2 and 4/29 Leptospira spp., 1/1 and 1/6 O.tsutsugamushi, 2/2 and 2/55 Rickettsia spp., but 0/2 and 0/10 Zika, 0/1 and 0/11 A.phagocytophylum, 0/3 Borrelia spp. diagnosed by serology and 1/7 Salmonella spp. diagnosed by blood cultures. 77/86 (89·5%) infections not detected by the panel were diagnosed by serology. Interpretation: The prototype panel allowed rapid and reliable diagnosis for malaria, dengue and chikungunya. Further improvements are needed to improve its sensitivity for Zika and important travel-related bacterial infections.

Dengue: A review of laboratory diagnostics in the vaccine age

“…As an RNA virus, DENV is labile and sensitive to deterioration, which is advantageous in reducing the risk of contamination in laboratory assays, but can reduce the sensitivity of molecular assays if pre-analytical handling is inappropriate [16]. A 37% reduction in specimens testing RT-PCR positive after 48 h storage refrigerated at 2–8 °C was observed, and and 20 % reduction after 15 days storage at −30 °C [39].…”

“…Multiplex automated PCRs (eg Biofire FilmArray) in combination with other pathogens of relevance for undifferentiated fever with tropical exposure are available, but have poorer sensitivity (80 %) compared with targeted NAAT [16]. Hydrolysis-probe based reverse-transcription-insulated isothermal PCR is also commercially available and can be performed on a handheld portable instrument.…”

“…RT-LAMP in combination with IgM/IgG ELISA detected 97 % of acute cases, and RT-LAMP is becoming increasingly accessible to less well-resourced environments [126]. A multiplex automated PCR had equivalent sensitivity to an NS1 antigen rapid diagnostic test for diagnosis as a single specimen, but was unsurprisingly less sensitive than the combination of RDT, paired serology and PCR, reinforcing that diagnostic certainty often requires multiple samples and does not always require the most expensive tests [16]. If NAAT are not available locally, consideration of stabilized serum blots for referral to a reference laboratory for RT-PCR or sequencing may be useful for epidemiologic assessment of circulating genotypes.…”

“…Finally, pre-transfusion screening of blood supplies can be considered in high-prevalence regions to reduce the risk of iatrogenic transmission [15]. In non-endemic areas, DENV is the most common cause of viral illness in returning travellers [16]. Therefore, diagnostic testing is an important component of DENV management.…”