Salmonella in humans is contagious to other humans and when you have salmonella infection then you can spread the infection from several days to several weeks after you've been infected.
So make sure to avoid people who do have salmonella and if you have salmonella try to avoid other people if possible for at least a month after the infection.
When the salmonella infection is no longer infecting you then you will not be contagious anymore.
But be cautious and if you do not have salmonella but someone else you know has salmonella infection then avoid the person if possible.
It's not worth the risk of possibly getting infected yourself.
Also stay home from work if you have salmonella and if it's a kid have them stay home from school until they are not longer contagious with the salmonella.