Pediatric urinary tract infection

　　The causes of pediatric urinary tract infection are numerous, and the specific descriptions are as follows:

　　First, the reasons why children are prone to urinary tract infections

　　1. Physiological Characteristics

　　Infants using diapers, the urethral opening is often contaminated with feces, plus poor local defense ability, easy to cause ascending infection. Small infants have poor antibacterial ability, prone to bacteremia, which can lead to descending infection.

　　2. Congenital malformations and urinary tract obstruction

　　Narrowing of the renal pelvis ureteral junction, hydronephrosis, posterior urethral valve, polycystic kidney can all lead to poor drainage and secondary infection. Urinary tract obstruction can be caused by neurogenic bladder, stones, tumors, etc.

　　3. Urinary bladder ureteral urine reflux (abbreviated as urinary reflux)

　　Common during the neonatal period. The harm of urinary reflux lies in causing reflux nephropathy and kidney scarring, which often occurs in children under the age of 5. The degree of reflux is proportional to the amount of kidney scarring. Mild reflux can disappear with age, but severe reflux often requires surgical correction. Therefore, it is of great significance to investigate the presence of reflux in children with urinary tract infections for accurate diagnosis and treatment guidance.

　　Second, Pathogenic Bacteria

　　80% to 90% of children are caused by enterobacteria. In the primary cases of primary urinary tract infections, Escherichia coli is the most common, followed by Proteus, Klebsiella, and Paracoccus, etc. A few cases are caused by Streptococcus faecalis and Staphylococcus aureus, etc. Occasionally, viruses, mycoplasma, or fungi can cause infection.

　　Third, Infection Routes

　　1. Ascending infection is more common in girls.

　　2. Hematogenous infection often occurs in newborns and young infants and is common during the course of scabies, pneumonia, and sepsis.

　　3. A few cases can be caused by direct involvement through the lymphatic pathway and adjacent organs or tissues.

　　4. Urinary tract instrumental examination can also be an infection route.

　　Urinary tract infections in children not only severely affect the daily life of patients but also can lead to other diseases if left untreated for a long time. The main complications of this disease include the following two types:

　　1. Pyonephrosis

　　Pyonephrosis, also known as empyema of the kidney, refers to widespread destruction of renal parenchyma caused by purulent infection, leading to the formation of abscess cavities. The main clinical manifestations are chronic purulent urine and systemic消耗 symptoms, such as fatigue, weakness, weight loss, malnutrition, anemia, and fever.

　　2. Perinephritis

　　Perinephritis, also known as perinephric abscess, is not common in pediatrics, but it can occur at any age. The site of infection is in the fatty tissue around the kidney, and it is usually unilateral. The causative bacteria are often Staphylococcus aureus. The severity of symptoms varies. Severe cases may present with high fever, chills, nausea, vomiting, back pain, and upper abdominal pain. Sometimes the pain can radiate to the abdominal wall or lower limb. Lesions stimulate the psoas muscle, causing psoas spasm and hip flexion, making it impossible for the lower limb to extend straight. When this condition coexists with pyelonephritis, symptoms such as frequent urination and purulent urine may also occur.

　　Urinary tract infections in children are often not obvious during the neonatal period, and misdiagnosis is easy. Older children have symptoms similar to adults, with obvious local urinary symptoms, making diagnosis easier. Urinary tract infections in children are divided into acute and chronic urinary tract infections. The specific manifestations are as follows:

　　First, Acute Urinary Tract Infection

　　Acute urinary tract infection refers to a course of illness within 6 months. Symptoms vary with age and the site of infection. The younger the child, the more obvious the systemic symptoms. Local urinary symptoms are often mild or easily overlooked.

　　1. Neonatal period

　　Urinary tract infections are often caused by hematogenous infection. The severity of symptoms varies, with systemic symptoms as the main manifestation, such as fever, poor feeding, pallor, vomiting, diarrhea, abdominal distension, and other non-specific manifestations. Most children may have growth and development stagnation and slow weight gain. Some children may have seizures, drowsiness, and sometimes jaundice. However, generally, local urinary symptoms are not prominent.

　　2. Neonatal period

　　In the neonatal period, systemic symptoms are still prominent, such as fever, slight cough, and recurrent diarrhea. As age increases, symptoms such as frequent urination, urgency, and dysuria become more pronounced.

