Just to make the structure absolutely clear, let's make the following substitutions...
nabbing a disease hotspot = A
epidemic control = B
locking up a serial perpetrator = X
crime investigation = Y
After substitution, we see that OP's two different structures are...
1: What A is to B is X to Y
2: What A is to B is what X is to Y
...from which it should be obvious that #1 isn't actually idiomatic1 - even with single-letter placeholders for the 4 elements being compared and contrasted. But although #2 is idiomatically acceptable in that shortened form, the syntactic relationships are a bit confusing when some or all of A, B, X, Y are relatively "extended" noun phrases.
To make that relationship clearer with longer texts, it would be better to expand on the second instance of the word is (which plays a completely different role to the first and last instances)...
2a: What A is to B
is corresponds to what X is Y
2b: What A is to B is the same as what X is Y
...both of which mean...
A relates to B in the same way that X relates to Y
1 The "idiomatic" way to draw a parallel between the A:B and X:Y relationships - or at least, the standard "formal, academic" phrasing - is...
A is to B as X is to Y