The Optimal Time for Initiating Probiotics for Preterm and VeryLow-Birth-Weight Infants: A 10-Year Experience in a Single Neonatal Intensive Care Unit / 대한소아소화기영양학회지

Purpose@#The starting time for probiotic supplementation in preterm infants after birth varies widely. This study aimed to investigate the optimal time for initiating probiotics to reduce adverse outcomes in preterm or very low birth weight (VLBW) infants. @*Methods@#Medical records of preterm infants born at a gestational age (GA) of <32 weeks or VLBW infants in 2011–2020 were reviewed respectively. The infants who received Saccharomyces boulardii probiotics within 7 days of birth were grouped into an early introduction (EI) group, and those who received supplemented probiotics after 7 days of birth were part of the late introduction (LI) group. Clinical characteristics were compared between the two groups and analyzed statistically. @*Results@#A total of 370 infants were included. The mean GA (29.1 weeks vs. 31.2 weeks, p<0.001) and birth weight (1,235.9 g vs. 1491.4 g, p<0.001) were lower in the LI group (n=223) than in the EI group. The multivariate analysis indicated that factors affecting the LI of probiotics were GA at birth (odds ratio [OR], 1.52; p<0.001) and the enteral nutrition start day (OR, 1.47; p<0.001). The late probiotic introduction was associated with a risk of late-onset sepsis (OR, 2.85; p=0.020), delayed full enteral nutrition (OR, 5.44; p<0.001), and extrauterine growth restriction (OR, 1.67; p=0.033) on multivariate analyses after adjusting for GA. @*Conclusion@#Early supplementation of probiotics within a week after birth may reduce adverse outcomes among preterm or VLBW infants.

Risk Factors and Effects of Severe LateOnset Hyponatremia on Long-Term Growth of Prematurely Born Infants / 대한소아소화기영양학회지

Purpose@#Sodium is an essential nutritional electrolyte that affects growth. A low serum sodium concentration in healthy premature infants beyond 2 weeks of life is called lateonset hyponatremia (LOH). Here, we investigated the association between LOH severity and growth outcomes in premature infants. @*Methods@#Medical records of premature infants born at ≤32 weeks of gestation were reviewed. LOH was defined as a serum sodium level <135 mEq/L regardless of sodium replacement after 14 days of life. Cases were divided into two groups, <130 mEq/L (severe) and ≥130 mEq/L (mild). Characteristics and growth parameters were compared between the two groups. @*Results@#A total of 102 premature infants with LOH were included. Gestational age ([GA] 27.7 vs. 29.5 weeks, p<0.001) and birth weight (1.04 vs. 1.34 kg, p<0.001) were significantly lower in the severe group. GA was a risk factor of severe LOH (odds ratio [OR], 1.328, p=0.022), and severe LOH affected the development of bronchopulmonary dysplasia (OR, 2.950, p=0.039) and led to a poor developmental outcome (OR, 9.339, p=0.049). Growth parameters at birth were lower in the severe group, and a lower GA and sepsis negatively affected changes in growth for 3 years after adjustment for time. However, severe LOH was not related to growth changes in premature infants. @*Conclusion@#Severe LOH influenced the development of bronchopulmonary dysplasia and developmental outcomes. However, LOH severity did not affect the growth of premature infants beyond the neonatal period.

Changes in Seroprevalence of Helicobacter pylori Infection over 20 Years in Jinju, Korea, from Newborns to the Elderly

Background@#The objective of this study was to examine changes in the prevalence of cytotoxic-associated gene A (CagA) positive Helicobacter pylori infection in Jinju, Korea, over the last 20 years. @*Methods@#Three cross-sectional analyses were conducted concurrently. A total of 1,305 serum samples were collected from 1994–1995, 2004–2005, and 2014–2015, respectively. The presence of immunoglobulin (Ig) G, IgA, and IgM antibodies against H. pylori CagA protein was examined by western blotting. @*Results@#Overall, seropositivity for anti-CagA IgG antibody was significantly decreased from 63.2% to 42.5% over the last 20 years (P < 0.001). Anti-CagA IgG seropositivities in children and young adults aged 10–29 years decreased from 1994 (60.0%–85.0%) to 2015 (12.5%– 28.9%). The age when plateau of increasing IgG seropositivity was reached in each study period shifted from the 15–19 year-old group in 1994–1995 (85.0%) to the 40–49 year-old group in 2014–2015 (82.5%). Overall seropositive rates of anti-CagA IgA and IgM antibodies did not change significantly either over the last 20 years. @*Conclusion@#H. pylori infection rate in children and young adults declined over 20 years in Jinju, probably due to improved sanitation, housing, or economy.

