title: Survival of Treponema pallidum in banked blood for prevention of Syphilis transmission.
abstract: BACKGROUND
  Every year, millions of people are exposed to avoidable, life-threatening risks through the trans-fusion of unsafe blood.
  
  
  OBJECTIVE
  To determine the survival time of Treponema pallidum in banked donor blood.
  
  
  METHODS
  Two groups of male Wistar rats (group A and B) were inoculated intratesticularly with 0.5ml of artificially infected donor blood (final density of Nichols treponemes: 5×10(5) /ml) stored at 4°C for various periods of time. In group A, a pair each of the rats was injected every 12 hours, starting at 0 hr, up to a maximal storage time of 96 hr. In group B, the rats were injected after 72, 120, 192 and 336 hours of storage of the treponemes-blood mixture. Group C which is a control group was injected with blood only, while group D rats were injected with heat-killed treponemes suspended in blood every 12 hours. The detection of Treponema pallidum IgG/IgM was based on the principle of double antigen sandwich immunoassay, in which purified recombinant antigens are employed sufficiently to identify antibodies to Syphilis. The outcomes of interest included the proportion of Syphilis positive rats and the maximal survival hours of T. pallidum in banked blood.
  
  
  RESULTS
  14 rats (77.8%) out of the 18 rats that were involved in group A developed orchitis and positive serology up to 72 hours of storage time, p<0.05. 2 rats (25%) in group B developed orchitis after 72hrs of storage time. All the 18 rats (100%) in the control group C and D showed neither clinical nor serological changes.
  
  
  CONCLUSIONS
  It was concluded that the survival time of T. pallidum in banked donor blood lies between 72-120hrs in this study. Regardless of blood banking temperature, T. pallidum and other transfusion transmissible infections should be screened for prior to allogeneic transfusion.
authors.affiliation: Department of Hematology and Transfusion Science, University of Benin Teaching Hospital, Benin City, Nigeria.
authors.forename: Adeolu O
authors.initials: AO
authors.lastname: Adegoke
authors.forename: Olufemi E
authors.initials: OE
authors.lastname: Akanni