The Changing Needs of the Public Health Lab
What current techniques do you need to know for a career in public health and how do you get experience? Public health, like any science field, is always evolving. In the past few decades, laboratory testing has shifted focus from culture-based to molecular-based approaches, improving the ability to detect pathogenic organisms, trace transmission clusters and identify antimicrobial resistance and virulence-related genes. Because many labs are currently dealing with too few personnel to sustain testing capacity, finding more laboratorians and technicians with the molecular skillset is critical.
How Molecular Biology Is Being Used in Public Health
For samples sent to public health laboratories, testing for the identification and characterization of pathogens has generally involved conventional methods, such as culture, phenotypic assays and various biochemical tests. While these tests have long been the “gold standard,” culture-based methods can be slow and, at times, unreliable. Organisms that don’t grow prevent subsequent tests, and visual or color-based tests can lead to subjective or inconclusive results. Using a molecular approach and amplifying the genetic material from the pathogen increases sensitivity and provides a quicker result. These are clear advantages, versus traditional methods, that are being used in many areas of public health.
PulseNet is a national database established in 1996 to detect foodborne outbreaks. In 2018, PulseNet transitioned to next-generation sequencing as the primary means of outbreak detection. The technique still involves the need to culture a sample; however, future plans to use a metagenomics approach will allow extraction of pathogen-specific nucleic acids directly from primary specimens, such as stool. This transition will remove the need for pure bacterial isolates and will heavily rely on molecular diagnostics.
In an effort to combat antimicrobial resistance (AMR) across the nation, the Centers for Disease Control and Prevention (CDC) established the Antibiotic Resistance Lab Network (ARLN). The guiding principle of this surveillance program is to “rapidly detect emerging antibiotic-resistant threats in healthcare, food and the community.” Many of the tests use molecular assays, such as real-time polymerase chain reaction and next-generation sequencing, to decrease turnaround time and allow for real-time infection control measures.
Other public health programs, such as environmental and newborn screening, are also turning toward molecular approaches to analyze wastewater or rapidly detect genetic diseases.
With the growing trend of molecular assays, many commercial companies now offer simple-to-use, standardized kits. However, laboratorians still need to understand the principle behind the assay, which allows for users to troubleshoot when issues arise and adequately train other users. Having a clear grasp of molecular biology allows a laboratorian to do the following:
- Detect emerging or re-emerging pathogens, such as Zika virus, West Nile virus and novel coronaviruses.
- Perform DNA sequencing on pathogens for identification, surveillance studies and outbreak investigations.
- Identify virulence and antibiotic resistance determinants.
- Screen for suspected bioterrorism agents.
- Track seasonal pathogens, such as flu and norovirus.
- Develop, validate and implement new molecular assays for the detection and characterization of infectious diseases.
- Evaluate, optimize and troubleshoot assays for the detection of emerging or re-emerging pathogens.
- Train current and new employees on novel surveillance and diagnostic methods.
Public Health Laboratorians Will Need Molecular Training
Due to funding issues, a retiring workforce and higher than average turnover rate, the United States public health workforce was estimated be understaffed by more than 250,000 people by 2020. Currently, public health laboratories are trying to deal with an unprecedented volume of testing due to the COVID-19 pandemic. The overwhelming testing needs of COVID-19 have emphasized how much public health labs need more trained personnel. While states are using different ways to meet capacity, such as implementing a 7-day work week and cross-training staff from different departments, many laboratories are now hiring additional employees to fill full-time, part-time or temporary “second-shift” positions. A range of testing methods were authorized by the FDA for use under Emergency Use Authorizations (EUAs). However, molecular diagnostics has so far been the standard for detecting current infections. Job openings will most likely have a strong focus on current or new molecular detection techniques:
- Nucleic acid amplification or real-time PCR, still considered the standard molecular approach for detecting active viral infections. As of December 2020, 311 EUAs have been issued for COVID-19 and more than half are listed as real-time PCR.
- Next generation sequencing. To increase capacity and provide more information for epidemiological purposes, such as identifying and tracking the new COVID-19 variants, laboratories with the infrastructure are prioritizing sequencing.
- Other molecular techniques. New assays, such as isothermal amplification and droplet digital PCR, are being implemented in laboratories to expand COVID-19 surveillance.
Opportunities for Training in Public Health
There are also fellowship opportunities to help with the public health laboratory response. The Association of Public Health Laboratories (APHL) has created a COVID-19 Laboratory Associate Program, which places associates in local and state public health laboratories throughout the U.S.
Laboratorians who lack a clinical science background, but have experience in molecular biology, can be excellent resources, providing needed expertise in the field of public health. For scientists with a bachelor’s, master’s or doctoral degree, there are several ways to start in the field without prior experience or licensure. Look for fellowships or consultant positions. Seeking careers in quality assurance or quality control at a public health lab is another great way to apply your knowledge of molecular biology across all phases of laboratory testing. Some states don’t require a medical laboratory license. In those cases, laboratorians should emphasize their hands-on technical experience and troubleshooting skills.
Having programs and universities train students in molecular biology techniques benefits public health testing, provides needed expertise and closes the gap in an understaffed field. Public health laboratories can also offer training and continuing education webinars on molecular topics to help current employees develop their skillset. APHL, the CDC and companies like ThermoFisher provide educational resources and on-demand training videos. As technology and testing strategies continue to change, public health laboratories need to adapt. That includes ensuring staff and personnel can meet testing demands.
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