Transfusion Transmissible infections are an important limiting factor in transfusion services1,2. It is the responsibility of blood transfusion services to provide a safe and sufficient supply of blood and blood products to all patients who require a transfusion. More viruses such as HIV, Hepatitis B, Hepatitis C, CMV, EBV, WNV have a significant effect on blood transfusion services. In Sri Lanka, hundred percentage of the donated blood received from voluntary non-remunerated donors. Before the blood donation, each blood donor will counsel and examine by a medical officer and pre-check will be done by PHI. All donated blood samples will screen for HIV, hepatitis B and hepatitis C, syphilis and malaria. Our national blood center has a strict quality control system which works in association with international laboratories to confirm high standards. Sri Lankan blood donors have lower Transfusion-transmissible infection rates when compare with other countries in the region. Hepatitis B virus (HBV) remains a major risk of transfusion-transmitted infections due to window period, infection with mutant viruses and occult transmission of HBV infection. Reduction of residual risk on HBV depends on the development of more sensitive HBV surface antigen (HBsAg) tests, and HBV nucleic acid tests (NAT). Despite significant improvements in blood donation screening, hepatitis B virus infection (HBV) remains a major risk for transfusion-mediated viral infection. The residual risk of transfusion-transmitted infection is the highest for HBV compared to hepatitis C or HIV, mainly because HBV screening is based solely on hepatitis B surface antigen. The detection of HBs antigen in the serum indicates an infection caused by the hepatitis B virus. It is the first marker that appears and can be observed two or three weeks before the clinical and biological symptoms of the disease. The period of presence can be very short or very long. If HBs antigen persists for more than 6 months in the serum indicates chronic hepatitis. Due to the existence of numerous asymptomatic chronic carriers, hepatitis B represents an important risk of transfusion and the prevention of transmission is based on the detection of the HBs antigen at the time of each blood donation. The Monolisa HBs Ag ULTRA assay is a qualitative one-step “sandwich” enzyme immunoassay for the detection of hepatitis B virus surface antigen (HBs Ag) in human serum or plasma. This test method is currently using by both MRI and NBTS.
hepatitis C virus (HCV) is an enveloped RNA virus that belongs to the family of
flavivirids, of which six major genotypes were identified. HCV is recognized as
the main cause of non-A and non-B viral hepatitis. HCV infection is
characterized by an acute and chronic condition that can lead to cirrhosis and
evidence of HCV infection can be found through blood tests to detect HCV
antigens and / or antibodies and / or RNA. Compared to a test for anti-HCV
antibodies alone, the use of a combined screening test for both anti-HCV
antibodies and for HCV capsid antigen can reduce the serological window period
and improve the detection of the infection.
HCV Ag-Ab ULTRA is a qualitative enzyme immunoassay for the detection of
infection by the hepatitis C virus (HCV) based on the detection of anti-HCV
antibodies and antigen in human serum or plasma. This hepatitis C screening
test is using by both MRI and NBTS. At NBTS there are significant number of
donors permanently defer from the system due to repeat reactive of Hepatitis B and
Hepatitis C screening test monthly because NBTS doesn’t have a conform test facility.
there for repeat reactive donors second samples are sending to the MRI for
further conformation by ELISA and PCR method recently. NBTS faces difficulties
to trace all repeat reactive donors specially donors with
significantly high OD values for hepatitis B & C screening tests due to several reasons. we don’t have a proper
system to trace conform positive Hepatitis B and Hepatitis C donors like HIV
conform positive cases traceable system. NBTS need to
postulate new strategies to improve the traceability and follow up of blood
donors who become positive for hepatitis B & C screening tests.
There is a significant different between MRI and NBTS ELISA test result even though both institutions are using same Monolisa test kits.