Tests when donating blood

Most people who are infected with the virus are perfectly well and never have any illness. These diseases are very rare. The infection is found most commonly in people from Japan, the West Indies and parts of the Middle East. The virus is commonly transmitted from mother to child by breast feeding, but is also passed on by sexual contact or by intravenous drug use.

We screen for antibodies against HTLV, and if the test is reactive further tests are performed to confirm the result. Some tests are not performed on every donation.

Extra tests are also done to provide specifically tested blood for particular types of patient. Malaria is caused by parasites which are transmitted by the bites of mosquitoes. The infection causes fever and is a major cause of death in some parts of the world. We test for antibodies to the malaria parasites. A confirmed positive result does not necessarily mean that the individual has active malaria, merely that they have had malaria at some time.

T-cruzi is a parasite called Trypanosoma cruzi , found in certain parts of Central and South America. It is transmitted to humans by biting insects or from mother to baby at the time of birth, or by blood transfusion.

Over many years, the parasite can cause damage to the muscles in the heart and intestines, leading to an illness called Chagas disease. Not all infected people become ill. Our tests look for antibodies to the infection. It can be transmitted by blood transfusion from a donor who has recently been infected. If you have visited an area where WNV is circulating, or tell us that you have previously been diagnosed with the virus, we may test your donation to make sure that your donation is free from any possible infection.

We will inform you if your test shows any sign of infection. Individuals in good health make a full recovery and are usually unaware of the infection. We may test for antibodies against the virus. A positive test indicates that the individual has had CMV infection and may still have the virus. Having antibodies to CMV is of no significance to the health of the donor. However, for patients with a poor immune system bone marrow recipients or small babies , CMV can cause a life-threatening illness.

The per-unit risk of HIV-1 infection through blood transfusion is less than 1 per 2 million units screened. NAT closes the window period between infection and antibody detection for those infected with HIV by about 2 weeks. This leaves an approximate period of 7 to 10 days when an infected donor may not be detected by blood donation screening.

The frequency of detecting HIV-1 in a blood donor is about 1 per 33, donations screened. However, detecting HIV-2 in a blood donor is extremely rare at 1 per 57 million donations, with only 5 such infected donors ever identified since HIV-2 screening began in While HTLV-1 has been associated with neoplastic conditions and various demyelinating disorders, HTLV-2 is not yet proven unequivocally to be of significant clinical concern.

False-positive donors by antibody may be reentered, except those that were confirmed positive by various tests used before the availability of an FDA licensed western blot. Screening for syphilis is performed using a qualitative test that detects the presence of antibodies to the spirochete corkscrew-shaped bacterium , Treponema pallidum , by an automated agglutination assay based on specific pattern recognition. Confirmation is performed using another serologic test for total antibodies, an enzyme-linked immunoassay, as well as a test for reagin a protein-like substance that is present during acute infection and for several months following resolution of infection.

Reagin testing was the first screening method used but was replaced by antibody testing in No cases of transfusion-transmitted syphilis have been recorded in more than 50 years. False-positive donors for syphilis may be reentered. ZIKV, a flavivirus, closely related to dengue viruses, resulted in a pandemic during ZIKV usually causes mild symptoms such as: fever, skin rash, conjunctivitis, muscle and joint pain, or headache. The virus is most commonly transmitted to humans through mosquito bites; but may also be transmitted by sexual contact, laboratory acquisition or blood transfusion.

Investigational NAT in mini-pools of 16 was introduced in June in 5 southeastern states, but as required by FDA, expanded to all US donations first as individual donations and by January in mini-pools using an FDA licensed assay. During the peak of the outbreak in , a rate of 1 per , was obtained all positives with naturally occurring infection had their exposure outside of the US or in Florida ; our last confirmed-positive donation was in March exposure in Cuba.

Any donor sample that is positive with any one of the tests above cannot be used for transfusion purposes and is discarded.

Further testing is carried out to confirm true infection as distinct from a non-specific false reaction. The IBTS also performs selective laboratory tests for certain disease markers on particular donors and these tests include Cytomegalovirus CMV West Nile Virus WNV Our testing systems are highly sensitive and specific for each disease marker even at low concentrations in donor blood samples.

Each donor sample is tested individually. The testing systems are fully automated and compliant with EU regulations to produce accurate, reliable and consistent results. Serology based assays test for viral antibodies in donor blood samples which trigger a positive test reaction. All positive donors are informed if any virus is detected in their donor sample s.

However, donor samples can also test falsely positive for any viral marker. Further testing will be carried out to confirm the presence or absence of true infection in conjunciton with consultation from our medical personnel.

Many improvements have been made in testing methodologies including the addition of testing for a second HIV agent HIV-2 in NAT closes the window period between infection and detection of an antibody for those infected with HIV by about 2 weeks for donations tested individually, significantly reducing the risk of HIV transmission by transfusion.

This leaves approximately 5 to 7 days when an infected donor may not be detected by blood screening. NAT closes the window period between infection and detection of an antibody for those infected with HCV by about 3 weeks. All HCV positive donors are informed if the virus is detected in their donor sample. This leaves aporoximately 16 days when an infected donor may not be detected by blood screening.

All HBV positive donors are informed if the virus is detected in their donor sample. Normally HEV infection will clear in the body by itself and the donor will be feeling fine, with no symptoms to report at clinics. However, patients with a suppressed immune system e. Transfusion-associated circulatory overload occurs when the volume of blood or blood components are transfused cannot be effectively processed by the recipient.

TACO can occur due to an excessively high infusion rate or volume or due to an underlying heart or kidney condition. Symptoms may include difficulty breathing, cough, and fluid in the lungs. Transfusion-related acute lung injury is a serious but rare reaction that occurs when fluid builds up in the lungs, but is not related to excessive volume of blood or blood products transfused.

Symptoms include acute respiratory distress with no other explanation for lung injury such as pneumonia or trauma occurring within 6 hours of transfusion. The mechanism of TRALI is not well understood, but is thought to be associated with the presence of antibodies in donor blood. Transfusion-associated graft vs. Symptoms include fever, a characteristic rash, enlargement of the liver, and diarrhea that occur between 2 days and 6 weeks post transfusion.

Though very rare, this inflammatory response is difficult to treat and often results in death. A transfusion-transmitted infection occurs when a bacterium, parasite, virus, or other potential pathogen is transmitted in donated blood to the transfusion recipient.

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