Monkeypox disease: agent, symptoms, management.

Monkeypox (MPX) is a viral zoonotic disease with symptoms similar to smallpox, although with less clinical severity. MPX was first discovered in 1958 in colonies of monkeys kept for research, hence the name ‘monkeypox.’ The first human case of monkeypox was reported from Democratic Republic of the Congo (DRC) in 1970.

According to World Health Organization (WHO), in the present series of outbreaks being reported, this is the first time that chains of transmission are reported in Europe without known epidemiological links to West or Central Africa.

Agent:

Monkeypox virus (MPXV) is an enveloped double-stranded DNA virus that belongs to the Orthopoxvirus genus of the Poxviridae family. There are two distinct genetic clades of the monkeypox virus – the Central African (Congo Basin) clade and the West African clade.

Host:

Natural reservoir is yet unknown. However, certain rodents (including rope squirrels, tree squirrels, Gambian pouched rats, dormice) and non-human primates are known to be naturally susceptible to monkeypox virus.

Incubation period:

The incubation period (interval from infection to onset of symptoms) of monkeypox is usually from 6 to 13 days but can range from 5 to 21 days.

Period of communicability:

1-2 days before the rash to until all the scabs fall off/gets subsided.

Mode of transmission:

Human-to-human transmission is known to occur primarily through large respiratory droplets generally requiring a prolonged close contact. It can also be transmitted through direct contact with body fluids or lesion material, and indirect contact with lesion material.

Animal-to-human transmission: may occur by bite or scratch of infected animals like small mammals including rodents (rats, squirrels) and non-human primates (monkeys, apes) or through bush meat preparation.

Case definition:

Suspected case:

A person of any age having history of travel to affected countries within last 21 days presenting with an unexplained acute rash AND one or more of the following signs or symptoms

Swollen lymph nodes
Fever
Headache
Body aches
Profound weakness

Probable case:

A person meeting the case definition for a suspected case, clinically compatible illness and has an epidemiological link.

Confirmed case:

A case which is laboratory confirmed for monkeypox virus (by detection of unique sequences of viral DNA either by polymerase chain reaction (PCR) and/or sequencing).

Clinical Features:

Monkeypox is usually a self-limited disease with the symptoms lasting from 2 to 4 weeks. Severe cases occur more commonly among children and are related to the extent of virus exposure, patient health status and nature of complications. In recent times, the case fatality ratio has been around 3-6%.

Common symptoms and signs:

Prodrome (0-5 days):

Fever
Lymphadenopathy
Headache, muscle aches, exhaustion
Chills and/or sweats
Sore throat and cough

Skin involvement (rash):

Usually begins within 1-3 days of fever onset, lasting for around 2-4 weeks
Deep-seated, well-circumscribed and often develop umbilication
Lesions are often described as painful until the healing phase when they become itchy
Stages of rash (slow evolution)
first lesions on tongue and mouth
Macules starting from face spreading to arms, legs, palms, and soles (centrifugal distribution), within 24 hours
The rash goes through a macular, papular, vesicular and pustular phase. Classic lesion is vesicopustular
Involvement by area: face (98%), palms and soles (95%), oral mucous membranes (70%), genitalia (28%), conjunctiva (20%).Generally skin rashes are more apparent on the limbs and face than on the trunk. Notably the genitalia can be involved and can be a diagnostic dilemma in STD population
By 3rd day lesions progress to papules
By 4th to 5th day lesions become vesicles (raised and fluid filled).
By 6th to 7th day lesions become pustular, sharpy raised, filled with opaque fluid, firm and deep seated. May umbilicate or become confluent
By the end of 2nd week, they dry up and crust
Scabs remain for a week before falling off
The lesion heals with hyperpigmented atrophic scars, hypopigmented atrophic scars, patchy alopecia, hypertrophic skin scarring and contracture/deformity of facial muscles following healing of ulcerated facial lesions.

Management:

Principles of Management:

Patient isolation
Protection of compromised skin and mucous membranes
Rehydration therapy and Nutritional support
Symptom alleviation
Monitoring and treatment of complications

Patient Isolation:

Isolation of the patient in an isolation room of the hospital/ at home in a separate room with separate ventilation
Patient to wear a triple layer mask
Skin lesions should be covered to the best extent possible (e.g. long sleeves, long pants) to minimize risk of contact with others
Isolation to be continued until all lesions have resolved and scabs have completely fallen off

Supportive management of Monkeypox:

Symptoms/Signs	Management
Skin rash	Clean with simple antiseptic Mupironic Acid/Fucidin Cover with light dressing if extensive lesion present Do not touch/ scratch the lesions In case of secondary infection relevant systematic antibiotics may be considered
Genital ulcers	Sitz bath
Oral ulcers	Warm saline gargles/ oral topical anti-inflammatory gel
Conjunctivitis	Usually, self-limiting Consult Ophthalmologist if symptoms persist or there are pain/ visual disturbances
Dehydration can occur in association with poor appetite, nausea, vomiting and diarrhoea	Encourage ORS or oral fluids Intravenous fluids if indicated Encourage nutritious and adequate diet
Fever	Tepid sponging Paracetamol as required
Itching/Pruritus	Topical Calamine lotion Antihistaminics
Nausea and vomiting	Consider anti-emetics
Headache/ malaise	Paracetamol and adequate hydration

Monitoring and treatment of complications:

The patient should closely monitor for the appearance of any of the following symptoms during the period of isolation:

Pain in eye or blurring of vision
Shortness of breath, chest pain, difficulty in breathing
Altered consciousness, seizure
Decrease in urine output
Poor oral intake
Lethargy