A novel mutation of ABCC8 gene in a patient with diazoxide-unresponsive congenital hyperinsulinism / 소아과

Congenital hyperinsulinism (CHI) is a rare condition that can cause irreversible brain damage during the neonatal period owing to the associated hypoglycemia. Hypoglycemia in CHI occurs secondary to the dysregulation of insulin secretion. CHI has been established as a genetic disorder of islet-cell hyperplasia, associated with a mutation of the ABCC8 or KCNJ11 genes, which encode the sulfonylurea receptor 1 and the inward rectifying potassium channel (Kir6.2) subunit of the ATP-sensitive potassium channel, respectively. We report the case of a female newborn infant who presented with repetitive seizures and episodes of apnea after birth, because of hypoglycemia. Investigations revealed hypoglycemia with hyperinsulinemia, but no ketone bodies, and a low level of free fatty acids. High dose glucose infusion, enteral feeding, and medications could not maintain the patient's serum glucose level. Genetic testing revealed a new variation of ABCC8 mutation. Therefore, we report this case of CHI caused by a novel mutation of ABCC8 in a half-Korean newborn infant with diazoxide-unresponsive hyperinsulinemic hypoglycemia.

Factors Associated with Removal of Impactted Fishbone in Children, Suspected Ingestion / 대한소아소화기영양학회지

PURPOSE: The management and clinical course in pediatric patients who had ingested foreign body were investigated retrospectively to evaluate the frequency and factor associated with successful removal of fishbone foreign body. METHODS: Based on the medical records of patients younger than 15 years old who visited emergency room because of foreign body ingestion from January 1999 to December 2012, the authors reviewed clinical characteristics including type of ingested foreign bodies, time to visits, managements and complications. RESULTS: Fishbone (50.1%) was the most common ingested foreign body in children. Among 416 patients with ingested fishbone, 245 (58.9%) were identified and removed using laryngoscope, rigid or flexible endoscope from pharynx or upper esophagus by otolaryngologists and pediatric gastroenterologists. The kind of ingested fish bone in children was diverse. The mean age of identified and removed fishbone group was 7.39 years old, and higher than that of unidentified fishbone group (5.81 years old, p<0.001). Identified and removed fishbone group had shorter time until hospital visit than the unidentified fishbone group (2.03 vs. 6.47 hours, p<0.001). No complication due to ingested fishbone or procedure occurred. CONCLUSION: Older age and shorter time from accident to hospital visit were the different factors between success and failure on removal of ingested fish bone in children.

White matter injury following rotavirus infection in neonates: new aspects to a forgotten entity, 'fifth day fits'? / 소아과

That rotavirus infection can cause neurological symptoms in young children has been well established. However, it is surprising why rotavirus infection has been overlooked as a cause of neonatal seizures for many years, despite significant research interest in neonatal rotavirus infection. Neonates are the age group most vulnerable to seizures, which are typically attributed to a wide range of causes. By contrast, because rotavirus infection is usually asymptomatic, it has been difficult to identify an association between this virus and neonatal seizures. The conventional wisdom has been that, although neonates are commonly infected with rotavirus, neurological complications are rare in this age. However, recent studies using diffusion-weighted imaging (DWI) have suggested a connection between rotavirus infection and neonatal seizures and that rotavirus infection can induce diffuse white matter injury without direct invasion of the central nervous system. The clinical features of white matter injury in rotavirus-infected neonates include the onset of seizures at days 4–6 of life in apparently healthy term infants. The recent findings seem to contradict the conventional wisdom. However, white matter injury might not be a completely new aspect of rotavirus infection in neonates, considering the forgotten clinical entity of neonatal seizures, 'fifth day fits'. With increased use of DWI in neonatal seizures, we are just starting to understand connection between viral infection and white matter injury in neonates. In this review, we discuss the historical aspects of rotavirus infection and neonatal seizures. We also present the clinical features of white matter injury in neonatal rotavirus infection.

