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

## TL;DR

This study found that higher temperatures improve detection of Hepatitis B surface antigen in swab samples, eliminating the need for cold storage.

## Contribution

The study demonstrates that HBsAg detection via gingival swabs is more effective at 50°C than at room temperature.

## Key findings

- 108 out of 138 HBsAg-positive samples were detected at 50°C, compared to 84 at 27-32°C.
- All HBsAg-negative samples remained negative at both temperatures.
- Higher temperature swab storage improves antigen detection without requiring cold chain transport.

## Abstract

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.