Pathogen EQA Control

Definition

Pathogens: Microorganisms that can cause disease, such as bacteria, viruses, fungi, and parasites.

Interlaboratory quality control (IQC) refers to an activity organized by an independent external organization (such as a clinical testing center) to evaluate the test results of multiple laboratories (i.e., "interlaboratory"), with the goal of assessing the consistency and accuracy of each laboratory's testing capabilities.

Quality control products: Samples used for quality control.

Thus, pathogenic IQC products can be defined as:

A sample with a known, unambiguous result (containing a specific pathogen or its nucleic acid, antigen, etc.) distributed by an authoritative organization to participating laboratories for testing. The purpose is to objectively evaluate and compare the accuracy and reliability of these laboratories in pathogen detection.

Thus, the definition of a Hereditary Genetic control is:

A standard material or sample containing a known, defined genotype (such as a specific point mutation, insertion/deletion, or gene copy number variation) distributed to different laboratories performing genetic testing to monitor and evaluate the accuracy, reliability, and comparability of the laboratory's testing process.

The Role of Pathogen External Quality Control Products

Their core role is to ensure that pathogen testing reports issued by different laboratories are accurate, reliable, and comparable. Specifically, they are:

*Evaluating test accuracy: Laboratories test quality control products using conventional methods and then report the results to the organizer. By comparing the reported results with known true results, the organizer can determine whether the laboratory's testing is biased.

*Ensuring interlaboratory comparability: This is one of the most important functions. For example, if Hospital A and Hospital B test samples from the same patient, the results should be consistent. External quality control ensures that test results for the same sample from laboratories in different hospitals, regions, and even countries are highly consistent and comparable, providing a reliable basis for clinical diagnosis, epidemic assessment, and patient referral.

*Monitoring the entire laboratory testing process: From sample processing, nucleic acid extraction (for PCR testing), reagent performance, instrument status, to personnel operation, problems at any stage can lead to erroneous results. External quality control products can help identify potential problems throughout the entire testing process.

*Evaluating New Methods or Reagents: When introducing new testing methods or reagents, laboratories can use external quality control products to verify their performance meets standards.

*Necessary Requirements for Laboratory Certification and Accreditation: Domestic and international laboratory certification systems (such as ISO 15189 and CAP) include regular external quality assessment (using external quality control products) as a mandatory requirement for laboratory accreditation.

Disease-Related

Pathogen external quality control products are relevant to all infectious diseases for which etiological testing is available.

As long as a disease is caused by a pathogenic microorganism and has a corresponding clinical test method, there will be a corresponding external quality control product. 

Common examples include:

1.Viral Diseases:

*Hepatitis B (HBV) and Hepatitis C (HCV): Used for quality control of viral nucleic acid (DNA/RNA) quantification and antigen-antibody testing.

*AIDS (HIV): Used for quality control of viral nucleic acid (RNA) quantification and antigen-antibody testing.

*Novel coronavirus (SARS-CoV-2): Widely used for quality control of nucleic acid and antigen testing during the epidemic.

*Influenza virus, respiratory syncytial virus (RSV), etc.: Used for quality control of respiratory pathogen testing.

2.Bacterial diseases:

*Tuberculosis: Used for quality control of Mycobacterium tuberculosis nucleic acid testing, culture, and drug susceptibility testing.

*Sexually transmitted diseases such as gonorrhea and Chlamydia trachomatis: Used for quality control of nucleic acid testing of related pathogens.

*Drug-resistant bacteria testing: Quality control for antimicrobial susceptibility testing of, for example, MRSA (methicillin-resistant Staphylococcus aureus) and CRE (carbapenem-resistant Enterobacteriaceae).

*Fungal diseases: For quality control of culture identification, antimicrobial susceptibility testing, and nucleic acid testing of, for example, Candida and Aspergillus.

*Parasitic diseases: For quality control of microscopy or nucleic acid testing of, for example, Plasmodium.

Application Scenarios

Pathogen external quality control products are primarily used in the following scenarios:

1.Laboratory/pathology departments/central laboratories at all levels of medical institutions:

This is the primary application scenario. Laboratories regularly receive quality control products, perform blind testing on them as "normal patient samples," and report the results to continuously monitor the laboratory's testing quality.

2.Centers for Disease Control and Prevention (CDC) system

The CDC not only organizes national external quality assessment activities, but also requires its internal laboratories to participate in higher-level international and domestic quality assessments to ensure their authority and accuracy in infectious disease surveillance and public health emergency testing (such as emerging infectious diseases).

3.Third-party independent medical laboratories

As commercial testing organizations, the accuracy of their results is paramount. Participating in external quality assessments is a key way to demonstrate their testing capabilities and earn the trust of hospitals and patients.

4.Reagent and instrument manufacturers

When developing new test kits or instruments, manufacturers use external quality control products or other standards to verify that their product's performance meets clinical requirements.

5.Laboratory accreditation and regulatory agencies

These agencies, such as the National Center for Clinical Laboratory Inspection and health authorities, organize large-scale external quality assessments to monitor and improve the testing standards of medical laboratories nationwide, ensuring public health safety.