Urinary tract infection is an inflammation of the urinary tract caused by pathogens invading the mucosa or tissues of the urinary tract. According to the site of infection, urinary tract infections can be divided into upper urinary tract infections, which are pyelonephritis, and lower urinary tract infections, which are mainly cystitis. According to the presence or absence of underlying diseases, urinary tract infections can also be divided into complicated and uncomplicated urinary tract infections.
Causes
More than 95% of urinary tract infections are caused by a single bacterium. In 90% of outpatients and 50% of inpatients, the pathogenic bacteria are Escherichia coli, which can be serotyped into more than 140 species. See re-infection, indwelling catheter, complications of urinary sensation; Candida albicans, new cryptococcal infections are seen in patients with diabetes and use of glucocorticoids and immunosuppressive drugs and after renal transplantation; Staphylococcus aureus is seen in skin trauma and drug addicts caused by bacteremia and sepsis; viruses, mycoplasma infections are rare, but in recent years there has been a gradual increase. Multiple bacterial infections are seen in indwelling catheters, neurogenic bladder, stones, congenital malformations, and vaginal, intestinal, and urethral fistulas.
Pathogenesis
1, Bacterial colonization in the intestine and around the urethral orifice spreads to the urethra.
2, Through urinary reflux, bacteria retrograde in the urinary tract and bind to the corresponding receptors in the epithelial cells of the urinary tract, multiplying locally and producing inflammation.
3, Through turbulent flow of urine in the ureter, bacteria travel up to the kidney, leading to kidney tissue damage and eventual fibrosis if the inflammation is not controlled in time.
Pathophysiology
1, Anatomical factors may be the reason why urinary tract infections are more common in women than in men. The female urethra is relatively short and the anus is close to the urethral opening. It is easy to be infected.
2, Vaginal lactobacilli, normal urinary flow and mucosal defense factors may provide protection against infection. Premenopausal vagina has peroxide-producing Lactobacillus colony, which can prevent the proliferation of uropathogens. The decrease in estrogen levels after menopause leads to a decrease in lactobacilli and an increase in vaginal pH, both of which tend to cause pathogen proliferation.
3, Mechanical abnormalities that cause urinary retention predispose to urinary tract infections, including pelvic organ prolapse or urinary tract obstruction associated with anti-incontinence surgery, lower urinary tract diverticula or stones. Urinary retention due to functional abnormalities, such as hypocontraction of the detrusor muscle or incomplete bladder emptying due to neurogenic bladder, can likewise cause urinary tract infections.
Susceptibility factors
1, Urethral obstruction, vesicoureteral reflux.
2, Invasive operations.
3, Pregnancy.
4, Diabetes mellitus and advanced age, immunodeficiency.
Clinical manifestations
The disease occurs in women of childbearing age, with a male to female ratio of about 1:8. Clinical manifestations include the following three groups.
I. Cystitis.
This is commonly referred to as lower urinary tract infection. The main manifestations of cystitis in adult women are urinary tract irritation, i.e., frequent, urgent and painful urination, leukocyturia, occasionally hematuria, or even carnal hematuria, and discomfort in the bladder area. There are usually no obvious symptoms of systemic infection, but a few patients may have back pain, low fever (usually not more than 38°C), and blood leukocyte counts are often not elevated. About 30% or more of cystitis is self-limiting and can heal spontaneously within 7 to 10 days.
Second, acute pyelonephritis.
The manifestations include the following two groups of symptoms: (1) urinary symptoms: including bladder irritation signs such as urinary frequency, urgency, and painful urination, lower back pain and/or lower abdominal pain; (2) symptoms of systemic infection: such as chills, fever, headache, nausea, vomiting, and loss of appetite, often accompanied by elevated blood leukocyte count and increased sedimentation. There is usually no hypertension and azotemia.
Third, the clinical manifestations of atypical urinary tract infection.
① systemic acute infection symptoms as the main manifestation, while the local symptoms of urinary tract are not obvious.
②Urinary tract symptoms are not obvious, while the main manifestations are symptoms of acute abdominal pain and gastrointestinal dysfunction.
(iii) Hematuria, mild fever and lumbago as the main manifestations.
(iv) No obvious urinary tract symptoms, but only back pain or lumbago.
⑤ a small number of people showed renal colic and hematuria.
⑥There are no clinical symptoms at all, but the quantitative culture of urine bacteria, colonies ≥ 105/ml.
IV. Urine culture and colony count.
The diagnosis of urinary sensation can be confirmed when the patient meets one of the following conditions.
① typical urinary tract infection symptoms + pus urine (urine sediment microscopy after centrifugation leukocytes > 5/HP) + positive urine nitrite test.
