English translation updated . This article reflects the source material at its original publication date. Read the Chinese source.
Safety and effectiveness across infection sites
The review summarized in the original article included 52 publications reporting the safety of phage therapy administered by different routes. Treatment was generally described as well tolerated in those reports. Adverse events were reported in 7% of patients receiving phages (33/441), compared with 15% of controls (37/249). Most events were mild and resolved after treatment ended. Reporting differed between case studies and randomized controlled trials, partly because adverse-event assessment was not standardized across studies.
A total of 54 articles provided effectiveness data. Clinical improvement was reported in 78.8% of phage-treated patients (1,500/1,904), compared with 50.0% of controls (17/34). Bacterial eradication was reported in 86.7% (1,266/1,461) of patients assessed after phage therapy. These figures describe the heterogeneous reports summarized in the source; they should not be interpreted as a universal treatment success rate or a direct, balanced comparison between groups.
Clinical improvement and bacterial eradication are two measures used to assess outcomes. Organisms, routes of administration and results vary with the infected organ system. The following sections describe the reports covered by the original article.
Lung infections
Eleven reports described phage treatment of lung infections in 16 patients. Fourteen bacterial isolates were obtained from seven of these patients: five Pseudomonas aeruginosa, one Staphylococcus aureus, three Achromobacter xylosoxidans, one Burkholderia, two Acinetobacter baumannii and two Mycobacterium abscessus isolates.
Phages were administered by nebulization, intravenous infusion or orally. The reports described no adverse reactions, reduced cough and sputum production, improved lung function and sputum cultures in which the target bacteria were no longer detected.
Urinary tract infections
Multidrug-resistant Klebsiella pneumoniae and P. aeruginosa were common pathogens in the urinary tract infection reports discussed. Phages were given orally, rectally or by bladder instillation, using one or more routes. Reported outcomes included symptom improvement, elimination of the target organism and no recurrence or adverse reactions during the reported observation periods.
Bone and joint infections
Three case series published during the six-year period described in the source involved 13 patients with S. aureus osteomyelitis. Following topical phage treatment, the reports described wound healing without adverse reactions, with radiographic evidence of bone re-formation after osteolysis.
Five other patients had knee or hip infections caused by P. aeruginosa, S. aureus or K. pneumoniae; three infections involved multidrug-resistant organisms. Clinical symptoms improved after intra-articular or intravenous phage therapy. Treatment was stopped in one patient because aspartate aminotransferase and alanine aminotransferase levels increased. No adverse reactions were reported in the other patients. Two successfully received joint prostheses.
Cardiovascular surgery
Three reports described infections involving two left ventricular assist devices and one aortic graft. One infection was caused by P. aeruginosa and two by S. aureus. Two patients received topical phages and one received intravenous phages; all also received antibiotics.
One patient experienced nausea after topical administration. No other adverse events were reported, and clinical symptoms improved in all three cases.
Skin and wound infections
The source describes 224 patients with difficult-to-treat wound infections, including bacterial skin infections, burns, radiation injuries and lower-limb venous ulcers. Frequently identified organisms included S. aureus, P. aeruginosa, Staphylococcus epidermidis, Escherichia coli, K. pneumoniae, Proteus and A. baumannii.
Most reports described no adverse reactions after topical or intravenous phage treatment. One patient developed hypotension after intravenous administration but did not require vasopressors. Heart rate, blood pressure, temperature, complete blood count, liver function and metabolic measurements subsequently returned to normal without additional intervention described in the source.
Complete healing was reported in 66% of the assessed patients with lower-limb venous ulcers (76/116), 100% with infected radiation injuries (3/3), and 63% with bacterial skin infections (46/73). Bacterial eradication was reported in 100% of the assessed patients with chronic lower-limb venous ulcers (22/22), 100% with infected radiation injuries (3/3), and 93% with bacterial skin infections (68/73). The different denominators are retained from the source and refer to different reported assessments.
Gastrointestinal infections
One study described a patient with necrotizing pancreatitis caused by multidrug-resistant A. baumannii. Phages were administered intraperitoneally and intravenously alongside broad-spectrum antibiotics. Treatment was reported as successful after 18 weeks.
Eye infections
One report described refractory infectious keratitis caused by vancomycin-resistant S. aureus. Phages were administered intravenously and locally, as eye drops and a nasal spray, without antibiotics. Eye symptoms stabilized and cultures became negative. The report described successful treatment, with no adverse events or reinfection during six months of follow-up.
Prospects and limitations
Phage therapy is being investigated as a potential option for drug-resistant bacterial infections. Research and case reports have increased, but wider clinical use remains limited. A central difficulty identified by the source is the lack of sufficiently robust clinical evidence for assessment by ethics bodies, insurers and government agencies.
Personalized therapy and targeted, potentially adaptive phage preparations—including combinations with antibiotics—offer ways to investigate safety and effectiveness. Combining phages into cocktails may broaden activity against bacterial strains and improve the feasibility of preparations intended for wider use. This could also make industrial production more practical. However, many questions about the development and manufacture of commercial phage products remain unresolved.
The reviewed reports suggest potential benefit in some difficult bacterial infections and generally describe few adverse events. High-quality clinical trials are still needed, particularly to establish longer-term outcomes. Case reports alone do not establish efficacy across patients, pathogens or treatment routes.
Source note: the archived article does not identify the review from which these pooled figures were taken. Its complete bibliographic reference requires confirmation.
