How serious is monkeypox?

Health officials are tracking more than 100 confirmed or suspected cases of smallpox from monkeys that have appeared in countries where the disease does not normally occur, such as Australia, Belgium, Canada, France, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, the United Kingdom. and United States.

On Sunday, US President Joe Biden addressed the highly unusual cases, saying that “it is a concern that if it spreads it will have serious consequences”. After more than two years of living in a pandemic, it’s understandable that news of a new virus spreading around the world could cause alarm, but health experts say monkeypox is unlikely to create a coronavirus-like scenario, even if more cases are found.

“As surveillance expands, more cases should appear. But we need to put that in context, because it’s not Covid,” Dr Maria Van Kerkhove, the World Health Organization’s technical lead on Covid-19, said in a briefing session. live online Q&A on Monday (23).

Monkeypox is not a new virus and does not spread in the same way as the coronavirus, so we asked experts for a better explanation of the pathogen — and how the disease it causes is different from Covid-19.

How contagious is monkeypox?

People typically get smallpox from monkeys by coming into close contact with infected animals. This could be through an animal bite or scratch, body fluids, feces, or the consumption of meat that has not been sufficiently cooked, said Ellen Carlin, a researcher at Georgetown University who studies zoonotic diseases, or zoonoses, which are transmitted from animals to animals. human beings.

Although it was discovered in laboratory monkeys in 1958, which gave the virus its name, scientists believe that rodents are the main carriers of monkey pox in the wild. It is mainly found in Central and West Africa, particularly in areas close to tropical forests. Squirrels, mice and voles were identified as potential carriers.

“The virus has probably been circulating in these animals for a long time,” Carlin said. “And for the most part, it stayed in animal populations.”

The first human case of monkeypox was detected in 1970 in the Democratic Republic of Congo. Since then, the virus has periodically caused small outbreaks, although it has been limited to a few hundred cases in 11 African countries.

A handful of cases reached other continents, brought by travelers or imported exotic animals, who passed the virus to domestic animals and then to their owners.

But human-to-human transmission of the monkeypox virus is quite rare, Van Kerkhove said. “Transmission is actually happening through close physical contact, skin-to-skin. So it’s quite different from Covid in that sense.”

The virus can also be spread by touching or sharing infected items, such as clothing and bedding, or through respiratory droplets produced by sneezing or coughing, according to the WHO.

This may sound strangely familiar because in the early days of the pandemic many experts said the coronavirus also had little human-to-human transmission other than in respiratory droplets and contaminated surfaces. Later research showed that the coronavirus can spread through much smaller particles called aerosols, capable of traveling distances of more than 2 meters.

But that doesn’t mean the same will happen with the monkeypox virus, said Luis Sigal, a poxvirus expert at Thomas Jefferson University in Philadelphia. The coronavirus is a small, single-stranded RNA virus, which may have increased its ability to spread through the air. The monkeypox virus, however, is made of double-stranded DNA, meaning the virus itself is much larger and heavier and unable to travel that far, Dr Sigal said.

Other routes of transmission of monkeypox include from mother to fetus via the placenta or by close contact during and after delivery.

Most of this year’s cases were in young men, many of whom identified as men who have sex with men, although experts are cautious in suggesting that monkeypox transmission may occur through semen or other bodily fluids exchanged during the sex. Instead, contact with infected lesions during sex may be a more plausible route.

“This is not a gay disease, as some people on social media have tried to label it,” Dr. Andy Seale, consultant to the WHO’s HIV, Hepatitis and STDs Programme, said during Monday’s question-and-answer session. “Anyone can get smallpox from monkeys through close contact.”

What are the symptoms and how serious can a monkeypox infection be?

Monkeypox is part of the smallpox family of viruses, but is typically a much milder condition, according to the US Centers for Disease Control and Prevention (CDC). On average, symptoms appear within six to 13 days after exposure, but can take up to three weeks. People who get sick often have a fever, headache, back and muscle pain, swollen lymph nodes, and general exhaustion.

About one to three days after the fever, most people also develop a painful rash characteristic of poxviruses. It starts with flat red marks that become raised and pus-filled over the course of five to seven days. The rash can start on the patient’s face, hands, feet, inside the mouth or on Organs genitals and progress to the rest of the body. (Although chickenpox causes a similar-looking rash, it is not a true poxvirus, but is caused by an unrelated virus, varicella-zoster.)

