Scientists sequence virus genomes because the genome is the virus’s playbook — the genome is an organism’s genetic material, and in the case of a virus, it tells us what the virus is, what it does, and how it’s likely to spread.
Monkeypox has mutated 50 times since 2018
In the Portugal study, researchers took samples from 15 monkeypox patients and compared the genomes of the virus that had infected them. The researchers found that each of the patients had a strain of monkeypox that could be traced to a previous outbreak of the virus in 2018-2019 in the United Kingdom, Israel and Singapore, and which originated in Nigeria. But more than that, their tests showed that the virus had mutated 50 times—up to 12 times more than they would have expected—since that previous outbreak in 2018. “These data completely challenge what is known about the mutation rate of monkeypox,” said study author João Paulo Gomes, a researcher at Portugal’s National Institute of Health.
West African smallpox has lower mortality rates
There are a few things we know about monkeypox, and this new genome sequence has helped researchers better understand the current epidemic. First, the strain of virus in the current outbreak is mutating at an unusually rapid rate. Second, the outbreak probably started with a single case infecting others in a large hyper-spread event. The strain is part of the West African branch of monkeypox, which is commonly reported in western Cameroon and Sierra Leone and has a fatality rate of less than 1%. A clade is defined as a group of organisms that can be traced back to common ancestors or a common genetic lineage. There is another common thread of monkeypox, known as the “Central African” clade, which is more present in the Congo Basin and has mortality rates of up to 10%. There are two main “branches” of monkeypox virus. The clade currently circulating throughout Europe and the US is the least lethal of the two, with a mortality rate of around 1%.
The incubation period of monkeypox makes monitoring difficult
There is also much more we don’t know about monkeypox in this current outbreak. Its incubation period, which ranges from five to 21 days, makes tracking its movement difficult. The World Health Organization identified a so-called “indicator case” – the first confirmed case – as one who traveled from Nigeria to the US in early May. But researchers in Portugal dispute that idea because, they say, there were confirmed cases in Portugal and the UK as early as late April. If the researchers in Portugal are right, we know less than we thought about the current outbreak, such as how it has evolved and what it is likely to do next.
So, where did the monkeypox outbreak start?
The scientists write in their study that it is highly likely that the virus was imported from a country where monkeypox is endemic, such as Nigeria, but they also say they cannot rule out other possibilities. They say it is also possible, for example, that the virus spread silently through humans and/or other animals to non-endemic countries, such as the UK or Singapore, after the 2018-2019 outbreak. And, they say, it’s unclear whether the mutated version is worse than the original version. “The authors describe an unexpectedly high number of mutations in the virus, but their implications for disease severity or transmissibility are unclear,” Hugh Adler, a researcher at the Liverpool School of Tropical Medicine, said in response to the paper. He did not engage in research. “We have detected no change in the severity of clinical disease in patients diagnosed in the current outbreak,” said Adler, who has worked with monkeypox patients in the UK during previous outbreaks.
Monkeypox research ‘still in its infancy’
Monkeypox is a double-stranded zoonotic DNA virus. DNA viruses mutate more slowly than RNA viruses, such as the one that causes COVID-19. But in general we lack a lot of knowledge about monkeypox. Researchers in Portugal, for example, report only one other study on the genetics of the virus. Symptoms of monkeypox can appear on the skin as small red dots, but can also include flu-like symptoms such as headache and sore throat Adler says the study of the virus’s genetics is “still in its infancy.” “We have the genome sequenced, so we have an idea of what the genes are,” Adler said. “But in terms of really understanding what they do and the implications for evolution if the genes change – there’s very little research that’s been done on that compared to a lot of the other big viruses that we know of.” Adler said the research by João Paulo Gomes’ group in Portugal yielded “exciting” new insights into the biology of monkeypox, but Adler noted that it appeared the study was only done because of the current spread of the virus in hgh-income countries . “As always, if the global community had applied these same scientific resources [previous] The monkeypox outbreaks in Africa, we may already have a stronger knowledge base,” Adler said. Monkeyox was first discovered in a monkey in 1958 and the first human case was found in a young child in 1970 in the Democratic Republic of Congo. Editor: Zulfikar Abbany
