Urinary tract fungal infection

　　Fungal infections of the urinary tract mainly affect the bladder and kidneys. The most common cause is Candida species, which are normal symbiotic bacteria in humans and are often found in the oral cavity, gastrointestinal tract, vagina, and damaged skin. However, all pathogenic fungi (such as Cryptococcus neoformans, Aspergillus species, Mucor species, Histoplasma, Blastomyces, and Coccidioides) can cause renal infection as part of systemic or disseminated fungal infections.

　　Candida lower urinary tract infections are mainly caused by local urinary tract catheters. Generally, although candidiasis and bacterial infections often occur simultaneously, most fungal infections associated with Foley catheters follow bacteriuria and antibiotic treatment.

　　Candida nephritis is usually hematogenously disseminated and often originates from the gastrointestinal tract. Infections can occur from catheters inserted during nephrostomy, as well as from other long-term indwelling devices and stents. High-risk patients include those with tumors, AIDS, or those with impaired immune function after chemotherapy or immunosuppressive drug use. The main source of candidemia in these patients is intravascular indwelling catheters. Renal transplantation increases the risk of fungal infections due to the presence of indwelling urinary catheters, stents, antibiotics, anastomotic leaks, obstruction, and immunosuppressive therapy.

　　Pyelonephritis, also known as upper urinary tract infection, generally accompanied by lower urinary tract inflammation. Acute pyelonephritis often occurs in women of childbearing age, and the patients often have lumbar pain, renal area tenderness, percussion tenderness, accompanied by chills, fever, headache, nausea and vomiting, and other systemic symptoms, as well as urinary urgency, frequency, and dysuria, and bladder irritation signs, and blood tests show an increase in white blood cells. Generally, there is no hypertension or azotemia. The patient's urine is turbid, and gross hematuria may occur. Urinalysis shows a large number of white blood cells or pus cells, a few red blood cells and casts, and a small amount to moderate amount of protein.

　　1, Cystitis:Acute cystitis often starts suddenly, with burning pain during urination, frequent urination, often accompanied by urgency, and in severe cases, it is similar to urinary incontinence. Urinary urgency and frequency are particularly obvious, reaching 5 to 6 times per hour, with little urine output each time, even only a few drops. There may be lower abdominal pain at the end of urination. The urine is turbid, and hematuria may occur, which is often obvious at the end. There is mild tenderness in the suprapubic bladder area. Some patients may have mild lumbar pain. When the inflammatory lesions are limited to the bladder mucosa, there is often no fever and an increase in white blood cells in the blood, systemic symptoms are mild, and some patients have a feeling of fatigue.

　　2, Ureteral obstruction:It is manifested as dynamic dysfunction at the upper pole junction (UPJ). Its characteristics are that there are no obvious intraluminal stenosis and extraluminal compression factors at the UPJ, the ureteral catheter can pass smoothly during retrograde ureterography, but there is significant hydronephrosis.

　　When candiduria that cannot be explained occurs, it is necessary to evaluate whether there are any urinary tract structural abnormalities. It has been confirmed that patients with candiduria can have clinical manifestations such as asymptomatic candiduria, urethritis and prostatitis, cystitis (with or without calculus formation or gas formation), primary renal candidiasis, and hematogenous candidiasis.

　　Unlike bacterial urinary tract infections, the level of candiduria reflects a true candidal urinary tract infection, and not just contamination of the catheter or urine specimen, and it is usually diagnosed in patients at high risk of cystitis or irritation with candiduria. The excretion of substances from fungi can sometimes be observed, and cystoscopy and renal, bladder ultrasound can help detect calculus formation and obstruction.

　　The presence of fever and candiduria, sometimes with nipple necrosis and the excretion of fungal balls suggesting the diagnosis of ascending renal candidiasis, although renal function often deteriorates, severe renal failure rarely occurs in the absence of post-renal obstruction. Urinary tract imaging can help evaluate the extent of involvement. Candida blood cultures are often negative.

　　Fungal urinary tract infections are more common in women of childbearing age, and it is very important to pay attention to the cleanliness and hygiene of the vulva. Urinary tract infections often have certain predisposing factors, so it is necessary to carefully examine whether the patient has urinary tract stones, renal or ureteral malformations, and other conditions. In addition to medication, drinking plenty of water and maintaining a daily urine output of more than 2000ml is very important, as this has the effect of urinary tract irrigation and is also very important for the treatment of urinary tract infections. The application of traditional Chinese medicine and herbs in the treatment of urinary tract infections has accumulated a large amount of clinical experience, and can be applied such as Radix Isatidis, Scutellaria baicalensis, Patrinia scabiosaefolia, Plantago asiatica, and so on. In addition, attention should also be paid to strengthening nutrition and enhancing physical fitness.

　　1. Costovertebral point tenderness, kidney area percussion tenderness.

　　2. Urinalysis shows an increase in white blood cells and purulent urine.

　　3. Urinary sediment smear staining finds bacteria.

　　4. Urinary bacterial culture finds bacteria.

　　5. Urinary bacterial colony count > 10^5/ml, with symptoms such as frequent urination, > 10^2/ml also has significance; cocci 10^3-10^4/ml also has diagnostic significance.

　　6. One-hour urine sediment count shows more than 200,000 white blood cells.

　　7. Blood routine shows an increase in white blood cells and left shift of neutrophil nuclei.

　　Patients with fever should eat liquid or semi-liquid foods and fruits. The diet of fever patients should be light, easy to digest, and rich in vitamins. Generally, liquid or semi-liquid foods are mainly used, such as congee, thin porridge, noodles, lotus root starch, etc., and some fresh fruits should be matched. After the fever subsides, foods such as clear chicken soup noodles and vegetable porridge can be eaten. In the later stage of recovery, more high-protein foods such as lean meat, fish, and tofu can be supplemented.

　　Candiduria is effective in the treatment of Candiduria with flucytosine 50 to 150mg/kg orally every 6 hours for 1 to 2 weeks, but resistance often occurs. Among the new antifungal derivatives, fluconazole seems to be the most effective for fungal urinary tract infections due to its high oral bioavailability, once-daily dosage, and good penetration into urine and cerebrospinal fluid. Flucytosine or fluconazole 200mg/d orally should be given to asymptomatic candiduria patients.

　　Symptomatic cystitis patients without indwelling catheters can be treated with flucytosine or fluconazole for 1 to 4 weeks. A single dose of amphotericin B 0.3mg/kg intravenously also has good efficacy. When long-term indwelling catheters are used, flucytosine and fluconazole can reduce fungaluria, but they rarely eradicate it. Bladder irrigation may be effective.

　　In patients with renal candidiasis, treatment with amphotericin B and high-dose fluconazole (≥400mg/d) is equally effective in the initial treatment of invasive infections caused by Candida albicans and Cryptococcus tropicalis. Even if amphotericin B is used at the beginning, oral fluconazole should also be replaced in the early stage of treatment. However, some rare Candida species are not sensitive to fluconazole.