Please select the eligibility criteria that correspond to the clinical trial below.
Title: Antibiotics in Patients With Acute Respiratory Tract Infections in Primary Care in Consideration of Procalcitonin as Additive Parameter
Brief Summary: Antibiotics in patients with acute respiratory tract infections in primary care in consideration of procalcitonin as additive parameter.

The purpose of this study is to compare the ordinary manner of antibiotic- prescription with the prescription in consideration of procalcitonin-value in patients with acute respiratory tract infections.


Options:
A: 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).
B: Inclusion Criteria:

* suspected lower respiratory tract infection
* must be able to give consent

Exclusion Criteria:

* age under 18 years
* not able to give consent
* admitted not primarily because of the respiratory tract infection
* hospital acquired infections
C: Inclusion Criteria:

* 18 years or older
* Informed consent
* Respiratory tract infection based on the clinical judgement of the primary care physician

Exclusion Criteria:

* Antibiotic pretreatment in previous 14 days
* 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
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: C