"Swine flu" also known as H1N1 2009 was first identified in March 2009 when cases began to appear in Mexico and the United States. According to the Centers for Disease Control and Prevention (CDC), as of December 26, 2009, the number of swine flu-related deaths is well above the epidemic threshold. The exact symptoms of swine flu vary from person to person. The most common symptoms are described by prevalence below.
Systemic Systems
Systemic symptoms reflect the burden of infection on the entire body. The single most common symptom of swine flu is fever. According to the "New England Journal of Medicine", 94 percent of infected patients exhibit fever greater than 101.3 degrees Fahrenheit (38 degrees Celsius). Some people including the elderly, those with multiple medical problems and those with compromised immune systems do not exhibit fever, even if they are infected with swine flu. Other systemic symptoms of swine flu include lethargy (92 percent of patients), headache (61 percent) and muscle pain (43 percent.)
Respiratory Symptoms
Swine flu causes both upper respiratory symptoms like sore throat, runny nose and nasal congestion and lower respiratory symptoms like cough and mild breathing problems. According to the ""Journal of Clinical Microbiology and Infection, after fever, cough is the second most common symptom of swine flu, reported by 92 percent of patients. Cough may also be the first symptom of swine flu, often appearing one to two days before the onset of fever, and it is usually the last, with 90 percent of patients reporting resolution within 12 days. The prevalence of other respiratory symptoms are listed in descending order: sore throat (70 percent), runny nose (64 percent), nasal congestion (56 percent) and mild breathing problems (22 percent.)
Gastrointestinal Symptoms
Gastrointestinal symptoms of swine flu include diarrhea, nausea and vomiting are reported in some, but not all people with swine flu. According to the "New England Journal Medicine", among swine flu cases identified between April 15 and May 5, 2009, about 25 percent of people reported diarrhea, vomiting or both. Both symptoms were usually mild and tended to resolve faster than other symptoms of swine flu.
References
- Centers for Disease Control and Prevention Influenza Weekly Report
- New England Journal of Medicine.Emergence of a Novel Swine-Origin Influenza A (H1N1) Virus in Humans. Novel Swine-Origin Influenza A (H1N1) Virus Investigation Team. June 18, 2009.
- Clinical Microbiology and Infections. Dynamics of Clinical Symptoms in a Case with Pandemic Influenza A (H1N1). Lee CS, Lee JH. November 13 2009.
