Urinary Tract Infection in Menopausal Women

　　一、发病原因

　　1、老年女性尿路感染发生的原因：角化细胞减少，使阴道自洁作用降低，细菌易于在前庭和阴道内繁殖。女性虽然易发生尿路感染，但是否发病，主要取决于机体的内在因素，与机体抵抗力减弱、尿道解剖及生理特点改变及内环境异常有密切关系。

　　2、引起尿路感染的细菌多为革兰阴性杆菌，约占62.6％，主要包括大肠埃希杆菌及副大肠埃希杆菌，占60％～80％。其次依次为变形杆菌、克雷白杆菌、产气杆菌、铜绿假单胞菌等。革兰阳性球菌为33.6％，其中55.6％为葡萄球菌和链球菌。另外还可见真菌、病毒、寄生菌等。还有复杂因素或院内感染的尿路感染。

　　3、多数情况下，大肠埃希杆菌的感染限于下尿道，变形杆菌感染常见于上尿道，肠道菌群中，厌氧菌比需氧菌多得多，但由厌氧菌引起的尿路感染则极少见。

　　二、发病机制

　　1、尿路防御功能

　　（1）卵巢分泌雌激素使前庭及阴道内pH值保持在4.5酸性环境，细菌不易繁殖，幼年或绝经后pH值可达7，在碱性环境下，细菌较易繁殖而发生感染。

　　（2）膀胱有规律地排尿，尿液不断流动，可稀释及排出进入膀胱的少量细菌，只要尿流通畅，膀胱排空正常，细菌在尿路内难以停留，因此残余尿越多，停留于膀胱内时间越长，发生尿路感染可能性越大。

　　（3）膀胱黏膜有杀菌能力，可分泌IgA，具有抗菌作用，尿液中高浓度尿素和有机酸不利细菌生长。膀胱黏膜内白细胞具有吞噬及杀灭细菌作用。尿液中类黏蛋白可阻止细菌黏附在尿路黏膜上。

　　（4）急性膀胱炎时，膀胱黏膜上皮可加快脱落，以加速消除黏附在膀胱黏膜上的细菌。

　　2、感染途径

　　（1）上行感染：正常情况下，尿道口常有细菌生长，并进入尿道，在排尿终末时，后尿道尿液可反流回膀胱，细菌随之进入膀胱，由于各种因素损伤了尿路黏膜防卫能力便引起炎症。

　　（2）血行感染：身体某处发生细菌感染，感染灶细菌进入血流，随血流循环到肾脏并形成多发性小脓肿，沿肾小管向下扩散而引起肾盂肾炎，仅见金葡菌败血症，约占3％。

　　（3）淋巴道感染：盆腔器官感染、阑尾炎、结肠炎时，细菌可通过淋巴管进入右肾，但极少见。

　　3、易感因素

　　（1）女性尿道短而宽，长约3.5cm，括约肌薄弱，细菌易侵入，加之女性尿道口与阴道及肛门靠近，如不注意外阴清洁，并有不良擦便习惯，会将细菌带入尿道口周围造成感染。

　　(2) Gynecological genital tract inflammation can easily cause cystitis and urethritis at the same time.

　　(3) Estrogen plays an important role in maintaining the integrity of the bladder and urethral mucosa. When the level of estrogen in elderly women is seriously reduced, it is easy to cause atrophic cystitis. Added to the atrophy and inward retraction of the vaginal mucosa, the urethral orifice is also pulled inward, making it easy to develop urethritis, urethral meatotomy, and cystitis.

　　(4) Any factor that destroys the function of the ureteral orifice valve causes urine to reflux into the ureter when the bladder pressure increases, easily carrying bacteria from the bladder into the renal pelvis and causing upper urinary tract infection. This factor causes urinary tract infection in adults accounting for 24.9% to 30.4%. Elderly diabetes or neurogenic bladder often leads to vesicoureteral reflux, which accounts for about 8.3% of the risk factors for urinary tract infection and is also a major cause of upper urinary tract infection.

