Please select the eligibility criteria that correspond to the clinical trial below.
Title: Comparative Study of C-reactive Protein vs. Procalcitonin to Guide Antibiotic Therapy in Patients With Severe Sepsis and Septic Shock Admitted to the Intensive Care Unit.
Brief Summary: In this study the investigators aim to test if C-reactive protein (CRP)or procalcitonin(PCT) - guided strategy allows to reduce the antibiotic use in patients wiht severe sepsis and septic shock. Therefore, the safety of this intervention will be carefully measured.


Options:
A: Inclusion Criteria:

* age \> 17 years
* patients in intensive care unit
* signed informed consent
* suspected or confirmed severe sepsis or septic shock

Exclusion Criteria:

* Infections caused by Listeria spp, Legionella pneumophilia, Mycobacterium tuberculosis
* Bacteremia due S. aureus
* Infections requiring prolonged therapies, such as endocarditis, cerebral abscess, chronic osteomyelitis
* Suspected or confirmed infection caused by virus, parasites
* Infections caused by P. aeruginosa ou A. baumannii
* Severe immunosuppression (ex: AIDS, post bone-marrow transplant,cystic fibrosis)
* Traumatism latest five days
* Surgery latest 5 days
* Carcinoid tumor, lung cancer, medullary thyroid cancer
B: Inclusion Criteria:

1. Patients 18 years of age or older, admitted from the community or a nursing home with acute (i.e., at least 1 day but less than 28 days) LRTI as the main diagnosis consisting of having at least two of the following:

   * new or increased respiratory signs or symptoms (i.e., cough, sputum production, dyspnea, auscultatory findings of abnormal breath sounds and rales, pleuritic chest pain) with or without inflammatory signs (core body temperature \> 38.0° C, leukocyte count \> 10 or \< 4 x 10\^9 cells L-1).
   * CAP is defined by the presence of LRTI along with a new or increased infiltrate on chest radiograph. Severity scores of CAP (pneumonia severity index \[PSI\] and CURB-65) will be calculated.
   * COPD is defined by post-bronchodilator spirometric criteria according to the GOLD-guidelines as a FEV1/FVC ratio below 70% and the severity categorized into mild (FEV1 \<= 80% of predicted), moderate (50% \>= FEV1 \< 80%), severe (30% \>= FEV1 \< 50%) and very severe (FEV1 \< 30%), respectively. Severity of acute exacerbations of COPD will be graded as proposed. Acute bronchitis is defined as LRTI in the absence of an underlying lung disease or focal chest signs and infiltrates on chest X-ray, respectively. Patients who are on admission judged as having an LRTI but have another final diagnosis, will be classified as "others".
2. Ability to understand verbal and written instructions and informed consent.

Exclusion Criteria:

1. Patients unable to give written informed consent, e.g. with severe dementia or patients not understanding German (or other local language) and no translation (e.g. family members) available.
2. Patients with active intravenous drug use.
3. Severe immunosuppression (e.g. patients infected with human immunodeficiency virus infection and a CD4 count below 350 x 10\^9/L, patients on immunosuppressive therapy after solid organ transplantation and neutropenic patients with present neutrophil count \< 500 x 10\^9/L and patients under chemotherapy with neutrophils 500-1000 x 10\^9/L with an expected decrease to values \< 500 x 10\^9/L); patients with cystic fibrosis, infection with M. tuberculosis, L. pneumophila, Listeria spp. hospital stay within 14 days of inclusion.
4. Accompanying chronic (e.g. osteomyelitis), abscess (e.g. brain, pleural empyema) infection or endocarditis.
5. Terminal and very severe medical co-morbidity where death is imminent or has to be expected in the current hospitalization (e.g. due to malignancy, cardiac, renal or hepatic failure, comfort therapy).
C: Inclusion Criteria:

1. Patients with clinically suspected or microbiologically confirmed bacterial sepsis
2. Informed consent

Exclusion Criteria:

1. Patients with microbiologically documented infections caused by the following microorganisms: Listeria spp, Legionella pneumophilia, Mycobacterium tuberculosis, Staphylococcus aureus
2. Patients with fungal infections
3. Patients with severe infections due to viruses or parasites (e.g. hemorrhagic fever, malaria)
4. Patients with suspected or confirmed bacterial meningitis or endocarditis
5. Patients with localized, deep-seated abscesses (e.g. brain abscess) without systemic sepsis
6. Patients with chronic, localized infections (e.g. chronic osteomyelitis) without systemic sepsis
7. Neutropenic and other severely immuno-compromised patients (patients infected with human immunodeficiency virus and a CD4 count \< 200; patients on immuno-suppressive therapy after solid organ transplantation; patients with cystic fibrosis)
8. Withholding of life-support
9. Early discharge or death (\< 24 hours after admission)
10. Complete absence of antimicrobial treatment despite suspicion of sepsis
D: Inclusion Criteria:

* written informed consent
* all types of respiratory tract infection according to investigator´s diagnosis

Exclusion Criteria:

* pretreatment with antibiotics in the past 2 weeks
* portal hypertension
* Major surgeries or multiple trauma which require hospitalization, in previous 4 weeks
* Autoimmune disease and systemic diseases (lupus erythematodes, wegener´s disease)
* Peritoneal dialysis
* Acute treated or recently operated medullary c-cell-carcinoma, SCLC, carcinoid
* Other inflammatory diseases (e.g. urinary tract infection, pyelonephritis, pancreatitis

Answer: A