Distinctive clinical features of HPeV-3 infection in 2 neonates with a sepsis-like illness / 소아과

We report a human parechovirus-3 (HPeV-3) infection in 2 neonates who had prolonged fever (>5 days) with palmar-plantar erythema. This distinctive rash was observed 4–5 days after fever onset, just before defervescence. Elevated aspartate aminotransferase, lactate dehydrogenase, and ferritin levels were characteristic laboratory findings in the 2 cases, suggesting tissue damage caused by hypercytokinemia. Case 1 was treated with intravenous immunoglobulin, considering the possibility of severe systemic inflammatory responses. The initial ferritin level was 385 ng/mL (range, 0–400 ng/mL); however, the level increased to 2,581 ng/dL on day 5 after fever onset. Case 2 presented with milder clinical symptoms, and the patient recovered spontaneously. HPeV-3 was detected in cerebrospinal fluid and/or blood samples, but no other causative agents were detected. The findings from our cases, in accordance with recent studies, suggest that clinical features such as palmar-plantar erythema and/or hyperferritinemia might be indicators of HPeV-3 infection in neonates with sepsis-like illness. In clinical practice, where virology testing is not easily accessible, clinical features such as palmar-plantar erythema and/or hyperferritinemia might be helpful to diagnose HPeV-3 infection.

Factors associated with mumps meningitis and the possible impact of vaccination / 소아과

PURPOSE: Mumps meningitis is a common complication of mumps infection; however, information on mumps meningitis in the postvaccine era is limited. The purpose of the present study was to determine factors associated with mumps meningitis and to discuss the effect of vaccination on this disease. METHODS: We retrospectively reviewed patients younger than 19 years with mumps, diagnosed at a university hospital in Korea between 2003 and 2013. Patients were divided into groups with and without meningitis, and the clinical features of the 2 groups were compared. RESULTS: The study enrolled 119 patients: 19 patients with meningitis and 100 patients without. Univariate analysis showed that older age (median: 15 years vs. 9.5 years, respectively), a longer interval from last vaccination (median: 10.2 years vs. 4.8 years, respectively), and febrile presentation (94.7% vs. 31.0%, respectively) were significantly associated with mumps meningitis. Sex, number of vaccination doses, bilateral parotitis, and the presence of complications other than meningitis did not differ between the 2 groups. In multivariate logistic regression analysis, age (odds ratio, 1.38; 95% confidence interval, 1.01-1.89; P=0.04) and fever (odds ratio, 30.46; 95% confidence interval, 3.27-283.61; P<0.01) remained independent factors for mumps meningitis. CONCLUSION: Clinicians in the postvaccine era should be aware of the possibility of mumps meningitis in febrile cases of mumps in adolescents, regardless of the number of vaccination doses. To establish the role of vaccination in mumps meningitis, further studies will be necessary.

Lupus Anticoagulant-hypoprothrombinemia Syndrome that did not Progress to Systemic Lupus Erythematosus: A Case Report / 임상소아혈액종양

Lupus anticoagulant-hypoprothrombinemia syndrome (LA-HPS) is a rare disorder, and appears mostly in children. The primary concern is its potential development into systemic lupus erythematosus (SLE). A 5-year-old patient was hospitalized with multiple purpuric lesions. A markedly prolonged prothrombin time and activated partial thromboplastin time were observed and were not corrected after mixing with normal plasma. Decreased factor II activity was consistent with LA-HPS. Identifying risk factors that play an important role in the development of SLE in patients with LA-HPS is of importance. Based on the case described here, anti-double stranded (ds) DNA antibody and the Sapporo criteria for antiphospholipid syndrome are related to subsequent SLE development, whereas there is no correlation with the results of the lupus anticoagulant (LA) test. We recommend an early and serial examination of anti-ds DNA antibody and full evaluation of Sapporo criteria for the screening of patients with LA-HPS who may progress to SLE.

A Natural Course of an Infantile Hypertrophic Pyloric Stenosis without Adequate Surgical Procedure / 소아외과

Infantile hypertrophic pyloric stenosis (IHPS) is one of the common surgical abdomen in infancy, characterized by progressive non-bilious vomiting. The etiology is unknown, but it likely develops after birth. The pylorus of the stomach becomes thick and triggers progressive vomiting. Abdominal ultrasonography (US) is widely used as a diagnostic tool. Currently, there is a rare IHPS patient with severe metabolic derangement because of general use of abdominal US and its accuracy. We experienced a natural course of a 62- day-old male infant with IHPS who was suffering from intermittent vomiting, loss of weight but had not been properly treated for 1 month. It is needed to make an effort to diagnose differentially in recurrent vomiting infant and check-up regularly, and also educate parents properly.

