Introduction

Monkeypox, also known as ‘mpox’, is a disease caused by the monkeypox virus affecting animals such as rats, and mice, or non-human primates such as monkeys, and humans. It belongs to the Orthopoxvirus genus within the Poxviridae family.¹ It was first discovered in 1958 when laboratory monkeys kept for research purposes developed a pox-like disease, and in 1970 its first human case was reported in the Democratic Republic of Congo.²

Since then, the majority of monkeypox cases have been found in several Central and Western African Countries.³ In 2022, a global outbreak occurred. However, the monkeypox virus cases were reported in countries where the disease is not endemic.⁴

Understanding the transmission of monkeypox

As monkeypox is a transmittable viral disease, understanding its zoonotic transmission from animals to humans and between individuals is crucial.

Animal-to-human contact

Infected animals such as squirrels, rats, and mice that live in areas where the monkeypox virus is present can spread the disease through direct contact with the rash, scab, saliva, and mucous⁵ and exposure to the faeces of infected animals in endemic areas. This is particularly prevalent where people sleep outside, on the ground, or live in or visit the forest where the infected animals are prevalent.⁶ Also, hunting, skinning, trapping, cooking, eating, or playing with carcasses can expose humans to the monkeypox virus.⁷

Human-to-human contact

This occurs primarily via close, direct, and frequent contact with an infected person:^8,9

• Skin lesions such as infectious rash, sores, and scabs
• Body fluids such as saliva, and snot
• Having intimate contact including oral, anal, or vaginal sex, kissing the mouth or the skin, hugging or touching the genitals (penis, testicles, and vagina) or anus
• Prolonged face-to-face contact (talking, cuddling, and breathing close to one who can generate droplets or short-range aerosols such as cough or sneeze)⁷

Another way to spread the monkeypox virus to humans is through contact with contaminated objects (such as sharing the same cup or plates with infected persons), surfaces, or fabrics such as bedding, clothing, and towels.¹⁰ In pregnancy and birth, the monkeypox virus can be spread to the foetus or newborn by close contact during and after birth.¹¹ The adverse outcome of mother-to-child transmission often results in miscarriage, stillbirth, and preterm delivery.⁹

Human-to-animal contact 

According to the World Health Organisation (WHO), there have been few reports of the monkeypox virus spreading from humans to pet animals. Symptomatic owners can spread this through close physical contact with their pet animals.¹² However, detailed advice on minimising the spread from pet owners and individuals can be found in WOAH risk guidance on reducing monkeypox virus transmission.

Factors influencing the transmission of monkeypox

Epidemiological factors

Since the first case in the 1970s, the increase in human monkeypox cases has likely been influenced by various factors:

• Changes in the environment - deforestation, climate change, and urbanisation of regions where the monkeypox virus thrives in a large number of animal hosts have led to the expansion in reservoirs or incidental animal hosts

Human behaviour

• Contact with live or dead animals
• Hunting and living in the same household with an infected person or animal
• Sharing the same room or bed for sleep
• Sharing kitchen utensils with an infected person
• Preparing and consuming dead bush meat or monkeys
• Travelling to endemic areas e.g. West Africa and Central Africa
• Working in healthcare facilities

Others include engaging in the exotic pet trade, poverty, war, and civil conflict.⁹ 

Diagnosis

As the Monkeypox virus belongs to the Poxviridae family, it contains a double-stranded DNA (Deoxyribonucleic acid)¹³ when observed microscopically, and this can be detected by polymerase chain reaction (PCR). This diagnostic approach is the most preferred laboratory test for monkeypox according to the WHO.¹⁴ Human samples from the rash including skin, fluid, or crust can be collected by vigorous swabbing.^15,16 In the absence of rash or blisters, the samples in the form of swabs are collected from the middle part of the throat behind the mouth (oropharyngeal), anus, or rectum.⁷,¹⁷

Signs and symptoms

The signs and symptoms of the monkeypox virus occur in three phases:

1. The incubation phase 
2. The prodromal phase
3. The rash phase

The incubation phase

This can take 7-14 days or up to 21 days from exposure. During this period, the person has no symptoms and feels fine.^18,3

