The qualitative Wondfo RCI was evaluated on patients in Brazil who tested positive for SARS-CoV-2 via RT-PCR and patients who tested negative for SARS-CoV-2 via RT-PCR but exhibited chest computed tomography that was consistent with SARS-CoV-2. For all of the patients who tested positive for SARS-CoV-2 through RT-PCR, the RCI sensitivity was 85.8%. However, the sensitivity of the RCI increased overtime after symptoms began to appear in the patients, with the highest sensitivity after 14 days from onset of symptoms (94.9%). The specificity of the RCI was 100%. Furthermore, patients who tested negative for SARS-CoV-2 via RT-PCR tested positive with the RCI. Overall, the RCI exhibits a high sensitivity and specificity for diagnosing SARS-CoV-2.