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WHO Approves First Mpox Diagnostic Test
Context:
The World Health Organisation (WHO) has taken a significant step in the fight against Mpox by approving the first in vitro diagnostic (IVD) test for emergency use.
More on News:
- This approval, under the Emergency Use Listing (EUL) procedure, is expected to enhance global access to mpox testing, particularly in regions grappling with outbreaks.
- The EUL process accelerates the availability of life-saving medical products (vaccines, tests, treatments) during public health emergencies, highlighting its importance in the global health response to Mpox.
Current Testing Capacity
- In India, 35 laboratories are currently equipped to test suspected Mpox cases.
- Since the WHO declared Mpox a public health emergency in mid-August 2024, India has reported 30 confirmed Mpox cases.
Key Highlights:
- The newly approved test, the Alinity m MPXV assay, is manufactured by Abbott Molecular Inc. Designed to detect monkeypox virus (clade I/II) DNA from human skin lesion swabs.
- The monkeypox virus is confirmed through nucleic acid amplification testing, including real-time or conventional polymerase chain reaction (PCR) tests.
- The recommended specimen for diagnostic confirmation is lesion material, specifically from pustular or vesicular rashes.
- This test is intended for use by trained clinical laboratory personnel proficient in PCR techniques and IVD procedures.
What is PCR?
- Polymerase Chain Reaction (PCR) is a fast, inexpensive technique used to amplify small segments of DNA, making molecular and genetic analyses possible.
- This method, developed by Kary B. Mullis, earned him the Nobel Prize in Chemistry in 1993 due to its revolutionary impact on DNA studies.
- PCR is crucial in fields like the Human Genome Project, DNA fingerprinting, pathogen detection (such as HIV/AIDS), and diagnosing genetic disorders.
- The process involves denaturing DNA by heating it, followed by synthesis of new strands using the enzyme Taq polymerase.
- This cycle repeats, producing billions of DNA copies in just a few hours, controlled by an automated thermocycler machine.
Limitations of PCR:
- Requires Prior Knowledge: PCR needs prior sequence information to design primers, limiting its use for unknown targets.
- Error-Prone Polymerases: DNA polymerases used in PCR can introduce mutations, potentially affecting accuracy.
- Sensitivity to Contamination: PCR is highly sensitive, and even small contaminations can lead to misleading or ambiguous results.
Addressing a Critical Need:
- The approval comes at a crucial time as countries face increasing mpox outbreaks.
- Early diagnosis is essential for timely treatment and containment of the virus. However, limited testing capacity and delays in confirming cases have been significant challenges, especially in Africa.
- In 2024 alone, over 30,000 suspected cases have been reported across the region, with the highest numbers in the Democratic Republic of the Congo, Burundi, and Nigeria1
- In the DRC, only 37% of suspected cases have been tested this year, highlighting the urgent need for improved diagnostic capabilities.
- The Alinity m MPXV assay will enable health workers to confirm suspected mpox cases efficiently, thereby aiding in the control of the virus.
Way Forward:
- With the approval of the Alinity m MPXV assay, WHO aims to bolster global testing capacities and ensure that countries can respond more effectively to mpox outbreaks.
- This development marks a pivotal step towards improving public health responses and safeguarding communities worldwide.
About Mpox:
- Mpox (formerly known as monkeypox) is a disease caused by the Monkeypox virus.
- It is caused by an orthopoxvirus, was first identified in humans in 1970 and is endemic to central and west Africa.
- It is characterised by a rash and fluid-filled bumps.
- It exists in two main strains: clade I and clade II.
- It spreads through contact with contaminated items such as utensils, towels, and bedding.
- The disease also has a long incubation period (5 to 21 days), which can lead to undetected transmission across borders.
- Initial symptoms, such as fever and swollen glands, are vague and can be mistaken for other illnesses.
- Proactive measures by WHO and international collaboration with Africa CDC, NGOs and civil society to manage the current outbreak and prevent further global spread of MPOX.