Emmanuel Mfitundinda, Richard Migisha, Joyce Owens Kobusingye, Emmanuel Okiror Okello, Daniel Wenani, Janet Lubega Kobusinge, Patrick Kwizera, Joanita Nalwanga, Charity Mutesi, Hannington Katumba, Loryndah Olive Namakula, Annet Mary Namusisi, Bridget Ainembabazi, Gertrude Abbo, Patricia Eyu, Ivan Lukabwe, Benon Kwesiga, Lilian Bulage, Allan Komakech, Dansan Atim, Prichard Kavuma, R. Kaliisa, I Park, Samuel Wasike, Daniel Kadobera, Alex Riolexus Ario
OBJECTIVE: In this study, we characterized the clinical severity of laboratory-confirmed mpox case-patients admitted in Mpox isolation and treatment units (MTUs) and identified factors associated with severity in Uganda from November 2024 to February 2025. METHODS: We used the mpox severity scoring system (MPSSS) tool to assess severity, a 7-parameter tool with each question assigned scores of 0-4 and summed up with totals ranging from 1 to 23. Total scores ≥10 indicated "severe disease." We fitted modified Poisson regression to identify factors associated with severe disease. RESULTS: Among the 244 case-patients, 128 (52%) were male, and the median age was 29 years. In total, 148 (61%) presented with severe disease, and 74 (30%) had underlying conditions; 65 (88%) had HIV. Among those with HIV, 58 (89%) had severe disease compared to 73 (47%) without HIV (adjusted prevalence ratio = 2.3, 95% CI = 1.6-3.3) after adjusting for age and pregnancy. CONCLUSION: The majority of mpox case-patients and nearly all with HIV admitted to MTUs had severe mpox disease. Case-patients with underlying conditions, especially, HIV, could be considered for inpatient care and mpox vaccination to optimize their care and protect them from severe disease.