Clinical features of COVID-19 rapid antigen test exposures reported by an Australian poisons information centre: a prospective study

Abstract

Introduction

Coronavirus disease COVID-19 rapid antigen tests are a useful tool in detecting infection, and their use has increased in many countries since they became commercially available in late 2021. Some rapid antigen tests contain sodium azide, which can be toxic in small doses. This study aimed to describe the clinical characteristics of exposures to COVID-19 rapid antigen tests.

Methods

This is a prospective study conducted by the New South Wales Poisons Information Centre. From 22 January 2022 to 31 August 2022, rapid antigen test exposures were followed up to obtain outcome information. Data collected included: brand/ingredients, exposure route, demographics, symptoms, and disposition.

Results

We recorded 218 exposures in the seven-month study period. Complete follow-up information was available in 75% (n = 164). There were 53 exposures to sodium azide-containing products (35 with follow-up data) and 165 to non-sodium azide-containing products and unknown ingredient exposures (129 with follow-up data). Overall, unintentional exposures predominated (n = 182), and 151 were ingestions. The vast majority (>90%) did not develop symptoms, and all symptoms that developed were mild. Most cases (95%, n = 208) did not require referral to a healthcare facility.

Conclusions

In this prospective series, few patients developed symptoms, regardless of the sodium azide content, likely due to low concentration and low volume within the test kits. However, ongoing toxicovigilance is warranted.

Keywords:

• COVID-19
• rapid antigen test
• sodium azide
• poisoning
• poisons information centre

Acknowledgement

The authors thank Simon Gilmore (National Poisons Register, Royal Prince Alfred Hospital, NSW), Elizabeth Nguyen, Genevieve Adamo, Darren Roberts and all staff of the New South Wales Poisons Information Centre.

Ethical approval

This study was approved by the Sydney Children’s Hospitals Network Human Research Ethics Committee (Ref: 2021/ETH00165).

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

RC is supported by an NHMRC Investigator Grant (ID: 1196516).