The prodromal phase 

This is the period between the appearance of the initial symptoms and the full development of a rash or fever. The following are clinical manifestations observed in infected persons at this stage:^18,3,19

• Fever (high temperature)
• Chills 
• Muscle aches
• Headaches
• Backaches
• Sore throat
• Tiredness (fatigue)
• Nasal congestion
• Cough
• Joint pain

The rash phase 

This phase starts as a flat sore that fills with liquid to form a blister. The blister may be itchy or painful, and these blisters or sores may appear anywhere on the body such as^7,3

• hands and feet
• face, mouth, and throat (affecting eating and drinking)¹³
• groins and genital areas
• anus

As the rash heals, the blisters eventually dry up, crust over,¹⁹ and fall off. Note that people with mpox are considered infectious until all sores have healed and a new layer of skin has formed. 

The images below show the rashes caused by the monkeypox virus

The goal of treatment is to take care of the rash, manage pain, and prevent further complications such as permanent skin scarring, vision loss, sepsis, or even death. 

Hence, early and supportive care is critical in symptom management.^7,1 

The W.H.O. recommends vaccination within four days of contact with a person diagnosed with monkeypox (or within up to 14 days if the person is asymptomatic) as a preventive measure against spreading the zoonotic virus.⁷

Vaccination is recommended for:

• Healthcare workers 
• Men who have sex with other men
• People with multiple sex partners
• Sex workers

Protecting yourself 

Other measures for reducing the contacting the disease include engaging in personal protective measures such as:

• Wash hands with soap and water or make use of hand sanitizers, especially before and after touching sores
• Wear a medical mask and cover lesions when social gathering (or around people)
• Avoid touching and sharing clothing, bedding, towels, objects, surfaces, or eating utensils with infected persons
• Disinfect shared items regularly and frequently 
• Do not pop blisters or scratch sores as this reduces the process of healing and also spreads the rash to other parts of the body
• Do not hug, kiss, cuddle, or have sex with people with monkeypox
• Avoid wild animals, including those that appear unwell or dead and their products such as meat while travelling in endemic places such as West and Central Africa

To prevent the spread of monkeypox to others, individuals with monkeypox should be isolated at home, or in the hospital if necessary, from the onset of symptoms until lesions have healed and scabs have fallen off (this is when they become non-infectious).^19,20,7,21

FAQs

Is monkeypox contagious?

Yes, Monkeypox is typically spread through direct, prolonged close, skin-to-skin contact with someone (including kissing, holding hands, sexual contact, or hugging ) or an animal infected by the zoonotic virus or through sharing contaminated materials like clothing and bedding.^8,9,7,10

Is monkeypox preventable?

Yes, it is. This can be achieved by avoiding contact with infected persons or animals, refraining from cooking or consuming dead wild animals such as monkeys or rodents, washing hands with soap and water, and using alcohol-based hand sanitiser.^19,20,7,21

How do you contact monkeypox? 

Getting close to someone who has monkeypox through kissing, sexual contact, bodily fluids, sores, or aerosols inform of sneezing and coughing, and also infected animals and their products e.g. meat.^8,9,7,10

How does monkeypox start in an infected person?

It starts first with fever, malaise, headache, and sore throat after one to three weeks of exposure to the disease. The monkeypox rash begins to show on the face and spreads over the body, including the hands and feet. After a while, the rash begins to heal and the blisters dry up, crust over, and fall off. The infected person can still spread the virus until all sores have healed and a new layer of skin has formed.^18,3,19,13

Summary

Monkeypox is a viral disease affecting both humans and animals. Since the 1970s, it has been prevalent in West Africa and Central Africa and has become a global concern in 2022. Epidemiological features such as travel patterns, and urbanisation have influenced the transmission dynamics of the zoonotic virus.

Monkeypox is primarily transmitted through direct contact with infected animals or humans, respiratory droplets through sneezing and coughing, and contact with contaminated objects or surfaces. To prevent or reduce the spread of monkeypox, vaccination, isolation from infected persons, handwashing with soap and water, and the use of sanitizers are some of the measures used to protect yourself.