Surveillance of human retroviruses in blood samples from patients with hepatitis B and C in São Paulo, Brazil

Abstract

Introduction: Human retroviruses and the hepatitis B and C viruses (HBV and HCV, respectively) share routes of transmission; thus, coinfections occur and could alter subsequent disease outcomes. A preliminary study on human T-lymphotropic virus types 1 and 2 (HTLV-1/2) in serum samples from HBV-and HCV-infected individuals in São Paulo revealed 1.3% and 5.3% rates of coinfection, respectively. These percentages were of concern since they were detected in HTLV-endemic regions and in high-risk individuals in Brazil. The present study was conducted to extend and confirm these data. Methods: HTLV-1/2 and human immunodeficiency virus (HIV) infection status were identified in 1,984 sera for HBV and HCV viral load quantification -1,290 samples from HBV-infected individuals (53.3% men, mean age: 47.1 years) and 694 samples from HCV-infected individuals (56.3% men, mean age: 50.1 years). HTLV-1/2 antibodies were detected by enzyme immunoassay, followed by western blotting and line immunoassay; HIV infection was detected by enzyme immunoassay. Results: HTLV-1/-2 infection was detected in 1.9% HBV-infected individuals (0.7% HTLV-1 and 1.2% HTLV-2) and in 4.0% (2.4% HTLV-1 and 1.6% HTLV-2) HCV-infected individuals; HIV infection was detected in 9.2% and 14.5%, respectively. Strong associations with HTLV and HIV, male sex, and older age were found in HBV/HTLV and HCV/HTLVcoinfected individuals (p<0.05). Conclusions: HTLV-1 and HTLV-2 were confirmed to be prevalent in individuals with HBV and HCV in São Paulo; coinfected individuals deserve further clinical and laboratory investigation.

Pooling of sera for human T-cell lymphotropic virus (HTLV) screening in a time of increasing health care expenditure and limited resources

“…After validating the five-sample pool using EIA Murex, the technique was employed for individual cost comparison in 2,625 serum samples previously screened, of which the final HTLV confirmatory results were published elsewhere: 1,300 from patients with hepatitis B, 700 with hepatitis C, and 625 with HIV/AIDS 19,20 . The results from individual and pooled samples confirmed the diagnostic sensitivity (100%) and specificity (100%) of the pooling (Cohen's Kappa = 1.0), and a cost minimization of 70.4%, 60.7% and 73.6% in these populations (Figure 3), depending on Murex and Gold ELISA assays according to the manufacturer's instructions; *Serum sample dilution in blood donor bags negative for all blood-borne infectious agents; OD/CO = optical density-to-cut off ratio; H = high reactive sample by EIA; L = low reactive sample by EIA.…”

“…In bold, the highest serum dilutions without loss of reactivity in low reactive samples. the prevalence of HTLV-1/2 (1.9% in HBV, 4.0% in HCV, and 1.1% in patients with HIV/AIDS) 19,20 . Briefly, the 1,330 HBV positive serum samples were grouped into 260 pools; HTLV-1/2 screening disclosed 25 HTLV-positive pools.…”

“…Briefly, the 1,330 HBV positive serum samples were grouped into 260 pools; HTLV-1/2 screening disclosed 25 HTLV-positive pools. When the sera that composed these 25 pools were analyzed separately (n=125), one pool had two positive samples; the same 26 samples were detected in individual analysis 20 . A cost minimization of 70.4% would have been achieved if this strategy had been employed (total of 385 reactions instead of 1,330 reactions, Figure 3A).…”

“…A cost minimization of 70.4% would have been achieved if this strategy had been employed (total of 385 reactions instead of 1,330 reactions, Figure 3A). The same calculation was employed in HCV: the 700 HCV positive serum samples were grouped in 140 pools; 27 were positive by EIA, and when the sera that formed the 27 positive pools were analyzed individually, two pools presented two positive samples; the same samples were detected in previous individual analysis 20 . For calculating the cost minimization, 140 reactions tested in pool plus 135 tested individually, totaling 275 reactions instead of 700 reactions, with a cost minimization of 60.7% ( Figure 3B).…”

“…Finally, for calculating the diagnostic sensitivity and specificity and the cost minimization of the HTLV-1/2 screening using individual samples and pooled samples, 2,000 serum/plasma samples from patients with viral hepatitis B and C and 625 plasma samples from patients with HIV/AIDS that had been individually screened using the same EIA, of which the results had been published elsewhere 19,20 , were employed. The cost minimization in percentage was calculated considering the value in American dollars (U$ 1.5 per reaction) in the EIA acquired in 2019.…”