Methods used in Microbial Forensics and Epidemiological Investigations for Stronger Health Systems
Authors: Castro Arizaldo E. , De Ungria Maria Corazon A. 
Published: March 2022

AbstractThis review discusses microbial forensics as an emerging science that finds application in protecting human health. It is important to distinguish naturally acquired infections from those caused by the intentional release of microorganisms to the environment. This information is crucial in formulating procedures against the spread of infectious diseases and prosecuting persons who may be involved in acts of biocrime, bioterrorism, or biowarfare. A comparison between epidemiological investigations and microbial forensic investigations is provided. In addition, a discussion on how microbial forensics strengthens health systems is included in this review. Microbial forensic investigations and epidemiologic examinations employ similar concepts and involve identifying and characterising the microbe of interest. Both fields require formulating an appropriate case definition, determining a pathogen’s mode of transmission, and identifying the source(s) of infection. However, the two subdisciplines differ in their objectives. An epidemiological investigation aims to identify the pathogen’s source to prevent the spread of the disease. Microbial forensics focuses on source-tracking to facilitate the prosecution of persons responsible for the spread of a pathogen. Both fields use molecular techniques in analysing and comparing DNA, gene products, and biomolecules to identify and characterise the microorganisms of interest. We included case studies to show methods used in microbial forensic investigations, a brief discussion of the public significance of microbial forensic systems, and a roadmap for establishing a system at a national level. This system is expected to strengthen a country’s capacity to respond to public health emergencies. Several factors must be considered in establishing national microbial forensic systems. First is the inherent ubiquity, diversity, and adaptability of microorganisms that warrants the use of robust and accurate molecular typing systems. Second, the availability of facilities and scientists who have been trained in epidemiology, molecular biology, bioinformatics, and data analytics. Human resources and infrastructure are critical requirements because formulating strategies and allocating resources in times of infectious disease outbreaks must be data-driven. Establishing and maintaining a national microbial forensic system to strengthen capacities in conducting forensic and epidemiological investigations should be prioritised by all countries, accompanied by a national policy that sets the legislative framework and provides for the system’s financial requirements. Key PointsMicrobial forensics and molecular epidemiology employ similar molecular analytical techniques in studying microbial infectious agents. Still, they differ in the rigor of standard, the requirement for a chain of custody of samples, and the strength of accredited operational procedures.National microbial forensic systems are envisioned to monitor incidents of microbial infections in a given population. Biosurveillance takes notice of emerging infectious diseases and those already controlled previously but are re-emerging in the population.National microbial forensic systems must address the challenges related to the inherent diversity of microorganisms, the requirement for robust molecular typing systems, and the availability of scientists with technical expertise in microbial forensics, molecular biology, bioinformatics, and data analytics.