URTIs, commonly presented in primary practice by both adults and children, are primarily viral (such as adenovirus, rhinovirus, influenza, coxsackievirus, herpes simplex virus, coronavirus, and respiratory simplex virus). Unfortunately, existing practices frequently overlook the etiological basis of upper respiratory tract infections (URTIs), resulting in the improper prescription of antibiotics for URTIs rooted in viral causes. This misuse and overreliance on antibiotics underscore the critical need to pinpoint alternative anti-infective agents. These alternatives become essential complements to physical and barrier interventions in order to prevent and interrupt the transmission of respiratory pathogens effectively.

The present study investigates the practical application of povidone-iodine (PVP-I) antiseptic in maintaining oral health and preventing or treating common oropharyngeal infections. The investigation comprehensively reviewed PVP-I's anti-infective profile, efficacy, and safety in addressing upper respiratory tract infections (URTIs), including the common cold, influenza, tonsillopharyngitis, etc.

The initial step in URTI development involves the adherence and colonization of respiratory pathogens to the oropharyngeal mucosa. Gargling with PVP-I (four times daily) has proven effective in reducing URTI incidence. In patients with chronic respiratory infections, PVP-I demonstrated a noteworthy reduction in episodes caused by various pathogens.

Furthermore, in patients experiencing chronic respiratory infections, PVP‐I has been shown to reduce the episodes of infections with P. aeruginosa, S. aureus (including MRSA), and H. influenzae by 50%. 

An early study has also shown that gargling may lead to the removal of oral/pharyngeal house dust mite protease, which may increase the infectivity of the influenza virus. Gargling with PVP-I may thus play a crucial role in preventing or reducing infections through droplet transmission.

The bactericidal activities of PVP-I gargle were explored in a study involving children in Japan, showcasing substantial reductions in bacterial counts and associated absenteeism due to colds or influenza. Further research examined the efficacy of PVP-I in reducing ventilator-associated pneumonia (VAP) prevalence and showed a significant decrease in the PVP-I group compared to controls.

Additional randomized studies assessed the efficacy of PVP-I in mechanical and chemical prophylactic oral cleansing in patients requiring endotracheal intubation and found significant reductions in microbial counts of S. pneumoniae and H. influenzae following PVP-I use. Another study assessed the prophylactic use of PVP‐I gargle in reducing the risk of nosocomial pneumonia and found that it eradicates both general bacteria and MRSA colonies in the pharynx before intubation and at the tip of the tube after extubation.

Notably, Japanese clinical respiratory guidelines recommend PVP-I gargling (four times a day) for inpatients and healthcare workers to prevent hospital-acquired pneumonia. PVP-I has also been suggested as a preventative measure against pandemic influenza.

These collective findings provide a strong rationale for considering PVP-I as an effective oral care measure, capable of reducing the burden of potential pathogens and minimizing infection risk in both community and hospital settings.

Despite limited evidence in the oropharyngeal setting, the demonstrated effectiveness of PVP-I against a broad spectrum of pathogens suggests its potential role in rationalizing antibiotic prescriptions.

Reference-

Kanagalingam J, Feliciano R, Hah JH, Labib H, Le TA, Lin JC. Practical use of povidone-iodine antiseptic in the maintenance of oral health and in the prevention and treatment of common oropharyngeal infections. Int J ClinPract. 2015 Nov;69(11):1247-56. Doi: 10.1111/ijcp.12707. Epub 2015 Aug 6. PMID: 26249761; PMCID: PMC6767541.