The outbreak of Monkey Pox,
its really a very dangerous disease, but the question is, why now???
Monkeypox is a rare viral zoonosis (a virus transmitted to humans
from animals) with symptoms in humans similar to those seen in the past in
smallpox patients, although less severe. Smallpox was eradicated in
1980.However, monkey pox still occurs sporadically in some parts of Africa.
Monkeypox is a member of the Orthopoxvirus genus
in the family Poxviridae.
The virus was first identified in the State Serum Institute in
Copenhagen, Denmark, in 1958 during an investigation into a pox-like disease
among monkeys.
Outbreaks
Human monkeypox was first identified in humans in 1970 in the
Democratic Republic of Congo (then known as Zaire) in a 9 year old boy in a
region where smallpox had been eliminated in 1968. Since then, the majority of
cases have been reported in rural, rainforest regions of the Congo Basin and
western Africa, particularly in the Democratic Republic of Congo, where it is
considered to be endemic. In 1996-97, a major outbreak occurred in the
Democratic Republic of Congo.
In the spring of 2003, monkeypox cases were confirmed in the
Midwest of the United States of America, marking the first reported occurrence
of the disease outside of the African continent. Most of the patients had had
close contact with pet prairie dogs.
In 2005, a monkeypox outbreak occurred in Unity, Sudan and
sporadic cases have been reported from other parts of Africa. In 2009, an
outreach campaign among refugees from the Democratic Republic of Congo into the
Republic of Congo identified and confirmed two cases of monkeypox. Between August
and October 2016, a monkeypox outbreak in the Central African Republic was
contained with 26 cases and two deaths.
Transmission
Infection of index cases results from direct contact with the
blood, bodily fluids, or cutaneous or mucosal lesions of infected animals. In Africa human infections have
been documented through the handling of infected monkeys, Gambian giant
rats and squirrels, with rodents being the major reservoir of the virus. Eating
inadequately cooked meat of infected animals is a possible risk factor.
Secondary, or human-to-human,
transmission can result from close contact with infected respiratory tract
secretions, skin lesions of an infected person or objects recently contaminated
by patient fluids or lesion materials. Transmission occurs primarily via
droplet respiratory particles usually requiring prolonged face-to-face contact,
which puts household members of active cases at greater risk of infection.
Transmission can also occur by inoculation or via the placenta (congenital
monkeypox). There is no evidence, to date, that person-to-person transmission
alone can sustain monkeypox infections in the human population.
In recent animal studies of the
prairie dog-human monkeypox model, two distinct clades of the virus were
identified – the Congo Basin and the West African clades – with the former
found to be more virulent.
Signs and symptoms
The incubation period (interval from infection to onset of
symptoms) of monkeypox is usually from 6 to 16 days but can range from 5 to 21
days.
The infection can be divided into two periods:
I.
the invasion period (0-5 days) characterized by fever, intense
headache, lymphadenopathy (swelling of the lymph node), back pain, myalgia
(muscle ache) and an intense asthenia (lack of energy);
II.
the skin eruption period (within 1-3 days after appearance of
fever) where the various stages of the rash appears, often beginning on the
face and then spreading elsewhere on the body. The face (in 95% of cases), and
palms of the hands and soles of the feet (75%) are most affected. Evolution of
the rash from maculopapules (lesions with a flat bases) to vesicles (small
fluid-filled blisters), pustules, followed by crusts occurs in approximately 10
days. Three weeks might be necessary before the complete disappearance of the
crusts.
The number of the lesions varies from a few to several thousand,
affecting oral mucous membranes (in 70% of cases), genitalia (30%), and
conjunctivae (eyelid) (20%), as well as the cornea (eyeball).
Some patients develop severe lymphadenopathy (swollen lymph nodes)
before the appearance of the rash, which is a distinctive feature of monkeypox
compared to other similar diseases.
Monkeypox is usually a self-limited disease with the symptoms
lasting from 14 to 21 days. Severe cases occur more commonly among children and
are related to the extent of virus exposure, patient health status and severity
of complications.
People living in or near the forested areas may have indirect or
low-level exposure to infected animals, possibly leading to subclinical
(asymptomatic) infection.
The case fatality has varied widely between epidemics but has been
less than 10% in documented eve
nts, mostly among young children. In general, younger age-groups
appear to be more susceptible to monkeypox.
Diagnosis
The differential diagnoses that must be considered include other
rash illnesses, such as, smallpox, chickenpox, measles, bacterial skin
infections, scabies, syphilis, and medication-associated allergies.
Lymphadenopathy during the prodromal stage of illness can be a clinical feature
to distinguish it from smallpox.
Monkeypox can only be diagnosed definitively in the laboratory
where the virus can be identified by a number of different tests:
·
enzyme-linked immunosorbent assay (ELISA)
·
antigen detection tests
·
polymerase chain reaction (PCR) assay
·
virus isolation by cell culture
Treatment and vaccine
There are no specific treatments or vaccines available for
monkeypox infection, but outbreaks can be controlled. Vaccination against
smallpox has been proven to be 85% effective in preventing monkeypox in the
past but the vaccine is no longer available to the general public after it was
discontinued following global smallpox eradication. Nevertheless, prior
smallpox vaccination will likely result in a milder disease course.
Natural host of monkeypox
virus
In Africa, monkeypox infection has been found in many animal
species: rope squirrels, tree squirrels, Gambian rats, striped mice, dormice
and primates. Doubts persist on the natural history of the virus and further
studies are needed to identify the exact reservoir of the monkeypox virus and
how it is maintained in nature.
In the USA, the virus is thought to have been transmitted from
African animals to a number of susceptible non-African species (like prairie
dogs) with which they were co-housed.
Prevention
Preventing
monkeypox expansion through restrictions on animal trade
Restricting or banning the
movement of small African mammals and monkeys may be effective in slowing the
expansion of the virus outside Africa.
Captive animals should not be
inoculated against smallpox. Instead, potentially infected animals should be
isolated from other animals and placed into immediate quarantine. Any animals
that might have come into contact with an infected animal should be quarantined,
handled with standard precautions and observed for monkeypox symptoms for 30
days.
Reducing the risk of
infection in people
During human monkeypox
outbreaks, close contact with other patients is the most significant risk
factor for monkeypox virus infection. In the absence of specific treatment or
vaccine, the only way to reduce infection in people is by raising awareness of
the risk factors and educating people about the measures they can take to
reduce exposure to the virus. Surveillance measures and rapid identification of
new cases is critical for outbreak containment.
Public health educational
messages should focus on the following risks:
·
Reducing the risk of human-to-human transmission. Close physical
contact with monkeypox infected people should be avoided. Gloves and protective
equipment should be worn when taking care of ill people. Regular hand washing
should be carried out after caring for or visiting sick people.
·
Reducing the risk of animal-to-human transmission. Efforts to
prevent transmission in endemic regions should focus on thoroughly cooking all
animal products (blood, meat) before eating. Gloves and other appropriate
protective clothing should be worn while handling sick animals or their
infected tissues, and during slaughtering procedures.
Controlling infection in
health-care settings
Health-care workers caring for
patients with suspected or confirmed monkeypox virus infection, or handling
specimens from them, should implement standard infection control precautions.
Healthcare workers and those
treating or exposed to patients with monkeypox or their samples should consider
being immunized against smallpox via their national health authorities. Older
smallpox vaccines should not be administered to people with comprised immune
systems.
(Samples taken from people and
animals with suspected monkeypox virus infection should be handled by trained
staff working in suitably equipped laboratories). A response from (WHO)

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