Monkeypox vs Chickenpox: Addressing a new concern in public health

Table of Content

What is Monkeypox?

Natural host: Monkeypox vs Chickenpox

Gender predilection:  Monkeypox vs Chickenpox

Symptoms of Monkeypox vs Chickenpox: WHO 

Monkeypox rash vs chickenpox rash

Diagnosis: Monkeypox vs Chickenpox

Monkeypox vs Chickenpox: How to make an accurate diagnosis

Management of Monkeypox vs chicken pox

Prevention of monkeypox vs chickenpox:

Why monkeypox vs chickenpox?

Monkeypox vs Chickenpox

Case fatality rate: Chickenpox vs Monkeypox and Smallpox vs Monkeypox

Self-care: Monkeypox vs chicken pox

FAQ on Monkeypox vs Chickenpox

Take-Home Points

What is Monkeypox?

Monkeypox is caused by the monkeypox virus of the genus Orthopoxvirus, family Poxviridae and is primarily reported in the African continent. The viral infection shares similarities with Smallpox and Chickenpox. After Smallpox eradication in 1970, Monkeypox emerged as the biggest cause of human health concern from the family of Orthopoxvirus. 

The first case of monkeypox:

The first case of the human infection of monkeypox was reported in 1970, in the Democratic Republic of Congo, Zaire. The case was related to animal-to-human transmission. This was the time when intensified efforts were made to eliminate smallpox.

A brief history of monkeypox:

• In the year 2003, the Centre for Disease Control and Prevention (CDC) reported cases of febrile rash illness in the USA in those patients who had contact with pet prairie dogs.

• A monkeypox outbreak occurred in Nigeria in 2017-2018.

• On May 9, 2019, one laboratory-confirmed case of Monkeypox was reported by the Ministry of Health in Singapore.

• On 23 July 2022 Monkeypox was declared a Public Health Emergency of International Concern (PHEIC) by the Director-General of WHO Dr Tedros Adhanom Ghebreyesus.

What is the cognition behind the name “Monkeypox”?

• An outbreak occurred in monkeys being used in research. It was a pox-like disease and was credited to the discovery of Monkeypox in 1958. 

• A human case was detected in 1970.

• There are consultations going on about whether the disease could be renamed or not.

• Monkeypox has been seen in Africa mostly. But today it has spread to many countries, almost 96 countries where monkeypox was never reported before (CDC).

Pathogenesis of Monkeypox:

• When one comes in contact with a virus from an animal, human or contaminated material, then they are likely to catch the infection.

• The virus can enter the body through broken skin, respiratory tract or mucous membrane.

• Animal-to-human transmission occurs by bites, scratches, preparation of bush meat, contact with contaminated bedding, etc.

• Types of close contact which could cause monkeypox are face-to-face, skin-to-skin, mouth-to-skin and mouth-to-mouth.

Natural host: Monkeypox vs Chickenpox

• There are animal species susceptible to the monkeypox virus-like rope squirrels, tree squirrels, Gambian pouched rats and other species.

• Humans are the only reservoir of Varicella-zoster virus and the disease occurs only in humans. The virus after causing chickenpox may get latent in the sensory nerve ganglia and cause Herpes zoster on reactivation.

Gender predilection: Monkeypox vs Chickenpox

For Chickenpox:

• The incidence is similar for both males and females in childhood and adolescence.

• During the reproductive year, occurs more in females than males.

• Virus reactivation occurs more in women and it may be due to low immunity in women.

For monkeypox:

• Sexual predilection is very different from Chickenpox.

• The virus is mostly encountered in gay and bisexuals.

• People at high risk are pregnant women, children and immunocompromised individuals.

Symptoms of Monkeypox vs Chickenpox: WHO 

• Some classical symptoms of monkeypox are Fever, Headache, Muscle pain, Back pain and Low energy while for chicken pox the symptoms include Stomach pain along with Fever, Tiredness, and Headache.

• Lymph node swelling is more likely in monkeypox than in people with chicken pox.

• Monkeypox sores develop at the same time but this is not the case with chicken pox as the rash develops in waves.

• The monkeypox rash persists for 2 to 4 weeks and takes longer time to heal compared to the chickenpox rash which tends to heal in 2 weeks.

