The story so far: The United Kingdom health authorities recently confirmed a case of the monkeypox virus in an individual who recently travel to the U.K. from Nigeria. The U.K. Health Security Agency (UKHSA), while saying that the rare viral infection does not spread easily among people, is taking precautionary measures with the country’s National Health Service (NHS) to trace those who came in close contact with the case prior to the confirmation of their infection.
Monkeypox cases were last recorded in the U.K. in 2018, when three people, including a health worker, had contracted the infection.
What is the monkeypox virus?
Monkeypox is a rare zoonotic (disease that spread from animals to humans) viral disease belonging to the Orthopoxvirus genus in the Poxviridae family, the same virus family as smallpox.
Monkeypox was first discovered in animals in 1958 when two outbreaks occurred in captive monkey colonies kept for research purposes. Hence, the name ‘monkeypox’.
The first case of the virus in humans was recorded in 1970 in the Democratic Republic of the Congo (DRC) in a nine-year-old boy. The case was recorded in a region from where smallpox had been wiped out in 1968.
It has since largely been reported in Western and Central Africa from rural and rainforest regions. In DRC, monkeypox is considered an endemic.
To date, two main strains or clades of the virus have been detected- one from the Congo Basin (Central Africa) and one from West Africa.
How does it spread?
Primary transmission of the virus occurs from animals to humans. It can happen through direct contact with the blood, fluids, or skin or mucus lesions (damaged or broken areas) of infected animals. Consuming undercooked meat and other animal products of infected animals also involves a possible risk. Evidence of monkeypox has been found in several animal species in Africa including rope squirrels, tree squirrels, Gambian poached rats, dormice and different species of monkeys. According to the World Health Organisation, the “natural reservoir of monkeypox has not yet been identified, though rodents are the most likely”.
The WHO says that secondary or human-to-human spread is fairly limited. The UKHSA has also emphasised that monkeypox does not spread easily among people and that “the overall risk to the general public is very low”.
In humans, it can spread through respiratory droplets, skin lesions, mucous membranes- eyes, nose, or mouth, and through contaminated objects like bedsheets used by infected persons.
What are the symptoms?
According to the UKHSA, monkeypox is usually a mild “self-limiting illness” and most people recover within a few weeks. As per the WHO, the incubation period of the virus or the gap between contracting the infection and symptoms showing up is “is usually from 6 to 13 days but can range from 5 to 21 days”.
The United States Centres for Disease Control (CDC) say that monkeypox symptoms are similar in nature to smallpox but are milder. The major difference between the symptoms of the two diseases is that monkeypox causes lymph nodes to swell up. Other symptoms include fever, headache, muscle aches, backache, chills and fatigue. Rashes develop starting on the face and spreading to other parts of the body. The goes through different stages of development before eventually forming a scab, which later falls off.
Most people recover within a few weeks but severe illness can occur in some cases. The fatality in monkeypox ranges between zero and 11% in the general population, being higher in younger people. In Africa, the virus has resulted in death among one in 10 persons who contracted the disease.
How can it be treated?
There is currently no specific treatment for monkeypox. However, several observational studies showed that the Vaccinia vaccine, which was used against smallpox, had shown 85% efficacy in monkeypox prevention.
While the original smallpox vaccine is not available any longer after the disease was largely eradicated, a new version of Vaccinia was approved for monkeypox prevention in 2019.
Past cases and outbreaks
Since 1970, monkeypox cases have been recorded in 11 African countries including the Central African Republic, DRC, Gabon, Ivory Coast, Liberia, Nigeria, and South Sudan. Overall, cases have been reported in 15 countries on four continents to date.
In 2003, the first human cases of the virus were reported outside of Africa when an outbreak occurred in the United States with 47 confirmed and probable cases in six states — Illinois, Indiana, Kansas, Missouri, Ohio, and Wisconsin. Those infected had come in contact with pet prairie dogs. The dogs had contracted the infection as they had been housed in close proximity with mammals imported from Ghana in an animal distributor’s facility in Illinois. The imported animals included 800 small mammals belonging to nine species, six of which were rodents. According to the CDC “no instances of monkeypox infection were attributed exclusively to person-to-person contact”.
In 2017, Nigeria reported the biggest documented outbreak of monkeypox, 40 years after it reported the last confirmed case of the virus. According to the BBC, there were a little over 170 suspected cases of the virus, about 75% of those infected being males between ages 21 and 40.
Besides the current confirmed case, the United Kingdom has reported three cases of monkeypox, all in 2018. Two cases were of individuals who had travelled to Nigeria and the third one was a health worker who came in contact with one of the infected persons prior to their diagnosis. Israel had also reported a case of monkeypox in 2019, while Singapore reported a case in 2019. Both had been found in those who had travelled to Nigeria.
Last year, two monkeypox cases were reported in the United States in Texas and Baltimore, with both individuals having returned from Nigeria.
