Effect of Temperature on Detection of Hepatitis B Surface Antigen by Gingival Swab.

Objective The objective of the study was to determine the effect of two temperature points (27-32 °C and 50 °C) on the detection of Hepatitis B surface antigen (HBsAg) by gingival swab. Method The study was conducted in 2024 in Shaikh Zayed Hospital, Lahore, Pakistan. It was a non-randomized controlled study done over a period of one year. The study included 138 known positive cases of hepatitis B and 138 known negative cases, as validated by serum enzyme-linked immunosorbent assay (ELISA). Patients with mouth ulcers, gum bleeding, or gingivitis were excluded. Two gingival swabs were obtained from each patient. The swabs were kept in phosphate-buffered saline solution at two different temperatures (27-32 °C and 50 °C) for 24 hours. Automated ELISA performed HBsAg detection on both samples from each patient. Results Out of 138 known hepatitis B positive individuals, 108 swabs tested positive for HBsAg at 50 °C and 84 at 27-32 °C. Swabs of all 138 known hepatitis B-negative patients were negative at both 50 °C and 27-32 °C. Conclusion HBsAg is more likely to be detected by swab samples at higher temperatures, and no cold chain is required to transport these swab samples.