Coinfections with monkeypox virus and varicella-zoster virus: a systematic review of case reports and case series.

Background: Many studies have shown that, during mpox outbreaks, concomitant infections with monkeypox virus and varicella-zoster virus (VZV) are not uncommon. Infection with either monkeypox virus or VZV may increase the host's susceptibility to contracting a subsequent infection. Here, we summarize the clinical presentation, diagnosis, and management of cases of reported monkeypox virus and VZV coinfection.

Methods: We conducted a thorough search of four databases: PubMed, Scopus, Medline, and Web of Science, covering the period up to 10 March 2025, and identified studies reporting coinfections with monkeypox virus and VZV. Data were extracted using a standardized sheet, and case reports and the quality of case series were assessed using the JBI critical appraisal tool. Cross-sectional and cohort quality was assessed using the NIH tool.

Results: Our systematic review included 18 studies with 448 cases of coinfection with monkeypox virus and VZV. The majority of cases were reported in African countries, particularly Nigeria and the DRC. Most of the patients were children or young adults, and 41.51% were male. Common predisposing factors included contact with animals, confirmed exposure to infected individuals, and immunocompromised status. Treatment approaches included antivirals (primarily acyclovir or tecovirimat) and supportive care. While most cases were managed successfully, four deaths (0.89%) were reported.

Conclusion: This review highlights the complex interplay between monkeypox virus and VZV in coinfections, emphasizing the need for heightened awareness, standardized diagnostic protocols, and tailored management strategies. It is important to consider coinfections when making diagnoses, especially in places where mpox is common or in cases in which the patient is at high risk.