Development and Pilot of an Mpox Severity Scoring System (MPOX-SSS).

Clinical severity scores facilitate comparisons to understand risk factors for severe illness. For the 2022 multinational monkeypox Clade IIb virus outbreak, we developed a 7-item mpox severity scoring system (MPOX-SSS) with initial variables refined based on data availability and parameter correlation. Application of MPOX-SSS to the first 200 patients diagnosed with mpox revealed higher scores in those treated with tecovirimat, presenting >3 days after symptom onset and with CD4 counts <200 cells/mm3 . For individuals evaluated repeatedly, serial scores were concordant with clinical observations. The pilot MPOX-SSS demonstrated good discrimination, distinguished change over time, and identified higher scores in expected groups.