Infection risk in patients increases by 1 percent each day of hospitalization, a new research reveals.

Researchers from the Medical University of South Carolina examined 949 documented cases of Gram-negative infection at their academic medical center. This study is the first to quantify the risks for patients over time.

The team noted that in the first few days of hospitalization the percentage of infections from Gram-negative bacteria (a multidrug-resistant one) was around 20 percent and the rate constantly went up as days passed and reached 35 percent at 10 days.

Researchers stated that the infections developed in hospitals represent a large and possibly preventable segment of hospital-related deaths. These infections are on the rise year by year. According to one European study, Gram-negative infections comprise of two thirds of the 25,000 hospital-acquired infection deaths each year.

Statistics released by Centers for Disease Control and Prevention in 2011 show that around 722,000 hospital-acquired infections resulted in 75,000 deaths. "Our findings emphasize one of the risks of being in the hospital, acquiring a multidrug-resistant infection" study author John Bosso said in the news release. "At the very least, this observation argues against both unnecessary hospitalization and unnecessarily long hospitalization."

The study was presented recently at the 54th Interscience Conference on Antimicrobial Agents and Chemotherapy.