Enrollment goal could not be met.

The purpose of this study is to determine the feasibility of identifying novel etiologic agents associated with SARI in patients who have required intubation and in whom, after analysis, a causative agent was not identified by standard microbiologic (culture) and multiplex real-time Polymerase Chain Reaction (PCR) platforms. Taking into account that isolation of any pathogens is generally time sensitive, the study will evaluate subjects that are culture negative at the time of consent. Not all subjects will actually prove to be culture negative. Additionally, the study will compare etiologic agents identified on broncho-alveolar lavage (BAL) to etiologic agents identified by routine upper airway testing on all subjects with SARI.

Inclusion Criteria:

• Age ≥ 18 years;
• Willing to provide informed consent; or a legal representative is willing to sign informed consent;
• Intubated due to an independent clinical decision by a clinician responsible for the patient's clinical care and NOT affiliated with the research);
• Meet WHO's SARI definition (modified) - all of the criteria below:
• History of fever, subjective feverishness or measured fever of ≥ 38.0 °C, or hypothermia as defined for Systemic Inflammatory Response Syndrome (SIRS) (<36.0 °C );
• Cough or other respiratory symptoms, such as rapidly progressing dyspnea;
• Onset within the last 21 days (as long as the clinical condition is considered acute and due to the severity it requires intubation); and
• Requiring hospitalization

Exclusion Criteria:

• Intubated for reasons other than SARI (cardiovascular accident, surgery);
• Known microbiologic diagnosis of SARI or respiratory illness:
• Any contraindication to BAL by bronchoscopy as determined by the treating physician
• Bacterial culture or other microbiologic testing for underlying etiology positive would be excluded;
• In women: Pregnancy

Subjects will be selected from hospitalized patients who seek medical care due to SARI at the participating sites of LaRed Network, and who meet inclusion criteria and do not meet any exclusion criteria. For those who accept participation, either personally or through a Legally Authorized Representative (per all applicable legal and regulatory requirements complying with the sites regulations) the study will be explained and informed consent will be obtained. The study population will not include children. Pregnant women are not eligible.

IPD will be shared at the end of the study, by establishing collaborations with LaRed. Initial contact would occur through the principle investigators.