Sporadic carriers of human T-cell lymphotropic virus type 1 among blood donors in Egypt

ABSTRACT

Human T-cell lymphotropic virus type 1 [HTLV-1] infected subjects although remain asymptomatic carriers but up to 7% may develop adult T-cell leukemia and chronic inflammatory neurological diseases represented by HTLV-1 associated myelophathy [HAM]/ tropical spastic paraparesis [TSP]. The impact of these diseases on individuals and their communities is often devastating and the prognosis is poor. This study was to assess the current incidence of asymptomatic HTLV-1 infected carriers in a group of Egyptian healthy blood donors to provide information for appropriate policies. The study was conducted on 90 apparently healthy blood donors that were selected from those attending gynecological and obstetric blood bank of Ain-Shams University for blood donations. They were serologically negative to HBs Ag, HCV Ab, and HIV Ab Enzymelinked immunosorbent assay [ELISA] was done to detect the circulating antibodies against HTLV-1 in their plasma. Four out of 90 subjects [4.4%] were serologically positive by ELISA technique. SYBRgreen real time polymerase chain reaction [RT-PCR] was performed for the detection of HTLV-1 proviral DNA in the peripheral blood mononuclear cells [PBMCs] to confirm results of ELISA.One sample out of 90 samples [1.1%] was determined to be positive for HTLV-1 proviral DNA by RTPCR. This sample was also ELISA positive. The positive predictive value of ELISA was 96% and the negative predictive value was 100%. HTLV-1 infection in Egypt showed sporadic carriers at low rate but the assessment of its prevalence is important. ELISA is a sensitive reliable technique for screening blood for HTLV-1 infection and ELISA positive results should be confirmed with PCR. Although SYBR- green RT- PCR has high level of specificity, it is not applicable to all cases due to high cost and is better to be used for confirmation. Epidemiological surveillance is recommended to verify the prevalence and incidence of HTLV-1 infection, so that preventive measures can be taken to decrease the spread and transmission of HTLV-1 in Egypt