Utility of TaqMan Array Cards for detection of acute febrile illness etiologies in patients suspected of viral hemorrhagic fever infections.

INTRODUCTION

Due to the difficulty in attributing a causative agent to acute febrile illnesses (AFI), multi-pathogen diagnostic tools should be prioritized in low-resource settings. A previously developed AFI-TaqMan Array Card (AFI-TAC), capable of detecting 26 pathogens within 2 h of nucleic acid extraction, was evaluated in Uganda.

METHODS

A cross-sectional retrospective study design was employed and utilized 182 viral hemorrhagic fever (VHF)-negative samples collected from Uganda, DRC, South Sudan and Kenya during routine surveillance from August 2018- March, 2019. These samples were tested on AFI-TAC targeting 17 viral, 8 bacterial and 3 protozoal pathogens known to cause fever. Patients with a body temperature of ≥ 38 °C, were bleeding, and had any other febrile symptoms were included. Previously confirmed VHF positive samples were used for assay verification.

RESULTS

Overall, 7 pathogens were detected in 59 samples (32.42%) as follows: Plasmodium spp. (n = 49, 26.92%), non-typhoidal Salmonella (n = 3, 1.65%), Yellow Fever (YF) virus (n = 2, 1.10%), Salmonella enterica serovar typhi (n = 2, 1.10%), Leptospira spp (n = 1, 0.55%), Streptococcus pneumoniae (n = 1, 0.55%) and Rickettsia spp. (n = 1, 0.55%). Final outcome (alive vs. dead) as abstracted from case report forms differed significantly by pathogen category (p = 0.002) was significantly associated with assay positivity. We compared outcome across pathogen categories using a chi-square/Fisher's exact test, as appropriate, reporting p-values (Table 2). Cough was the only clinical symptom significantly associated with Plasmodium infection (p = 0.016).

CONCLUSION

The TAC is a feasible, readily adoptable diagnostic tool for use in Uganda and other sub-Saharan countries, particularly when incorporated into the national testing algorithm for differential diagnosis during AFI outbreaks and surveillance.

CLINICAL TRIAL NUMBER: Not applicable.