<unk>  is a nonspecific respiratory<unk>  characterized by fever, fatigue, cough, and other symptoms that stop within a few days. Most cases of<unk>  are caused not by<unk>  but by other viruses (e.g., rhinoviruses, coronaviruses, human respiratory syncytial virus, adenoviruses, and human parainfluenza viruses). Less common causes of<unk>  include bacteria such as Legionella, Chlamydia pneumoniae, Mycoplasma pneumoniae, and Streptococcus pneumoniae.<unk> , RSV, and certain bacterial infections are particularly important causes of<unk>  because these infections can lead to serious complications requiring hospitalization. Physicians who examine persons with<unk>  can use a combination of epidemiologic and clinical data (information about recent other patients and the individual patient) and, if necessary, laboratory and radiographic tests to determine the cause of the<unk> . The use of multiplexed point-of-care testing such as CRP (C-reactive protein) along with an examination by a doctor may help to identify a bacterial and avoid an unnecessary antibiotic prescription. During the 2009 flu pandemic, many thousands of cases of<unk>  were reported in the media as suspected swine flu. Most were false alarms. A differential diagnosis of probable swine flu requires not only symptoms but also a high likelihood of swine flu due to the person's recent history. During the 2009 flu pandemic in the United States, the CDC advised physicians to "consider swine<unk>  infection in the differential diagnosis of patients with acute febrile respiratory<unk>  who have either been in contact with persons with confirmed swine flu, or who were in one of the five U.S. states that have reported swine flu cases or in Mexico during the 7 days preceding their<unk>  onset." A diagnosis of confirmed swine flu required laboratory testing of a respiratory sample (a simple nose and throat swab). In rare cases If a person with<unk>  also has either a history of exposure or an occupational or environmental risk of exposure to Bacillus anthracis (anthrax), then a differential diagnosis requires distinguishing between<unk>  and anthrax. Other rare causes of<unk>  include leukemia and metal fume fever.
Influenza-like illness
Anaphylaxis
Intermittent fever
Asymptomatic
Proteus-like syndrome
Bilious fever
Morning sickness
Fever of unknown origin