Case-Control Study of Risk Factors for Syphilis Among Blood Donors in Sao Paulo, Brazil

Abstract

Background/Case Studies: Syphilis is considered as a major public health problems in Brazil. To determine the risk factors associated with syphilis serological status among blood donors. Study Design/Methods: At Fundação Pro-Sangue, a cross section study was conducted from 2005 to 2008. At time of counseling, donors that were repeat reactive at screening for Syphilis, were invited to answer a questionnaire related to risk behavior and donor motivation. Donors were classifi ed according to their serological results into three groups: a) recent infection (EIA+, VDRL+ and FTA-abs+); b) previous infection or serological scar (EIA+, FTA-abs +, VDRL−) and c) false positive test result (EIA + at screening but EIA − and VDRL − at retest). Results/Findings: Recent syphilis infection was associated with younger age, single, lower education level and higher number of sexual partners in the past 12 months (Table). There was no statistical difference among groups regarding illicit drugs use, except. From the total, 30.7% of cases considered they had been in risk for HIV infection in the last 12 months compared to 12.5% of donors with past infection and 9.1% of false-positive results group (p = 0.004). Conclusion: Recent syphilis is still closely related to the number of sexual partners and male-male-sex among blood donors. Illicit drug use was not linked with the epidemiology of the infection in this population. Donors exposed to syphilis also referred risk exposition to HIV since both disease share the sexual transmission route. To monitor the profi le of syphilis among blood donors can help to treat and to prevent this infection and can add further benefi ts for Public Health. Disclosure of Commercial Conflict of Interest C. S. Alencar: Nothing to disclose; C. de Almeida-Neto: Nothing to disclose; C. Di-Lorenzo-Oliveira: No Answer; J. E. Ferreira: Nothing to disclose; S. C. Ferreira: Nothing to disclose; J. E. Levi: Nothing to disclose; A. Mendrone: Nothing to disclose; A. S. Nishiya: Nothing to disclose; E. C. Sabino: Nothing to disclose; N. A. Salles: Nothing to disclose Disclosure of Grants Conflict of Interest C. S. Alencar: Nothing to disclose; C. de Almeida-Neto: Nothing to disclose; C. Di-Lorenzo-Oliveira: No Answer; J. E. Ferreira: Nothing to disclose; S. C. Ferreira: Nothing to disclose; J. E. Levi: Greiner Bio One, Grants or Research Support; A. Mendrone: Nothing to disclose; A. S. Nishiya: Nothing to disclose; E. C. Sabino: Nothing to disclose; N. A. Salles: Nothing to disclose Demographics and sexual behavior among blood donors Recent syphilis N (%) Past syphilis N (%) False-positive N (%) Gender p = 0.189 Male 58 (77.3) 52 (65) 26 (76.5) Female 17 (22.7) 28 (35) 8 (23.5) Age (years) p < 0.0001 < 39 35 (46.7) 4 (5) 12 (35.3) ≥ 39 < 60 38 (50.7) 67 (83.8) 20 (58.8) ≥ 60 2 (2.6) 9 (11.2) 2 (5.9) Education p < 0.0001 < 8 years 15 (20) 50 (62.5) 10 (29.4) Completed 8 Years 17 (22.7) 12 (15) 5 (14.7) 11 years 36 (38) 13 (16.2) 15 (44.1) College/above 7 (9.3) 5 (6.3) 4 (11.8) Marital status p = 0.004 Single 31 (41.3) 14 (17.5) 9 (26.5) Married 26 (34.7) 55 (65) 21 (61.8) Divorced 12 (16) 9 (11.3) 1 (2.9) Other 18 (24) 14 (17.6) 4 (11.7) N sexual partners (last 12 months) p = 0.021 0-1 37 (49.3) 59 (73.7) 33 (97.1) 2-5 32 (42.7) 18 (22.5) 1 (2.9) >5 6 (8) 3 (3.8) 0 (0)