Influenza in the elderly
Introduction
Introduction to the elderly influenza Influenza (influenza) is an acute respiratory infection caused by influenza virus. Clinical manifestations of fever, body muscle aches and mild respiratory symptoms, short duration, self-limiting, it can be local outbreaks or widespread. Elderly patients with influenza are prone to pneumonia, and the prognosis of elderly, infirm or with cardiopulmonary disease is often severe. basic knowledge The proportion of illness: 1% Susceptible people: the elderly Mode of infection: contagious Complications: viral pneumonia hemoptysis bacterial pneumonia acute renal failure viral myocarditis pericarditis septic shock adult respiratory distress syndrome
Cause
The cause of influenza in the elderly
Influenza virus (35%):
Influenza viruses are divided into groups A, B, and C. They are spread by droplets. The influenza virus belongs to the Orthomyxoviridae family. It is an RNA virus. The influenza virus is different in that the antigenicity changes frequently, especially the antigenicity of the influenza A virus. Every year, the disease caused by the mutant strain is rarely resistant in the population, so the flu is prevalent every year.
Low immunity (20%)
The elderly have weakened immune function due to old and weak, organ atrophy, and decreased immunity, especially secreted IgA, non-specific nuclear protein, which is secreted by mucosa secreted by people with chronic bronchitis, cilia damage, local defense barrier Reduced, it is easy to get infected with the flu.
Pathogenesis
The droplets with influenza virus are ejected when the patient coughs or sneezes. The relatively low temperature, low humidity environment is conducive to the survival of the influenza virus. When the virus particles fall on the respiratory epithelium of the susceptible person, they are connected to the cells by the hemagglutinin. In vivo, and then penetrate the epithelial cells and replicate in the cells. The replication cycle of the virus is 4-6 hours. Before the cells are necrotic, the virus is released and the surrounding cells are infected. As a result, a large number of respiratory ciliated epithelial cells are infected, degenerated and necrotic. Exfoliation, inflammatory response, secretory IgA of the respiratory mucosa, non-specific nuclear proteins and normal ciliary movement can prevent the virus from penetrating cells.
Prevention
Elderly influenza prevention
1. General management: Find patients with early epidemic reports, isolate patients on the spot, actively treat patients, reduce assembly and group activities during the epidemic, and wear masks.
2. Vaccine prevention: Although the drift of influenza virus antigen greatly affects the effect of vaccine prevention, the best prevention method is still inactivated virus vaccine, which contains two inactivated viruses, A and B. Influenza vaccination should be carried out a few weeks before the start. Foreign literature reports that its effective rate is 67% to 92%, reducing the mortality rate of hospitalized elderly people by about 75%. The only contraindication for influenza vaccination is those who are allergic to eggs.
3. Drug prevention: the effective rate of amantadine, rimantadine prevention is 75% to 90%, and oral amantadine or rimantadine 100 mg once a day for 5 to 7 weeks before the start of the season. The flu vaccine is for 2 weeks).
Complication
Elderly influenza complications Complications, viral pneumonia, hemoptysis, bacterial pneumonia, acute renal failure, viral myocarditis, pericarditis, septic shock, adult respiratory distress syndrome
The incidence of complication of senile flu with aging is significantly increased. It is believed that this is related to the decline of cellular immunity, and its complications can be divided into two categories: intrapulmonary and extrapulmonary.
Intrapulmonary complication
(1) Primary influenza virus pneumonia: With the typical flu onset process, rapid high fever, cough, difficulty breathing, cyanosis, hemoptysis, palpitation, etc., the lungs have low breath sounds and small inhalation Sexual squirrels, full lungs wheezing, but no lung consolidation, X-ray examination, diffuse peri-infiltration around the hilar, low total white blood cells, neutropenia, influenza virus pneumonia is relatively rare, occurs in The original heart and lung disease, the prognosis is sinister, and the mortality rate is high.
