Monkeypox, also known as Mpox, is a zoonotic disease that has emerged as a global health concern. This monkeypox disease is primarily transmitted from animals to humans, with rodents and primates being common carriers. Recognizing monkeypox symptoms is crucial for early diagnosis and containment. Typical symptoms include fever, rash, and swollen lymph nodes, which can be mistaken for other illnesses. As immunity from smallpox vaccination declines, the threat of Mpox increases, making awareness of monkeypox symptoms and preventive measures vital in managing the spread of this monkeypox disease.
Monkeypox is a member of the Poxviridae family, specifically within the Orthopoxvirus genus. Other members of this group are Variola Virus(small pox), Vaccinia Virus, Cowpox Virus, Camelpox Virus, Akhmeta Virus. Infection with one Orthopoxvirus often provides partial immunity to others, which is why the smallpox vaccine (derived from vaccinia) can protect against monkeypox.
Origin of MPOX
The monkeypox virus was named after monkeys because it was first discovered in them, but the real source of the virus lies elsewhere. Rodents, such as squirrels and rats, are the primary reservoirs—meaning they are the animals that typically carry and spread the virus in the wild. Human infections with monkeypox mostly occur in Africa, when people come into direct contact with these infected animals, either through hunting, handling, or consumption.
Human Transmission and Changing Immunity
Monkeypox is a zoonotic disease, meaning it is transmitted from animals to humans. Historically, human-to-human transmission of monkeypox has been rare. However, as immunity from smallpox vaccination has decreased over time —because smallpox was eradicated and vaccination campaigns stopped—there is concern that the virus could spread more easily among people. This phenomenon was observed during a 2013 outbreak in the Democratic Republic of the Congo, where the reduction in cross-reactive immunity from smallpox vaccination led to a noticeable increase in monkeypox transmission among humans. Following are the various mechanisms through which the
virus spreads:
Animal-to-Person Transmission
- Direct Contact with Infected Animals:
- Humans can contract mpox by handling or coming into direct contact with infected animals, particularly rodents or primates. This can occur during hunting, handling, or consumption of bushmeat.
- Bites or Scratches:
- Contact with the bodily fluids, blood, or lesions of infected animals can lead to infection. Animal bites or scratches that break the skin also pose a risk.
- Handling Infected Animals:
- Activities like cleaning or butchering infected animals can expose individuals to the virus..
Person-to-Person Transmission
- Close Contact:
- Mpox can spread between people through close physical contact with an infected person’s skin lesions, bodily fluids, or respiratory droplets. This includes touching the rash or lesions, or coming into contact with contaminated bedding or clothing.
- Respiratory Droplets:
The virus can be transmitted through large respiratory droplets when an infected person coughs or sneezes, especially in close or prolonged contact settings. - Contaminated Surfaces and Objects:
Touching surfaces, clothing, or other objects that have been contaminated with the virus from an infected person can lead to transmission, particularly if they come into contact with broken skin or mucous membranes.
Symptoms and Diagnosis: Differentiating Monkeypox from Other Diseases
Monkeypox presents as a systemic illness, meaning it affects the entire body. It typically causes fever, a distinctive vesicular rash, and swollen lymph nodes (lymphadenopathy).
These symptoms can be confusing because they resemble smallpox (variola) and chickenpox (varicella-zoster virus), which are both better-known viral diseases. However, there
are some key differences:
| • Monkeypox lesions tend to be more uniform, meaning they are usually at the same stage of development when they appear, unlike chickenpox, where the lesions may be in different stages (some new, some healing). |
| • The rash in monkeypox is often diffuse (spread across many areas) and appears peripherally, on the face, hands, and feet. |
| • Lymphadenopathy, or the swelling of the lymph nodes, is a prominent feature of monkeypox and is not as commonly seen in chickenpox, making it an important diagnostic clue. |
Monkeypox in the United States: The 2003 Outbreak
The first outbreak of monkeypox in the Western Hemisphere occurred in 2003, in the Midwestern United States. More than 70 people became infected during this event. Investigations
revealed that the outbreak was linked to contact with pet prairie dogs that had been infected after being housed with rodents imported from Ghana. These animals carried the
virus and passed it to the prairie dogs, which then transmitted the infection to humans.
