TAG: GS 3: SCIENCE AND TECHNOLOGY
THE CONTEXT: Recently, another poxvirus, mpox, has garnered attention due to global outbreaks and its ability to rapidly evolve and infect humans.
EXPLANATION:
- Poxviruses have historically posed significant threats to human health, with smallpox being a notorious example.
- Smallpox, a devastating disease, highlighted the importance of vaccination and global public health initiatives in combating infectious diseases.
- Efforts to administer the smallpox vaccine led to the eventual eradication of the disease, showcasing the power of sustained public health interventions.
Mpox Emergence and Global Outbreak
- Mpox, initially known as monkeypox, gained prominence during a global outbreak spanning 2022-2023.
- Despite its previous sporadic occurrences, this outbreak marked a significant expansion of mpox infections across 118 countries, prompting the World Health Organization (WHO) to declare it a public health emergency.
- The mortality rate of mpox infections ranges from 1-10%, underscoring its potential threat to global health security.
Genomic Insights into Mpox Evolution
- Researchers have delved into the genomic structure of mpox viruses to understand their evolutionary dynamics.
- The mpox genome, approximately 197 kilobases in size, exhibits unique features that contribute to its adaptability and virulence.
- Notably, sections of the genome previously considered less significant were found to play crucial roles in the virus’s ability to transmit between humans.
- Mpox viruses employ a mechanism termed “genomic accordion,” characterized by rhythmic expansions and contractions of the genome.
- These fluctuations allow the virus to adapt to selective pressures, such as host immune responses, by duplicating or deleting genes.
- Such genomic plasticity enables mpox viruses to evolve rapidly and evade host defenses.
Impact of Clades on Virulence
- Mpox viruses are categorized into distinct clades, each associated with varying levels of virulence and transmissibility.
- Clade IIb, identified during the 2022 outbreak, demonstrated heightened human-to-human transmission, highlighting the importance of genomic variations in viral adaptation.
Recent Outbreak in the Democratic Republic of the Congo (DRC)
- A significant mpox outbreak occurred in the DRC between September 2023 and February 2024, with distinct genomic features associated with increased mortality and human-to-human transmission.
- This outbreak underscored the ongoing threat posed by mpox and the need for vigilant surveillance and intervention strategies.
Genomic Surveillance for Disease Prevention
- Genomic sequencing plays a crucial role in monitoring and understanding the spread of mpox viruses.
- By analyzing viral genomes, researchers can track evolutionary changes and identify emerging lineages associated with increased transmission and virulence.
- Such insights inform public health interventions aimed at preventing and controlling outbreaks on a global scale.
Clade:
- A clade is a group of organisms that includes an ancestor and all its descendants.
- In the case of the Monkeypox virus (MPXV), it is categorized into two main clades: Clade I and Clade II, with Clade II further divided into Clade IIa and Clade IIb.
- It has been identified that only Clade I MPXV has been found in the Democratic Republic of the Congo (DRC)
Clade Classification:
- Mpox virus (MPXV) is categorized into Clade I and Clade II (further divided into Clade IIa and Clade IIb).
- Only Clade I MPXV has been identified in the DRC.
Sexual Transmission of Clade I:
- Before April 2023, no documented cases of sexual transmission involving Clade I MPXV existed globally.
- However, the report highlighted the first-ever confirmed case of sexual transmission in March 2023, originating from a Belgian traveler in Kwango province and spreading through sexual contacts within the DRC.
- Viral sequences showed a close genetic relationship among cases.
MPox:
- Mpox (monkeypox) is a viral illness caused by the monkeypox virus, a species of the genus Orthopoxvirus. Two different clades exist: clade I and clade II.
- Common symptoms of mpox are a skin rash or mucosal lesions which can last 2–4 weeks accompanied by fever, headache, muscle aches, back pain, low energy, and swollen lymph nodes.
- Mpox can be transmitted to humans through physical contact with someone who is infectious, with contaminated materials, or with infected animals.
- Laboratory confirmation of mpox is done by testing skin lesion material by PCR.
- Mpox is treated with supportive care. Vaccines and therapeutics developed for smallpox and approved for use in some countries can be used for mpox in some circumstances.
- In 2022–2023 a global outbreak of mpox was caused by a strain known as clade IIb.
- Mpox can be prevented by avoiding physical contact with someone who has mpox. Vaccination can help prevent infection for people at risk.