　　(5) Cystocele causes a change in the physiological angle between the bladder and the urethra, making it difficult to fully empty the bladder each time. Due to long-term small amounts of urinary retention, it is easy to lead to urinary system infection.

　　(6) During urinary tract instrumentation or treatment, it often damages the urinary tract mucosa. If bacteria are introduced into the urinary tract during the operation, it facilitates bacterial invasion. There are reports that the incidence of infection caused by catheterization is 1% to 3%, reaching 10% to 15% in critically ill bedridden patients. The infection rate is 5% after leaving an open drainage tube in place for one day, and it is difficult to avoid urinary tract infection after four days. Catheterization or urinary catheter placement accounts for 6.6% of the risk factors for elderly urinary tract infections. In recent years, closed-system catheterization devices have been used, which can prevent infection within two weeks, but it is also difficult to avoid infection over a long period of time.

　　(7) Systemic diseases, long-term use of adrenal cortical hormones or immunosuppressive drugs, etc., are prone to urinary tract infections. Elderly women also have low local and systemic immune function during physiological decline.

　　Most urinary tract infections, especially cystitis, are self-limiting diseases. In severe cases, even after treatment, if there is persistent high fever and significantly increased blood leukocytes, one should be vigilant for the occurrence of complications. The main ones are as follows:

　　1, Renal papillary necrosis often occurs in severe pyelonephritis accompanied by diabetes or urinary tract obstruction. It may complicate with Gram-negative bacterial sepsis or lead to acute renal failure.

　　2, Perinephric abscesses often arise directly from severe pyelonephritis. There are often unfavorable factors such as diabetes and urinary tract stones.

　　3, Pyelonephritis caused by urease-decomposing bacteria such as Proteus mirabilis can often lead to kidney stones, known as infectious calculi. Due to the difficulty of antibiotics reaching this area, it is easy to cause failure of urinary tract infection treatment. The combination of infection and urinary tract obstruction can lead to renal parenchymal damage and renal function impairment.

　　Gram-negative bacilli sepsis often occurs in acute urinary tract infections, especially after cystoscopy or catheterization. Severe complicated urinary tract infections, especially those with acute renal papillary necrosis, are also prone to Gram-negative bacilli sepsis.

　　1. Upper urinary tract infection

　　The clinical manifestations vary greatly depending on the severity of the inflammation, in addition to the above urinary tract irritation symptoms and bladder area tenderness, there are often systemic manifestations, onset is acute, chills, fever, headache, nausea, vomiting, back pain, renal area tenderness, and mild cases may be asymptomatic.

　　2. Lower urinary tract infection

　　It can be asymptomatic or manifest as frequent urination, urgency, dysuria, and in severe cases, cloudy purulent urine, known as urinary tract irritation syndrome. Sometimes, it is accompanied by difficulty in urination and a sense of residual urine, fullness and pain in the lower abdomen, difficulty in urination, and sometimes urge incontinence. In severe cases, there may be extreme bladder spasm, frequent urination, and difficulty in urination.

　　Due to the anatomical and physiological characteristics of women, the incidence of urinary tract infection is significantly higher than that of men, with a ratio of 1:9. The incidence of elderly women increases gradually, and the bacterial infection rate can reach 9% to 33% in women over 65 years of age. Urinary tract infection in postmenopausal women is prone to recurrence, and it is advisable to develop good habits of drinking plenty of water. Since the increase in urine flushes the urethra, it can prevent and reduce infection.

