An estimate of the number of human immunodeficiency virus (HIV)-positive blood donations by HIV-seronegative donors in a Northern Thailand HIV epicenter

Pathom Sawanpanyalert, Hideki Yanai, Somporn Kitsuwannakul, Kenrad Edwin Nelson

Research output: Contribution to journalArticle


Despite mandatory antibody testing, human immunodeficiency virus (HIV) can be transmitted from HIV-infected blood that is seronegative. The objective of this study was to estimate the probability of HIV-infected blood donations during the seronegative 'window period' in a northern Thailand HIV epicenter. Thus, a retrospective cohort of repeat blood donors was created. With the assumptions that the probability of HIV seroconversion is distributed uniformly between the last HIV-negative and the first HIV- positive donation and that the seronegative window is 45 days, the rate of window-period donations was calculated by multiplying the incidence by the window duration. Of 11,232 repeat donors, 273 seroconverted daring 9,518,863 person-days of observation (i.e., a window-period donation rate of 1/775). There were more window-period donations among 21- to 30-year-old men and in donors replacing blood of friends or relatives. Additional measures are needed to reduce the high number of HIV-infected window-period donations.

Original languageEnglish (US)
Pages (from-to)870-873
Number of pages4
JournalJournal of Infectious Diseases
Issue number4
Publication statusPublished - 1996
Externally publishedYes


ASJC Scopus subject areas

  • Public Health, Environmental and Occupational Health
  • Immunology

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