Lupus Anticoagulant-hypoprothrombinemia Syndrome that did not Progress to Systemic Lupus Erythematosus: A Case Report / 임상소아혈액종양

Lupus anticoagulant-hypoprothrombinemia syndrome (LA-HPS) is a rare disorder, and appears mostly in children. The primary concern is its potential development into systemic lupus erythematosus (SLE). A 5-year-old patient was hospitalized with multiple purpuric lesions. A markedly prolonged prothrombin time and activated partial thromboplastin time were observed and were not corrected after mixing with normal plasma. Decreased factor II activity was consistent with LA-HPS. Identifying risk factors that play an important role in the development of SLE in patients with LA-HPS is of importance. Based on the case described here, anti-double stranded (ds) DNA antibody and the Sapporo criteria for antiphospholipid syndrome are related to subsequent SLE development, whereas there is no correlation with the results of the lupus anticoagulant (LA) test. We recommend an early and serial examination of anti-ds DNA antibody and full evaluation of Sapporo criteria for the screening of patients with LA-HPS who may progress to SLE.

The first pediatric case of tularemia in Korea: manifested with pneumonia and possible infective endocarditis / 소아과

Tularemia is a potentially severe zoonotic disease caused by Francisella tularensis. A lack of awareness about tularemia can be embarrassing and could result in delayed treatment because of improper diagnosis. The diagnosis of tularemia is difficult, because the infections are rare and the clinical spectrum is broad. As only 1 adult case has been reported in Korea thus far, pediatricians in Korea may be unfamiliar with tularemia. We report our experience with a 14-year-old male adolescent with tularemia who presented with atypical pneumonia and possible infective endocarditis. Although the infectivity and mortality rates for tularemia are very high if left untreated, we did not suspect tularemia in this case until the incidental isolation of F. tularensis. The present case suggests that clinicians in Korea should be more aware of tularemia. This case also suggests that tularemia should be considered in undetermined cases of atypical pneumonia or acute febrile illness without local signs.

Differences in Clinical and Laboratory Findings between Group D and Non-Group D Non-Typhoidal Salmonella Gastroenteritis in Children / 대한소아소화기영양학회지

PURPOSE: To investigate the differences in clinical features and laboratory findings between group D and non-group D non-typhoidal Salmonella (NTS) gastroenteritis in children. METHODS: A retrospective chart review of children diagnosed with NTS confirmed by culture study was performed. The clinical features and laboratory findings of group D and non-group D NTS were compared. RESULTS: From 2003 to 2012, 75 cases were diagnosed as NTS at our center. The number of group D and non-group D patients was 45 and 30, respectively. The mean age was higher in group D than in non-group D patients (5.1 years vs. 3.4 years, p=0.038). Headaches were more frequently observed (p=0.046) and hematochezia was less frequently observed (p=0.017) in group D than in non-group D NTS gastroenteritis patients. A positive Widal test result was observed in 53.3% of group D and 6.7% of non-group D NTS cases (O-titer, p=0.030; H-titer, p=0.039). There were no differences in white blood cell counts, level of C-reactive protein and rate of antimicrobial resistance between group D and non-group D cases. CONCLUSION: The more severe clinical features such as headache, fever, and higher Widal titers were found to be indicative of group D NTS gastroenteritis. Additionally, group D NTS gastroenteritis was more commonly found in older patients. Therefore, old age, fever, headache, and a positive Widal test are more indicative of group D NTS than non-group D NTS gastroenteritis. Pathophysiological mechanisms may differ across serologic groups.

Differences in Clinical and Laboratory Findings between Group D and Non-Group D Non-Typhoidal Salmonella Gastroenteritis in Children / 대한소아소화기영양학회지

PURPOSE: To investigate the differences in clinical features and laboratory findings between group D and non-group D non-typhoidal Salmonella (NTS) gastroenteritis in children. METHODS: A retrospective chart review of children diagnosed with NTS confirmed by culture study was performed. The clinical features and laboratory findings of group D and non-group D NTS were compared. RESULTS: From 2003 to 2012, 75 cases were diagnosed as NTS at our center. The number of group D and non-group D patients was 45 and 30, respectively. The mean age was higher in group D than in non-group D patients (5.1 years vs. 3.4 years, p=0.038). Headaches were more frequently observed (p=0.046) and hematochezia was less frequently observed (p=0.017) in group D than in non-group D NTS gastroenteritis patients. A positive Widal test result was observed in 53.3% of group D and 6.7% of non-group D NTS cases (O-titer, p=0.030; H-titer, p=0.039). There were no differences in white blood cell counts, level of C-reactive protein and rate of antimicrobial resistance between group D and non-group D cases. CONCLUSION: The more severe clinical features such as headache, fever, and higher Widal titers were found to be indicative of group D NTS gastroenteritis. Additionally, group D NTS gastroenteritis was more commonly found in older patients. Therefore, old age, fever, headache, and a positive Widal test are more indicative of group D NTS than non-group D NTS gastroenteritis. Pathophysiological mechanisms may differ across serologic groups.

