Influenza
Summary
Influenza is an acute respiratory illness caused by infection with influenza viruses. Outbreaks and epidemics of illness of variable extent occur within the scope of the world.
Although influenza is an acute, self-limited illness, it causes primary influenza viral pneumonia in some patients. Primary influenza viral pneumonia is the most severe of the pneumonic compliactions. In more advanced cases, could die with acute respiratory distress syndrome and/or Multiple organ failure1.
Although influenza is an acute, self-limited illness, it causes primary influenza viral pneumonia in some patients. Primary influenza viral pneumonia is the most severe of the pneumonic compliactions. In more advanced cases, could die with acute respiratory distress syndrome and/or Multiple organ failure1.
Causes
Influenza viruses are members of the Orthomyxoviridae family, of which influenza A, B, C and D viruses constitute four separate genera. The major human pathogens are influenza A (H1N1, H3N2) and influenza B (Victoria and Yamagata). Influenza virus is sensitive to disinfectant such as ethanol, lodophors, iodine, etc. And it could be inactivated under the condition of 56℃, with 30 minutes1.
Symptions
Influenza is described as a respiratory illness characterized by systemic symptoms, such as headache, feverishness, chills, and myalgia, as well as accompanying respiratory tract signs and symptoms, particularly cough and sore throat. The spectrum of clinical presentations is wide, ranging from a mild, afebrile respiratory illness similar to the common cold (with either a gradual or an abrupt onset) to severe prostration with relatively few respiratory signs and symptoms. In most of the cases, the patient has a fever, with tempera tures of 38℃-41℃. A rapid temperature rise within the first 24 h of illness is generally followed by gradual defervescence over 2-3 days, although, on occasion, fever may last as long as 1 week. Patients report a feverish feeling and chilliness. Myalgias may involve any part of the body but are most common in the legs and lumbosacral area. Complications of influenza occur most frequently in patients >65 years old and in those with certain chronic disorders, including cardiac or pulmonary diseases, diabetes mellitus, and renal dysfunction. Children <5 years old (especially infants) are also at high risk for complications2.
Treatment
1.Clinically diagnosed cases and confirmed cases should be isolated for treatment as soon as possible.
2.Early antiviral treatment for high-risk groups of influenza (within 48h after onset)
1. 國家衛生健康委員會. 流行性感冒診療方案(2018年版修訂版). 傳染病信息. 2019(6): 500-504.
2. T. R. Harrison; R. G. Petersdorf; W. R. Resnick, et al. Harrison's Principles of Internal Medicine. 19th Edition. McGraw-Hi11 Education. 2015: 1620-1628.
2.Early antiviral treatment for high-risk groups of influenza (within 48h after onset)
- Neuraminidase inhibitors (NAI) are effective for influenza A and B: Oseltamivir Zanamivir and Peramivir
- The ion channel M2 blockers amantadine and rimantadine are only effective against influenza a virus, but the current monitoring data show that influenza A virus is resistant to them, so it is not recommended to use.
- High fever - physical cooling or antipyretic drugs.
- Cough phlegm serious - cough expectorant drugs.
- Hypoxia - oxygen therapy in an appropriate manner.
1. 國家衛生健康委員會. 流行性感冒診療方案(2018年版修訂版). 傳染病信息. 2019(6): 500-504.
2. T. R. Harrison; R. G. Petersdorf; W. R. Resnick, et al. Harrison's Principles of Internal Medicine. 19th Edition. McGraw-Hi11 Education. 2015: 1620-1628.
CP-91376-20190517