Epidemiological study on SARS-CoV Ab among volunteer blood donors during SARS epidemic phase and non-SARS epidemic phase in Guangzhou / 中国输血杂志

ABSTRACT

Objective To investigate the situation and distribution of Severe Acute Respiratory Syndrome coronavirus (SARS-CoV) infection in volunteer blood donors during SARS epidemic phase and non-SARS epidemic phase in Guangzhou and provide scientific basis for developing preventive strategies. Methods Blood samples from volunteer donors were tested for SARS-CoV Ab by ELISA,and samples from 31 plasma donors recovered from SARS were tested as control. Donors with positive SARS-CoV Ab were further tested for SARS-CoV RNA by fluorescent polymerase chain reaction. Standardized questionnaires were adopted to conduct investigation by telephone on 20 donors with positive SARS-CoV Ab. Results SARS-CoV Ab was positive in 56 of 6120 volunteer blood donors and in 30 of 31 plasma donors recovered from SARS. The positive rates of SARS-CoV Ab were 0.92% and 96.77% respectively. In volunteer blood donors of SARS epidemic phase and non-SARS epidemic phase, the positive rates of SARS-CoV Ab were 0.91% and 0.92% respectively, and there was no significant difference between them. The mean S/CO and the titer of SARS-CoV Ab were 2.34 and ≤1∶2 respectively in the 56 volunteer blood donors, significantly lower than those of the 30 plasma donors recovered from SARS (S/CO 14.8,titer ≤1∶32). All donors with positive SARS-CoV Ab were negative for SARS-CoV RNA. Telephone consultation of 20 random blood donors with positive SARS-CoV Ab found that they were in good health and had not have close contact with SARS patients. Conclusion There is a low positive rate of SARS-CoV Ab among random blood donors in Guangzhou. Further studies are needed to find out whether those donors have been infected by SARS. It is also possible that those reactions were false positive, which might be caused by cross reactions. It is suggested that the present measures of SARS prevention could ensure blood safety.