If you were to look it up in the dictionary on this site, it says that one means cold and one means flu. under flu it says cold So you could conclude that they were the same thing.

When you use the word gripa it generally refers to the common cold (rhinovirus); whereas, the word gripe is usually used to refer to the flu (influenza). For example:

gripe porcina - swine flu

La gripe porcina es como la gripe regular en que se esparce de la misma manera de persona a persona - The swine flu is like the regular flu in that it is spread from person to person.

The flu comes from a family of viruses called virus gripales (flu viruses)

If you are interested in more information, try checking the CDC (Centers for Disease Control) or WHO (World Health Organization) websites that use only "gripe" to refer to the flu.

This from the RAE

gripa.

1. f. Col. y Méx. gripe.

So this would suggest it is a mexican version of the flu. My Collins dictionary does not list "gripa"

In Mexico "gripa" is used; "gripe" is used in Spain. At least that's my experience.

On Mexican web sites I have seen "la influenza porcina" used for "swine flu".

The right word is "gripe"; if you look up for the word ·"gripa" in an authorized Dictionary of the Spanish Language, you'll notice that the word is not there.

In Spain, at least, we never refer to the "gripe porcina". We call it the "gripe A"

Here in America, the flu is also generally referred to as "influenza A/gripe A." My intention was to provide examples of how the term "gripe" might be used and they were meant to be taken as just that - examples.

However, as to the strain of flu that is making headlines, yes it is influenza type A, but the particular strain is labeled "H1N1" and is popularly referred to as "swine flu/gripe porcina." I think that it might be a bit of a misrepresentation to say that "nobody" in Spain ever refers to it as "gripe porcina" being that the Spanish newspaper El Pais by itself has 296 articles in the last six months where this term is used. El Pais: Gripe Porcina

In the same newspaper there are 537 articles that use the term H1N1 to describe it which is understandable as this is the more specific medical term for the virus. There are also 1664 articles that refer to gripe A. Again, this should be expected as "gripe A" or even just "gripe" is the more general term for "the flu."