Swine flu is the common name for the H1N1 influenza strain first identified in March 2009. According to the World Health Organization, the swine flu officially became a pandemic with laboratory-confirmed cases identified in more than 200 countries and implicated in more than 12,000 deaths in 2009 alone. Although the spectrum of swine flu disease varies from person to person, some symptoms seem to last longer than others.
Lower Respiratory Symptoms
Lower respiratory symptoms of swine flu include cough and breathing problems. According to a 2009 article in the New England Journal of Medicine, cough was the second-most common symptom of swine flu, present in 92 percent of people. In 10 percent of people, cough associated with swine flu persisted longer than 12 days. In five percent of people, it was still present after 15 days.
In uncomplicated swine flu, breathing problems can persist for up to seven days in 90 percent of people. However, this statistic is somewhat misleading, because the overall rate of breathing problems in uncomplicated swine flu is low--approximately 22 percent--and the presence of breathing problems is often a marker for complications of swine flu such as pneumonia. People at high risk for respiratory complications of swine flu include infants, the elderly, people with medical problems--especially preexisting respiratory disease--and disabled people.
Upper Respiratory Symptoms
Upper respiratory symptoms of swine flu include sore throat, runny nose and nasal congestion. These symptoms typically appear after the onset of fever and lower respiratory symptoms. According to a 2009 article in the Journal of Clinical Microbiology and Infections, they are often also among the most persistent symptoms of swine flu. In 90 percent of patients, sore throat took up to eight days to resolve, even in people treated with Tamiflu (oseltamivir.) Runny nose and congestion resolved slightly faster at seven and six days, respectively.
Muscle Pain and Headache
Systemic symptoms of swine flu include fever, muscle pain and headache. In healthy adults, fever typically peaks within two to three days of onset and resolves shortly thereafter. According to a 2009 article in the Journal of Clinical Microbiology and Infections, muscle pain and headache usually peak in severity with fever but take much longer to resolve completely. More than 10 percent of patients complain of persistent symptoms after eight days. In five percent, symptoms are still present after 10 days.
References
- World Health Organization Pandemic Flu
- 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); C.S. Lee and J. H. Lee; November 13 2009
