By Odewoye Yetunde Theresa
Every unit of blood donated has the potential to save a life. However, if the blood is infected and not properly screened, it can also transmit diseases such as hepatitis B to the person receiving it. This is why proper surveillance in the blood bank is very important. Medical laboratory scientists play a major role in this process because they are involved in the testing, interpretation of results, quality control, and proper handling of blood and blood samples.
WHY HEPATITIS B IS A THREAT IN BLOOD TRANSFUSION
Hepatitis B is a viral infection that affects the liver. It can be transmitted through infected blood and other body fluids. When blood from an infected donor is transfused into another person, there is a risk of transmitting the virus.
This is why every donated blood unit has to be properly screened before it is released for transfusion. A person who receives infected blood may not develop symptoms immediately. In some cases, the infection can become chronic and may eventually lead to serious complications such as liver cirrhosis and liver cancer.
Blood banks face certain challenges that can affect the safety of donated blood. Some of these include:
The window period:
A recently infected donor may test negative because the markers being tested for have not yet reached detectable levels. This period is one of the challenges associated with screening donated blood.
Human error:
Errors can occur during sample collection, labeling, testing, documentation, or recording of results. A mistake at any of these stages can affect the safety of the blood supply.
Limited resources:
Some blood banks may have challenges with adequate testing kits, equipment, trained personnel, or quality-control systems. These challenges can affect the effectiveness of surveillance.
When these problems are not properly controlled, there is an increased risk that infected blood could be released for transfusion. This can have serious consequences for the patient and can also affect public confidence in the blood transfusion system.
WHAT BLOOD BANK SURVEILLANCE MEANS
Blood bank surveillance involves monitoring the safety of donated blood from the time the donor is assessed until the blood is either released for use or removed from circulation. The main purpose is to identify possible risks, detect infections, prevent errors, and ensure that only suitable blood is available for transfusion. Three important areas involved in this process are screening, tracking, and quality control.
- Screening: The First Step
Before blood is collected, the donor is assessed to determine whether they are suitable to donate. This may involve questions about the donor’s health history, previous illnesses, medications, and possible risk factors. The donated blood is then tested for transfusion-transmissible infections, including hepatitis B. Proper screening is important because it provides an early opportunity to identify blood that may not be safe for transfusion.
2. Tracking Every Blood Unit
Every donated blood unit should have proper identification and documentation. Information such as the donation number, blood group, date of collection, test results, and expiry date should be recorded. Proper documentation makes it easier to trace a blood unit if a problem is discovered later. For example, if a test result is found to be unreliable or a safety concern is raised, the blood bank should be able to identify the affected unit and determine whether it has already been released or transfused. Therefore, record keeping is not just an administrative responsibility. It is also an important part of transfusion safety.
3. Quality Control
Quality control is another important part of blood bank surveillance. Testing equipment, reagents, and laboratory procedures need to be monitored to ensure that they are working properly. Medical laboratory scientists also need to follow standard procedures and participate in quality assurance activities. Staff training is important as well because even a good testing system can be affected by poor technique or incorrect procedures. The main question is whether the laboratory can depend on the result before making a decision about the blood unit. Reliable results are essential because the decision to release or discard a unit can directly affect a patient’s safety.
ROLES OF MEDICAL LABORATORY SCIENTISTS IN TRANSFUSION SAFETY
Medical laboratory scientists have an important responsibility in maintaining the safety of the blood supply. Their work in the blood bank is not limited to carrying out tests. They are also involved in interpreting results, maintaining quality standards, investigating problems, and ensuring that unsuitable blood is not released.
1. Performing and Validating Laboratory Tests
Medical laboratory scientists are involved in the screening of donated blood for transfusion-transmissible infections such as hepatitis B. Depending on the laboratory and the resources available, different testing methods may be used. These can include rapid tests, Enzyme-linked Immunosorbent Assay (ELISA), other immunoassays, and nucleic acid testing (NAT) where available. They also monitor reagents, equipment, and testing procedures to help ensure that the results obtained are reliable.
2. Interpreting and Investigating Results
A reactive screening result does not necessarily mean that the result should immediately be treated as a final diagnosis. The result has to be interpreted according to the laboratory’s testing procedure or algorithm. Where necessary, further or repeat testing may be carried out. Medical laboratory scientists therefore have to pay attention to results and investigate unusual or questionable findings before a decision is made about a blood unit. This helps reduce the risk of releasing infected blood while also preventing suitable donations from being discarded unnecessarily.
3. Ensuring That Unsafe Blood Is Not Released
When a blood unit is found to be unsuitable, it should not be released for transfusion. Medical laboratory scientists are involved in ensuring that such units are properly identified, documented, and handled according to established blood bank procedures. The appropriate information must also be recorded so that the unit can be traced if necessary.
4. Training and Monitoring Laboratory Practice
Medical laboratory scientists also contribute to staff training and quality assurance. Proper specimen collection, identification, labeling, handling, testing, and documentation are all important in reducing errors. They may also participate in internal quality control, audits, and other activities aimed at identifying weaknesses in the laboratory system. Although patients may not see most of this work, it contributes directly to their safety. Every correctly performed test and every properly investigated result helps reduce the possibility of an unsafe blood transfusion.
WHEN SURVEILLANCE FAILS
When blood bank surveillance is not properly carried out, the consequences can be serious. Blood that has not been adequately tested or a reactive result that is incorrectly cleared could expose a patient to a transfusion-transmissible infection such as hepatitis B. The effects may not be noticed immediately because hepatitis B infection can sometimes remain without obvious symptoms for a period of time. In some individuals, infection may become chronic and cause serious liver complications. The problem also affects the blood bank and the healthcare system. For this reason, blood safety surveillance should be continuous and properly documented. Every stage matters, from donor selection and sample collection to testing, documentation, quality control, and final release of the blood unit.
In conclusion, safe blood transfusion depends on careful screening, proper documentation, reliable laboratory testing, and good quality-control practices. Hepatitis B remains an important concern because it can be transmitted through infected blood, making effective surveillance necessary in every blood bank.
Medical laboratory scientists play a major role in maintaining this safety. Through testing, interpretation of results, quality control, documentation, and proper handling of unsuitable blood, they help reduce the risk of transfusion-transmitted infections. A safe blood supply does not happen by chance. It depends on the consistent work of healthcare professionals who follow proper procedures and take every test result seriously. For the medical laboratory scientist, even a decision to withhold one blood unit can be an important step in protecting a patient’s life.