A large-scale influenza epidemic will break out every winter and spring exchange. The influenza epidemic in the spring of 2018 makes everyone quite afraid. At the beginning of 2019, a new influenza epidemic is about to make a comeback. How to monitor the influenza epidemic in 2019, and what are the symptoms and transmission methods of influenza?
The flu season lasts from October to February every year. It is understood that from January 1 to October 10, 2018, the number of influenza cases reported in Shijiazhuang increased by more than 40% over the same period in 2017, of which the number of cases reported from January to March accounted for 57.51%. The risk of influenza epidemic gradually increases in winter and spring of 2018-2019, and will reach the peak from January to February of 2019. So, what is influenza? Is the harm serious? What are the popular characteristics? What are the main clinical manifestations? How to prevent? With these questions, the reporter interviewed Zhang Shiyong, director of the Institute of epidemic prevention and control of Shijiazhuang CDC. You might as well listen to what experts say.
Influenza season in winter and spring 2018-2019
It is expected to peak from January to February 2019
According to Zhang Shiyong, from January 1 to October 10, 2018, the number of influenza cases reported in Shijiazhuang increased by more than 40% over the same period in 2017, of which 57.51% were reported from January to March; The positive rate of influenza virus in 2018 was also significantly higher than that in the same period in 2017, but no virus was detected in the non epidemic period of influenza in 2018 (week 13 - week 40).
The city CDC has carried out a comprehensive analysis of influenza incidence / incidence rate, influenza like case visits ratio (ILI%), influenza virus positive rate and the number of cluster outbreaks, and combined with meteorological data such as temperature to analyze the epidemic situation of influenza. Zhang Shiyong said that after expert risk assessment, the risk of influenza epidemic in winter and spring 2018-2019 gradually increased, from low risk to high risk, that is, there were fewer influenza patients from October to November 2018, the intensity of influenza activity was low, and the incidence of influenza was in a low-risk period; After December 2018, the number of influenza patients began to increase, the influenza activity increased, the influenza epidemic entered an active period, and the predicted risk level reached medium risk; From January to February 2019, it reached the peak, that is, high risk, and then gradually decreased.
At present, the influenza epidemic in the city is mainly sporadic. With the temperature falling, there will be aggregation or outbreak in schools, kindergartens, nursing homes and other places where people are concentrated.
Influenza has the characteristics of acute onset, rapid transmission and wide range of influence
Influenza is a legal class C infectious disease caused by influenza virus. It has the characteristics of acute onset, rapid transmission and wide range of influence. It mainly includes types A, B and C. influenza a mainly includes subtypes such as new A H1N1 and seasonal H3N2, which are easy to mutate. Important antigen variants will appear every 2-3 years, causing seasonal epidemics, and pandemic when antigen transformation occurs; Influenza B, including by and bv subtypes, has less variation and generally causes seasonal epidemics; Influenza C virus is relatively stable, and the infection in childhood is common. Generally, it only causes sporadic cases.
Infants, the elderly and other people have a higher risk of influenza
Influenza is an infectious disease that seriously endangers people's health. It causes seasonal epidemics every year. Outbreaks can occur in schools, kindergartens, nursing homes and other places where people gather, affecting normal life and teaching order. Seasonal influenza pandemic can cause 3-5 million severe cases and 290000-650000 deaths worldwide every year; Pregnant women, infants, the elderly, patients with chronic basic diseases and other high-risk groups have a higher risk of serious diseases and death after suffering from influenza. In the past 100 years, there have been four influenza pandemics around the world, causing tens of millions of deaths.
Influenza is mainly transmitted by droplets from respiratory secretions
Influenza patients and latent infections are the main sources of infection of influenza. They are mainly transmitted by droplets from their respiratory secretions, and can also be transmitted by direct or indirect contact with mucous membranes such as oral cavity, nasal cavity and eyes. People are generally susceptible. The incubation period is generally 1-4 days, with an average of 2 days; Generally, the virus can be excreted 1-2 days before the symptoms appear after infection, reaching the peak within 24 hours after the onset. Adults and older children generally continue to detoxify for 3-8 days. The detoxification time of low immune function or defective people such as young children, the elderly and HIV infected people is longer (the infection period is longer).
In northern China, the influenza epidemic mainly occurred from October of that year to the end of March of the next year, and the influenza activity was the highest from December to February.
Influenza is generally characterized by acute onset and fever
Influenza is generally characterized by acute onset and fever (some can reach 39 ℃ - 40 ℃), accompanied by chills, chills, headache, muscle and joint soreness, extreme fatigue, loss of appetite and other systemic symptoms, including sore throat, cough, nasal congestion, runny nose, post sternal discomfort, flushing of face, mild congestion of conjunctiva, vomiting, diarrhea and other symptoms.
Mild influenza is often similar to the common cold, but its fever and systemic symptoms are more obvious, and other symptoms are not obvious.
Severe cases may have extrapulmonary manifestations and a variety of complications, such as viral pneumonia, secondary bacterial pneumonia, acute respiratory distress syndrome, shock, diffuse intravascular coagulation, cardiovascular and nervous system.
Schools, kindergartens and kindergartens shall be well ventilated and disinfected in public places such as classrooms
Earnestly implement the morning and afternoon inspection and disease tracking system. Actively monitor the patients with fever and respiratory tract and other suspected infectious disease symptoms and students absent from work due to illness every day to find possible influenza patients as soon as possible.
Isolate and treat patients. Influenza patients are treated in isolation at home or hospital, and they can go to class only after they recover; Focus on close contacts with influenza, and isolate and treat them as soon as possible in case of influenza symptoms.
Ventilate and disinfect classrooms and other public places. In addition to routine preventive disinfection in the season of high incidence of influenza, classes and dormitories with influenza cases should be disinfected at any time.
Do a good job in health education and publicity. During the high incidence period of influenza and other infectious diseases, carry out health and disease prevention publicity of infectious diseases in various forms and ways to enhance the health and disease prevention awareness of students, teachers and parents.
Report the epidemic situation in time. In case of influenza epidemic, the school shall report to the county-level CDC under its jurisdiction as soon as possible, and cooperate with epidemiological investigation and specimen collection.