Once an individual’s pustules heal, in two to four weeks, they are no longer infectious, said Angela Rasmussen, a virologist at the Vaccine and Infectious Disease Organization at the University of Saskatchewan in Canada.

Children and people with underlying immune deficiencies may have more severe cases, but monkeypox is rarely fatal. Although a strain found in Central Africa can kill up to 10% of infected individuals, estimates suggest that the version of the virus currently in circulation has a fatality rate of less than 1%.

And the easily identifiable outbreak of monkeypox, as well as its early symptoms, can be considered beneficial. “One of the most challenging things about Covid is that it can be transmitted asymptomatically or pre-symptomatic, by people who have no idea they are infected,” Rasmussen said. “But with monkeypox there doesn’t seem to be any pre-symptomatic transmission.”

Still, as the recent surge in cases has shown, there are many opportunities to transmit smallpox from monkeys in the early days of an infection, when symptoms are not specific, Dr. Rasmussen said.

Do I need to worry about a bigger threat?

The good news is that there is still no evidence that the monkeypox virus has evolved or become more infectious. DNA viruses like monkeypox are generally very stable and evolve very slowly compared to RNA viruses, Dr Sigal said. Scientists are sequencing the viruses from recent cases to check for possible mutations and will soon know whether infectivity, severity or other characteristics have changed, he said. “But my expectation is that they won’t be different.”

However, experts have some explanations for the recent rise in monkeypox cases. According to research, incidences of humans contracting viruses through contact with animals — also known as zoonotic spillovers — have become more common in recent decades. Increasing urbanization and deforestation means humans and wildlife are coming into contact more frequently. Some animals that carry zoonotic viruses, such as bats and rodents, become more abundant, while others have expanded or adapted their habitats due to urban development and climate change.

“There are more opportunities for relatively rare pathogens to enter new communities, find new hosts and travel to new places,” said Dr. Rasmussen.

Despite a brief pause in the pandemic, people are also traveling more often and to more parts of the world than they did a decade ago. And while many of the new monkeypox cases are intriguing because the patients have no history of direct travel to endemic countries in Africa, epidemiologists may discover an indirect travel connection until they complete contact tracing in the coming weeks.

“The main risk for people today from viruses remains Covid,” Rasmussen said. “The good news is that many of the same measures that will reduce the risk of Covid — social distancing, wearing masks in public spaces, good hand hygiene and disinfecting surfaces — will also reduce the risk of contracting monkeypox.”

What is the treatment for monkeypox?

If you do get sick, treating the condition usually involves managing your symptoms. Two antiviral drugs — cidofovir and tecovirimat — and an intravenous antibody treatment originally developed for smallpox could also be used to control smallpox in monkeys, although they have only been studied in the laboratory and in animal models.

There is also a vaccine that the Food and Drugs Agency approved in 2019 for people over 18 years old that protects against smallpox and monkeypox. But health officials stopped routinely vaccinating Americans against smallpox in 1972, when the disease was eradicated in the United States, and smallpox vaccines and treatments are now stored primarily for national security purposes.

“The sporadic outbreaks of monkeypox that have occurred in the past have not been enough to justify restarting the smallpox vaccination program,” Dr. Rasmussen said. Health officials in the US and elsewhere may consider using some of the stockpiled vaccines in a “ring vaccination” strategy to prevent the spread of smallpox from a patient to their healthcare workers and close contacts, she said.

If you have a new rash or are concerned about monkeypox, you should contact your doctor. The US CDC urged doctors to be on the lookout for signs of the rash, and said potential cases of monkeypox should be isolated and referred to the agency. Doctors should also not limit their concerns to men who identify as gay or bisexual, or patients who have recently traveled to Central or West African countries.

“It’s really difficult to set a time frame for it to be contained, or how difficult that will be,” Rasmussen said. “But we have the pharmacological tools, along with the classic isolation and quarantine procedures, that have helped contain outbreaks of monkeypox in the past. We can contain it again. The key will be to identify all cases.”

^{Translated by Luiz Roberto M. Gonçalves}