Mpox (Monkeypox)

What is Mpox (Monkeypox)?

The monkeypox (mpox) virus was first discovered in 1959, when monkeys sent from Singapore to a research facility in Denmark got sick. But it wasn’t until 1970 that the first confirmed case in a human was found, in a child from the Democratic Republic of Congo who was believed to have smallpox.

In the past, people were protected from the mpox virus thanks to the smallpox vaccine. However, when smallpox was eliminated and the vaccination programs ceased, the mpox virus started to become a clinical concern. Additionally, it’s suspected that mpox is underreported because many cases are in rural Africa, which could mean we’re underestimating how dangerous this virus could be.

What Causes Mpox (Monkeypox)?

Mpox is a type of virus that belongs to the Poxviridae family, the chordopoxvirinae subfamily, the orthopoxvirus genus, and the mpox virus species. When viewed under an electron microscope, the mpox virus is quite large, measuring about 200 to 250 nanometers. These viruses are shaped like bricks, and they are surrounded by a protective covering made of lipoprotein. They contain a double-stranded DNA genome, which is the virus’s genetic material. Unlike many other viruses, poxviruses carry all the necessary proteins for replication and other processes within their own genome. This means they don’t rely as heavily on the host’s cellular machinery as other viruses do.

Mpox is passed from animals to people, a type of disease known as a zoonosis. It is thought that various animals act as hosts for this disease, such as squirrels, rats, monkeys, primates, prairie dogs, hedgehogs, pigs, and mice, particularly those found in certain regions in Africa where mpox is commonly reported. However, the main way the disease spreads is from person to person. This happens through respiratory droplets, touching contaminated objects, or direct contact with the sores of an infected person.

Recent studies have shown that the virus is present in high amounts in various bodily fluids, like urine, saliva, semen, and feces. This has been shown through samples taken from the mouth and rectum. This suggests that the virus might also spread through sexual contact.

Risk Factors and Frequency for Mpox (Monkeypox)

Monkeypox, often known as mpox, is a disease that can be passed from animals to humans and is commonly found in central and western Africa, especially in the Democratic Republic of Congo. It was first identified in monkeys, which is where the name originates from, but it is thought that African rodents might be the natural carriers of the disease. Different types of animals and humans, including squirrels, rats, mice, monkeys, prairie dogs, and even humans themselves have been known to be infected.

Currently, two main types of the disease have been identified. One is found mostly in the Congo Basin (Central African) area and is more common and can be passed from one human to another, while the other is found in West Africa and doesn’t show cases of human-to-human transmission.

Incidents of monkeypox have been reported outside Africa too. Here are few that have occurred in recent History:

• In 2003, a group of Gambian giant rats from Ghana infected prairie dogs that were kept as domestic pets in the Midwestern United States. This led to fifty-three cases of monkeypox in humans.
• In October 2018, a man who traveled from Nigeria to Israel was infected.
• In May 2019, a man who had visited Nigeria and then went to Singapore contracted the disease.
• In May 2021, a family, who visited Nigeria and then returned to the United Kingdom, had three family members infected with monkeypox. This could potentially represent human-to-human transmission as the symptoms developed in one family member after another.
• In July 2021, a case was reported in a man who traveled from Nigeria to Texas.
• In November 2021, a man who traveled from Nigeria to Maryland was diagnosed with monkeypox.
• As of May 2022, they’re investigating a case of a man who returned to Massachusetts from Canada. Another cluster of monkeypox cases are being investigated in the United Kingdom.

It’s a challenge to accurately track how prevalent the disease is and how often it occurs due to problems with reporting the disease and confirming its diagnosis. Though, it’s been observed that both these metrics have increased since we stopped routine smallpox vaccination. This is because smallpox vaccination was also effective against monkeypox.

Risk factors for getting monkeypox include living in heavily forested and rural areas of central and western Africa, handling and preparing bushmeat, caring for someone infected with monkeypox, and not having the smallpox vaccine. Getting monkeypox seems to be more common in males, although that could be due to the cultural norm of men more frequently hunting and coming into contact with wild animals.