(ii) clean centrifuged mid-phase urine sediment leukocyte count or >10/HP in those with symptoms of urinary tract infection.
③ those with symptoms of urinary tract infection + formal early morning quantitative culture of clean middle urine bacteria with a colony count ≥ 105 /ml and two consecutive urine bacterial counts ≥ 105/ml with the same bacteria and subtypes on both occasions.
④ for cystocentesis urine culture, such as positive bacteria z regardless of the number of bacteria {.
⑤ typical urinary tract infection symptoms, clean mid-morning urine centrifuged urine sediment Gram stain before treatment to find bacteria, bacteria > 1 / oil microscopic field.
Differential diagnosis
(1) Systemic infectious diseases. Some local symptoms of urinary tract infections are not obvious while systemic acute infection symptoms are called prominent, and are easily misdiagnosed as influenza, malaria, sepsis, typhoid and other febrile diseases. If you can take a detailed history, pay attention to the lower urinary tract symptoms of urinary tract infection and kidney pain, and do urine sediment and bacteriological examination, it is not difficult to differentiate.
(2) Chronic pyelonephritis. The differential diagnosis needs to be made with recurrent urinary tract infections. It is now believed that the diagnosis of chronic pyelonephritis can be made only if there is focal rough renal cortical scarring with corresponding deformation of the renal calyces on imaging, otherwise the disease cannot be diagnosed despite a long history of urinary tract infection. Chronic pyelonephritis rarely occurs in the absence of complications in the urinary tract and only occurs when there is functional or organic obstruction of the urinary tract. Functional obstruction of the urinary tract is commonly associated with bladder-ureteral reflux, whereas organic cases are most often associated with kidney stones, etc.
(3) Renal tuberculosis. This disease is more prominent in urinary frequency, urgency and painful urination, and general antibacterial drug therapy is ineffective. Morning urine culture is positive for Mycobacterium tuberculosis, and urine sediment can find Mycobacterium antacidum, while common bacterial culture is negative. Positive tuberculin test and positive serum antibodies against Mycobacterium tuberculosis. The X-ray signs of renal tuberculosis foci can be found on intravenous pyelogram, and some patients may have extra-renal tuberculosis such as lung and epididymis, which can be differentiated. However, it should be noted that renal tuberculosis can often coexist with urinary tract infection. The possibility of renal tuberculosis should be highly noted in patients with residual symptoms of urinary tract infection or abnormal urine sediment even after treatment of urinary tract infection with antibacterial drugs.
(4) Urethral syndrome. Patients with urinary frequency, urinary urgency, and urinary pain, but no true bacterial urine on multiple examinations, can be differentiated. Urethral syndrome is divided into: (1) infectious urethral syndrome: about 75% of patients have leukocyturia, which is caused by pathogenic microorganisms, such as chlamydia and mycoplasma infection. Non-infectious urethral syndrome: about 25% of patients do not have leukocyturia, and the pathogen test is also negative.
Treatment principles
I. Female uncomplicated acute urinary tract infection
1, acute cystitis treatment program: three-day therapy treatment is recommended, namely oral compound sulfamethoxazole; orloxacin; or levofloxacin,. Since single-dose therapy is not as effective as three-day therapy, at present, it is no longer recommended. For areas where the pathogenic bacteria are resistant to sulfamethoxazole at rates as high as 10% to 20%, furantoin may be used for treatment,.
2, acute pyelonephritis treatment plan: 14 days of antibiotic therapy is recommended, and the course of highly effective antibiotics can be shortened to 7 days for patients with mild acute pyelonephritis. For mild symptomatic cases, oral quinolones can be used for treatment. If the causative organism is sensitive to compound sulfamethoxazole, this drug can also be taken orally for treatment,. If the causative organism is gram-positive, it can be treated with amoxicillin or amoxicillin/potassium clavulanate, alone. For severe cases or those who cannot take oral drugs, they should be hospitalized and treated intravenously with quinolones or broad-spectrum cephalosporin antibiotics. For those who are resistant to β-lactam antibiotics and quinolones, amoxicillin can be used for treatment; if the causative organism is gram-positive cocci, ampicillin/sulbactam sodium can be used, and if necessary, combined drug therapy can be used. If the condition improves, a sensitive antibiotic can be selected for oral treatment with reference to the urine culture results. Adjustment of the regimen and follow-up during the medication period is important. Urine culture should be done every 1 to 2 weeks to observe whether the urinary bacteria are negative. Quantitative urine bacterial culture should be done at the end of the course of treatment and at the 2nd and 6th week after discontinuation of the drug, and should preferably be reviewed once a month for 1 year afterwards.
