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:

The total number of COVID-19 positive cases in Latvia has escalated rapidly since October 2020, peaking in late December 2020 and early January 2021. Children generally develop COVID-19 more mildly than adults; however, it can be complicated by multisystem inflammatory syndrome in children (MIS-C). This case study aims were to assess demographic characteristics and the underlying medical conditions, and clinical, investigative and treatment data among 13 MIS-C patients using electronic medical records. All 13 had acute illness or contact with someone who was COVID-19 positive two to six weeks before MIS-C onset. Only five of the 13 were symptomatic during the acute COVID-19 phase. The median age was 8.8 years; 11/13 patients were male, 10/13 had been previously healthy, and all 13 patients tested positive for SARS-CoV-2 by RT-PCR or antibody testing. The most commonly involved organ systems were the gastrointestinal (13/13), hematologic (13/13), cardiovascular (13/13), skin and mucosa (13/13), and respiratory (12/13) ones. The median hospital stay was 13 (interquartile range, 11 to 18) days; 7/13 patients received intensive care, 6/13 oxygen support, and 5/13 received inotropic support. No deaths occurred. During the current pandemic, every child with a fever should have a clearly defined epidemiological history of COVID-19, a careful clinical assessment of possible multiple organ-system involvement, with a special focus on children with severe abdominal pain and/or skin and mucocutaneous lesions.
["Diagnosis", "Treatment"]