Association between Gastric pH and Helicobacter pylori Infection in Children / 대한소아소화기영양학회지

PURPOSE: To assess gastric pH and its relationship with urease-test positivity and histological findings in children with Helicobacter pylori infection. METHODS: Fasting gastric juices and endoscopic antral biopsy specimens were collected from 562 children and subjected to the urease test and histopathological examination. The subjects were divided into 3 age groups: 0-4, 5-9, and 10-15 years. The histopathological grade was assessed using the Updated Sydney System, while the gastric juice pH was determined using a pH meter. RESULTS: The median gastric juice pH did not differ significantly among the age groups (p=0.655). The proportion of individuals with gastric pH >4.0 was 1.3% in the 0-4 years group, 6.1% in the 5-9 years group, and 8.2% in 10-15 years (p=0.101). The proportions of moderate and severe chronic gastritis, active gastritis, and H. pylori infiltration increased with age (p<0.005). Urease-test positivity was higher in children with hypochlorhydria (77.8%) than in those with normal gastric pH (31.7%) (p<0.001). Chronic and active gastritis were more severe in the former than the latter (p<0.001), but the degree of H. pylori infiltration did not differ (20.9% vs. 38.9%; p=0.186). CONCLUSION: Gastric pH while fasting is normal in most children regardless of age. Urease-test positivity may be related to hypochlorhydria in children, and hypochlorhydria is in turn related to H. pylori infection.

Neonatal Late-onset Hypocalcemia: Is There Any Relationship with Maternal Hypovitaminosis D? / 대한소아소화기영양학회지

PURPOSE: Neonatal late-onset hypocalcemia is defined as hypocalcemia developed after postnatal 3 days and associated with hypoparathyroidism, high phosphate diets and vitamin D deficiency. We experienced the increment of neonatal late onset hypocalcemia over 1 year. We tried to evaluate the relationship between late onset hypocalcemia and maternal hypovitaminosis D. METHODS: The medical records in the neonates with late-onset hypocalcemia during January 2007 to July 2008 were retrospectively reviewed. Among those patients, 17 paired sera of mothers and neonates had collected. The levels of 25-OH vitamin D (25OHD) and intact parathyroid hormone (iPTH) were measured and were compared with neonate and the mother. RESULTS: The mean gestational age was 38+1 weeks, and the mean body weight was 2,980 g. The onset time of hypocalcemia was 5.9 days of age. Most of them (88.2%) were feeding with formula and no one was only breast milk feeding. Of the 17 patients, 13 were born in spring or in winter. The median levels of calcium, phosphorus, alkaline phosphatase, iPTH and 25OHD were 7.0 mg/dL, 8.6 mg/dL, 191.0 U/L, 57.2 pg/mL and 24.0 ng/mL in neonates. The levels of 25OHD of 6 neonates were <20 ng/mL. A total of 16 mothers were considered vitamin D-deficient (<20 ng/mL), and vitamin D insufficient (20<25OHD<30 ng/mL). CONCLUSION: Neonatal late-onset hypocalcemia in our study seems to be influenced by maternal vitamin D deficiency and insufficiency. Sun tanning and vitamin D supplements from winter to spring would be helpful to prevent maternal vitamin D deficiency, one of the causes of neonatal late-onset hypocalcemia.

Correlation between Positive Rate and Number of Biopsy Samples on Urease Test in Childhood Helicobacter pylori Infection

To identify the correlation between the number of gastric biopsy samples and the positive rate, we compared the results of urease test using one and three biopsy samples from each 255 children who underwent gastroduodenoscopy at Gyeongsang National University Hospital. The children were divided into three age groups: 0-4, 5-9, and 10-15 yr. The gastric endoscopic biopsies were subjected to the urease test. That is, one and three gastric antral biopsy samples were collected from the same child. The results of urease test were classified into three grades: Grade 0 (no change), 1 (6-24 hr), 2 (1-6 hr), and 3 (<1 hr). The positive rate of urease test was increased by the age with no respect to the number of gastric biopsy samples (one biopsy P = 0.001, three biopsy P < 0.001). The positive rate of the urease test was higher on three biopsy samples as compared with one biopsy sample (P < 0.001). The difference between one and three biopsy samples was higher in the children aged 0-9 yr. Our results indicate that the urease test might be a more accurate diagnostic modality when it is performed on three or more biopsy samples in children.

