Campylobacter enteritis

　　The occurrence of Campylobacter enteritis is mainly due to oral infection with Campylobacter, and the specific causes and mechanisms of onset are described as follows.

　　1. The causes of Campylobacter enteritis

　　Campylobacter species that can cause human disease include Campylobacter jejuni, Campylobacter coli, Campylobacter laridis, the fetal subspecies of Campylobacter fetus, and the mucosal subspecies of Campylobacter sputorum. This bacterium is Gram-negative, spiral or S-shaped, does not form spores, and has a single flagellum at one or both ends, moving actively. The bacterium is microaerophilic, invasive, contains endotoxins, and can also secrete exotoxins such as enterotoxins. Campylobacter jejuni has strong viability in vitro and can survive in milk at 4℃ for 160 days and at room temperature for more than 2 months, but it is sensitive to general disinfectants and can be killed in 5 minutes at 58℃.

　　2.Campylobacter enteritisPathogenesis

　　After Campylobacter infection through the mouth, it proliferates in the bile and micro-oxygen environment of the upper small intestine, and the pathogenesis is not yet fully understood. It is currently believed that the pathogenicity in the intestines mainly depends on the direct invasion force of the bacteria. It is currently clear that soluble protein PEB1 and chemotactic protein play a role in the adhesion and colonization of the bacteria. In addition, some strains can produce enterotoxins similar to cholera enterotoxins, which can cause watery diarrhea in patients; the release of a large amount of endotoxin after bacterial lysis can cause systemic symptoms such as fever.

　　The pathological changes are mainly in the jejunum, ileum, and colon. The intestinal mucosa shows diffuse hemorrhage, edema, and exudative lesions; under the microscope, the villi of the small intestine show degeneration and atrophy, and there is a large number of neutrophils and monocytes infiltrating the lamina propria of the mucosa. Sometimes ulcers and abscesses can be seen, with enlargement of mesenteric lymph nodes and accompanied by inflammatory reactions.

　　Campylobacter enteritis can cause sterile inflammation and cholecystitis, and the specific concurrent symptoms are described as follows.

　　1. Sterile inflammation:There is no bacterial infection in the parts of the body where there are organ disorders and persistent pain. Pathological examination and tissue sections do not show any signs of microorganism invasion. From the perspective of pathological changes, it is a sterile inflammation without pathogenic bacteria, so antibiotic treatment is ineffective. Sterile osteoarthritis refers to the condition of osteoarthritis without bacterial infection. Inflammation can be divided into infectious inflammation and sterile inflammation. When the human body is infected with pathogenic microorganisms and bacteria, viruses, protozoa, and other pathogens, and causes the body to produce exudation, necrosis, and proliferation, etc., it is collectively called infectious inflammation. If the inflammatory response is caused by physical, chemical factors, etc., it is collectively called sterile inflammation.

　　2. Cholecystitis:Gallbladder inflammatory lesions caused by bacterial infection or chemical stimulation (change in bile components) are common gallbladder diseases.

　　The incubation period of Campylobacter enteritis ranges from 2 to 11 days, usually 3 to 4 days, and the incubation period of food poisoning can be as short as 20 hours. Typical symptoms in patients include fever, abdominal pain, diarrhea, and mucous pus stool, and the specific clinical manifestations are as follows.

　　1、发热：发热常首先出现，可高达40℃，伴全身乏力、头痛、眩晕、肌肉酸痛，有时有寒战和谵妄。

　　2、腹泻：发热12～24h后开始水样腹泻，量多，每天多者可达20余次，1～2天后部分患者出现痢疾样粪便，有血液及黏液，伴里急后重。

　　3、腹痛：2/3以上病人有腹痛，以痉挛性疼痛为主。腹痛部位常在脐周及下腹，少数在右下腹，类似急性阑尾炎。

　　4、其他胃肠道反应：近半数病人有恶心、呕吐。

　　病程多数一周内自行缓解，但少数病人可持续数周，有时腹泻可反复发作。外周血白细胞及中性粒细胞轻到中度增多，少数患者在肠炎后发生无菌性关节炎，亦可发生弯曲菌性胆囊炎。

