Infections

Infectious diseases are caused by microorganisms (viruses, bacteria, fungi, and parasites) that invade the body when the immune system fails to respond adequately or at all. Laboratory testing can assess the nature and severity of infections. The identity of the pathogen can also be determined, which provides important support in treatment selection. Depending on infected organs or tissues, infections are categorized into different diseases such as flu, cold, pneumonia, bladder infection, urinary tract infections, sexually transmitted diseases, skin conditions, and inflammation in the brain or blood vessels.

In vitro diagnostics

Examples, categorized by different types of infections and diseases, illustrate the added value of laboratory tests in detecting, diagnosing, monitoring, and treating infections.

In vitro diagnostics

• Chlamydia and Gonorrhea

  With nearly sixteen thousand diagnoses annually, chlamydia is the most common sexually transmitted disease in the Netherlands. This sexually transmitted infection (STI) results from bacterial infection with Chlamydia trachomatis (CT), occurring primarily in young people. Gonorrhea is also a sexually transmitted disease resulting from bacterial infection with Neisseria gonorrhoeae (NG). In the Netherlands, over four thousand people annually receive a gonorrhea diagnosis. This STI occurs more frequently in men who have sex with men than in heterosexual men and women. Both STIs are easily curable with antibiotics. However, the problem is that these STIs often remain unnoticed due to lack of symptoms. This allows the infection to be unknowingly transmitted to sexual partners. Untreated STIs can lead to serious complications. Therefore, timely detection has high priority. Good, simple, and reliable tests are essential. For chlamydia and gonorrhea, there's the CT/NG assay.

  CT/NG Test

  This diagnostic test determines if people with symptoms or suspected STI are infected with Chlamydia trachomatis (CT) or Neisseria gonorrhoeae (NG). With a confirming CT or NG diagnosis, treatment can begin within the same consultation. The CT/NG assay is a molecular test detecting CT and NG based on their DNA. This uses nucleic acid amplification testing (NAAT) combined with PCR technology. It's a fully automated method with integrated sample processing, analysis, detection, and data processing. Results are available within ninety minutes. The analyzer is also available as a point-of-care version, allowing the test to be performed during patient consultation.

• Respiratory infections

  Respiratory infections usually present flu-like symptoms, but these symptoms are nonspecific and often cannot be traced to a specific pathogen. Conventional diagnostics to identify the pathogen are time-consuming (culture) and/or labor-intensive (separate detection of all possible pathogens). This impedes effective, rapid, and appropriate treatment. A solution to this diagnostic problem is a so-called syndromic approach, an all-in-one test simultaneously testing for over twenty possible causes of respiratory infections.

  Multiplex PCR rapid test

  Multiplex PCR technology forms the basis for syndromic diagnostics. The test is performed in a point-of-care system where diagnostics occur directly on-site, eliminating time lost to sample transport and result feedback. The throat-nasal mucus sample is placed in a cartridge inserted into the analyzer. The polymerase chain reaction multiplies several different DNA sequences of potential pathogens within one run. For respiratory infections, this involves simultaneous detection of 23 viruses and bacteria in total. This all-in-one rapid test provides immediate identification of the respiratory infection type and its causative agent. Diagnosis can be made and appropriate treatment started after just one hour.

• Sepsis

  Sepsis is a severe inflammatory response of the body to infections such as bladder and lung infections or following flu or erysipelas. The immune response leads to widespread organ dysfunction. Characteristic early symptoms such as fever, chills, and increased heart rate are atypical and can also indicate other, less severe diseases. However, in case of sepsis, a patient can die within 24 hours after initial symptoms. As dangerous as sepsis can be, if detected in time, it's usually easily treatable with antibiotics and fluid administration.

  Multiplex PCR rapid test

  Multiplex PCR technology forms the basis for rapidly testing for sepsis. The sample is placed in a cartridge inserted into the analyzer. The polymerase chain reaction multiplies several different DNA sequences of potential pathogens within one run. The test enables rapid identification of pathogen(s) including polymicrobial infections and resistance mechanisms. Especially in clinically urgent situations, like sepsis, a rapid test can be lifesaving. Based on test results, targeted treatment can begin immediately.

• Urinary tract infection

  Urinary tract infection is one of the most common reasons for consulting a primary care physician. Usually it's bladder infection, but it can also involve infections in kidneys, ureter, or urethra. Urine dipstick testing is the standard diagnostic tool used in primary care practice. A quick and simple method, but not very accurate. The diagnostic gold standard is urine culture, but results take two to three days. Lack of rapid and reliable diagnostics hinders targeted and responsible antibiotic prescription. This often leads to treating urinary tract infections with broad-spectrum antibiotics, contributing to increased antibiotic resistance risk. Rapid and reliable diagnostics offer a solution.

  Rapid test for urinary tract infection including antibiotic sensitivity

  The rapid test integrates lab-on-a-chip technology, phase contrast microscopy, and an image processing algorithm into a point-of-care analyzer. This allows primary care physicians to diagnose bacterial urinary tract infection within fifteen minutes and prescribe targeted antibiotics within thirty minutes.

  The lab-on-a-chip technology enables miniaturization of microbiological laboratory testing (urine culture and antimicrobial sensitivity tests). The chip consists of thousands of nanochannels through which the urine sample is flushed directly, without preprocessing. Large cellular components are filtered and the passed bacterial cells collect in the nanochannels, where they're exposed to different types and amounts of antibiotics. Resistant bacteria continue growing, while sensitive bacteria grow poorly or not at all. Cell growth is monitored in real-time using phase contrast microscopy and images are analyzed with a smart algorithm. The analysis results in an antibiogram after thirty minutes, allowing the physician to prescribe targeted antibiotics. Treatment of the urinary tract infection can begin immediately.

• Virus or bacteria

  Most patients with respiratory infection symptoms are treated with antibiotics, although the infection is often viral. However, incorrect antibiotic use should be avoided as much as possible due to (rapidly) increasing resistance. A diagnostic test can determine whether it concerns a viral or bacterial infection.

  Immune response test

  Instead of directly detecting the virus or bacteria, this test focuses on detecting the immune response to the infection. The immune response leads to production of specific proteins released into the blood. The pattern of three specific proteins (TRAIL, IP 10, and CRP) differs between viral and bacterial infections and thus forms a biomarker to differentiate between bacterial and viral infections. The test is performed in a fully automated analyzer. Based on results, physicians can immediately determine whether to treat with antiviral medication or antibiotics. This test helps prevent unnecessary and redundant antibiotic use.

• Tuberculosis

  Tuberculosis (TB) is an infectious disease caused by Mycobacterium tuberculosis bacteria. Without appropriate treatment, tuberculosis can be fatal. Infection often initially results in latent tuberculosis infection (LTBI), which is asymptomatic and non-infectious. In five to ten percent of infected individuals, the infection progresses to active tuberculosis. Effective tuberculosis control requires timely detection and appropriate treatment.

  IGRA blood test

  The Interferon Gamma Release Assay (IGRA) can detect Mycobacterium tuberculosis (MTB) in blood. The test is based on the response of MTB to MTB antigens, which leads to the release of interferon gamma. The released interferon gamma is detected using fluorescence technology.

  Key advantages of this blood test compared to the skin test (Mantoux) for detecting latent tuberculosis:

  • Standardized laboratory procedure
  • Unambiguous test results
  • No cross-reactivity with tuberculosis vaccine
  • Single patient contact (blood draw only)

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