You are presented with a paragraph from a COVID-19 literature. Classify the topics of this piece of text by choosing from the following categories:

- Epidemic Forecasting: The content relates to predictions about the spread of COVID-19.
- Treatment: The paragraph discusses therapeutic methods or medication for COVID-19.
- Prevention: The content covers measures to prevent the spread of COVID-19.
- Mechanism: The paragraph explains the biological mechanisms of the virus.
- Case Report: The content is a report of a COVID-19 case.
- Transmission: The paragraph discusses how COVID-19 is transmitted.
- Diagnosis: The content is about diagnosing COVID-19 in individuals.

Your classification should be provided as an element within a JSON array. The array should be formatted with topics enclosed in double quotes and separated by commas, following the JSON format, for example: ["Topic1", "Topic2", ...]. Include all applicable topics within the array. Your output should be a valid JSON array, and no additional text should be included in your response.

Article:

Oropharyngeal and nasopharyngeal specimens collected by swabbing are the pillars of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) diagnostics. Commercially available rapid antigen tests and self-sampling polymerase chain reaction services have made specimen collection available anytime and anywhere in nonmedical settings. In this study, we report the case of a 45-year-old man who accidentally ingested a swab during self-performed SARS-CoV-2 rapid antigen testing. Imaging studies revealed an elongated foreign body in the stomach. Urgent gastroscopy confirmed the presence of the swabbing applicator in the gastric lumen, which was retrieved using a loop without any complications. Millions of SARS-CoV-2 tests are performed daily, of which an increasing proportion are performed by laypeople. Foreign bodies account for a particular set of complications, which can be avoided by cautious sampling and using the correct technique. Radiopaque labeling of instruments would be useful. Otherwise, rare serious events can occur that may require immediate medical interventions.
["Case Report"]