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Culture-independent Diagnostics

Culture-independent diagnostic tests (CIDTs) rapidly detect pathogens in patient samples but do not provide the crucial isolates that disease surveillance networks rely on. APHL is monitoring the continued use and development of new CIDTs and working with laboratories to adapt to new technologies while maintaining robust disease monitoring systems.

Questions?

Contact the Food Safety team: [email protected]

IMPACT OF CIDTS

Faster Diagnoses, Fewer Surveillance Opportunities

Advances in technology make clinical diagnosis and patient management of foodborne illnesses faster than ever before. These diagnostic tests eliminate the need to culture organisms for the diagnosis of patient illnesses. While this is highly beneficial to patient care, surveillance systems such as PulseNet—which utilize isolates as the basis of their national and international surveillance programs—will no longer be able to detect foodborne outbreaks in the population. The burden of culturing pathogens then falls on public health laboratories, which incurs additional costs and labor on already strained resources.
WHAT APHL DOES

Supporting Laboratories and Surveillance Systems

Ensuring Effective Surveillance Systems

APHL works with the US Centers for Disease Control and Prevention (CDC) and partners in clinical and public health laboratories to maintain effective enteric disease surveillance systems as CIDT usage increases and new testing technologies advance.

APHL and CDC are monitoring the expansion of CIDTs into clinical and public health laboratories. A 2020 CDC report describes the uptake of CIDTs in clinical laboratories through the Foodborne Diseases Active Surveillance Network (FoodNet). For longer term solutions, CDC has undertaken applied research, such as the HMAS pilot project, to adapt our surveillance systems for foodborne pathogens to accommodate changes resulting from increased use of these tests.

Support for Culture-independent Method Adoption

APHL works with CDC and other partners in several working groups to address the regulatory, surveillance and technological issues associated with CIDT usage within clinical and public health laboratories. These working groups include the APHL CIDT Subcommittee and other CDC work groups. 

APHL has published several CIDT resources, including a fact sheet on the use of CIDTs and their impact on isolate-based surveillance programs such as PulseNet. APHL has also released multiple best practice workflows, which include guidance on cost effective but efficient ways to isolate and identify significant bacterial pathogens from CIDTs. Visit the CIDT Resources section, below, for the most recent materials.

WHAT WE KNOW

The Use and Impact of CIDTs

Explore the dashboard below for more information about the use and impact of CIDTs at public health laboratories.

 

LEARN MORE

CIDT Resources

  • Shigella Isolation and Identification Workflow
    A recommended workflow for the culture and isolation of Shigella species from human fecal specimens identified as positive for Shigella and enteroinvasive Escherichia coli (EIEC) by a culture-independent diagnostic test (CIDT).
  • STEC Isolation and Identification Workflow
    A recommended workflow for the isolation and identification of Shiga toxin-producing Escherichia coli (STEC) from human fecal specimens identified as positive for STEC by a culture-independent diagnostic test (CIDT).
  • Salmonella Isolation and Identification Workflow
    A recommended workflow for the culture and isolation of Salmonella species from Culture independent diagnostic tests.
  • 2024 CIDT Fact Sheet
    This resource outlines the benefits and challenges of widespread CIDT use and provides recommended actions that laboratories, federal agencies and test manufacturers can take to preserve critical public health surveillance infrastructure.
  • CIDT Survey Summary Report
    This report combines 2018 and 2022 CIDT survey data and provides insights into how the expanded use of CIDTs has influenced public health laboratory practice and foodborne disease surveillance.