Atypical Varicella‐Like Presentation of an Imported Mpox Case in Austria Confirmed to be Infected With Clade Ib

ABSTRACT The recent upsurge of cases caused by the newly identified Clade Ib monkeypox virus (MPXV) in the Democratic Republic of the Congo and other countries has emerged as a significant public health concern. A 34‐year‐old male tourist from Venezuela presented in Vienna, Austria, during his travels through Europe with fever, pharyngitis and an evolving rash. Cutaneous lesions were sparse and consisted of papules, pustules and a few partially ulcerated lesions of different stages of evolution, localized primarily on the trunk and extremities, clinically resembling chickenpox. In addition, prominent yellow‐coated erosions with erythematous borders and ulcerative papules were present on the labial mucosa. While varicella‐zoster virus and HSV type 1 and 2 DNA were not detected by PCR, Orthopoxvirus DNA was identified in the patient's oral lesions. Subsequent metagenomic sequencing from primary samples confirmed the infection with MPXV Clade Ib. This case shows that, first, mpox Clade Ib is circulating across Europe; second, its presentation may differ from the Clade IIb outbreak, potentially including atypical rash morphology/distribution; and third, although the patient self‐identified as MSM and attended an MSM sauna in Rome 1 week before onset, he denied anogenital/oral sexual contact and reported no similar exposure. This suggests that non‐sexual close‐contact transmission or environmental exposure contributed to infection. Heightened awareness of clinicians, diagnostic evaluations for mpox even in the absence of classical rash morphology or reported sexual exposure and establishment of Clade Ib‐specific diagnostics, which are reliable, accessible and easy to perform, are crucial to enable early identification of infected individuals in order to limit further transmission. Continued genomic surveillance of MPXV remains critical for monitoring of virus spread beyond the traditional endemic regions and for the early detection of new variants. Finally, the effectiveness of mpox vaccination and antiviral therapeutics against Clade Ib MPXV requires further evaluation.