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:

A 55 year old patient of COVID-19, with no known comorbidities presented with fever, myalgia and headache and at presentation had leukopenia and thrombocytopenia, however did not have any bleeding manifestations. The patient's inflammatory markers including ferritin and C-reactive protein were elevated at admission. Later in the course of illness went on to develop severe thrombocytosis and leukocytosis. We discuss the course and outcome of illness in an unusual case of COVID-19 with severe and diametrically opposite haematological abnormalities.
["Case Report"]