Let me pitch you a setting: The year is 2017, and some suicidal scientist (let's call him Shintaro) decides that humans shouldn't be able to feel emotions.
So he designs a disease that strips humans of their ability to feel emotions (they can still feel anger). Now the only thing left to do is to choose an area to begin an outbreak.
My question is... What would be the best place to start an outbreak of a pathogen (within the USA)?
It depends a slight bit on exactly how the disease is spread and how the symptoms show up; if it's not easily spread and if the symptoms show too early and too specific, then people will go into isolation and, thus, prevent a pandemic catastrophe. I will assume that it's airborne and that one becomes contagious well before any strong symptoms set in (i.e., it should start by looking like a common cold with just some minor coughing and sneezing to be unnoticed). One extra important aspect is that one need to become contagious almost immediately, otherwise it won't really matter where you start as people will get sick, but leave the major area before they pass it on; if it becomes contagious slowly, then it's extra important that it goes unnoticed for a long time so it can spread to as many as possible.
If it does spread almost immediately (i.e., withing minutes to few hours), then anywhere with a lot of people gathered is the best place to go:
If it takes days before one becomes contagious, then it's best to give it to a few, select, persons he knows are going to travel through major airports and to infect well enough ahead them so that they are coughing viruses on everyone they meet. Kindergartens would work well too, but the other places mentioned will likely not work as well as people will be there too short time to make a major spread. If you are on a major event, then you might only meet a few dozen people close enough to spread anything to them, they will get sick but the rest of the people there will not catch the disease; it is also likely that among those dozen people, the infectious person will know most of them (one usually does go to even with friends, after all) and thus the spread will be localized.
The first-grade classroom of the schools used by the UN ambassador families in New York City. You just need to get it to one kid. Their immune systems don't do enough at that age, they have poor hygiene, and no personal boundaries yet. They all take it home to their respective families, which spread both around the world and in the dense city of New York.
One of the most awesome/scary moments an adult can have is being mobbed by a class of first-graders who love you and want to say thanks. You've made 20+ kids really happy, which feels great, but in the back of your mind, you're calculating how much sick leave you've accumulated.
Shintaro only has deposit his infectious agent in the toilets and lifts of public buildings. For those in more benighted countries, this means public bathrooms (where there no actual baths) and elevators.
He should choose public places like transport hubs (railways, airports, bus stations, subway trains, etc), hotels, clubs, food outlets, sports facilities, theatres, supermarkets, and essentially any public place where people gather in confined spaces. Hospitals, for example, could be a good place too. Prisons too, but access is restricted.
More depends on the nature of the infectious agent. For example, it can be spread by contact like SARS or by expired air for respiratory diseases like and influenza and again SARS. This will determine how the disease is spread through the population, and how the initial outcome needs to be triggered.
