The monkeypox virus is mutating at an unprecedented rate, arising from a single human case, according to results from a Portuguese study.
The study, published in Nature Medicine, details the analysis of viral genome sequences from 15 infected individuals from the 2022 monkeypox outbreak. When compared with strains from previous outbreaks of monkeypox, the researchers found that the virus had many more mutations than expected, which the authors claimed provide evidence of 'continuous accelerated evolution' of the virus.
'Considering that this 2022 monkeypox virus is likely a descendant of the one in the 2017 Nigeria outbreak, one would expect no more than five to ten additional mutations [when compared with the 2018–2019 imported viruses] instead of the observed about 50 mutations,' said Dr João Paulo Gomes, head of the genomics and bioinformatics unit at the National Institute of Health in Lisbon, Portugal, who co-authored the study.
Monkeypox is a rare skin disease, typically endemic to West and Central Africa. However, more recently, the first multi-country outbreak has been reported in areas where the virus had not previously been observed. Since the first reported case in the UK on 7 May 2022, more than 2500 cases have now been confirmed worldwide.
Dr Gomes and colleagues determined that the circulating viruses in the samples from infected individuals were genetically similar to one another, suggesting that the current outbreak likely resulted from the virus being imported from a country where monkeypox is endemic.
'We hope that now, specialised groups will perform laboratory experiments in order to understand if this 2022 virus has increased its transmissibility.' Dr Gomes told Newsweek.
Lack of clarity on why the virus appears to have mutated far more than is normal has introduced a feeling of uncertainty among other researchers. Dr Hugh Adler, from the Liverpool School of Tropical Medicine who was not involved in the study, stated: 'The authors describe an unexpectedly high number of mutations in the virus, but their implications for disease severity or transmissibility are unclear.'
The findings from this study highlight the need to fill the many gaps in our knowledge about the role of different genes in the transmission of monkeypox. The researchers were able to demonstrate that viral genome sequencing of the monkeypox virus may be precise enough to track the spread of the current outbreak and observe the rate of transmission. This, in turn, may be used to inform future therapeutic interventions and enable decision makers to introduce measures to curb monkeypox spread.