Patients infected during this outbreak commonly developed fever, rash, and swollen lymph nodes around 14 days after being exposed to the infected animals. This time frame reflects the incubation period of the virus, the time it takes from exposure to the appearance of symptoms. Read more
Growing Risk Factors for Monkeypox Outbreaks
There are two major factors contributing to the increased risk of monkeypox infections:
- 1. Decreasing Immunity from Smallpox Vaccines: In the past, widespread smallpox vaccination provided cross-protection against monkeypox because the two viruses are similar. AS smallpox was eradicated and vaccination stopped, immunity against monkeypox in the general population has weakened, making more people vulnerable to the virus.
- 2. Increased Human-Animal Contact: More people are coming into contact with wild and exotic animals, either through pet ownership or by encroaching on wildlife habitats, such as rainforests. These zoonotic diseases infections that spread from animals to humans become more common as humans interact with animals that naturally carry these viruses.
The Global Challenge of Monkeypox
Monkeypox presents a growing public health challenge as human immunity wanes and contact with infected animals increases. Recognizing the symptoms—including fever, rash, and lymphadenopathy—and understanding the role of animals in spreading the virus are crucial to preventing and controlling outbreaks. The 2003 U.S. outbreak serves as a reminder that zoonotic diseases like monkeypox are not confined to certain regions and can emerge in unexpected places, especially when exotic pets and wildlife trade are involved.
How Monkeypox Can be Prevented?
Monkeypox can be prevented through several measures:
- Vaccination: The smallpox vaccine, which is cross protective against mpox, can be administered, especially to those exposed or at high risk.
- Avoid Contact with Infected Animals: Minimize contact with rodents and other wildlife that may carry the virus.
- Practice Good Hygiene: Regular handwashing with soap and water, and using hand sanitizers, can reduce the risk of transmission.
- Use Personal Protective Equipment (PPE): For healthcare workers and those in contact with infected individuals, appropriate PPE (such as gloves and masks) should be used
- Isolate Infected Individuals: Individuals with mpox should be isolated to prevent the spread of the virus to others.
- Disinfect Contaminated Surfaces: Regularly clean and disinfect surfaces that may be contaminated with the virus.
Investigation and Management of Monkeypox
Investigation
Patient History: Focus on recent travel, contact with animals (especially exotic pets or wild animals), and potential exposure to infected individuals.
PCR Testing: Confirm diagnosis by testing skin lesion samples for monkeypox virus DNA via PCR.
Blood Tests: May be used to detect antibodies or rule out other infections, though not definitive for early diagnosis.
Management
Isolation: Patients must be isolated to prevent human-to-human transmission.
Supportive Care: Includes hydration, rest, fever reduction (using acetaminophen/ibuprofen), and maintaining skin cleanliness to avoid secondary infections.
Antibiotics: Prescribed if secondary bacterial infections are present in the skin lesions.
Antiviral Treatment: In severe cases, antiviral drugs like tecovirimat may be considered, especially for immunocompromised patients.
Complications
Skin Infections: The skin lesions from monkeypox can become infected with bacteria, leading to serious conditions like infections in the skin or bloodstream.
Respiratory complications: In severe cases, the virus can cause pneumonia or other respiratory problems.
Brain Inflammation: Rarely, the virus can lead to brain inflammation, causing neurological issues.
Eye Problems: The virus can affect the eyes, leading to infections or other eye-related issues.
Mortality
Monkeypox usually has a low risk of death, but it can be more dangerous for young children, pregnant women, or people with weakened immune systems.
Bibliography
Heymann, D. L. (Ed.). (2020). Contro/ ofcommunicable diseases manual(21st ed.). American Public Health Association.
Gordon, P,, & Seals, R. (2020). /nfectious disease epidemiology: Theory andpractice (2nd ed.). Jones & Bartlett Learning.
Sullivan, N. J., & Ksiazek, T. G. (2021). Emerging viruses: From influenza to SARS (1st ed.). Cambridge University Press.
Hotez, P. J., &Alonge, O. (2021). The emerging infectious diseases ofthe 21st century: A guide to prevention and management. Elsevier.
Miller, A. S., & Thompson, G. L. (2022). Poxvirus infections: Current research and clinical management (1st ed.). Springer.
Find out our latest blog here