In 2022, there’s an ongoing outbreak of monkeypox affecting multiple countries on several continents. The outbreak is primarily targeting men who have sex with men (MSM) with most of them developing genital lesions. In Spain, a study of 595 confirmed cases discovered that 99% of the cases were in this population, with the lesions largely affecting genital, perineal or perianal areas. As a result, the study concluded that sexual transmission was the main way the disease was spreading. Germany has reported 1304 confirmed cases in this population as of July 6th, 2022. The 2022 outbreak has been traced back to the West African type of monkeypox, although there’s emerging data that suggests a new type of the virus might be causing the current outbreak.

Monkeypox can be transmitted by coming into contact with body fluids, skin lesions, or respiratory droplets from infected animals or through infected surfaces. Human-to-human transmission has previously been rare but is now a growing concern as immunity to orthopoxviruses decreases. The CDC recommends isolating patients in a room with negative air pressure and taking standard, contact, and droplet precautions in a healthcare setting, with airborne precautions if feasible.

Signs and Symptoms of Mpox (Monkeypox)

Mpox infection can be suspected based on certain historical clues like recent travel to areas where the disease is common, contact with wild animals from these areas, or taking care of an infected animal or person. But, it’s really the symptoms that are crucial for diagnosis.

• Initial symptoms: fever, headache, muscle aches, tiredness, and swollen lymph nodes. Swollen lymph nodes are especially important because they distinguish mpox from a similar disease, smallpox.
• After 1 to 2 days: sores develop on the mouth lining. Soon after, skin sores appear on the face and limbs, including the hands and feet; these are thicker in the middle than on the edges. The rash can sometimes cover the entire body. The total number of sores can vary from a few to thousands.
• Over the next 2 to 4 weeks: the sores go through different stages. They first become flat and reddened, then raised, then fluid-filled, and finally pus-filled. All the sores change at the same time, they are hard, sit deep in the skin, and are 2 to 10 mm in size. They remain pus-filled for 5 to 7 days, after which they start to scab over. The scabs fall off over the next 1 to 2 weeks, and then the condition usually resolves 3 to 4 weeks after the symptoms first began. A person is considered non-infectious once all the scabs have fallen off.

Certain reports suggest that men who have sex with men (MSM) are particularly at risk during the current outbreak. The symptoms in this group mainly consist of skin sores, fever, fatigue, headache, and regional lymphadenopathy. Sores are commonly found in the genital or anus area and often cluster together, likely due to the infection being sexually transmitted.

Testing for Mpox (Monkeypox)

The Centers for Disease Control and Prevention (CDC) set standards on how to identify cases of monkeypox in humans during a 2003 outbreak in the U.S. However, these criteria don’t work as well in areas where monkeypox is common. This is because, the more people are exposed to infected animals or humans, the less specific these criteria become. Similarly, if there are many similar illnesses around, like chickenpox, the criteria are also less specific. This is especially true in Africa where chickenpox vaccines are not common.

As the specific criteria for identifying monkeypox can vary depending on different factors, such as location, the only way to definitively verify a human infection is through laboratory tests.

Because monkeypox and smallpox show similar symptoms, a protocol created by the CDC titled “Acute, Generalized Vesicular or Pustular Rash Illness Protocol” can be used to determine which patients need further testing. This protocol also takes into account the presence of swollen lymph nodes. The CDC suggests collecting two test samples from different lesions on the patients’ body. These samples are then tested further, including for other types of Orthopoxvirus, a group of viruses that include monkeypox and smallpox.

Confirmation of monkeypox infection can be achieved by isolating the virus in viral culture or by looking for the presence of monkeypox virus DNA in a sample taken from the patient using a technique called polymerase chain reaction (PCR). Other tests that can help diagnose this infection include looking for the presence of Orthopoxvirus under an electron microscope, testing for Orthopoxvirus proteins in patient samples, or checking the patient’s blood for certain types of antibodies (proteins our body makes to defend against infections), specifically IgM (which indicates recent exposure) and IgG (which indicates past exposure or vaccination).

