Papers

Incidence of transfusion associated B and non-A, non-B hepatitis in Italy

BMJ 1995; 311 doi: https://doi.org/10.1136/bmj.311.7009.846 (Published 30 September 1995) Cite this as: BMJ 1995;311:846
  1. Alfonso Mele, research epidemiologista,
  2. Tommaso Stroffolini, research epidemiologista,
  3. Raffaele Catapano, postgraduate trainerb,
  4. Filippo Palumbo, epidemiologistc,
  5. Angela Moiraghi, professord,
  6. Francesca Novaco, epidemiologiste
  1. a Laboratorio di Epidemiologia e Biostatistica, Istituto Superiore di Sanita, 00161 Rome, Italy
  2. b Dipartimento di Sanita Pubblica, II Universita di Roma, Rome
  3. c Assessorato alla Sanita, Regione Campania, Naples
  4. d Dipartimento di Sanita Pubblica, Universita di Torino, Turin
  5. e Assessorato alla Sanita, Regione Emilia Romagna, Bologna
  1. Correspondence to: Dr Stroffolini.
  • Accepted 2 June 1995

Screening of donated blood for hepatitis B surface antigen and for serum alanine aminotransferase concerntration has been performed in Italy since the early 1970s. Screening for other surrogate markers, such as antilbody to hepatitis B core antigen has never been done. Screening for antibodies to hepatitis C virus was routinely done in a few blood banks since 1990; it became compulsory in 1991. Second generation enzyme linked immunosorbent assay (ELISA) was introduced in 1992 in all blood banks.

Using data from the surveillance system for acute viral hepatitis (SEIEVA), we have evaluated the incidence of transfusion associated B and non-A, non-B hepatitis in Italy from 1987 to 1993.

Methods

and results

SEIEVA, which is coordinated by the Istituto Superiore di Sanita in collaboration with health districts, started in 1985.1 From 1985 to 1993 the number of health districts participating in SEIEVA has greatly increased, in 1992 covering about 40% of the Italian population. SEIEVA uses weekly notification of cases and a standard questionnaire for data collection on risk factors.

Patients with acute hepatitis with hepatitis B surface antigen and IgM antibodies to hepatitis B core antigen, without antibodies to hepatitis A, are classified as having hepatitis B. Those without IgM antibodies to hepatitis B core antigen and without IgM antibodies to hepatitis A are classified as having non-A, non-B hepatitis. Tests for IgM antibodies to hepatitis B core antigen have been available since 1987. Assays of hepatitis markers are performed in different laboratories scattered all over the country. No changes were made in the notification system during the study period.

Using as denominators the catchment populations of the participating health districts, incidence rates per 1000000 of notified cases of transfusion associated hepatitis decreased from 1.4 in 1987 to 0.5 in 1992 for hepatitis B and from 4.4 in 1987 to 0.3 in 1992 for non-A, non-B hepatitis. Although for hepatitis B the incidence increased from 1992 to 1993, the 95% confidence intervals for these periods overlapped. For non-A, non-B hepatitis the low 1992 rate remained virtually unchanged in 1993. Compared with 1989, the incidence of cases of non-A, non-B hepatitis reporting blood transfusion decreased from 4.1 per 1000000 in 1989 to 2.9 in 1990 (−29%), when screening with first generation ELISA (ELISA-I) was routinely done in a few blood banks, to 1.4 in 1991 (−66%) when this screening became compulsory, and to 0.3 (−93%) in 1992, after ELISA-II was introduced.

Incidence rates per 1000000 of notified cases of hepatitis B and non-A, non-B with history of blood transfusion in Italy 1986-93

View this table:

Comment

Our findings show a small residual risk of transfusion associated hepatitis B and indicate the effectiveness of the screening policy for antibodies to hepatitis C virus in reducing the incidence of cases of non-A, non-B hepatitis after blood transfusion.

Because the viral surface antigen may be present in the serum at a low concentration or may be masked in immune complexes, it has been shown2 that blood donors testing negative for hepatitis B surface antigen may transmit hepatitis B virus infection.2 Transfusion with “HBsAg negative” blood is thus a potential source of infection.

Cohort studies from Japan3 and the USA4 have documented decreases of 60 to 80% in the incidence of post-transfusional non-A, non-B hepatitis after the implementation of donor screening for antibodies to hepatitis C virus by ELISA-I in addition to, or at the same time as, screening for surrogate markers. A recent report from Spain has shown that for antibodies to hepatitis C virus testing by ELISA-II further reduces the incidence of non-A, non-B hepatitis by 57% when compared with ELISA-I.5 Although information obtained through passive surveillance is likely to be less accurate than data from these cohort studies, we found similar decreases after starting donor screening policies for antibodies to hepatitis C virus in Italy (−66% and −93% after introduction of ELISA-I and ELISA-II, respectively). These findings suggest that, although non-notified or asymptomatic blood associated cases of non-A, non-B hepatitis may still occur, in Italy the current risk is likely to be very low.

Footnotes

  • Funding This study was partially supported by Regione Campania, Assessorato alla Sanita, Italy.

  • Conflict of interest None.

References

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