Sure, you can display the summarized field as a string. When you created the crosstab, the default summary function is count()
which is what you're seeing. Instead, go into your crosstab, select your summarized field, and hit the 'Change Summary' button. Instead of count you can use minimum or maximum (interchangeably, since I'm guessing that you will ever only have on entry for each row/column combination).
Once that change has been made, "5,1" will display for HCC and "5" will display for Legionella on Feb 14, and all other summarized fields will be null.