　　First, Urinalysis

　　It is the simplest and most reliable detection method. It is recommended to collect the first urine of the morning for testing. Any urine with more than 5 white blood cells per high-power field (>5/HP) is called pyuria. More than 96% of symptomatic urinary tract infection (UTI) patients may have pyuria. Direct microscopic examination is very unreliable. The detection of urinary white blood cell excretion rate is relatively accurate, but it is too繁琐. Currently, it is advocated to use the white blood cell lipase test, which shows a positive reaction when the white blood cell count exceeds 10/ml. The sensitivity and specificity are 75% to 96% and 94% to 98%, respectively. In addition to pyuria, acute urinary tract infection often presents with white blood cell casts, bacteriuria, and sometimes microscopic or gross hematuria, especially in the case of Brucella, Nocardia, and actinomycetes (including tuberculosis bacilli) infection. Occasionally, trace proteinuria may be seen. If there is more proteinuria, it suggests involvement of the glomeruli.

　　Second, Urinary Bacterial Examination

　　More than 95% of UTIs are caused by Gram-negative bacteria, and among sexually active women, saprophytic Staphylococcus aureus and Enterococcus faecalis may be present, while bacteria that reside at the urethral opening, skin, and vagina, such as Staphylococcus epidermidis, lactobacilli, anaerobes, and corynebacteria (diphtheria bacilli), rarely cause UTIs. In most cases, the presence of two or more bacteria in urine culture suggests sample contamination. Previously, it was believed that colony counts greater than 10^5/ml in clean midstream urine cultures had clinical significance, while counts less than 10^4/ml were considered contamination. Now, it is found that many UTI patients have low colony counts, even only 10^2/ml. The possible reasons include: acute urethral syndrome; saprophytic Staphylococcus aureus and Candida infection; initiation of antibiotic treatment; rapid diuresis; extreme acidification of urine; urinary tract obstruction; extravesical infection, etc. The Infectious Diseases Society of America recommends the following criteria: presence of lower urinary tract infection symptoms with colony counts ≥10^3/ml; presence of pyelonephritis symptoms with colony counts ≥10^4/ml may be considered as infection, with sensitivity and specificity of 80% and 90% for the former, and 95% for the latter.

　　Three, UTI localization examination

　　1. Including invasive and non-invasive examinations, bilateral ureteral catheterization has a high accuracy, but it must be performed through cystoscopy or percutaneous puncture of the renal pelvis to obtain urine, so it is a traumatic examination that is not commonly used. Cystic lavage is simple and easy to perform, commonly used in clinical practice, and has an accuracy greater than 90%. The specific method is to inject 40ml of 2% neomycin solution into the bladder through the catheter to sterilize the bladder, then rinse with saline, and then collect the urine flowing into the bladder for culture. Urine samples are taken every 10 minutes, for a total of three times. If it is cystitis, the bacterial culture should be negative; if it is pyelonephritis, it will be positive, and the number of colonies will increase sequentially.

　　2. Non-invasive examinations include urinary concentration function, urinary enzymes, and immune response detection. Acute and chronic pyelonephritis often accompany renal tubular concentration dysfunction, but this test is not sensitive enough to be used as a routine examination. Some patients with pyelonephritis may have elevated levels of lactate dehydrogenase or N-acetyl-B-D-glucosaminidase in their urine, but they lack specificity. To date, urinary enzymes that can help localize UTI are still under study. Recently, more attention has been given to the detection of antibody-coated bacteria in urine. Bacteria from the kidneys are coated with antibodies, while bacteria from the bladder are not. Therefore, it can be used to distinguish between upper and lower urinary tract infections, but the accuracy is only 33%. Contamination from vaginal or rectal flora, large amounts of proteinuria, or infection invasion, as well as urinary epithelium outside the kidneys (such as prostatitis, hemorrhagic cystitis, etc.) can all lead to false positives. About 16% to 38% of adult acute pyelonephritis and most children can show false negatives, so it is not used routinely.

