The purpose of the study is to learn if a blood test is helpful to the doctors in deciding whether you need antibiotic therapy for possible pneumonia. The blood test is called a Procalcitonin level and sometimes the test reflects infection with certain bacteria (germs). When the doctors learn the results of these blood tests, they may be able to stop some of the antibiotic medications that they may have given to the patients. The study is designed, so that on a randomized basis (50/50 chance) the results from measuring Procalcitonin will be given to the patients' doctor. When the doctor receives these results, he/she may use this information, along with other information, to decide whether to continue antibiotic therapy.

To evaluate the usefulness of serum Procalcitonin level measured to guide the antibiotic treatment of patients with radiographic lung infiltrates.The subjects involved in the study will be divided in two arms ,study arm where the caregivers will know the result of Procalcitonin level and they can change /withheld the antibiotic for the subjects.In other arm only investigators will know the Procalcitonin level. We expect to enroll 100 patients.

Inclusion Criteria:

• Adults
• New radiographic findings consistent with the presence of infiltrates
• Antibiotic therapy

Exclusion Criteria:

• Critically ill patients on admission

Adults admitted to Winthrop University Hospital with Lung Infiltrates undergoing antibiotic therapy