Monkeypox rash vs chickenpox rash:

The monkeypox vs chickenpox rash can be differentiated as:

Stages of rash:

In Stages of Chickenpox rash: This has three stages. In stage 1 the rash is red. In stage 2 it gets filled with fluid and in stage 3 the blister breaks and the scab formation occurs over it.

In Stages of monkeypox rash: There are 5 stages of monkeypox rash. In stage 1, the rashes are flat and red, in stage 2 they are bumpy and hardened, in stage 3 they get fluid-filled, in stage 4 they get pus-filled and in stage 5 there is scab formation and falling.

Site:

Monkeypox rash appears on the face, palms, soles, groin, genitals, mouth, throat, anus and eyes while the chicken pox rash begins on the face, trunk, chest and back

Diagnosis: Monkeypox vs Chickenpox

• PCR examination: In varicella-zoster virus (VZV), vesicle fluid is the best specimen. VZV-specific primers are used in PCR to establish differential diagnosis between Monkeypox and Chickenpox.

• Genome sequencing: A study confirmed chicken pox and differentially diagnosed it from Monkeypox by molecular diagnosis laboratory, from nucleotide sequencing, study results have shown that homology to Varicella-zoster strains is 99.26 % and to that of Monkeypox nucleotide is only 46.88 %. (Tumewu et al)

• Lesion scraping

• Crust

• Tissue biopsy

• Cerebrospinal fluid.

Diagnostic challenges: Monkeypox vs Chickenpox

A comparative study was done in 1988 by Jezek et al and was published as “Human monkeypox: Confusion with chickenpox”. This article highlights diagnostic challenges when it comes to Monkeypox vs Chickenpox

The characteristic clinical features of chickenpox make diagnosis difficult. They are:

• Regional pleomorphism in 46 % of misdiagnosed cases.

• Indefinite body distribution of skin eruption accounts for 49 %

• Skin lesions are centripetally distributed accounting for 17 %

Monkeypox vs Chickenpox: How to make an accurate diagnosis

The accurate diagnosis of Monkeypox vs Chickenpox can be made by the following criteria:

• Lymphadenopathy: Swelling of lymph nodes. A study mentioned that in 76 % of misdiagnosed patients lymph node enlargement is observed.

• Pre-eruption fever

• Skin lesions mature slowly.

Complications of monkeypox:

The complications of the monkeypox virus are mentioned below:

• Secondary bacterial infections.

• Respiratory distress

• Bronchopneumonia/Pneumonitis

• Gastrointestinal involvement

• Dehydration.

• Sepsis

• Encephalitis (Infection in the brain)

• Encephalomyelitis: Two Cases were reported in Colorado and the District of Columbia (July–August 2022).

• Corneal infection.

• Sight-threatening keratitis.

• Neurological complications are rare.

The complications of chickenpox are:

• Bacterial infections.

• Dehydration

• Encephalitis 

• Pneumonia 

• The complication of clotting.

• Liver complications.

Management of Monkeypox vs chicken pox:

The management of monkeypox includes Antivirals and Smallpox vaccination whereas for chicken pox it includes Antivirals, rash care, etc.

Prevention of monkeypox vs chickenpox:

Monkeypox can be prevented by preventing contact with animals, eating thoroughly cooked food, proper hand washing, mask use, etc compared to chicken pox which is best prevented by vaccination according to CDC.

Why monkeypox vs chickenpox?

It is very important to understand monkeypox vs chickenpox as explained below:

• The rashes of monkeypox resemble chickenpox so it is very challenging for healthcare professionals to identify monkeypox just by looking at the rash appearance.

• In a study of 730 patients diagnosed with chickenpox in Zaire, 3.3 % had monkeypox and 7.3 % had atypical chickenpox.

Monkeypox vs Chickenpox: 

• Monkeypox is a zoonotic disease while Chickenpox is a non-zoonotic disease.

• Monkeypox is caused by Orthopoxvirus while Chickenpox is caused by the varicella-zoster virus.

• Monkeypox is transmitted through close contact with infected persons and animals while Chickenpox is transmitted via humans only.

