Sulfureous Water Therapy in Viral Respiratory Diseases

The study is a double-blind, interventional, randomized case-control, pilot trial assessing the efficacy of sulfureous thermal water (STW) inhalations in patients diagnosed with long-COVID. The study was performed from May to October 2023 at the Acque Albule spa facility, Terme di Roma, Tivoli Terme, Rome, Italy. The SPA-center rehab program included 12 consecutive sessions for 20 minutes each from day 1 for 12 days. Re-assessment of study analyses was performed on day 14 after (Visit 2). The follow-up (Visit 3) was 90 days after Visit 1. Eligible subjects were adult outpatients, presenting to the spa facility with an independent prescription of inhalation therapy with sulfurous water for post-COVID respiratory issues. The participants had previously tested positive in certified PCR screening for SARS-Cov-2 infection (data from the Regional Archive of Health Service for SARS-Cov-2 Infection) and, at the time of the study, had a positive diagnosis of long-COVID syndrome with pulmonary involvement. Neither the participants nor any of the medical researchers or laboratory staff involved in the screening, enrolment, clinical evaluation, monitoring, and laboratory as well as statistics of the participant's analyses were aware of the study intervention received (STW vs SDW). A randomization list (1:1 active vs placebo) was created prior to recruiting. The inhalation assistant randomized the participant according to the list and administered the intervention. Therefore, the inhalation assistant was unblinded to the treatment assigned but blinded to the medical condition of the participants. At each session of treatment delivered at Visit 1 and Visit 2, participants were tested for SARS-Cov-2 infection, underwent resting plus forced spirometry and alveolar-capillary diffusion of carbon monoxide (DLCO) spirometry, and performed the the six minutes walking test (6MWT). St George Respiratory Questionnaire (SGQ) used to determine the impact of pulmonary impairment on the quality of life was completed at Visit 1 and Visit 3, patient satisfaction survey was submitted to participants at Visit 3 only. Moreover, blood samples for routine analysis, urine sample collections, and nasal swabs for microbiome sampling were collected at each visit. At the end of Visit 1 (screening/enrolment day), the eligible subjects were randomized in a 1:1 ratio to either: active (STW) or placebo (SDW) group for the inhalation therapy. Both active and controls underwent inhalation therapy once a day for 12 days (from day 1).