Context: 

Recently, scientists from the Nigerian Centre for Disease Control applied metagenomic sequencing for pathogen surveillance and detection in three cohorts of patients.

More on News: 

• The first cohort represented population-level surveillance of individuals presenting with symptoms consistent with Lassa fever.
  • Lassa fever is a viral haemorrhagic fever caused by the Lassa virus endemic to West African countries. 
• The second cohort consisted of people from outbreaks with suspected infectious aetiologies. 
• The third cohort consisted of people with clinically challenging but undiagnosed conditions.

About Genome:

• The genome is the blueprint of life, a collection of all the genes and the regions between the genes contained in our 23 pairs of chromosomes. 
• Each chromosome is a contiguous stretch of DNA string. In other words, our genome consists of 23 different strings, each composed of millions of individual building blocks called nucleotides or bases. 

Genome sequencing:

• Genome sequencing is the process of determining the complete DNA sequence of an organism’s genome. 
• The DNA consists of a double-stranded molecule built up by four bases – adenine (A), cytosine (C), guanine (G) and thymine (T). 
• The process of deciphering the order of base pairs, to decode the genetic fingerprint of a human is called genome sequencing.

Impact of COVID-19 on Genomic Surveillance:

• Initial Breakthrough in Identification: A crucial breakthrough in identifying SARS-CoV-2, the virus causing COVID-19, came from unbiased genome sequencing of patient samples.
  • Traditional microbiology was bypassed in favor of direct genome sequencing and bioinformatic analysis, enabling swift virus identification.
• Emergence of Metagenomics: A novel approach called metagenomics emerged, allowing rapid and direct application to patient samples.
  • Metagenomics played a key role in quickly identifying SARS-CoV-2 and became a revolutionary tool in pathogen identification.

Image Source: American Society for Microbiology

Transformative Technologies and Applications:

• Genome-Based Technologies: Genome sequencing technologies developed post-COVID-19, like the CovidSeq assay, drove various SARS-CoV-2 genome surveillance initiatives.
• India initiated a national SARS-CoV-2 genome-sequencing and surveillance program, supported by state governments and private initiatives.

Advantages and Future Prospects:

• Faster identification: Genome surveillance furnishes crucial information for early response strategies, identifying emerging strains, and monitoring key species.
• Future Ready: Genomic technologies are poised to become essential tools in combating future pathogenic challenges.

News Source: The Hindu

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