The number of participants with severe Mpox lesions. Severity of lesions will be assessed by the peak number of lesions and peak number of sites. Participants with ≥100 lesions at peak severity will be classified as having "severe lesions".

Skin lesion severity could not be analysed for all participants as the number of lesions were not available due to the retrospective data collection nature of this study.

Complications which will be collected are as follows:

• Severe rectal and/or perianal pain (i.e. due to perianal/anal abscess, proctitis)
• Tonsillitis and/or dysphagia
• Secondary bacterial infection on affected skin
• Urological complications (genital oedema, urinary retention)
• Ocular involvement (conjunctivitis, corneal involvement, periorbital cellulitis)
• Central nervous system involvement (encephalitis, meningitis, focal neurology signs)
• Pneumonia/pulmonary abscess or necrotizing involvement
• Myocarditis
• Diarrhoea

A composite outcome representing the presence of any specified clinical complication will be analysed. This composite outcome will be derived by identifying participants who have experienced one or more of the listed clinical complications during the observation period.

Clinical complication data was not available for available for all participants due to the retrospective data collection nature of this study.

Number of hospitalisations for clinical reasons only (i.e. not for precautionary measures or quarantine).

Number of any Mpox related mortality observed during the 3 month observation period

The severity of lesions will be determined based on the peak/maximum severity score over the observation period. Lesion severity will be classified ordinally as follows:

• Not presenting with skin lesions (0 skin lesions)
• Mild (1-24 lesions)
• Moderate (25-99 skin lesions)
• Severe (100-250 skin lesions)
• Very severe (>250 skin lesions) Individuals with severe or very severe lesions (ie, ≥100 skin lesions) will be classified as having "severe lesions".

Differences in the clinical manifestation of Mpox in PLWHIV and PrEP users by site of lesions. Site of lesions include genital (vulva/vaginal mucosa/penis/pubic area), ano-rectal/perianal, oral mucosa (lips/gums/oral/pharynx), face, trunk (chest/torso/abdomen/back) and limbs (arms/forearms/legs/hands/feet).

Site of lesion data was not available for all participants due to the retrospective data collection in this study.

Presence of severity indicators, below, was assessed in PLWHIV and PrEP Users with Mpox

• Significant lower respiratory symptoms
• Confusion/encephalitis,
• Other complications (e.g. secondary bacterial infection, sepsis)
• Widely disseminated lesions and very many in number (≥100)
• Suspected infection of the cornea
• Severe, refractory pain from lesions requiring hospitalisation
• Lesions associated with complications due to pain or swelling

Severity indicators were not available for all participants due to the retrospective nature of this data collection study.

National Early Warning Score [NEWS] 2 score of ≥5 was reported for PLWHIV and PrEP Users with Mpox.

NEWS2 is a summary score of six physiological parameters (respiratory rate, oxygen saturation, systolic blood pressure, heart rate, level of consciousness, temperature, and supplemental oxygen dependency) routinely recorded for inpatients. Each parameter is assigned a score between 0-3 based on how far it deviates from the normal range. These parameters are used to generate an aggregate severity score classified as low: aggregate score 0-4, low -medium/medium: score of 3 in any individual parameter/aggregate score 5-6,high: aggregate score 7 or more. Minimum scale score is 0, Maximum scale score is 20.

A higher score indicates a greater clinical risk and worse outcome. A score ≥5 is a key threshold for urgent clinical review and signifies severe disease.

NEWS2 score was not available for all participants due to the retrospective nature of this data collection study.

Differences in the drug treatments (clinical manifestation) of Mpox in PLWHIV and PrEP users

Drug treatment for mpox data was not available for all participants. Due to the retrospective nature of this data collection study, only available data was collected for analysis.

Differences in the drug treatments for complications of Mpox (secondary infections, bronchopneumonia, sepsis, encephalitis, and infection of the cornea with ensuing loss of vision) in PLWHIV and PrEP users

Drug treatment for Mpox complications data was not available for all participants. Due to the retrospective nature of this data collection study, only available data was collected for analysis.

First symptom at Mpox onset including lesion onset, prodromal symptoms (e.g., fever, myalgia, etc), rectal pain or other symptoms.

First symptom at Mpox onset was not available/unknown for all participants due to the retrospective data collection in this study.

Differences between Mpox transmission characteristics in PLWHIV and PrEP users

Differences in days between symptom onset and positive PCR test between PLWHIV with mpox and PrEP Users with mpox

Days between symptom onset and positive PCR test data was not available for all participants due to the retrospective nature of this data collection study.

Predicted risk factors (chronic kidney or liver disease, diabetes, lymphoma, AIDS defining condition, mental health condition, other comorbidities, and immunosuppression) will be analysed for presence or absence of severe mpox lesions (≥100 skin lesions)

Severe lesion endpoint data was not available for all participants due to the retrospective nature of this data collection study. No events occurred in some groups and were therefore not included in this analysis.

Risk factors (CD4 count) for severe mpox lesions (≥100 skin lesions) for PLWHIV

CD4 data was not available for all participants due to the retrospective nature of this data collection study.

The number of mpox patients attending sites as a percentage of total number of patients the sites have seen over a set period of time (from first Mpox patient to last Mpox patient)

All patient data was not available at 2 sites, Hospital Clinic Barcelona and EECE Warsaw, and are excluded from this analysis.

The length of stay in hospital for inpatients treated for Mpox. In the case of multiple hospitalisations, the sum of the length of all stays will be analysed.

The estimate the time to lesion resolution for participants with at least one lesion during the observation period and with a known date of lesion resolution will be included.