above and whether results are recommended prospectively. “Prospective results” in the context of organ donation refers to results that are made available prior to the transplantation of organs (as opposed to prior to organ retrieval). Test results that are not recommended to be made available prospectively should be obtained as early as possible, but transplantation may proceed prior to results being available. April 2021 version 1.5 11 Table 2.1: Recommended laboratory investigations for the detection of potentially transmissible infectious diseases in solid organ donors. a While HTLV-1/2 screening is recommended for all donors, donors at high risk of HTLV-1 include Aboriginal people from Central Australia and persons born in southwestern Japan, sub-Saharan Africa, the Middle East, the Caribbean, and parts of South America (French Guyana, Peru). Screening is recommended for all donors since information in the donor record might not identify all persons at high risk and outcomes in the rare event of transmission can be extremely severe or fatal. See Section 2.3.2.9. 2.2.5 Haemodilution assessment Where the donor receives multiple blood transfusions or significant infusions of intravenous fluids prior to donation, haemodilution may occur such that circulating antigens, antibodies and targets for NAT are at a low concentration that is difficult to detect, introducing the potential for false negative results. False positive results may also occur due to interactions between serological tests and molecules present as a result of infused products. The degree to which a potential donor’s plasma has been diluted is a product of blood loss as well as fluids infused. Test Recommended for all donors Recommended for specified donors Comments Serology and nucleic acid testing (NAT): HIV Ag/Ab (positive results confirmed with anti-HIV-1/2). X Results should be available prior to transplantation proceeding HBsAg, HBcAb and anti-HBs X Results should be available prior to transplantation proceeding anti-HCV X Results should be available prior to transplantation proceeding HIV/HBV/HCV NAT X Prospective NAT is required wherever this is logistically feasible, and is strongly advised for increased-risk donors (see Table 2.2 for definition of increased-risk donors). If results are not available in a timely manner transplantation may proceed at the discretion of the transplant team and with appropriate recipient consent. anti-CMV (IgG) X Prospective results are preferable where possible anti-EBV (IgG) X Prospective results are preferable where possible anti-T.pallidum (IgG) X Prospective results are preferable where possible anti-T.gondii (IgG) X No urgency on test results Anti-HTLV-1/2 Xa Prospective results are preferable where possible Coronavirus (SARSCoV-2) X Prospective results are preferable where possible. In a suspected case of COVID-19, only proceed to donation once a negative NAT result is received. If it is not possible to obtain COVID-19 NAT results, do not proceed in a suspected case. Where COVID-19 is not suspected, donation can proceed without prospective NAT results being available. Microbiological testing Urine microscopy and culture X Microbiological testing should be performed on all donors for whom a urine sample can be obtained, with results of urine culture and sensitivity testing to be followed up as they become available (post transplantation) Blood culture X Recommended where there is clinical suspicion of bacteraemia Respiratory culture X Respiratory tract samples for microbiological testing should be collected for lung donors or if respiratory infection is suspected April 2021 version 1.5 12 Serological tests and NAT have not been validated for use on all haemodiluted samples, and therefore serological screening and NAT should ideally be performed on non-diluted blood samples. For all donors, blood products and colloids given in the 48 hours piror to the date and time the sample was drawn are entered into the EDR (Australia) or Confidential Donor Referral (New Zealand). This information is used to autocalculate whether the sample is haemodiluted. If either plasma dilution or blood dilution exceed defined thresholds, a pre-transfusion/ infusion sample should be used for donor screening. If a suitable sample is not available, the risk of false negative results from testing a haemodiluted sample should be communicated to the transplanting teams. 2.2.6 Special donor groups Donors under 18 months or breastfed children Microbiological screening for neonatal and infant donors (of less than 18 months old, or up to 6 months beyond breast feeding) should be performed as for other donors, including HIV/HBV/HCV NAT, taking into account that positive antibody results may reflect passive transfer of antibodies from the mother. The potential for eclipse/ window period infections should also be considered, and prospective NAT is recommended in this context. Given the limited volume of blood that can be taken from a neonate or infant for the purposes of screening and the likelihood of haemodilution, complementary testing of the mother is required in these cases. If the mother is not at increased-risk of infectious diseases (see Table 2.2) and is sero-negative for markers of infection, the successful screening of the neonate/infant is less critical. Discussion with an infectious diseases physician or microbiologist is