　　3. In addition, the determination of urinary beta2-microglobulin can also help in distinguishing between upper and lower urinary tract infections. Upper urinary tract infection is more likely to affect the reabsorption of small molecular proteins by renal tubules, resulting in an increase in urinary beta2-microglobulin, while urinary beta2-microglobulin does not increase in lower urinary tract infection. Some literature reports that serum C-reactive protein is significantly increased during pyelonephritis and can reflect the therapeutic effect, while it does not increase during acute cystitis. However, since C-reactive protein can also increase during other infections, it affects the reliability of the test.

　　Four, X-ray examination

　　Due to the fact that acute urinary tract infection itself is prone to cause vesicoureteral reflux, intravenous or retrograde pyelography should be performed 4 to 8 weeks after the infection is eliminated. There is no routine recommendation for pyelography in acute pyelonephritis and uncomplicated recurrent UTI. For patients with chronic or refractory cases, urinary tract plain film, intravenous pyelography, retrograde pyelography, and cystoureterography during micturition can be performed as needed to check for obstruction, calculi, ureteral stenosis or compression, nephroptosis, congenital malformations of the urinary system, and vesicoureteral reflux. In addition, it can also understand the morphology and function of the renal pelvis and calyces, thereby distinguishing from renal tuberculosis, renal tumors, and so on. Renal angiography can show varying degrees of tortuosity of small blood vessels in chronic pyelonephritis. If necessary, renal CT scan or magnetic resonance imaging can be performed to rule out other kidney diseases.

　　Five, Radionuclide renal scan

　　Can understand the function of each kidney, urinary tract obstruction, vesicoureteral reflux, and bladder residual urine. The renal image characteristics of acute pyelonephritis are peak shift after peak, secretion segment appearing slower than normal by 0.5-1.0 minutes, and excretion segment descending slowly; the secretion segment of chronic pyelonephritis has a reduced slope, the peak becomes blunt or widened and shifted, the starting time of the excretion segment is delayed, showing a parabolic shape, but the above changes have no obvious specificity.

　　Six, Ultrasonic examination

　　It is the most widely used and simplest method at present, which can screen for incomplete urinary tract development, congenital malformations, polycystic kidney, renal artery stenosis, uneven kidney size, stones, severe hydronephrosis, tumors, and prostatic diseases, etc.

　　Dietary therapy for urinary tract infection during menopause:

　　1, Persimmon cake and reed heart grass soup:Two pieces of persimmon cake, 6 grams of reed heart grass, appropriate amount of sugar, decoct into soup for drinking. It has the effects of clearing heat and promoting diuresis, and relieving stranguria and止血. Can treat urethritis, cystitis, and hematuria patients.

　　2, Mung bean and plantain grass soup:Mung beans 60 grams, red beans 30 grams, plantain grass, appropriate amount of sugar, boil and drink. Clear heat and detoxify, promote diuresis and relieve stranguria.

　　3, Mung bean porridge:Mung beans 50 grams, glutinous rice 50 grams, appropriate amount of sugar. Wash the mung beans, soak in water for 8 hours, boil with strong fire, then change to low fire to cook until the mung beans burst, add glutinous rice and continue to cook until soft. Add sugar. Take twice a day, each time a bowl, as breakfast and afternoon snack. It can be eaten as cold drink frequently in summer.

　　4, Plantain seed bean soup:Mung beans 50 grams, black beans 50 grams, plantain seed 15 grams, honey 1 spoon. Wrap the plantain seed with gauze, put the mung beans and black beans into the pot, add an appropriate amount of water, boil until the beans are soft, turn off the fire, discard the medicine bag, and add honey. Eat the beans and drink the soup. Suitable for patients with difficulty in urination, short and urgent pain, and lumbar pain.

　　5, Green soybean and wheat porridge:Wheat 50 grams, green soybean 50 grams, tangcao 5 grams, first boil 500 milliliters of water with tangcao, remove the dregs and then add the washed green soybean and wheat grains to cook into porridge. Eat as breakfast.

　　6, Jinhuahua tea:Jinhuahua 30-50 grams,甘草末10克,boil in hot water for 10 minutes, drink as tea. Clear heat and detoxify, promote diuresis and relieve stranguria. Can treat fever and dysuria.