Treatment Options for Mpox (Monkeypox)

Currently, there are no specific, proven treatments for monkeypox (mpox) infection. As is typical with many viral illnesses, the primary treatment focuses on managing the symptoms. However, there are steps that can be taken to prevent an outbreak. People who are infected should stay away from others, wear a surgical mask, and keep any lesions covered as much as possible until all crusts have naturally fallen off and new skin has formed. For serious cases, it may be worth looking into experimental treatments that have shown some promise against orthopoxviruses (the family of viruses that includes monkeypox) in animal studies, as well as for severe complications from the vaccinia vaccine.

There are several compounds, such as the oral DNA polymerase inhibitor brincidofovir, the oral intracellular viral release inhibitor tecovirimat, and the intravenous vaccinia immune globulin, that we’re not certain yet how effectively they work against the mpox virus. In severe cases, clinicians may consider using tecovirimat and brincidofovir together. Brincidofovir is already approved in the United States for treating smallpox, a related virus.

People who have been exposed to the virus should check their temperature and look out for symptoms twice a day, for 21 days, because that’s the longest time it typically takes for symptoms of mpox to appear after being exposed. People exposed to the virus, but not yet showing symptoms, don’t need to isolate themselves because it isn’t until symptoms appear that a person can spread the virus to others. In certain cases, it may be recommended to offer the exposed person a preventative vaccination for smallpox and mpox, particularly if they have been in close contact with the infected person’s body fluids, respiratory droplets, or scabs.

The vaccine is a replication-defective modified vaccinia Ankara vaccine, given in two shots, four weeks apart. This vaccine is safer and doesn’t pose the risk of spread or create a skin lesion like live vaccinia virus preparations. Clinical trials have shown that the vaccine safely stimulates production of disease-fighting antibodies in users with atopy (a tendency to be hyperallergic) and compromised immune systems, which are known to have adverse reactions to live vaccinia.

Much more data collection and feasibility analysis is needed to determine the potential benefits and drawbacks of preventative mpox vaccination in communities where the disease is common. Access to medical care, testing capabilities, and necessary infrastructure are currently limitations to making informed decisions about managing this neglected tropical disease.

What else can Mpox (Monkeypox) be?

These are some other conditions that may be confused with smallpox due to similar symptoms:

• Generalized vaccinia
• Disseminated zoster
• Chickenpox
• Eczema herpeticum
• Disseminated herpes simplex
• Syphilis
• Yaws
• Scabies
• Rickettsialpox
• Measles
• Bacterial skin infections
• Drug-associated skin reactions

What to expect with Mpox (Monkeypox)

The mpox virus can be categorized into two unique groups, or clades, while a third separate group might be linked to the current outbreak. The group from West Africa usually results in a better recovery with less than 1% fatality rate. But, the group found in the Central Basin or Central Africa, is more dangerous and can have a death rate of up to 11% in unvaccinated children. Aside from possible skin scars and color changes, most patients typically get better within a month of when symptoms appear.

In an ongoing outbreak in Spain, Germany, Italy, and the United Kingdom, out of 1119 confirmed mpox cases, there have been no deaths reported. This includes some patients who have HIV, which suggests that the strain of the virus spreading currently may be less harmful. However, the quality of healthcare could also have an impact on these results.

Possible Complications When Diagnosed with Mpox (Monkeypox)

Some of the severe consequences that can result from certain health complications include:

• Infection of the skin by bacteria
• Permanent skin scarring
• Changes in skin color (either darker or lighter)
• Damaging scars on the eye’s surface leading to vision loss
• A lung infection known as pneumonia
• Dehydration, which could be due to repeated vomiting or diarrhea, difficulty eating or drinking because of painful mouth sores, or loss of skin moisture
• A widespread, potentially lethal infection known as sepsis
• A severe brain inflammation called encephalitis
• Death

Preventing Mpox (Monkeypox)

Teaching patients and healthcare workers about the mpox virus is very important, especially in places where the virus is common. The best way to prevent the virus from spreading globally is by controlling it locally. Historically, the mpox virus hasn’t easily spread between humans. However, as fewer people are getting vaccinated against smallpox, it opens the door for the mpox virus to become more common in humans. This could potentially lead to more changes in the virus. So, it’s essential for patients to recognize this disease, report it accurately, and have access to testing facilities. This is necessary for gathering the data we need to better understand the mpox virus and learn how to defend ourselves against it.