How to extract columns in which their name containing the word "chronic" from CSV file

I have a big csv file ( around 1000 columns ) and I want to extract to a new file only columns that contain the word "chronic" in their header name. How can I do that ? For example if I have:

gender,chronic_disease1,chronic_disease2
male,2008,2009

The desired output is:

chronic_disease1,chronic_disease2
2008,2009

Note: the column/field separators is comma ",". if there was no chronic match then no output at all.