3. Complex acute pyelonephritis: Due to the presence of various underlying diseases, complex acute pyelonephritis is prone to serious complications such as renal dermatomal abscess, perinephric abscess and renal papillary necrosis. Such patients need to be hospitalized. Firstly, the underlying diseases such as diabetes mellitus and urinary tract obstruction should be effectively controlled in a timely manner, and if necessary, joint treatment with urology and other related specialists is required; otherwise, it is difficult to cure the disease with antibiotic therapy alone. Secondly, treatment with broad-spectrum antibiotics should be used intravenously according to experience. During the medication period, the treatment plan should be adjusted in a timely manner according to changes in the condition and/or the results of bacterial drug sensitivity tests, and some patients still need a combination of drugs for at least 10 to 14 days.
Second, male cystitis
Prostatitis should be excluded in all men with cystitis. For uncomplicated acute cystitis can be treated with oral compounded sulfamethoxazole or quinolones at the same dose as female patients, but the course of treatment needs to be 7 days, while for patients with complicated acute cystitis can be treated with oral ciprofloxacin, or levofloxacin, for 7 to 14 days.
Third, urinary sensation during pregnancy
1, asymptomatic bacteriuria: the incidence of asymptomatic bacteriuria during pregnancy is as high as 2% to 7%, often occurring in the first month of pregnancy, in which up to 40% of cases can develop acute pyelonephritis during pregnancy, so it is recommended that urine culture tests should be routinely performed on pregnant women in early pregnancy in order to detect patients with asymptomatic bacteriuria. Anti-infective therapy is currently recommended for this group of patients. One of the following regimens may be used: (1) furantoin; (2) cefpodoxime; and (3) amoxicillin/potassium clavulanate. Ask the patient to come to the hospital for a repeat urine culture at 1 week after stopping the drug and then monthly until the end of the pregnancy. For those with recurrent asymptomatic bacteriuria, antibiotic prophylaxis can be taken during pregnancy by taking furantoin or cefadroxil at bedtime every night.
2. Acute cystitis: First, one of the following regimens may be used: ① furantoin, ② cefpodoxime, ③ amoxicillin/clavulanic acid potassium. Then, the treatment regimen is adjusted according to the urine bacterial culture results. The recommended course of treatment is generally 7 days.
3. Acute pyelonephritis: treatment with antibiotics must be mainly intravenous. After 48 hours of normal questioning or significant improvement in clinical symptoms, treatment can be changed to oral antibiotics. Empirical treatment can be taken first, using ceftriaxone, and then adjust the treatment plan according to the results of urine bacterial culture, the total course of treatment is 10 to 14 days.
IV. Asymptomatic bacteriuria
Treatment is not required for premenopausal women, non-pregnant patients, diabetic patients, the elderly, patients with spinal cord injury and asymptomatic bacteriuria with indwelling catheters. However, patients with asymptomatic bacteriuria who have undergone transurethral prostate surgery or other urological procedures or examinations that may result in bleeding from the urinary mucosa should be treated with sensitive antibiotics based on bacterial culture results.
V. Catheter-associated urinary tract infection
Urethra-associated asymptomatic bacteriuria does not require antibiotic treatment; female patients who still have asymptomatic bacteriuria 48 hours after catheter removal should be treated with sensitive antibiotics for 14 days based on urine culture results.
Precautions
In general, patients with urinary tract infections should drink plenty of water and urinate regularly. Drinking at least 2 liters of water and urinating every 2-3 hours is the most practical and effective method. By the flushing effect of large amounts of urine, some of the bacteria can be removed. Pay frequent attention to the cleanliness and hygiene of the pubic area so that bacteria from the urethra do not enter the urinary tract and re-cause urinary tract infections. Avoid catheterization as much as possible to avoid bringing bacteria into the urinary tract. Women who are prone to urinary tract infections should advise their husbands to clean their pubic area when having sex, in addition to cleaning their own vulva beforehand, because bacteria around the female urethra and urethral opening can be squeezed into the posterior urethra and bladder during sexual intercourse, thus causing infection.
The diet of urinary tract infections should not be flatulent. The things that are flatulent include milk, soy milk, cane sugar, etc.
The diet of urinary tract infection avoid hairy things. The hairy things (such as pork, chicken, mushrooms, scallops, crabs, bamboo shoots, peaches, etc.).
The diet of urinary tract infection avoid products that promote dampness and heat. This includes alcohol, desserts and high-fat foods.
The diet of urinary tract infection avoid spicy and stimulating things. These foods can worsen the symptoms of urinary tract irritation and make it difficult to urinate.
The diet of urinary tract infection avoid acidic food. Acidic foods include pork, beef, chicken, duck, eggs, carp, oysters, shrimp, and flour, rice, peanuts, barley, beer, etc. The acidity of the urine is closely related to the growth of bacteria and the antibacterial activity of drugs. The purpose of avoiding acidic foods is to make the urine an alkaline environment and enhance the ability of antibiotics to work
The diet of urinary tract infection high sugar food. Because sugar can also raise acidity in the body, so foods high in sugar also need to be restricted.
