The taintedblood Timeline - what really happened...
Fifth Disease (Erythema Infectiosum)
Fifth disease is a mild rash illness with a red, patchy, "slapped cheek" rash on the face. The rash may appear on other parts of the body, such as arms, torso, buttocks, and thighs. Other symptoms such as fever, headache, body ache, sore throat, congestion, runny nose, cough, nausea, or diarrhoea may come before the rash.
Parvovirus B19 can lead to a seronegative arthritis and joint pains in adults and possibly in children.
Foetal Anaemia in Pregnancy
"Parvovirus infection in pregnant women is associated with hydrops fetalis due to severe foetal anaemia, sometimes leading to miscarriage or stillbirth. The risk of foetal loss is about 10% if infection occurs before week 20 of pregnancy and especially between weeks 14-20, but is minimal after then. This risk may be reduced with correct diagnosis of the anaemia (by ultrasound scans) and treatment (by blood transfusions). Once the baby is born, there is evidence to suggest no developmental abnormalities due to B19 infection during pregnancy."
Chronic Anaemia in the Immunocompromised
In people with a compromised immune system, the B19 parvovirus can manifest clinically as chronic anaemia or pure red cell aplasia.
Type: Research Development
Surprisingly, in discussion, there was no agreement as to the degree of risk B19 posed in fractionated blood products. It was stated that although Parvovirus B19 could be eliminated, that effective testing could only be done on single donations and not on pools.
Detection of Parvovirus B19 in Blood Products:
In an Edinburgh study conducted over 3 months, the DNA of Parvovirus B19 "was detected in two-thirds (18 out of 27) separate batches of non heat-treated factor VIII and IX concentrate manufactured from plasma donations unscreened for B19 DNA."
"Dry heat treatment of 8O°C for 72 hours reduced but did NOT always eliminate detectable B19 from factor VIII concentrates, consistent with recent observations that current methods of viral inactivation during blood product manufacture are insufficient to entirely eliminate B19 infectivity." (see 2nd source below, page 3 of PDF.)
There is convincing serological evidence for transmission of B19 by non-heat treated factor VIII and prothrombin complex concentrates. In one study, serological testing of haemophiliacs found elevated rates of Parvovirus B19 infection in recipients of dry or steam-treated Factor VIII.
"The frequency of PCR-positive donations detected in the above study (1/3300 donations) indicates that B19 might frequently contaminate blood products where pools of 3,000-10,000 plasma donations are used as raw material in the manufacturing process."
NOTE: It is horrifying to learn that another pathogen, Parvovirus B19, made its way into our factor concentrates in the 1980s and early 1990s. We pose the question: How many people with bleeding disorders were exposed to Parvovirus in this period?
Type: Guidance Note
The test, manufactured by MedImmune Inc./ Biotrin International, is an enzyme immunoassay which works by detecting the B19 virus IgM antibodies in human serum and plasma. The test will be helpful in diagnosing and managing parvovirus B19 infection.
The test is expected to be available commercially in the U.S. by 2001.
Type: First Diagnostic Test - Parvovirus B19
"Parvovirus B19 is difficult to inactivate, as it is resistant to many of the current inactivation techniques." Inactivation of the virus in coagulation factors by pasteurisation or heat treatment is only partly effective, or not effective at all. Filtration requires an extremely small pore size, and such filters have not been practical for blood products.
New inactivation techniques are in development. "Testing of plasma mini-pools and pools by NAT for parvovirus B19 DNA in order to reduce virus load on the manufacturing process can diminish product contamination and complement other safety measures."
"Virally inactivated pooled FFP is subjected to a single virus reduction step. Two viruses (hepatitis A and parvovirus) are not susceptible to this form of inactivation. It is also possible that a new virus could appear that is not susceptible to the inactivation treatment and could spread to those transfused via the pooling of many donations."
Type: Written Hansard
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