Hawaii is a vacation destination for millions of people. Are the locals at a greater risk for vulnerability to disease transmission?

Many people think warmer regions or weather nullify some diseases (colds, flu, etc.).  In reality, these diseases are just as prevalent in July and August as they are in December and January.  They are also just as prevalent in warmer regions as in colder ones.  These types of diseases are best spread through by human contact or through the air.  In winter months people are gathered inside (warmth, holiday shopping, etc.).  The closer people are to each other, the easier it is for these diseases to spread (germs love warm, moist environments).  People are also more sedentary in the winter months.  When its cold or raining/snowing, or dark, people tend to stay inside.  Less exercise can lower the body's immunity system.  In the summer months, the weather's warm so people are more apt to go outside and move around, thus having less direct contact with others. (less direct contact less chance for the disease to spread.)  Ever notice that the flu season starts just after school starts?  All those kids jammed together in small classrooms.  One 'Achoo!' and off go the germs.
Some people head to warmer regions in order to escape these diseases.  Yet the germs are already there, plus people take the germs with them.  While people may not be sick (or even get sick), they are always carriers of these germs.  The more people there are, the greater the chance for a germ to spread.  The fewer people, the less the chance.