　　3. Childhood

　　When lower urinary tract infection occurs, it is often manifested as symptoms such as frequent urination, urgency, and dysuria, and sometimes terminal hematuria and enuresis, while systemic symptoms are often not prominent. When upper urinary tract infection occurs, systemic symptoms are often more prominent, manifested as fever, chills, malaise, and may be accompanied by back pain and renal area percussion pain, as well as urinary irritation symptoms. Some patients may have hematuria, but proteinuria and edema are often not obvious. Generally, it does not affect renal function.

　　Secondly, chronic urinary tract infection

　　Chronic urinary tract infection refers to a course of more than 6 months, with prolonged symptoms. The severity of symptoms varies, ranging from no obvious symptoms to renal failure (firstly, the impairment of concentrating function). Recurrent attacks can manifest as intermittent fever, back pain, fatigue, weight loss, progressive anemia, and other symptoms. Local lower urinary tract irritation symptoms may be absent or intermittent. Pyuria and hematuria may be present or not obvious.

　　Pediatric urinary tract infections not only severely affect the daily life of patients but also, if left untreated for a long time, can lead to other diseases. Therefore, prevention of this disease is particularly important. When preventing the disease, attention should be paid to the following points:

　　1. Clean the external genitalia daily and change underwear frequently. Do not use the water used to wash feet to clean the external genitalia.

　　2. After each bowel movement, infants should clean their anal area. After washing the diapers, they should be boiled or sterilized with boiling water if possible. The towels and basins used by infants should be separated from those used by adults.

　　3. Treat enterobiasis thoroughly.

　　4. Do not let children hold their urine. Because urine stays in the bladder for too long, on one hand, it is easy for bacteria to multiply, and on the other hand, the long-term filling of the bladder will reduce the contraction ability of the bladder muscle, making it difficult to empty the urine, thereby causing urinary tract infection.

　　6. Try to shorten the time children wear open pants.

　　5. Discover any congenital urinary system malformations in children and seek timely surgical treatment.

　　7. Enhance the child's resistance to various infections to reduce the opportunity for infections.

　　The examination methods for pediatric urinary tract infections mainly include urine examination. If the number of white blood cells in the urine sediment is greater than 5/HP, it should be considered as a possible urinary tract infection. The diagnostic value is greater if the white blood cells are aggregated in clumps or if there are white blood cell casts and proteinuria. White blood cell casts and proteinuria indicate kidney involvement. Urine culture and colony count are important for the diagnosis of this disease. A colony count of more than 100,000/ml can be diagnosed as a urinary tract infection, 1 to 100,000/ml may be suspected, and less than 10,000/ml is often considered contamination. The nitrate reduction test can be used as a screening test for the disease, with a positive rate of up to 80% to 90%. If there is a lack of nitrates in the urine, a large amount of diuresis, or the use of antibiotics, it may be negative.

　　In terms of diet, children with urinary tract infections should avoid the following foods:

　　1. Avoid flatulent foods.

　　Flatulent foods such as soy milk, milk, and sucrose can cause abdominal distension, making urination more difficult.

　　2. Avoid irritant foods.

　　Mushrooms, crabs, pork head meat, chicken, hairtail fish, bamboo shoots, peaches, and other foods can worsen inflammation and fever.

　　3. Avoid spicy and stimulating foods.

　　Spicy and stimulating foods can worsen urinary tract irritation symptoms, making urination difficult, and even causing redness and inflammation of the urethral opening and congestion and pain in the inflamed area, so they should be avoided.

　　Urinary tract infections in children can severely affect the daily life of the children, so they should be treated actively. The main treatment methods are the following three:

　　One: General treatment

　　During acute infections, patients should rest in bed, drink plenty of water, urinate frequently, and reduce the time bacteria stay in the bladder. Girls should pay attention to the cleanliness of the vulva and actively treat pinworms.

　　Two: Antibacterial therapy

　　Antibacterial drugs should be used early in the disease. For pyelonephritis, drugs with high blood concentrations should be selected, and for lower urinary tract infections, drugs with high urine concentrations, such as furan or sulfonamides, should be selected. Acute primary infections can be treated with sulfonamide drugs, pipemidic acid, furazolidone, norfloxacin, ampicillin, cefamycin, and other drugs. Symptoms usually improve within 2 to 3 days, and bacteriuria disappears. If symptoms do not improve after 2 to 3 days of treatment, or if bacteriuria persists, it often indicates that the bacteria may be resistant to the drug, and it should be adjusted early. If necessary, two drugs can be used in combination.

　　Three: Active treatment of urinary tract structural abnormalities

　　About half of the children with urinary tract infections have various causes. In chronic or recurrent urinary tract infections, there are often abnormalities in the urinary tract structure, which must be actively searched for and treated early to prevent renal parenchymal damage.