title: A probable case of hepatitis B virus transfusion transmission revealed after a 13-month-long window period.
abstract: BACKGROUND
  Transfusion-transmitted hepatitis B virus (HBV) infection in recipients with drug-related immunodeficiency is rarely described in endemic areas. Hepatitis B surface antigen (HBsAg)-negative infectious donor blood can be identified by sensitive nucleic acid testing (NAT). Two immunodeficient patients who received blood components from a single seronegative blood donor subsequently found to contain HBV DNA are described.
  
  
  METHODS
  Multiple samples from the implicated donor and the two recipients were tested for HBV serologic and molecular markers. HBV genome fragments were amplified, sequenced, and phylogenetically analyzed.
  
  
  RESULTS
  The implicated donation had low-level HBV DNA due to the donor being in the window period before the donor's seroconversion. Recipient 1 had been vaccinated to HBV and carried anti-HBs but remained negative for all other HBV markers until she developed acute hepatitis B (viral load 2.7 x 10(8) IU/mL and alanine aminotransferase [ALT] level 1744 IU/L) 13 months after transfusion of red cells. Identical HBV sequences from both donor and recipient provided evidence of transfusion-related infection. Recipient 2, who received platelets from the same donation while receiving major chemotherapy, remained uninfected.
  
  
  CONCLUSIONS
  In unusual circumstances, HBV incubation time can be considerably prolonged. Both active and passive neutralizing antibodies to HBV likely delayed, but did not prevent, acute infection when the immune system was impaired. HBV NAT may have interdicted the infectious unit, although the donation viral load could not be quantified and odds of detection calculated.
authors.affiliation: Blood Bank, Hospital Sirio Libanês, São Paulo, Brazil. snwendel@uninet.com.br
authors.forename: Silvano
authors.initials: S
authors.lastname: Wendel
authors.forename: José E
authors.initials: JE
authors.lastname: Levi
authors.forename: Silvana
authors.initials: S
authors.lastname: Biagini
authors.forename: Daniel
authors.initials: D
authors.lastname: Candotti
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Allain
mesh_terms: D000208:Acute Disease; D001782:Blood Donors; D002648:Child; D004279:DNA, Viral / Q000097:blood; D005260:Female; D006509:Hepatitis B / Q000209:etiology* / Q000635:transmission*; D006515:Hepatitis B virus / Q000235:genetics / Q000302:isolation & purification*; D006801:Humans; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000628:therapy*; D013997:Time Factors; D065227:Transfusion Reaction
chemical_list: D004279:DNA, Viral