Death and destruction. There are those who leave it in their wake.

Ever wondered why things seem to go "wrong" when a solid co-worker shows up on the scene? Turns out there are certain types of person who may cause those problems without even knowing.

1. Some know what they are doing. They use "whatever it takes" to get ahead or to ensure that their programs are the ones that move forward.

The good news about them - yes there is good news - is that sooner or later they tip their hands. At that point, others in the organization start to see them for what they are: single minded and prepared to win at the expense of others.

When busted, they usually profess their company loyalty of course. But they've been shown for who they are -they won't be able to screw you / the company over in the same way again.

These are the easy ones to deal with.

2. But others don't know what they're doing. Consequently, the trail of damage they create can be far more harmful. These people are well intentioned. They care about the organization and, in most cases; they really want it to succeed. Which is why their actions can be so damaging.

Call them the "Typhoid Marys" of corporate life.

Who was Typhoid Mary?
Her real name was Mary Mallon. She was the first person in the United States identified as a healthy carrier of the pathogen associated with typhoid fever. She lived in New York working as a cook during the early part of the 1900s. She infected 53 people with the deadly disease.

Authorities took a long time to make the connection; it wasn't until they recognized that wherever she was working, people got sick. Some died. Because she wasn't outwardly sick, she may have never considered that she was responsible for transmitting the illness.

Whether she did or not, when confronted she denied that she had anything to do with the spread of the death and destruction. Ultimately she was forced to live in quarantine until she died herself. A post-mortem showed that she was the carrier.

Watch out for your organization's Typhoid Mary. Most organizations have them. They'll appear to be caring. You may hear them making suggestions to fix problems which have started popping up.

And they'll be the last to admit they have had a hand in anything that's going south.