What is Monkey-pox?
Monkeypox is a disease caused by a virus known as the ‘Monkeypox virus’. It mainly infects animals (rodents and primates) but can be transmitted to humans from them. There are 2 types (or clades) of monkeypox virus.
1. West African clade which causes milder disease
2. Central African or Congo Basin clade which causes a more severe disease
The 2022 outbreak in various countries has been due to the West African clade.
Human cases have been seen since 1970 but were limited to Central and West African areas. Only a few cases have been reported in other regions of world and all were linked to either travel to endemic area or import of animals from these areas.
The virus is related to Smallpox virus which once terrified the world as it swept the globe with high death rate and disfigured survivors.
Why do we need to know about Monkeypox?
In 2022, increasing number of monkeypox cases is seen even in non-endemic countries, including India. Many have no link to the known endemic areas of African continent. In India 9 cases were reported till 3rd Aug 2022. Some have a history of international travel but not to the typical endemic areas of Africa.
The source of infection, ways of spread and clinical patterns are still under study. Hence one needs to remain updated so as to protect oneself and other members of the society.
How dangerous is Monkeypox?
In the current outbreak with West African clade, the death rate is around 1 in 100 (1%). Nevertheless, it causes painful condition and requires 2 to 4 weeks to recover. Some degree of skin scarring may result from the rash. The severity of the disease and the death rate is high for the following individuals:
• People with compromised immune system e.g. HIV/AIDS, immune-suppressive drugs
• Children below the age of 8 years
• People with eczema
• Pregnant or breastfeeding women
The Congo Basin (Central African) type of Monkeypox virus has a high fatality rate of approximately 10%.
What are the symptoms and signs?
Usually the symptoms begin 1-2 weeks after the infection is acquired, however the time of onset may range from 5days to 3 weeks.
1. In the initial phase k/a ‘Prodrome’ (0 – 5 days):
• Fever
• Intense headache
• Swelling of lymph nodes (a distinct feature, usually not seen in other rashes like smallpox, chickenpox or measles)
• Backache and muscle pain
• Severe lack of energy
2. In the second phase (after 1 – 3 days of fever), skin rash appears:
Characteristics of Monkeypox rash:
• More concentrated on face, arms and legs rather than on the main body
• Typically, palms of hands and soles of the feet show lesions
Other commonly affected body areas are:
• Oral mucous membrane (rash inside the mouth)
• Genitalia
• Conjunctiva of the eyes; even cornea may be affected in severe cases
Monkeypox rash progresses step by step, in the following sequence:
I. Begins with flat spots on skin (macules)
II. The spots become tiny nodules (papules)
III. These become fluid-filled (vesicles)
IV. Subsequently, the fluid turns into yellow pus (pustules)
V. Lesions start drying and turn into crusts which ultimately fall off
The number of lesions may vary from a few to thousands. In more severe cases, the skin lesions may join to form large areas which ultimately slough off.
3. Recovery occurs in 2 – 4 weeks. Skin scarring may be left behind. In severe cases, the corneal involvement may affect vision.
The higher age groups (> 45 years age) may already have some protection due to smallpox vaccination in the past (smallpox vaccination was stopped in 1980). Hence the susceptibility and severity is expected to be higher among those born after 1980.
Monkeypox may get complicated in some cases. The complications include:
• Bacterial infection of the skin lesions may make the patient sicker for longer and cause scarring.
• Chest infection (pneumonia)
• Generalized sepsis
• Encephalitis (inflammation of the brain)
• Blindness due to corneal scarring
Can some persons have and spread the infection without having any symptom themselves?
The percentage of asymptomatic infection is not known as yet.
How is Monkeypox diagnosed?
Other diseases which can be similar to Monkeypox (differential diagnosis):
• Chickenpox
• Disseminated herpes zoster
• Measles
• Infectious mononucleosis
• Scabies
• Rickettsia pox
• Meningococcemia
• Secondary syphilis
• Smallpox etc.
Monkeypox can be the most probable among the list of differential diagnoses if:
• Patient has a history of travel to endemic area or contact with a case of monkeypox
• Has history of contact with a wild or pet animal (live/dead) of African origin
• Lymphadenopathy (enlarged lymph glands) is found during the initial (prodromal) phase
• Presence of lesions on palms of hands and soles of feet
• All the lesions on one body part are in the same phase of evolving
• Patient has lesions inside mouth and/or in the genitalia
However, in the current outbreak, monkeypox patients have atypical features.
Confirmation of Monkeypox diagnosis:
Monkeypox diagnosis can be confirmed by detecting its DNA on PCR (polymerase chain reaction)
The samples which can be used for PCR are:
• Scrapings from the lesion roof and base
• Lesion fluid: sucked out with the help of a thin needle and syringe
• Naso-pharyngeal or oro-pharyngeal swab
If lesions have not yet appeared or detected, then following samples may be used for the PCR:
• Blood
• Urine
How is Monkeypox transmitted?
Human to Human transmission:
• Occurs via large respiratory droplets and requires a prolonged and close contact with a case. It also means that face masks can be effective in preventing transmission.
• Direct contact with the lesions, lesion fluid and even lesion crusts
• Indirect contact with lesion fluid or crusts via contaminated clothes or linen
• Intimate contact with a case e.g. sexual contact
Animal to human spread:
• Through bite or scratch of infected animal e.g. rodents (squirrels, rat) and non-human primates (monkey, apes)
• Via preparation of bush meat
Period of communicability
A monkeypox patient can transmit the infection (remains contagious) from the day of onset of the first symptom till all the crusts have fallen and a new layer of skin has formed
This usually amounts to 2 – 4 weeks of communicability
How do I keep myself safe?
• Frequently wash hands with soap or use alcohol based sanitizer
• Do not touch skin lesions which look like that of Monkeypox.
• Do not touch any bedding, clothing or any article that has been in contact with a Monkeypox patient
• Avoid hugging, kissing or sexual contact with a suspected or confirmed case. Avoid all skin to skin contact.
• Hand hygiene after any contact with patient or infected animal: Washing hands with soap and water or using hand sanitizer (alcohol based)
• Do not share food, glasses, cups and other utensils with a suspected or confirmed case
• Avoid touching sick or dead animals or even the items that may have been in their contact
If caring for a Monkeypox patient:
• Isolate the patient
• Follow the Government of India guidelines for management of monkeypox disease. It is available online
• Use personal protective equipment
• Do not share towels, bedding, linen, utensils etc. with the patient.
• Wash hands with soap or use alcohol based sanitizer after caring for the patient.
• Contaminated waste disposal e.g. cotton swabs, dressings etc. must be done in the manner listed in the Biomedical Waste Management guidelines for infectious waste
CDC in USA has also issued guidelines regarding this at: https://www.cdc.gov/poxvirus/monkeypox/specific-settings/home-disinfecti...
• Keep the patient under isolation until all lesions have healed and a new layer of skin has grown over them.
• Do not let the pets come in contact with the patient
Coming up soon: Frequently Asked Questions about Monkeypox
References:
GOI, MoHFW, 2022. Guidelines for Management of Monkeypox Disease. Available at: https://main.mohfw.gov.in/sites/default/files/Guidelines%20for%20Managem... accessed on 19th July 2022
WHO website, Monkeypox available at: https://www.who.int/news-room/fact-sheets/detail/monkeypox accessed on 19th July 2022
Isalker Umesh. Monkeypox virus in Indian patient is milder West African clade. National Institute of Virology. 28th July 2022. https://timesofindia.indiatimes.com/city/pune/monkeypox-virus-in-indian-...