Haemophilus influenzae pneumonia

　　Pneumonia caused by Haemophilus influenzae is a disease caused by lung infection with Haemophilus influenzae in individuals with low immunity. Haemophilus influenzae, as a Gram-negative small bacillus, is about 1.5mm × 0.3mm in size and has a polymorphic shape, such as rod-shaped and filamentous. In acute infection specimens, it mostly appears in the form of short spherical bacilli. This group of bacteria does not form spores, has no flagella, cannot move, and some strains have a polysaccharide capsule. This bacterium is an aerobic bacterium with high nutritional requirements and needs X and V two growth factors. The X factor is a heme existing in hemoglobin, which is an iron-containing porphyrin, heat-resistant, and serves as a cofactor for the synthesis of catalase, peroxidase, and cytochrome oxidase by bacteria. These enzymes are important substances for the transfer of electrons in bacterial redox reactions. The V factor is a type of vitamin B substance, and the V factor in the blood is usually in a suppressed state. After being heated for 10 minutes at 80～90℃, the V factor can be released. Therefore, Haemophilus influenzae grows better on chocolate agar. After 24 hours of culture, the colonies can present three morphologies: M type (mucoid), R type (rough), and S type (smooth). The colonies of encapsulated strains are M type, sticky and glossy, and have strong virulence to humans. When Haemophilus influenzae and Staphylococcus aureus are co-cultured on blood agar, a satellite phenomenon can be seen, because Staphylococcus aureus can synthesize V factor, making the colonies of Haemophilus influenzae around the colonies larger, and those far away smaller. In addition, nicotine can promote the growth of Haemophilus influenzae.

　　The pathogenicity of Haemophilus influenzae is related to various virulence factors. In addition to endotoxins, Haemophilus influenzae can also produce histamine, causing bronchial smooth muscle contraction, mucus secretion, increased permeability of epithelial cells, and the ability to destroy ciliary movement. Pathogenic Haemophilus influenzae has IgA protease, which can hydrolyze the secretory IgA of the respiratory tract mucosa and exert pathogenic effects.

　　Under normal circumstances, the Haemophilus influenzae that is colonized is not pathogenic. After the bacteria are inhaled into the trachea or bronchi from the oropharynx, they are expelled from the body by the ciliary movement. At the same time, the secretory IgA in the respiratory tract mucosal secretions can protect the body from infection. However, when the body's resistance is reduced and the immune function is not perfect, infection can occur, leading to Haemophilus influenzae pneumonia, even sepsis, purulent meningitis, and life-threatening conditions. This disease is prone to occur in infants aged 6 months to 5 years, which is related to the body's immune defense status. Most infants breastfed from their mothers can obtain passive immunity by obtaining the Haemophilus influenzae capsular polysaccharide antibody from the maternal body, but this immunity gradually weakens and even disappears as the infant grows older. Older children and adults, due to their well-developed immune systems, obtain protective antibodies after infection. Therefore, pneumonia caused by Haemophilus influenzae is less common in infants under 6 months of age, older children, and adults. However, in recent years, the incidence of the above age groups has shown an increasing trend, which may be related to the improvement of detection technology, the increase in drug-resistant strains, and the change in bacterial virulence. The occurrence of adult Haemophilus influenzae pneumonia is also related to the lack of specific antibodies in patients' bodies, and therefore often occurs with diabetes, nephrotic syndrome, gamma globulin deficiency, alcoholism, or those using antitumor chemotherapy drugs, immunosuppressive drugs; in patients with chronic obstructive pulmonary disease, cystic fibrosis, and long-term smokers, due to the damage to local defense mechanisms, Haemophilus influenzae is prone to invade the lower respiratory tract and cause pneumonia.

　　The main complication of Haemophilus influenzae pneumonia is empyema. Empyema refers to the invasion of pathogenic bacteria into the pleural cavity, causing infection and pus accumulation. It can occur at any age from neonates to the elderly. Empyema is often caused by pyogenic bacteria. Most empyemas are secondary to pulmonary infection. In children, Staphylococcus aureus pneumonia is an even more common cause. Some may also be caused by open chest trauma, intrathoracic surgery, subphrenic abscess, or sepsis. When pus fills the entire pleural cavity, it is called total empyema; if the pus is localized to a part of the pleural cavity, it is called localized (encapsulated) empyema.

