Demographic, risk factors and motivations among blood donors with reactive serologic tests for syphilis in São Paulo, Brazil

Abstract

SUMMARY Objective To identify the demographic characteristics, risk factors and motivations for donating among blood donors with reactive serologic tests for syphilis. Background Post-donation interviews with syphilis seropositive blood donors improve recruitment and screening strategies. Methods This case–control study compares 75 Venereal Disease Research Laboratory (VDRL)> 8, EIA+ (enzyme immunoassay) and FTA-ABS+ (fluorescent treponemal antibody); 80 VDRL−, EIA+ and FTA-ABS+; and 34 VDRL− and EIA− donors between 2004 and 2009. Donors were assessed by their demographic characteristics, sexual behaviour, history of alcohol and illicit drugs use, and motivations to donate. Results Donors with VDRL> 8weremore likely to be divorced [AOR = 12·53; 95% confidence interval (CI) 1·30–120·81], to have had more than six sexual partners (AOR = 7·1; 95% CI 1·12–44·62) and to report male–male-sex in the past 12 months (AOR = 8·18; 95% CI 1·78–37·60). Donors with VDRL−, EIA+ and FTA-ABS+ were less likely to be female (AOR = 0·26; 95% CI 0·07–0·96), more likely to be older (AOR = 10·2; 95% CI 2·45–42·58≥39 and <60 years old) and to have had more than six sexual partners in the past 12 months (AOR = 8·37; 95% CI 1·49–46·91). There was no significant difference among groups regarding illicit drugs use; 30·7% (VDRL> 8) and 12·5% (VDRL−, EIA+ and FTA-ABS+) of donors reported that they had been at risk for HIV infection (P =0·004). One-third of donors came to the blood bank to help a friend or a relative who needed blood. Conclusion Although donors exposed to syphilis reported and recognised some high risk behaviour, most were motivated by direct appeal to donate blood. Monitoring the risk profile of blood donors can benefit public health and improve blood safety.

Detection and analysis of blood donors seropositive for syphilis

“…We identified 35 cases that were negative for syphilis by VDRL but were anti‐ T. pallidum IgM and INNO‐LIA positive. These findings are consistent with a study by Moore et al, who showed that non‐treponemal tests for primary syphilis infection were negative in 30%–50% of infected individuals 12‐17 . They strongly suggest that there remains a risk for transfusion‐transmitted syphilis in those blood banks that exclusively use the VDRL test for syphilis donor screening.…”

“…This would have been of value to provide evidence of the possible presence of intact organisms. This limitation was also reported by Ferreira et al in 2014 12 . Other limitations include the absence of data on the length of syphilis infection and mode of acquisition in positive donors.…”

“…When they returned for assay results, notification and counselling, the donors filled out a questionnaire to assess their risk factors for becoming infected with syphilis and motivations for blood donation. The questions asked included: “In the past 12 months, with how many different people have you had sex?” “Concerning your steady sexual partners, what was the frequency of condom use when you had sex?” and “Have you ever exchanged (given or received) money or drugs to have sex with someone?” Motivations for blood donation were classified as direct appeal, altruism and self‐interest according to a previous publication 12 …”

Evaluation of positive and false‐positive results in syphilis screening of blood donors in Rio de Janeiro, Brazil

“…A study conducted by Ferreira et al . () in São Paulo showed that a reactive treponemal test and negative nontreponemal test profile were more common among older people.…”

Avaliação de marcadores sorológicos treponêmicos e não-treponêmicos em doadores inaptos para sífilis atendidos em um hemocentro brasileiro

“…É muito comum relacionar as infecções sexualmente transmissíveis (IST) às pessoas menos escolarizadas e com menor acesso à informação. No entanto, ressalta-se também a negligência, por parte da população, às ISTs, bem como o uso de métodos para prevenção delas 16 .…”