It hurts to the bone! You must know this information about influenza B

[Danger! #Woman's two lungs turned white after enduring the flu for 10 days#] Recently, Ms. Chen, 51, from Jiangsu, contracted the flu. After enduring it for more than 10 days, she suddenly fainted while receiving intravenous drip. CT scans showed that due to multiple viruses in her lungs, Ms. Chen had developed severe pneumonia, had basically lost her lung function, and was in severe respiratory failure, and her life was in danger at any time.

Following mycoplasma pneumonia and influenza A (H1N1), influenza B (H1N1) has recently attracted public attention.

On social platforms, some people shared their experience of catching a cold and having a fever: persistent high fever, muscle and joint pain all over the body, and continued fatigue after the virus turned negative.

After comparing the symptoms of influenza and COVID-19, one netizen said: "Influenza B is the 'king of kings'. My whole body aches, even the joints between my bones hurt."

The 2024 No. 1 "Influenza Surveillance Weekly Report" (January 1-7, 2024) released by the National Influenza Center shows that the proportion of influenza A (influenza A) has dropped significantly, while the proportion of influenza B (influenza B) has increased. Most people will recover quickly after being treated after being infected with influenza B, but some people will develop severe or critical illness, and clinicians must pay attention to identification.

Those who have any of the following conditions are considered severe cases

1. Continuous high fever for more than 3 days, accompanied by severe cough, coughing up purulent or bloody sputum, or chest pain.

2. Rapid breathing rate, difficulty breathing, and purple lips.

3. Changes in mental status or convulsions such as slow reaction, drowsiness, agitation, etc.

4. Severe vomiting, diarrhea, and signs of dehydration.

5. Combined with pneumonia.

6. The original underlying disease is significantly aggravated.

7. Other clinical conditions requiring hospitalization.

A critical case is one of the following:

1. Respiratory failure.

2. Acute necrotizing encephalopathy.

3. Shock.

4. Multiple organ dysfunction.

5. Other serious clinical conditions requiring monitoring and treatment.

People who meet one or more of the following criteria can be considered as being at high risk of severe illness.

1. Pregnant women or women who are 4 weeks postpartum.

2. People with low immune function, such as patients with tumors and those with suppressed or defective immune function (such as long-term use of hormones or immunosuppressants, HIV infection, especially those with CD4+T cells <200×106/L).

3. Cases with the following underlying diseases: chronic respiratory diseases (such as asthma, tracheopulmonary dysplasia, cystic fibrosis, chronic bronchitis and emphysema), cardiovascular diseases (except hypertension), kidney disease, liver disease, blood system diseases, nervous system and neuromuscular diseases that affect the ability to clear respiratory secretions (such as cognitive dysfunction, spinal cord injury, epileptic seizures, neuromuscular disorders and cerebral palsy), metabolic and endocrine system diseases.

4. Obese cases (body mass index > 30 kg/m2).

5. People aged 65 and above.

Why do bones hurt after being infected with influenza B?

Lin Hua, deputy chief physician of the Department of Respiratory Medicine at the Third Xiangya Hospital of Central South University, explained, "Upper respiratory tract infections caused by pathogenic bacteria such as rhinovirus, adenovirus, and influenza virus can cause patients to experience body aches and fatigue. When pathogenic bacteria enter the body, they destroy immunity and release inflammatory mediators, such as prostacyclin. Inflammatory mediators circulate throughout the body through the blood. When they act on bones, they can cause bone pain in patients. In addition, pathogenic bacteria can cause skeletal muscle spasms and contractions. If they stimulate the peripheral central nervous system, some patients will also experience bone pain."

Can we differentiate between influenza A and influenza B by judging the severity of symptoms?

Qian Liling, head of the respiratory medicine department at the Children's Hospital affiliated to Shanghai Jiao Tong University School of Medicine, said: "There is no significant difference in the symptoms caused by influenza A and influenza B among the children who come for treatment, and there is no significant difference in the proportion of intensive care units. All of them have an acute onset, with sudden high fever, chills, sore throat, cough, and muscle aches all over the body. The body temperature can reach a peak within a few hours to 24 hours, reaching 39~40℃ or even higher. In simple terms, it is 'one fever' (fever), 'two pains' (muscle aches), and 'three fatigue' (general fatigue)."

How to grasp the timing of anti-influenza virus treatment?

Severe cases or influenza-like cases with high risk factors for severe influenza should be given empirical anti-influenza virus treatment as soon as possible. Antiviral treatment within 48 hours of onset can reduce complications, reduce mortality, and shorten hospitalization time; severe patients with onset time exceeding 48 hours can still benefit from antiviral treatment. Patients who are not seriously ill and do not have high risk factors for severe influenza should fully evaluate the risks and benefits and consider whether to give antiviral treatment.

How to choose antiviral drugs?

According to the mechanism of action, current antiviral drugs can be mainly divided into neuraminidase inhibitors, hemagglutinin inhibitors and RNA polymerization inhibitors. The main anti-influenza virus drugs currently approved in my country are shown in Table 1. Table 1 Clinical application strategies and plans for neuraminidase inhibitors, hemagglutinin inhibitors and RNA polymerization inhibitors

References:

[1] Emergency Physicians Branch of Chinese Medical Doctor Association, Emergency Medicine Branch of Chinese Medical Association, China Emergency Medical Association. Emergency Expert Consensus on Diagnosis and Treatment of Influenza in Adults (2022 Edition) [J]. Chinese Journal of Emergency Medicine, 2022, 42(12):1013-1026.

[2] Expert consensus group on antiviral treatment of influenza in adults. Expert consensus on antiviral treatment of influenza in adults[J]. Chinese Journal of Infectious Diseases, 2022, 40(11): 641-655.

[3] General Office of the National Health Commission, General Office of the State Administration of Traditional Chinese Medicine. Diagnosis and Treatment Program for Influenza (2020 Edition) [EB/OL]. http://www.nhc.gov.cn/yzygj/s7653p/202011/a943c67d55c74e589d23c81d65b5e221.shtml, 2020-10-27.