one health lecture 3- mpox Flashcards
what is the mpox disease?
- Previously called monkeypox virus
- First discovered in 1958
Two outbreaks of a pox-like disease in monkeys kept in research colonies - First human case documented in 1970
In what is now the Democratic Republic of Congo (DRC)
what is the MPXV?
Linear double-stranded DNA
Genus: Orthopoxvirus
Family: Poxviridae
Brick-shaped virion
Enveloped
Host cell-derived membrane
how does the poxvirus replicate?
1- Binding / Attachment
2- Fusion / Entry
3- Nucleocapsid Release
4- Transcription
5- Translation
6- Replication
7- Lysis or budding
8- Release / Egress
compare the clade I and clade II mpxv?
Clade I
Responsible for
the current rise of cases in
Central and Eastern Africa
Incidence (2024): 16,000
Fatality rate of 3.6%
Clade II
Caused the global
outbreak that began in 2022
Incidence (2022): 92,167
Fatality rate 0.03%
Clade I is endemic to Central Africa whereas Clade II is endemic to West Africa
Historically, Clade I causes more severe disease than Clade II
what were the outbreaks in mpox?
Discovered in 1958
- Initial cases of mpox were misdiagnosed as chickenpox
- WHO began actively monitoring human mpox cases in Congo in the 1980’s
- Cases remained largely endemic to Africa with some cases exported internationally
- In 2022, over 60,000 cases of mpox had been reported in over 105 countries
WHO declares mpox a public health emergency of international concern
how does mpox spread?
First spreads to people from animals
Zoonotic infection
Mpox virus can infect various mammalian species
Rodents, gazelles, hedgehogs, prairie dogs, non-human primates, and humans
Animal reservoir species
Unknown
Problem for eradication
what is the specified method of how it spreads?
its unknown but these are expected
Direct transmission (touch, bite, scratch)
Indirect transmission (blood, body fluids, cutaneous lesions, or mucosal lesions)
The virus enters the body through:
Skin breaks (some of which are not apparent)
Eyes, mouth, nose, and other regions of the respiratory tract
what are the symptoms of mpox
Usually begin within 7 days but can take up to 21 days
- Typically, last 2-4 weeks
- May last longer in those with weakened immune systems
such as fever, chills, exhaustion, headache, muscle ache
how is it diagnosed?
- The gold standard for MPXV diagnostics
- Highly sensitive and fast diagnostics
- Multiple different targets available
- Important for determining which clade is present
- Highly important techniques for determining seroprevalence of MPXV within a population
- Integral to vaccine efficacy studies
- Limited use for MPXV diagnostics
- Potential cross-reactivity with other circulating orthopoxviruses
- IgM maybe more informative than IgG tests
- Used in addition to traditional diagnosis
- Due to high reagent and infrastructure costs as well as the requirement for specialist training makes this unsuitable for clinical use
- Therefore, only a small proportion of clinical samples are being sequenced
- to combat this, new approaches such as MinION sequencers are being used to increase the number of sequences available
- Like COVID-19, these sequences are crucial to public health decision making
what is the vaccination for mpox?
Smallpox vaccination protects against MPXV
Two approved vaccines against MPXV
Third-generation smallpox vaccines
Both vaccines are live-attenuated
MVA-BN and LC16m8
Effective against both clades: I & II
People born after 1971 are at higher risk of infection
what is the treatment of mpox?
No proven effective antiviral therapies for mpox
Three drugs commonly used in clinic
-Tecovirimat
-Cidofovir
-Brincidofovir
-Often prescribed as combination therapy to avoid drug resistance
Supportive Care:
Oral or intravenous fluids
Treat the symptoms
Treat other infections as necessary
what is preparedness?
Community engagement is key and the outbreak control relies on suitable prevention and control methods - vaccination is key
- Similarities to the COVID-19 pandemic community prevention
- Large emphasis on getting vaccinated where possible
- Strong advocacy presence from MSM community
what are the stages of mpox?
stage 1 = macule - the rash is red and flat for 1-2 days
stage 2 = papule - the spots become hard and raised for 1-2 days
stage 3 = vesicle - bumps are large and are filled with clear liquid for 1-2 days
stage 4 = pustule- the blisters fill with puss for 5-7 days
stage 5 = scabs - the spots crust over and become scabs that eventually fall off for 7-14 days
what was the may 2023 outbreak of mpox?
- The spread of clade II mpox had reduced by 90% between Feb-May 2023 in comparison to the previous 3 months
-Therefore, after more than 87,000 cases and 140 dealths reported in 111 countries the PHEIC was ended
what was the august 2024 outbreak of mpox?
-The more deadly Clade Ib began to spread across borders.
-Concerns are heightened by increasing evidence of mpox-HIV co-infection
-Mirroring the historical spread of HIV on the continent via transport corridors and sexual networks, raising the risk of infection among women and children.