　　Haemophilus influenzae pneumonia has a history of upper respiratory tract infection before onset, manifested as fever, cough, sputum with pus, rapid breathing, cyanosis, similar to general pneumonia, low respiratory sound, and wet rales. A few cases have concurrent empyema, and there are signs of pleural effusion.

　　After infection with Haemophilus influenzae type b, the body can be stimulated to produce protective antibodies, but the duration is short, so the improvement of the vaccine has become an important topic in recent years. Currently, the vaccines used include the following three types:

　　1, Capsular Polysaccharide Vaccine (PRP) It contains no protein component and is a hapten, which can stimulate the body to produce IgM antibodies. It cannot stimulate the activation of helper T lymphocytes, so it does not amplify the immune and recall responses, and has a short duration.

　　2, Polysaccharide-Carrier Protein-Bound Vaccine The capsular polysaccharide antigen is combined with carrier protein (commonly diphtheria or tetanus toxoid), which enhances immunogenicity, strengthens the immune response of the body, and has a persistent recall response. It is applied to infants and young children aged 1 to 18 months, with an efficacy of 80% to 90%.

　　3, Capsular Oligosaccharide-Variant Diphtheria Toxin-Binding Vaccine They are combined by covalent bonds. It is currently believed that the vaccine has strong immunogenicity and safety, with an efficacy of up to 97%.

　　The examination of Haemophilus influenzae pneumonia is mainly for diagnosing the pathogenic bacteria. The main examination items include:
　　Section I: Laboratory Examination
　　1, Serum adenosine deaminase (ADA) is elevated. Normal range of serum adenosine deaminase (ADA): 1-25U. Adenosine deaminase (ADA) is a system named adenosine amino hydrolase, which mainly catalyzes adenosine and deoxyadenosine to produce inosine monophosphate and ammonia, and is one of the important enzyme systems in the degradation metabolism of adenosine acid. ADA is widely distributed in various tissues of the human body, with the highest content in the mucosa of the small intestine and the spleen, followed by the liver, kidney, bone, and skeletal muscle. In the cell, ADA is mainly located in the cytoplasm, and the activity of ADA in white blood cells is higher than that in red blood cells.
　　2, The total white blood cell count is mostly elevated.

　　3, Pathogen examination.
　　Section II: X-ray Findings
　　1, Usually presents as consolidation of lung segments and lobes.
　　2, Presenting as bronchopneumonia, characterized by patchy or multi-lobular infiltration, rarely forming lung abscesses, and about 20% developing empyema.

　　Recommend 4 dietary recipes suitable for patients with Haemophilus influenzae pneumonia.

　　1, Celery Stir-fried鲤鱼: Ingredients include 250 grams of crucian carp, 50 grams of fresh celery, starch, ginger slices, garlic slices, soy sauce, sugar, vinegar, refined salt, monosodium glutamate, cooking wine, pickled chili, and vegetable oil. Preparation involves cutting the crucian carp into shreds, cutting the celery into segments, and mixing soy sauce, sugar, vinegar, monosodium glutamate, cooking wine, salt, and starch with some broth to make a sauce. Heat a wok over high heat, add oil to 5 degrees, add the fish shreds and stir-fry until they disperse, drain the excess oil, add ginger slices and pickled chili. Stir-fry the celery segments until fragrant, then add the sauce, add some glossy oil, and remove from heat. Benefits include: Crucian carp has the effects of clearing heat and detoxifying, promoting diuresis and reducing swelling, and relieving cough and reducing phlegm; celery has the effects of calming the liver and clearing heat, dispelling wind and promoting diuresis, and nourishing the spirit and invigorating Qi. Eating crucian carp and celery together is suitable for the auxiliary treatment of acute and chronic pneumonia.

