Emerging Monkeypox Virus Sublineage C.1 Causing Community Transmission, Vietnam, 2023

Abstract

We studied a community cluster of 25 mpox cases in Vietnam caused by emerging monkeypox virus sublineage C.1 and imported into Vietnam through 2 independent events; 1 major cluster carried a novel APOBEC3-like mutation. Three patients died; all had advanced HIV co-infection. Viral evolution and its potential consequences should be closely monitored.

Keywords: HIV co-infection; Vietnam; genetic changes; monkeypox virus; mpox; sexually transmitted infections; sublinear C1; viruses.

Figure 1

Heat map showing changes in the number of skin lesions over the course of hospitalization of 3 fatal (P04, P13, and P17) and 22 nonfatal cases in study of emerging monkeypox virus sublineage C.1 causing community transmission, Vietnam, 2023. Median follow-up was 3 (range 3–5) days. P, patient number.

Figure 2

Natural progression of skin lesions of mpox patient who died in study of emerging monkeypox virus sublineage C.1 causing community transmission, Vietnam, 2023. Skin lesions shown are on the right hand (A), right leg (B), and perianal and buttock areas (C) of a patient with a CD4 cell count of 16 cells/µL.

Figure 3

Assessment of genetic diversity of the monkeypox virus genomes obtained in study of emerging monkeypox virus sublineage C.1 causing community transmission, Vietnam, 2023. Time-scaled phylogenetic tree of 14 Vietnam monkeypox virus genomes from this study (asterisk) highlights 2 nonsynonymous substitutions shared by 13 sequences (red arrow), with substitution OPG068: S428L uniquely found in those 13 sequences. D, aspartate; L, leucine; N, asparagine; OPG, orthopoxvirus gene; S, serine.