What Are the Most Common H1N1 Flu Symptoms?

H1N1 influenza is an acute respiratory infectious disease, and its pathogen is a new type of H1N1 influenza virus, which is transmitted among people. Unlike previous or current seasonal influenza viruses, this virus strain contains the gene fragments of three influenza viruses: swine flu, bird flu, and human flu. The population is generally susceptible to the H1N1 influenza virus and can infect people. The early symptoms of human infection after influenza A are similar to ordinary influenza, including fever, cough, sore throat, physical pain, headache, chills and fatigue, etc. There may also be diarrhea or vomiting, muscle pain or fatigue, and red eyes. Beginning in 2009, the H1N1 influenza pandemic was widespread worldwide. In August 2010, WHO announced that the H1N1 influenza pandemic period had ended.

Basic Information

English name: influenza A
Visiting department: Respiratory and Infectious Diseases
Multiple groups: General susceptibility

Common causes: H1N1 influenza virus
Common symptoms: Flu-like symptoms with signs of pharyngeal congestion and tonsil enlargement
Contagious: Have
way for spreading: Transmitted mainly through the respiratory tract through droplets

Causes of H1N1 influenza

Source of infection

Patients with H1N1 influenza are the main source of infection, and those with asymptomatic infection are also infectious. There is no evidence of animal-to-human transmission.

2. Ways of transmission

It is mainly transmitted through the respiratory tract through droplets, and can also be transmitted through direct or indirect contact with mucous membranes in the oral cavity, nasal cavity, and eyes. Contact with respiratory secretions, body fluids, and items contaminated by the virus may also cause infections.

3. Susceptible people

The crowd is generally susceptible.

4. High-risk population

(1) Women during pregnancy.

(2) People with the following diseases or conditions: chronic respiratory disease, cardiovascular system disease (except hypertension), kidney disease, liver disease, blood system disease, nervous system and neuromuscular disease, metabolic and endocrine system disease, immune function suppression ( Including immunosuppression caused by the use of immunosuppressive agents or HIV infection), long-term use of aspirin under 19 years of age.

(3) Obese people have a high risk of body mass index 40. Body mass index of 30 to 39 may be a high risk factor.

(4) Children <5 years of age Children <2 years of age are more prone to severe complications.

(5) Elderly persons 65 years old

Clinical manifestations of H1N1 influenza

The incubation period of H1N1 influenza is longer than that of influenza and bird flu. The incubation period is 1 to 7 days, and most of them are 1-3 days. Some patients can progress rapidly, with fierce onset, sudden high fever, body temperature exceeding 38 ° C, and even secondary to severe pneumonia, acute respiratory distress syndrome, pulmonary hemorrhage, pleural effusion, systemic blood cell reduction, renal failure, sepsis, shock and shock Syndrome (Reye syndrome), respiratory failure and multiple organ damage leading to death. Patient's original underlying disease can also be exacerbated.

It usually presents with flu-like symptoms, including fever, sore throat, runny nose, stuffy nose, cough, expectoration, headache, general soreness, and weakness. Vomiting and diarrhea occurred in some cases. A few cases have only mild upper respiratory symptoms and no fever. Signs mainly include pharyngeal congestion and tonsil enlargement.

H1N1 influenza test

Laboratory inspection

(1) The total number of white blood cells in peripheral blood examination is generally not high or decreased.

(2) Blood biochemical examination showed hypokalemia in some cases, and creatine kinase, aspartate aminotransferase, alanine aminotransferase, and lactate dehydrogenase were elevated in a few cases.

(3) Etiological examination Viral nucleic acid detection RT-PCR (preferably using real-time RT-PCR) method to detect type A H1N1 in respiratory specimens (pharyngeal swab, nasal swab, nasopharyngeal or tracheal extract, sputum) Influenza virus nucleic acid, results can be positive. Virus-isolated respiratory specimens can isolate influenza A H1N1 virus. Serum antibody test dynamic detection of double serum H1N1 influenza virus-specific antibody levels showed a 4-fold or more increase.