Disease prevention
Recurrence of urinary sensation can be divided into recurrence and reinfection. It is generally believed that the recurrence of the same bacterial infection within 2 weeks after the urinary tract infection has been cured is a recurrence of urinary tract infection; on the contrary, if the infection recurs after 2 weeks after the urinary tract infection has been cured, it is diagnosed as a reinfection regardless of whether the causative organism is the same as the previous one.
1. General measures: ① Drink more water, preferably more than 2000ml per day, and urinate every 2 to 3 hours. ②Patients with sexual life related to timely urination after intercourse, if necessary, need to consult with an obstetrician and gynecologist and choose an appropriate form of contraception. ③Avoid the use of urinary tract devices as much as possible. ④cranberry juice, experimental studies have shown that cranberry juice can prevent Escherichia coli from adhering to the epithelial cells of the urinary tract, which can help prevent urinary tract infections.
2, antibiotic prevention: antibiotic prevention can significantly reduce the chance of recurrence of urinary tract infections in women. Antibiotic treatment is recommended for female patients with two or more recurrences of urinary tract infection within six months, or three or more recurrences within one year (Level A). Prevention regimens include continuous dosing regimens and post-coital dosing regimens for 6 to 12 months. These regimens must be used only after the original urinary tract infection has resolved (negative urine culture after 1 to 2 weeks of drug withdrawal), and antibiotics may be selected based on the results of previous drug sensitivity tests and the patient’s drug allergy history. Compared with the continuous drug delivery method, the post-coital dosing method is more convenient and easier to be accepted by patients related to sexual life, which can be taken within 2 hours after sexual intercourse with cephalexin or ciprofloxacin or furantoin
3.Prevention for menopausal female patients: topical application of estrogen ointment to the vagina can restore the local environment of the vagina and can reduce the chance of recurrence of urinary tract infection (Grade A).
4. Patients with frequent recurrence of urinary sensation should be examined in detail for anatomical abnormalities of their urinary system, underlying pathologies (such as stones, polycystic kidney, medullary sponge kidney, etc.) and overall immune system abnormalities.
Chronic pyelonephritis disease profile
Chronic pyelonephritis is often caused by complicated urinary tract infections that do not resolve, and there are three types depending on the underlying cause: ①
(1) chronic pyelonephritis with reflux (reflux nephropathy); (2) chronic pyelonephritis with obstruction (obstructive chronic pyelonephritis); and (3) idiopathic chronic pyelonephritis. The first two types are particularly common.
Clinical manifestations
The course of chronic pyelonephritis is insidious. Clinical manifestations are divided into the following three categories: (1) manifestations of urinary tract infection: symptomatic pyelonephritis may occur intermittently in only a few patients, but more commonly manifests as intermittent asymptomatic bacteriuria, and/or intermittent lower urinary tract infection symptoms such as urinary urgency and frequency, lumbar and abdominal discomfort and/or intermittent low-grade fever. (ii) Chronic interstitial nephritis manifestations, such as hypertension, polyuria, increased nocturia, and susceptibility to dehydration. (iii) manifestations associated with chronic kidney disease.
In patients with the above clinical manifestations, signs such as focal, rough cortical seizure marks seen on X-ray intravenous pyelogram (IVP) with dilatation and blunting of accessory renal papillary constriction can confirm the diagnosis.
Treatment principles
The treatment plan for complex acute pyelonephritis is only considered in acute attacks of pyelonephritis; for the rest of the treatment, refer to the treatment plan for chronic kidney disease.
Expert opinion
Urinary tract infections, mostly seen in women of childbearing age and postmenopausal women, it is important to pay attention to the cleanliness and hygiene of the vulva. Urinary tract infections mostly have certain causative factors, so patients should be carefully checked for urinary stones, kidney or ureteral malformations, etc. In addition to medication, it is important to drink more water and keep the daily urine volume above 1500-2000ml (with the exception of patients with renal insufficiency), which plays the role of urinary tract flushing for the treatment of urinary tract infections. Western medicine treatment is prone to drug resistance, so the application of Chinese herbal medicine for the treatment of urinary tract infections is also very effective, can be applied, such as clearing heat and detoxification of Pan Lan Gen, Che Qian Cao, etc., can also be applied to Chinese preparations such as Ning Ju Tai, etc. In addition, more importantly, should also pay attention to strengthening nutrition, enhance physical fitness. Of course, during the treatment of the disease in addition, gonococcal urethritis is also very common at present, if any, should first be treated according to gonorrhea.