　　婴儿弯曲菌肠炎症状常不典型，患儿全身症状轻微，大多数无发热和腹痛，仅有间断性轻度腹泻，较少因腹泻引起发育停滞。

　　弯曲菌肠道外感染多见于35～70岁的患者或免疫功能低下者。常见症状为发热、咽痛、干咳、颈淋巴结肿大或肝脾肿大等。部分血行感染者可发生败血症、血栓性静脉炎、心内膜炎、肺炎、肺脓肿、腹膜炎、肝脓肿、关节炎及泌尿系感染等。少数还可发生脑病如脑膜脑炎、脑脓肿，脑脊液呈化脓性改变。孕妇感染者常见上呼吸道症状、肺炎及菌血症，可引起早产、死胎或新生儿败血症等。

　　弯曲菌肠炎的预防措施与其他肠道感染病相同。空肠弯曲病最重要的传染源是动物，因此控制动物的感染，防止动物排泄物污染水、食物至关重要。做好三管（即管水、管粪、管食物）是防止弯曲菌病传播的有力措施。注意饮食卫生和个人卫生，以切断传播途径；对病人实行消化道隔离；加强对已感染本菌的家禽、家畜的管理及治疗；食物及饮水均应煮沸消毒。目前正在研究减毒活菌苗及加热灭活菌苗，可望在消灭传染源、预防感染方面起重要作用。

　　弯曲菌肠炎的检查主要是检测到致病菌，包括直接涂片、细菌培养及血清学的检查，具体检查方法如下叙述。

　　一、直接涂片检查

　　1、悬滴检查：取新鲜粪便置于载玻片上，加生理盐水少许混匀后，覆盖玻片制成悬滴标本，在显微镜下观察，可见呈特征性突进运动的螺旋形细菌。

　　2、染色检查：采取急性腹泻病人粪便，作涂片后，进行革兰染色，镜检可见弯曲菌呈S形、螺旋形，革兰染色阴性菌。

　　II. Bacterial culture Campy-BAP culture medium is generally used, which is incubated at 42℃ for 48 hours in a culture chamber with 95% nitrogen and 5% carbon dioxide.

　　III. Serological examination Tube agglutination, indirect fluorescence, ELISA, or passive hemagglutination methods can be used to detect specific antibodies against Campylobacter.

　　The most important thing for patients with Campylobacter enteritis is to pay attention to dietary hygiene and prevent infection by the pathogen. The specific dietary precautions are described as follows.

　　I. Pay attention to supplementing antioxidants such as vitamin C and vitamin E. Good sources of vitamin C include various fresh vegetables, citrus fruits, hawthorn, fresh jujube, kiwi, strawberry, etc.

　　II. Avoid unclean diet: Gastroenteritis patients should pay special attention to dietary hygiene, especially in summer. Unwashed fruits and vegetables should not be eaten raw, and deteriorated food should not be consumed. Because contaminated and deteriorated food contains a large number of bacteria and bacterial toxins, which have a direct destructive effect on the gastric mucosa. Food stored in the refrigerator should be thoroughly cooked before eating, and if spoilage is detected, it should be discarded and not consumed.

　　Campylobacter enteritis mainly focuses on pathogen treatment, and symptomatic treatment is also very important. The specific methods of treatment are briefly described as follows.

　　I. Treatment of Campylobacter enteritis

　　I. General treatment:Implement gastrointestinal isolation, thoroughly disinfect the patient's feces, and isolate from onset to negative stool culture. For those with severe fever, abdominal pain, and diarrhea, symptomatic treatment should be given and bed rest should be ensured. Easy-to-digest semi-liquid food should be provided, and fluid replacement should be administered as necessary.

　　II. Pathogen treatment:Campylobacter is sensitive to gentamicin, erythromycin, chloramphenicol, streptomycin, kanamycin, neomycin, lincomycin, and ciprofloxacin. It is resistant to penicillin and cephalosporins. Quinolone antibacterial drugs, such as norfloxacin, are also effective, but they can affect the skeletal development of children. Gentamicin is the first choice for bacterial endocarditis, chloramphenicol is the first choice for meningitis, and the treatment course for severe infections should be extended to 3-4 weeks to prevent recurrence. Symptomatic treatment should also be emphasized, and dehydration should be corrected if necessary.

　　II. Prognosis of Campylobacter enteritis

　　The prognosis is generally good, but those with serious chronic diseases and extraintestinal lesions have a very poor prognosis.