Development and clinical evaluation of a monkeypox antigen-detecting rapid diagnostic test

To address the global emergence of monkeypox after the 2022 epidemic, a rapid and accurate diagnostic tool is needed at the point of care to identify individuals infected with monkeypox virus (MPXV) to prevent and control the spread of the virus. We designed an antigen-detecting rapid diagnostic test that exclusively detects MPXV without cross-reacting with the vaccinia virus by developing monoclonal antibodies against the MPXV nuclear capsid protein A5L (MPXV-A5L). The test established a limit of detection sensitivity of 0.5 ng/mL of MPXV-A5L, with high sensitivity (87%) for clinical specimens collected from MPXV patients, a qPCR cycle threshold value ≤ 25 and 100% specificity for qPCR-negative samples. The test is an ideal rapid diagnostic tool for supporting clinical decision-making for people suspected of having MPXV infection in resource-poor settings.