• For monkeypox, the effectiveness of smallpox vaccination has been observed while in Chickenpox, the varicella vaccine is available in two doses and the Single-antigen varicella vaccine is to prevent the disease.

Case fatality rate: Chickenpox vs Monkeypox and Smallpox vs Monkeypox

• West African clade of monkeypox has a 1 % case fatality rate.

• Congo basin or central African clade of monkeypox has a 10 % case fatality rate.

• Variola minor with a mortality rate of 1 %.

• Variola major with a mortality rate of 30 %

Monkeypox vs Chickenpox: Relation with past exposure

Chickenpox is caused by the varicella virus and Monkeypox is caused by the monkeypox virus. These are two different viruses so previous exposure to chickenpox does not confer any protection against Monkeypox.

Where do we lack in monkeypox?

• Monkeypox is a fast-spreading outbreak that has spread in 75 countries and its resemblance to other skin lesions like smallpox, chicken pox and cowpox so diagnosing it just by looking at the rash is very challenging for healthcare professionals.

• Just now the public had started emerging from COVID-19 and it has come to monkeypox, about which there exists a lot of knowledge gap between the known and the unknown. It is not easy to tackle it, although scientists are trying their best to use supervised machine learning to address the current outbreak and focus on early diagnosis.

• At this time, mass vaccination is not recommended.

The latest research on monkeypox vs chickenpox

Data related to patient images for monkeypox detection is very limited. So, Islam et al. and the team came up with a project published in Springer Nature. In this project, the researchers have introduced the Monkeypox Skin Dataset 2022, a comprehensive image database which is publicly available and will prove to be helpful for developing a machine learning algorithm so that monkeypox can be detected at the earliest in the clinical settings.

Even though the mortality rate related to monkeypox infection is 1-10 % but if it is detected early, the patient can be isolated and the community spread can be contained.

How the database solves monkeypox vs chicken pox?

Skin lesion images are the only alternative to developing machine learning and deep learning-based Monkeypox Infection Detection Algorithm.

The database contains images of skin lesions which represent five different conditions, i.e, Monkeypox, Chickenpox, Smallpox, Cowpox, Measles and healthy skin images. More web-scrapped pox and measle image data are available. The patient’s eyes and private parts are blocked to maintain privacy. To increase the number of data by 49 times, augmentation techniques are used.

Latest vaccination updates on Monkeypox:

CDC launched the monkeypox vaccine equity program on 15 September 2022. The main target is the population who face barriers to awareness, education and prevention which includes vaccination.

CDC website mentioned,”10,000 vials of vaccine (enough for up to 50,000 intradermal doses) have been set aside for this national pilot program.” 50,000 doses of the Jynneos vaccine have been allocated by CDC for the program. The main target group for vaccination is Black and Hispanic gay, bisexual and other men who have sex with men and the LGBTQ community.

Self-care: Monkeypox vs chicken pox

• The 11 tips for self-care in monkeypox are given below. 

• The self-care for chicken pox includes the application of calamine lotion, a cool bath with baking soda added, the use of colloidal oatmeal to reduce itching, etc. The affected person must make sure to trim the nails and the scratching of the rash should be avoided.  According to the CDC, after touching the scratch the hands should be washed with soap and water for 20 seconds.

Take-Home Points:

• Monkeypox is a zoonotic disease. The differential diagnosis of Monkeypox from Chickenpox is critical and could be accurately established by PCR and genomics.

• Chickenpox is only transmitted from humans but monkeypox being a zoonotic disease can be transmitted from both animals and humans.

Message from Sprint Medical:

The health burden has dramatically increased in the last two years. The COVID-19 pandemic and the Monkeypox virus in 2022, have evolved as a major burden on the public health crisis. Those who are recovering at home, take good care of the rash. Take good care of your mental health by eating, drinking and sleeping well. Contact your healthcare provider immediately if you find any trouble with your health. It is always better to take advice from healthcare professionals.

You should protect yourself and others in this situation.

Our consultants are always here to guide you. Visit our website for more details.

References

National Center for Biotechnology Information

The Lancet

Centers for Disease Control and Prevention

World Health Organization (WHO)

Cleveland Clinic

bioRxiv