　　2, Rabbit Meat Mushroom Shreds: Ingredients include 100 grams of cooked rabbit meat, 50 grams of mushrooms, 25 grams of scallion whites, appropriate amounts of chili oil, soy sauce, vinegar, sugar, sesame oil, sesame paste, Sichuan pepper powder, and monosodium glutamate. Preparation involves cutting the cooked rabbit meat and scallion whites into shreds, and boiling the mushrooms. Place the scallion whites and mushrooms at the bottom, cover with the rabbit meat shreds, and serve in a dish. Dissolve the sesame paste in soy sauce in stages, mix with sesame oil to make a sauce, and pour it over the rabbit meat shreds. Benefits include: Rabbit meat has the effects of clearing heat and detoxifying, invigorating the spleen and building Qi, dispelling dampness and cooling the blood, and promoting defecation; mushrooms have the effects of detoxifying and moistening the intestines, invigorating the spleen and building Qi, and dispelling dampness and stopping diarrhea. Eating rabbit meat and mushrooms together is suitable for treating acute pneumonia.

　　3, Quail Lily Soup: Ingredients include 1 quail, 25 grams of lily, appropriate amounts of ginger, scallion, monosodium glutamate, and fine salt. Preparation involves killing the quail, removing feathers, feet, and internal organs, washing, and then boiling in boiling water, removing and cutting into pieces; separating the lily petals, washing, and setting aside. Wash the ginger and scallion, smashing the ginger, and cutting the scallion into segments. Place a pot on a high heat, add some water, add the quail, bring to a boil, add the lily petals, ginger pieces, and scallion segments, then reduce the heat to simmer until the quail is cooked. Add salt and monosodium glutamate, cover and simmer for a few minutes, then serve in a bowl. Benefits include: Quail meat is good for nourishing the five internal organs, benefiting the liver and clearing the lungs, clearing heat and promoting diuresis, and resolving accumulation and stopping diarrhea; lily has the effects of moistening the lungs and relieving cough, nourishing yin and clearing heat, and calming the mind. Both are suitable for acute and chronic pneumonia.

　　4, Lean meat and cabbage soup: Ingredients: 100 grams of lean meat, 100 grams of cabbage heart, a little ginger, garlic, salt, monosodium glutamate, and chicken oil. Preparation: slice the lean meat, wash and slice the cabbage, put it in boiling water, take it out when it is just cooked, rinse it with cold water, drain the water and set aside; place the pot on a high heat, add a little chicken oil to heat to 50%, add garlic and stir-fry until golden, then add the lean meat and stir-fry together, add fine salt, cook in the soup, add the cabbage heart and bring to a boil, add monosodium glutamate and it is ready to eat. Benefits: Lean meat has the effects of replenishing the middle, benefiting the Qi, and moistening the intestines; cabbage is mild in nature and sweet in taste, with the effects of clearing heat and detoxifying, resolving phlegm and stopping cough, and relieving irritability and promoting bowel movements. Eating lean meat and cabbage together is suitable for acute and chronic pneumonia.

　　Due to the widespread use of antibacterial drugs, resistant strains are constantly emerging, among which some can produce beta-lactamase and are resistant to ampicillin. The resistant strains of Haemophilus influenzae isolated from children and patients with COPD complicated by the disease are particularly common. Novel macrolide antibiotics such as azithromycin, clarithromycin, amoxicillin/clavulanate potassium, and ampicillin/sulbactam sodium, combined with beta-lactamase inhibitors, fixed-dose combinations, doxycycline, and sulfamethoxazole/trimethoprim (SMZ/TMP) can generally be selected according to circumstances; second-generation cephalosporins such as cefaclor and cefuroxime have strong antibacterial activity against this bacterium and are recommended for mild to moderate infections; third-generation cephalosporins ceftriaxone and cefotaxime, as well as quinolones, are more effective for moderate to severe Haemophilus influenzae pneumonia; severely ill patients can use fourth-generation cephalosporins or carbapenems.

　　Prognosis is related to the age of the patient, the presence of underlying diseases or complications. The mortality rate of pediatric patients is 5%, of which 90% have multisystem lesions, such as meningitis or acute epiglottitis. The mortality rate of adult patients over 50 years old with underlying diseases is 30%. After the absorption of pneumonia in pediatric patients, pulmonary emphysema or bullae changes may remain.