Abstract
<title>Abstract</title> <p>Blood group has been linked to susceptibility, severity and recovery from several infectious diseases, but evidence from South Asian student populations is limited. This study examined whether ABO blood group is associated with self-reported recovery outcomes among university students in the Anuradhapura District, Sri Lanka. A cross-sectional survey was administered, both online and on paper, to 322 students aged 18 years and above with a history of infectious disease within the preceding five years, based on self-report rather than clinical or laboratory confirmation, with no medical records reviewed to verify responses. Data on blood group, recovery duration, symptom severity, symptom progression, relapse, hospitalisation level and perceived influence of blood type on recovery were analysed using χ² tests, a χ² goodness-of-fit test, and one-way analysis of variance. Blood group O was markedly over-represented (62.4%) relative to published Sri Lankan population norms (χ²(3) = 125.490, p < 0.0001, Cohen's w = 0.62). None of the tests linking blood group to symptom severity, recovery time, symptom progression, relapse or hospitalisation reached significance (all p > 0.21, all Cramer's V < 0.12), and analysis of variance showed no significant difference in mean recovery time across blood groups (p = 0.299, η² = 0.011). The findings suggest that, in this sample, ABO blood group is not a statistically reliable predictor of self-reported recovery, and that perceived symptom severity may exert a stronger influence on healthcare-seeking behaviour than blood type itself.</p>