Why do doctors order multiple infection tests instead of one?

Author: Wang Chaoqun, Taian Central Hospital Affiliated to Qindao University

Review: Zhang Xin, Chief Technician, Qilu Hospital of Shandong University.

When receiving treatment at a hospital, if a doctor suspects that a patient may have an infection, they often prescribe a series of tests for infection indicators. Faced with these seemingly complex examination items and high costs, patients may wonder: why do we need to check so many infection indicators? Is it not sufficient to check just one? This article will address these questions and provide an overview from a medical professional's perspective.

The Importance of Infection Indicator Testing

In the medical field, infection marker detection is a vital means of diagnosing infectious diseases. By examining various biomarkers and pathogens in the patient's body, doctors can more accurately determine whether the patient has an infection and the type and severity of the infection. This is crucial for developing treatment plans, assessing treatment effectiveness, and predicting disease progression.

First, infection indicator testing helps doctors clarify the type of infection. Infectious diseases include bacterial infections, viral infections, fungal infections, and others. Different pathogens require different treatment methods. By detecting specific antibodies, antigens, or nucleic acids of the pathogens, doctors can accurately identify the type of infection and provide targeted treatment for patients.

Secondly, infection marker testing can assess the severity of an infection. Some biomarkers, such as white blood cell count and C-reactive protein, reflect the degree of the inflammatory response in the patient’s body. Changes in these markers can inform doctors about the severity of the condition, allowing for the development of more appropriate treatment plans.

Additionally, the detection of infection indicators can predict the trend of disease progression. By continuously monitoring the patient's infection indicators, doctors can gain insights into the evolution of the condition and the treatment effectiveness, enabling timely adjustments to the treatment plan and improving treatment outcomes.

Why is it necessary to check multiple infection indicators?

In actual clinical practice, doctors often need to evaluate multiple infection indicators to form a comprehensive assessment of a patient's condition. This is necessary because different infection indicators have varying sensitivities and specificities, and a single indicator may not fully reflect the patient's situation. Several key reasons support this approach.

The sensitivity and specificity of different infection indicators vary.

Different infection markers exhibit varying sensitivities and specificities when diagnosing infectious diseases. For instance, white blood cell count often increases during bacterial infections but may be normal or even decrease in viral infections; meanwhile, C-reactive protein can be elevated in both bacterial and viral infections. Therefore, doctors need to consider multiple indicators to assess the patient's condition.

Diversity of Infection Types

Infectious diseases come in many varieties, and different pathogens necessitate different treatment methods. A single indicator may not encompass all types of infections. For example, specific antibodies for certain pathogens may only test positive after a period following the infection, while others can only be diagnosed through nucleic acid testing. Hence, doctors should test multiple indicators to enhance diagnostic accuracy.

The Complexity of the Illness

In actual clinical practice, patients' conditions can be quite complex. Some patients may have multiple infections or infections caused by various pathogens simultaneously; others may have other diseases or complications accompanying the infection. In these instances, a single indicator may not adequately reflect the patient's condition. Therefore, doctors assess multiple indicators to gauge the patient's status and devise an appropriate treatment plan.

Is it not sufficient to check just one infection indicator?

Although some infection indicators possess high sensitivity and specificity for diagnosing infectious diseases, relying solely on one indicator to assess a patient's condition is insufficient. Different indicators may have varying limitations and reflect the patient's status differently. Specific antibodies for certain pathogens might only test positive after a specific period following infection, while others require nucleic acid testing for definitive diagnosis. Therefore, dependence on just one indicator could lead to missed or inaccurate diagnoses.

Thus, when doctors prescribe examination items, they will comprehensively select multiple indicators based on the specific conditions and needs of the patient. This not only enhances diagnostic accuracy but also provides patients with more comprehensive and precise medical services.

Summary and Recommendations

In summary, doctors issue examination items based on medical principles and standards, striving to provide patients with more comprehensive and accurate diagnostic services. Additionally, it is important to understand and accept the necessity of this examination approach and actively cooperate with doctors in undergoing checks and treatments. Furthermore, enhancing our health awareness and medical literacy will enable better understanding of the diagnosis and treatment methods for common infectious diseases, helping us maintain our health.

References

Tan Chen, Chen Wei, Zhang Lei, et al. Study on the Evaluation Effect of Inflammatory Indicators on the Condition of Hospitalized Patients with Severe Infections. Chinese Journal of Nosocomiology, 2018, 28(22): 3378-3380.

Shen Lilei, Chen Guofei. The Early Diagnostic Value of Combined Detection of Multiple Inflammatory Markers for Septicemia Caused by Different Pathogenic Bacteria. International Journal of Laboratory Medicine, 2023, 44(15): 1820-1825.