Denys-Drash syndrome, Septated Vagina And Low Level Of Anti-mullerian Hormone In male neonate

There is a wide variety of genital abnormalities observed in patients with Denys-Drash syndrome (DDS). WT1 is thought to influence the genes related to genital development and mutations in this gene have been associated with DDS. DDS should be considered in the differential diagnosis of newborns with genital anomalies. In contrast to other conditions with 46,XY disorders of sex development, individuals with DDS often have duplicated genital organs (a double vagina, cervix or uterus). A double uterus has not yet been reported with 1390G>A (Arg464 Asn) mutation. However, duplicated genitals have been reported with other genetic mutations in patients with DDS. The duplicated genitals in DDS may be associated with low anti-Mullerian hormone (AMH) secretion. Measurement of the AMH levels may add to our understanding of variations in genital development and their abnormalities in disorders such as DDS. In conclusion, this is first case of low level of AMH and double uterus in 1390G>A (Arg464 Asn) mutations of DDS male.

Orthostatic symptoms does not always manifest during tilt-table test in pediatric postural orthostatic tachycardia syndrome patients / 소아과

PURPOSE: Chronic day-to-day symptoms of orthostatic intolerance are the most notable features of postural orthostatic tachycardia syndrome (POTS). However, we have encountered patients with such symptoms and excessive tachycardia but with no symptoms during the tilt-table test (TTT). We aimed to investigate whether POTS patients with chronic orthostatic intolerance always present orthostatic symptoms during the TTT and analyze the factors underlying symptom manifestation during this test. METHODS: We retrospectively examined patients who presented with POTS at the Gyeongsang National University Hospital between 2008 and 2011. Diagnosis of POTS was based on chronic day-to-day orthostatic intolerance symptoms as well as excessive tachycardia during the TTT. The patients were divided two groups depending on the presentation of orthostatic symptoms during the TTT. Clinical data and the results of the TTT were compared between these groups. RESULTS: In 22 patients, 7 patients (31.8%) did not present orthostatic symptoms during the test. Diastolic blood pressure (BP) was significantly lower in the symptom-positive group. The head-up tilt resulted in a significant increase in diastolic BP in the symptom-negative group (P=0.04), while systolic BP had a tendency to decrease in the symptom-positive group (P=0.06). CONCLUSION: Significant patients with POTS did not present orthostatic symptoms during the TTT despite having chronic daily symptoms. This finding may be important for establishing definitive diagnostic criteria for pediatric POTS. Development of symptoms during TTT might be related to low diastolic BP and abnormal compensatory responses to orthostasis.

Influencing Factors to Results of the Urease Test: Age, Sampling Site, Histopathologic Findings, and Density of Helicobacter pylori / 대한소아소화기영양학회지

PURPOSE: We investigated the positivity rate and the time period to the positive color change of the urease test in children and adults and assessed the correlation of the urease test to histopathologic findings. METHODS: From 1995 to 2000, endoscopic biopsies of the antrum and body were collected from 811 children and 224 adults and subjected to urease tests and histopathology. RESULTS: The positivity rate of the urease test was 49.4% for 0-4 years, 48.4% for 5-9 years, 47.3% for 10-15 years, and 62.5% for 20-29 years in the antrum. The positivity rate was 85.1% in 0-4 years, 82.3% in 5-9 years, 74.7% in 10-15 years, and 74.1% in 20-29 years for the body. In the antrum, the highest positivity rate was <1 hour for the group aged 10-29 years and 6-24 hours in the group <10 years old (p<0.0001). In the body, the highest positivity rate was <1 hour in adults and 6-24 hours in children (p<0.0001). The proportions of the positive reactions within 1 hour were similar for the antrum and the body. In the cases of more severe chronic gastritis, active gastritis, and Helicobacter pylori infiltration, a positive urease test reaction occurred more quickly (p<0.0001). CONCLUSION: There were significant differences in urease tests according to age and sampling site. The discrepancy between the antrum and the body was greater in younger children. These results might be related to the low density and patchy distribution of bacteria in children and in the body.