(2) secondary bacterial pneumonia: more flu symptoms appear when the flu symptoms gradually improve, fever increased, cough increased, cough and sputum, difficulty breathing, chest pain, cyanosis, etc., physical examination showed signs of lung consolidation and intensive wetness The voice, the total number of white blood cells is high, the neutrophils are elevated, X-ray examination shows large leaf or lobular infiltration, the pathogens are mostly pneumococci, Staphylococcus aureus, Haemophilus influenzae and Gram-negative bacilli.
(3) virus-bacterial mixed pneumonia: more at the peak of the flu course, cough, sputum, dyspnea, hemoptysis, palpitation, X-ray examination showed lobular or large leaf pneumonia, in addition to elevated influenza antibody titer The culture of external sputum is positive, and the disease is dangerous and the prognosis is serious.
2. Extrapulmonary complications
(1) myositis: local or systemic striated muscle necrosis, manifested as myalgia and muscle weakness, elevated serum creatine phosphokinase, often associated with acute renal failure.
(2) Myocarditis, pericarditis: elderly patients with influenza may occasionally have viral myocarditis and pericarditis.
(3) toxic shock syndrome: This is a dangerous complication of elderly influenza patients, mostly after the flu, manifested as septic shock and adult respiratory distress syndrome, pneumonia signs are not obvious, tracheal secretions can often be cultured Golden Staphylococcus.
Older flu patients may even have Guiuain-Barre syndrome, transverse myelitis and encephalitis. Older patients sometimes have temporary olfactory sensations and loss of taste.
Symptom
Influenza symptoms in the elderly Common symptoms Fever with cough, slightly... Nasal breath sounds Rough cold warfare pharyngeal congestion Cough fever with eye congestion, cold and hot, nausea fever with lymph nodes...
The incubation period is 1 to 3 days. Most of the symptoms are typical. There are chills, fever, headache, muscle pain, discomfort, anorexia, etc. The fever of the old flu is not as high as that of young adults. The most prominent early symptoms are headache, joint pain and muscle pain. Myalgia is mainly manifested in the long muscles of the extremities and back. Eyes often have eye muscle pain. The elderly patients often have photophobia, redness and burning, nausea, anorexia, bloating, diarrhea, upper respiratory tract symptoms such as nasal congestion. , rogue and other relatively relatively mild, often covered by systemic toxic symptoms, 2 to 3 days later, fever and systemic symptoms gradually decline, cough, no convulsions, often have a burning sensation of the sternum, sometimes have anxious, palpitation, early examination Visible flushing, mild conjunctival hyperemia and eye tenderness, pharyngeal congestion but no secretions, about 25% of patients with mild lymph nodes and tenderness in the neck, late in the breath sounds, scattered wheezing Or limited karaoke.
Examine
Elderly influenza check
1, bloody viral infection see white blood cell count is normal or low, the proportion of lymphocytes is elevated, bacterial infection has white blood cell count and neutrophil enlargement and nuclear left shift phenomenon.
2, the determination of virus and viral antigens can be determined by immunofluorescence, enzyme-linked immunosorbent assay, serological diagnostics and virus isolation and identification to determine the type of virus, distinguish between viral and bacterial infections, bacterial culture to determine the type of bacteria and drug allergy testing.
Diagnosis
Diagnosis of influenza in the elderly
The flu should be distinguished from the following diseases:
1. Upper sensation: This disease often has obvious climate change incentives. The symptoms of upper respiratory tract are prominent and the symptoms of systemic toxic blood are mild. There is no epidemiological history and it is different from flu.
2. Legionnaires' disease: This disease can sometimes be localized, but it occurs mostly in summer and autumn. There are often pollution factors in the water supply or air conditioning system. The clinical manifestations are relatively slow pulse, watery diarrhea, cough and sputum, and the total number of white blood cells is high. There are liver and kidney dysfunction, effective against macrolides and other antibiotics, and the diagnosis depends on pathogens and immunological examinations.