　　7, Thousand cart and snake meat soup:Clear heat and detoxify, promote diuresis and relieve stranguria. Mainly used for damp-heat stranguria and acute attack of chronic stranguria. Mile light 60 grams, snake slide 30 grams, plantain seed 15 grams, pork 100 grams. First decoct mile light, plantain seed, and snake slide into water, remove the dregs and take the juice. Boil the meat with the medicinal juice, and the meat is cooked until soft. Eat the meat and drink the soup. Take 1 time in the morning and evening, for 3-5 days. For those who cannot eat fatty meat, lean meat can be used. Contraindications: People with spleen and stomach deficiency should not take this medicine.

　　8, Clam meat soup:Clam meat 20 grams, begonia 30 grams, appropriate amount of rock sugar, boil with water, eat the meat and drink the soup. Clear heat and promote diuresis, treat urinary tract infections.

　　9, Winter melon and mung bean soup:Clear heat and promote diuresis. Mainly used for urinary tract infections, heat stranguria, and blood stranguria. Fresh winter melon 500 grams, mung beans 50 grams, add appropriate amount of sugar, boil into soup and drink. It can both clear heat and promote diuresis, and prevent summer heat and lower body temperature. It is the best beverage for preventing and treating urinary tract infections.

　　10, Mung Bean Sprout Juice:Mung bean sprouts 500 grams, sugar as appropriate. Wash the mung bean sprouts, crush them, squeeze the juice with gauze, and drink it as tea with sugar. Can treat urinary tract infection, red urine, frequent urination, turbid urine, etc.

　　11, Celery Juice for Cooling and Anti-inflammatory:Celery 2500 grams. Wash the fresh celery, crush and squeeze the juice, heat it to boiling, take 60 milliliters each time, three times a day, avoid spicy food.

　　12, Wheat and Glutinous Rice Porridge:Wheat 100 grams, glutinous rice 30 grams, sugar, osmanthus sugar as appropriate. Soak wheat and glutinous rice separately until they swell, wash them clean, cook them together in a pot, and cook until the grains are soft and turn into porridge. Add sugar and osmanthus sugar for seasoning, and eat it warm as breakfast or dinner. Suitable for: difficulty in urination, senile dribbling.

　　13, Barley and Ginger Juice:Barley 100 grams, ginger 15 grams, a little honey. Wash barley and ginger, boil them in water, discard the residue, add honey for seasoning, and take it three times before meals. Suitable for: dribbling and painful urination.

　　14, Amaranthus cruentus and Plantago asiatica Drink:Amaranth 50 grams, Plantago asiatica 20 grams, raw licorice 10 grams. Wrap Plantago asiatica in gauze, place it with Amaranthus cruentus and raw licorice in a pot, and boil 500 milliliters of water to get 400 milliliters of juice. Take it three times a day. Suitable for: acute and chronic urethritis, cystitis, dysuria caused by damp-heat, etc. Contraindicated for pregnant women.

　　15, Amaranthus cruentus Soup:Old roots of Amaranthus cruentus seedlings 50 grams, raw licorice 10 grams. Wash the roots of Amaranthus cruentus and licorice, boil them in water to make 1000 milliliters of decoction as tea. Drink multiple times a day, for a week. Suitable for:涩痛 urination in urinary tract infection.

　　Prevention: Reducing known susceptible factors is the key to preventing urinary tract infections. Pay attention to the cleanliness of the vulva, change underwear frequently, drink plenty of water, urinate once every 2-3 hours, which is the simplest and most practical method to clear bacteria in the urinary tract. Try to avoid urinary tract instrumental examinations, and urine bacterial culture should be performed 48 hours after examination. For those who have had recurrent urinary tract infections, or have urinary tract functional or anatomical abnormalities, antibiotics should be taken orally to prevent infection 48 hours before and after instrumental examination.