Comparison of Cepheid® Xpert Flu and Roche RealTime Ready Influenza A/H1N1 Detection Set for detection of influenza A/H1N1

OBJECTIVE: To compare two influenza polymerase chain reaction (PCR) methods. METHODS: A total of 749 suspected MERS-CoV patients presenting at Johns Hopkins Aramco Healthcare, Saudi Arabia, each submitted a clinical sample for influenza A reflex testing using the on-site Cepheid® Xpert Flu assay and at the Ministry of Health laboratory by the Roche PCR assay. RESULTS: There was 92.12% overall agreement between the two methods. Specificity of the Cepheid® Xpert Flu was 95.8% for H1N1 and 94.4% for total influenza A. Cepheid® Xpert Flu sensitivity for influenza A was 100% for younger patients (0–19-year age group) but significantly lower both for older patients (68.2% for 60–79-year and 50% for ≥80-year age groups) and overall for males compared to females (72.6% and 94.0%, respectively). CONCLUSIONS: Specificity of the Cepheid® Xpert Flu test was high; however, sensitivity for total influenza A was lower particularly in males and older patients.