Residual transfusion risk for hepatitis B and C in southern Brazil, 1991–99

Abstract

A retrospective study of 139 188 blood donor records for the period 1991–99 was conducted in the largest blood bank in the federal state of Santa Catarina, in southern Brazil. The incidence/window method, based on 11 286 repeat donors with 8917 person‐years of follow‐up, was used to estimate the residual risk for transfusing hepatitis B and C due to infectious window periods for early, mid and late years of the decade. The residual risk for transfusing HBsAg contaminated blood decreased almost three times over the 1990 decade but still remains very high at 1 : 2077 (95% confidence limits 1 : 1075–1 : 4624), with a corresponding incidence of 3.00 (1.35–5.77) per 1000 person‐years. Similarly, although residual risk for hepatitis C was reduced more than 30 times in late 1990s, compared with the earlier period, the risk of 1 : 13721 (1 : 7102–1 : 30820) and corresponding incidence of 0.51 (0.23–0.99) per 1000 person‐years are still very high compared to developed countries. In addition to vaccination against hepatitis B and health promotion efforts aimed at reduction of hepatitis transmission, special measures such as PCR screening of pooled blood donations might be needed to rapidly achieve a further residual risk reduction in high prevalence areas.

Changes in the prevalence, incidence and residual risk for HIV and hepatitis C virus in Southern Brazilian blood donors since the implementation of NAT screening

“…An HIV residual risk of 2.51 per 100,000 per year observed in HEMOSC between 2007 and 2013 is close to the value of 2 per 100,000 per year reported at the turn of the century in the Florianópolis metropolitan area 5,7 and in the City of Lages 9 but lower than the 3.82 estimated for the entire State 1 . The data compiled from the blood banks of São Paulo, Belo Horizonte and Recife during the 2007-2008 period produced an HIV residual risk of 1.13 per 100,000 and projected its reduction by a factor of 1.66 when using six-sample minipools and an immunologic window duration of nine days, or by a factor of 2.69 when using individual NAT screening and a window period of 5.6 days 10 .…”

“…The quantifi cation of residual risk is an important part of blood safety policies worldwide 2 . In Brazil, the methodology of residual risk estimation had been disseminated in the Portuguese language by the end of the 1990s 3,4 and has been sporadically applied in the country since then 1,[5][6][7][8][9][10] . The results of these studies showed high prevalence, incidence and residual risk in Brazil compared with the United States of America (USA), Europe, Japan and Australia, thus reinforcing the need to monitor these parameters in a systematic way and to use them to evaluate the effectiveness of transfusion safety measures.…”

Residual Risk of Hepatitis-B-Infected Blood Donations: Estimation Methods and Perspectives

“…As the countries that have initiated universal child vaccination against HBV did so a decade or two ago, the influx of the vaccinated blood donors has only started to reduce the HBV residual risk very slowly due to the vast majority of unvaccinated donors. Targeting blood donors with HBV vaccine has been recommended to increase the blood safety in such situation [74,99], and a study showed that its costeffectiveness may be as high as introducing HBV ID NAT in a low-prevalence country such as Germany (Ringwald 2005) [35]. In moderate-to-high prevalence countries, the costeffectiveness is bound to lean even more towards enhancing the targeted vaccination strategy.…”

“…The first didactic introduction of the incidence/window-period model and the residual risk calculation appeared in 1998 [73], followed by a report on significant risk reduction in Santa Catarina state during the 1990 decade [74]. Nevertheless, the HBV incidence was approximately 300 per 100.000 personyears and corresponding residual risk close to 1 : 14.000, based on the standalone HBsAg method [63].…”

Efetividade das vacinas anti-VHB (DNA-recombinante) em doadores de sangue de uma região endêmica para hepatite B no sul do Brasil

“…Durante esse mesmo período, a prevalência do anti-HBc também reduziu de 8,8% para 5,3%. Contudo, apesar dos grandes avanços promovidos na seleção dos doadores e na testagem sorológica, o risco residual da transmissão do VHB através de transfusões sangüíneas na capital catarinense foi superior a 1:2.077 doações no final da década de 1990, devido principalmente a elevada incidência do vírus VHB de 3 (1,35-5,77) por 1.000 pessoas-ano em doadores de sangue de repetição 10 . A melhor forma de prevenção contra a infecção pelo VHB é a vacinação 18 .…”