Question

The physician has ordered cultures for cytomegalovirus (CMV). Which statement is true regarding collection of cultures for cytomegalovirus? A. Stool cultures are preferred for definitive diagnosis. B. Pregnant caregivers may obtain cultures. C. Collection of one specimen is sufficient. D. Accurate diagnosis depends on fresh specimens.

Short answer

Answer: D. Accurate diagnosis depends on fresh specimens.

Step-by-step solution

Understand the question

Start by understanding the question and the provided options. We need to determine the true statement regarding the collection of cultures for cytomegalovirus.

Review information about cytomegalovirus (CMV)

CMV is a common virus that can infect people of all ages. Infection with CMV is typically harmless and rarely causes health problems. However, it can be dangerous for people with weakened immune systems and for unborn babies. Diagnosis of CMV infection usually involves testing samples from blood, urine, saliva, or tissues.

Analyze each option

A. Stool cultures are preferred for definitive diagnosis. This statement is false. Although CMV can be detected in stool samples, it is not the preferred method for definitive diagnosis. Blood, urine, saliva or tissue samples are more commonly used. B. Pregnant caregivers may obtain cultures. This statement is false. Pregnant women should not handle specimens for CMV testing due to the risk of infection. If a pregnant caregiver must handle a specimen, proper precautions must be taken, including wearing gloves and a mask. C. Collection of one specimen is sufficient. This statement is false. Depending on the type of test, multiple samples may be required for accurate diagnosis. For example, detecting CMV in urine usually requires a series of samples collected over several days. D. Accurate diagnosis depends on fresh specimens. This statement is true. Fresh specimens provide the most accurate results for diagnosing CMV infection. Old or improperly stored specimens may give false negative or false positive results.

Identify the correct statement

After analyzing each option, we can conclude that the correct statement is: D. Accurate diagnosis depends on fresh specimens.

Key concepts

CMV Diagnosis

Cytomegalovirus (CMV) diagnosis is a critical aspect of detecting and managing infections, particularly in individuals with weakened immune systems and pregnant women. CMV is a type of herpesvirus that can cause symptomatic disease in these vulnerable populations. The process of diagnosing CMV typically involves a range of laboratory tests designed to detect the virus or antibodies produced in response to the infection.

Testing for CMV may include methods such as serological tests, which look for CMV-specific antibodies, polymerase chain reaction (PCR) tests, which detect CMV DNA, and antigenemia tests, which detect viral proteins. Diagnosing an active CMV infection often relies on PCR testing due to its high sensitivity and specificity. Timely diagnosis is crucial as it can help in the initiation of appropriate antiviral therapy, potentially reducing the risk of complications such as congenital CMV infections which can lead to birth defects.

Infectious Disease Testing

Infectious disease testing encompasses a broad array of laboratory methods used to detect the presence of pathogenic organisms, such as bacteria, viruses, fungi, or parasites. These tests are paramount for the diagnosis, treatment, and prevention of infections. They vary from simple rapid diagnostic tests, which provide results within minutes to hours, to more complex culture techniques and molecular diagnostic methods that may take days to yield results.

Choosing the appropriate test is vital, with factors such as the suspected infectious agent, the site of infection, and the patient's clinical presentation guiding the selection. For viral infections such as CMV, molecular techniques like PCR have become widely accepted due to their ability to identify the genetic material of the virus swiftly and with high accuracy.

Specimen Collection for Viral Testing

The collection of specimens for viral testing is a precise science, with the accuracy of testing heavily dependent on proper specimen handling. Specific types of samples, such as blood, urine, saliva, or tissue biopsies, are collected based on the virus in question and the body site it typically affects.

For CMV, it is crucial to collect fresh specimens as these are more likely to yield a definitive diagnosis. Additionally, the handling and transport of these specimens must ensure that they remain intact and do not degrade before analysis, as this could affect the test results. Healthcare professionals responsible for specimen collection must adhere to stringent guidelines to protect themselves and to prevent sample contamination, with special considerations for pregnant caregivers due to the risks associated with CMV exposure.