2. Chest imaging

In the presence of pneumonia, flaky shadows can be seen in the lungs.

H1N1 influenza diagnosis

Diagnosis is mainly based on epidemiological history, clinical manifestations and etiological examination. Early detection and early diagnosis are the key to prevention and control and effective treatment.

Suspected case

A suspected case can be diagnosed if:

(1) Close contact with confirmed cases of H1N1 influenza in infectious period within 7 days before the onset of illness and clinical manifestations of influenza-like illness. Close contact refers to the diagnosis and treatment of patients with influenza A H1N1 influenza during infectious period without effective protection; living together with the patient; having contact with the respiratory secretions and body fluids of the patient.

(2) In areas where influenza A (H1N1) epidemic (continuous human-to-human transmission and community-based epidemics and outbreaks) occurred within 7 days before the onset of illness, clinical manifestations of influenza-like illness occurred.

(3) Influenza-like clinical manifestations, influenza A virus test positive, no further virus subtypes have been detected.
For the above three cases, if conditions permit, we can arrange the pathogenic examination of influenza A H1N1.

2. Clinically diagnosed cases

Clinical diagnosis is limited to the following cases: In the same outbreak of influenza A H1N1, cases of influenza-like symptoms that have not been confirmed by the laboratory can be diagnosed as clinically diagnosed cases when other influenza-like symptoms are excluded.
A H1N1 influenza outbreak refers to an abnormal increase in influenza-like cases in a region or unit for a short period of time, which has been confirmed by laboratory testing as an H1N1 influenza epidemic.
Where conditions permit, clinical diagnosis of cases can be arranged for pathogenic examination.

3. confirmed cases

Onset of flu-like clinical manifestations, with one or more of the following laboratory test results:

(1) H1N1 influenza virus nucleic acid test is positive (real-timeRT-PCR and RT-PCR methods can be used).

(2) H1N1 influenza virus was isolated.

(3) The specific antibody levels of the double serum H1N1 influenza virus were increased 4 times or more.

H1N1 flu treatment

General treatment

Rest, drink plenty of water, and closely observe changes in the condition; antipyretic treatment can be given to high fever cases.

2. Antiviral treatment

Studies have shown that this type of H1N1 influenza virus is currently sensitive to neuraminidase inhibitors oseltamivir and zanamivir, and resistant to amantadine and rimantadine.

For cases of influenza A H1N1 with mild clinical symptoms without comorbidities and tending to be self-limiting, there is no need to actively apply neuraminidase inhibitors. For cases that are severe at the time of the onset and show a dynamic deterioration after the onset, high-risk groups infected with influenza A H1N1 influenza should be treated with neuraminidase inhibitors for antiviral treatment. Dosing should be started within 48 hours of onset (preferably within 36 hours). For high-risk groups who are more likely to become severe cases, once influenza-like symptoms occur, antiviral treatment may not necessarily be waited for viral nucleic acid test results. Pregnant women should be treated with neuraminidase inhibitors as soon as possible after having flu-like symptoms.

H1N1 influenza prevention

1. Wash your hands frequently and develop good personal hygiene habits.

2. Get enough sleep and drink plenty of water to maintain good health.

3. Ventilation should be maintained indoors, and less frequent and unventilated places.

4. Separate raw and cooked food when cooking, and cook pork to above 71 ° C to completely kill H1N1 influenza A virus.

5. Avoid contact with live pigs or go to places with pigs.

6. Cover your mouth and nose with a tissue when coughing or sneezing.

7. Always prepare medicines for treating colds. Once flu-like symptoms (fever, cough, runny nose, etc.) occur, you should take symptomatic treatment as soon as possible.

8. Avoid contact with patients who have flu-like symptoms.

9. Since the virus that is circulating this time is A / H1N1 influenza virus, human vaccines against H1N1 influenza have begun to be produced. Humans can not effectively prevent H1N1 influenza by injecting ordinary influenza vaccine.

10. Ordinary households can also use alcohol to disinfect daily necessities.