Transfusion-Transmitted Dengue and Associated Clinical Symptoms During the 2012 Epidemic in Brazil

Abstract

Background: A linked donor-recipient study was conducted during epidemics in 2 cities in Brazil to investigate transfusion-transmitted (TT) dengue virus (DENV) by DENV RNA-positive donations.

Methods: During February-June 2012, samples were collected from donors and recipients and retrospectively tested for DENV RNA by transcription-mediated amplification. Recipient chart review, using a case (DENV positive)-control (DENV negative and not known to be exposed) design, was conducted to assess symptoms.

Results: Of 39 134 recruited blood donors, DENV-4 viremia was confirmed in 0.51% of donations from subjects in Rio de Janeiro and 0.80% of subjects in Recife. Overall, 42 DENV RNA-positive units were transfused into 35 recipients. Of these, 16 RNA-positive units transfused into 16 susceptible recipients were identified as informative: 5 cases were considered probable TT cases, 1 possible TT case, and 10 nontransmissions. The TT rate was 37.5% (95% confidence interval [CI], 15.2%-64.6%), significantly higher than the viremia rate of 0.93% (95% CI, .11%-3.34%) in nonexposed recipients (P < .0001). Chart review did not find significant differences between cases and controls in symptoms or mortality.

Conclusions: During a large epidemic of DENV-4 infection in Brazil, >0.5% of donations were RNA positive, and approximately one third of components resulted in TT. However, no significant clinical differences were evident between RNA-positive and RNA-negative recipients.

Keywords: NAT; clinical symptoms; dengue; transfusion-transmission.

Figure 1.

Flow chart defining blood donor and recipient dengue virus (DENV) RNA testing results and selection of subjects for analysis of clinical manifestations. Abbreviations: −, negative; +, positive; D, donor; R, recipient; TMA, transcription-mediated amplification assay.

Figure 2.

Time to occurrence of symptoms consistent with dengue fever. Symptoms status for case and control patients during the 45-day chart review period. A, Comparison of all cases, defined as persons receiving a dengue virus (DENV) RNA–positive unit and/or who tested positive for DENV RNA, to controls. B, Comparison of cases, separated into 3 groups based on whether a patient tested positive for DENV RNA and/or was exposed to a DENV RNA–positive unit, to controls. The number of subjects at risk for each group and at each time point of interest are listed at the bottom of the graphs. The number at risk at each specific time point is the number of remaining subjects after all of the events and censoring (time of loss-to-follow-up in the medical chart and indicated with by + sign in each plot) have been accounted for. Abbreviations: −, negative; +, positive; D, donor; R, recipient.

Figure 3.

Survival status for case and control patients during the 45-day chart review period. A, Comparison of all cases, defined as persons receiving a dengue virus (DENV) RNA–positive unit and/or who tested positive for DENV RNA, to controls. B, Comparison of cases, separated into 3 groups based on whether a patient tested positive for DENV RNA and/or was exposed to a DENV RNA–positive unit, to controls. The number of subjects at risk for each group and at each time point of interest are listed at the bottom of the graphs. The number at risk at each specific time point is the number of remaining subjects after all of the events and censoring (time of loss-to-follow-up in the medical chart and indicated with by + sign in each plot) have been accounted for. Abbreviations: −, negative; +, positive; D, donor; R, recipient.