There are no clear answers about how humans become infected, as the host animal has not been identified
There are no clear answers about how humans become infected, as the host animal has not been identified
Monkeypox was first reported in 1958 in laboratory monkeys, and the first human case was reported in 1970 in a nine-month-old baby in the Democratic Republic of the Congo. Nigeria reported its first case of smallpox in humans in 1970 when a case was detected; there were two human cases of monkeypox in Nigeria in 1978. And after almost four decades without reporting any cases, the monkeypox (clade of West Africa) re-emerged in Nigeria in September 2017. from September 2017 to April 30, 2022, Nigeria has reported 558 cases, of which 231 have been confirmed in the laboratory. There have been dozens of confirmed cases in Nigeria every year since 2017: 88 in 2017, 49 in 2018, 47 in 2019, eight in 2020 and 34 in 2021. There have been 15 confirmed cases between 1 January and 30 April 2022.
Based on the epidemiological and clinical features of 122 confirmed or probable cases of human smallpox cases in Nigeria between September 22, 2017 and September 16, 2018, the researchers found a primary and human-to-human zoonotic transmission. Two cases of infection associated with health care were reported. From genome sequencing, the researchers found multiple introductions of the virus and a single introduction along with human-to-human transmission in a prison. The results were published in the journal Infectious diseases The Lancet.
Since the outbreak began in Nigeria in 2017 and before the last outbreak in Europe and North America, there have been at least eight cases in which monkeypox has been exported to countries outside Africa: the United Kingdom , the US, Israel and Singapore. Like all diseases that are only endemic to Africa, history repeats itself again. Although efforts were made to prevent an outbreak in non-endemic countries outside Africa, no serious international attempts were made to stop the outbreak in Nigeria or to study the characteristics of the virus.
Seconds Statistical news, Dr. Chikwe Ihekweazu, the former director general of the Center for Disease Control in Nigeria, had called for help in trying to decipher what was going on with the monkey’s smallpox but without success. While in 2003, the US reported the first human case of monkeypox, the virus had only crossed the barrier of the rodent species imported from Ghana to one person. Human-to-human transmission outside of Africa was first reported in September 2018, when the monkeypox virus spread from a patient to a healthcare worker in the UK.
Current outbreak
The current outbreak in Europe and North America is the first instance of large-scale human-to-human transmission outside Africa. The index case was a resident of the United Kingdom, who traveled to Nigeria on April 20 and returned on May 3; he was diagnosed with monkeypox on May 6, 2022. Since then, it has spread to 219 people through May 25 in 20 countries.
Wealthy nations are now waking up to the reality of the monkeypox that crosses international borders and causes outbreaks in countries where it is not endemic.
“Only attention is paid when certain diseases affect high-income countries, which exemplifies our collective failure to properly address ‘epidemic preparedness’ and ‘global health’. It also illustrates the double standard how the health of people between rich countries and the rest of the world is valued ”, Dr. Emmanuel Nakoune of the Pasteur Bangui Institute, Central African Republic and Dr. Piero Olliaro of the Pandemic Sciences Institute of the University of ‘Oxford BMJ.
There are no clear answers about how humans become infected, as the host animal that acts as a reservoir for the virus has not been identified in nature. And it is not known how the virus spreads from animals to humans.
Also, how many people, on average, an infected person will transmit the virus is unclear.
“So far there hasn’t been much interest in supporting this work, unfortunately,” Dr. Ihekweazu said. Statistical news. “He never received the interest needed to answer some of these questions.”
The current outbreak appears to have spread mainly among men who have sex with men. The virus is not transmitted through semen or vaginal fluids, but skin-to-skin contact during intercourse can cause the virus to spread.
Draft genome sequences first published by researchers in Portugal and later in Belgium indicate that the virus circulating in Europe and North America belongs to the West African clade, which causes a mild infection.
Low mutation rate
To date, more than 15 genomes of monkeypox have been sequenced. But the monkeypox virus has a lower mutation rate (about two mutations per year) compared to about 25 mutations in a year in the case of the SARS-CoV-2 virus.
This is because monkeypox is a DNA virus unlike SARS-CoV-2, which is an RNA virus.
The low mutation rate of DNA viruses is largely due to differences in the mechanisms that create the mutation and also to the proofreading mechanisms used by the viruses.
“Mutation rates of monkeypox are not well known, but generally other smallpox viruses have a much lower mutation rate. But almost all outbreaks have been caused by animal overflows, while transmission sustained person-to-person and sequences of these events are not widely available to accurately estimate rates, ”says Dr. Vinod Scaria, a senior scientist at the Institute of Genomics. and Integrative Biology (CSIR-IGIB).
Genome sequencing
Despite the low mutation rate, sequencing more genomes could be prudent, especially from the point of view of genetic epidemiology.
According to Dr. Scaria, in addition to providing information on emergencies, genetic epidemiology helps to understand evolution through surveillance and fine-grained contact networks.
“The first is still applicable, while even with the loss of resolution, the second is still useful,” he says.
Although an additional mutation has been found in sequenced genomes, there is a need for more genome sequences and epidemiological knowledge to conclusively establish what this mutation really means. The mutation is unlikely to have made the virus more transmissible, although a large number of cases have been reported.
This is due to the fact that two rave parties in Spain and Belgium have turned out to be super-diffuse events, leading to cases in many countries. It is not yet clear whether the virus has acquired sustained transmission capacity between humans.
“Many of the new cases seem to have come from people who have no history of travel or known contact with someone who has traveled. It’s still too early to tell. [due to] sustained human-to-human transmission, ”says Dr. Scaria.