• Pediatric Infection and Vaccine
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• v.15 no.2
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• pp.162-166
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• 2008

Purpose : It has been previously reported that for patients with Mycoplasma pneumoniae pneumonia was previously recognized that overt illness is unusual under the age of three and the peak incidence of illness occurs in school-aged children. However, a higher incidence of this illness in younger children has been recently noted. Thus we investigated the incidence of M. pneumoniae pneumonia. Methods : The study subjects were 414 children who were diagnosed with M. pneumoniae pneumonia from January 2004 to December 2006 at Myong Ji Hospital were enrolled. The diagnostic criteria consisted of an anti-mycoplasma antibody (AMA) titer greater than 1: 320 or a four-fold rise in the titer at follow up. Results : The age distribution was as follows: before 2 years of age: 58 patients (14%), 2-4 years of age 157 patients (37.9%) and 5-15 years of age 199 patients (48.1%). The yearly incidence for the children before 5 years of age was 52 (44%), 49 (44.6%) and 114 (61.3%), respectively. The distribution according to the antibody titer was as follows; 1: 320 in 130 patients, 1:640 in 63 patients and greater than 1:1,280 in 221 patients. The hospital stay according to the antibody titer was not significant according to either age or the AMA titers. Conclusion : M. pneumoniae pneumonia showed a peak incidence in preschool children with a higher prevalence in children under the age of three than was previously recognized. The emergence of M. pneumoniae pneumonia as a cause of community acquired pneumonia in younger children calls for an epidemiologic study to investigate the changes of the pathogens in this age group and to recommend the proper treatment.

• Pediatric Infection and Vaccine
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• v.26 no.1
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• pp.60-65
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• 2019

Antiphospholipid antibodies may be produced in cases involving autoimmune diseases and can sometimes be caused by infections, such as Mycoplasma pneumoniae infection. However, antiphospholipid antibodies causing thrombosis associated with M. pneumoniae pneumonia in children have rarely been reported. We report a case of an 8-year-old boy with M. pneumoniae pneumonia with antiphospholipid antibodies, complicated by brachial artery thrombosis. He was found to have antiphospholipid antibodies and low protein S levels. The brachial artery thrombus was removed via thrombectomy. The titers of antiphospholipid antibodies turned normal within 5 months. This is a rare case of M. pneumoniae infection with brachial artery thrombosis associated with transient antiphospholipid antibodies.

• Pediatric Infection and Vaccine
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• v.30 no.3
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• pp.121-128
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• 2023

Purpose: This study aimed to investigate the recent age distribution of Mycoplasma pneumoniae in patients with respiratory infections and the differences in diagnostic usefulness according to the methods used in these patients. Methods: We retrospectively reviewed the medical records of patients aged ≤18 years with respiratory infectious diseases who underwent polymerase chain reaction (PCR) or a specific immunoglobulin M (IgM) test between July 2016 and February 2019. The diagnosis of M. pneumoniae infection was confirmed by a positive result in the PCR or IgM test. Results: Of the 2,721 patients tested for M. pneumoniae, 2,197 underwent IgM, and 1,144 underwent PCR, with positivity rates of 17% and 20%, respectively. Among the 620 patients tested for both IgM and PCR tests simultaneously, 35% had M. pneumoniae infection, with 14% under 1 year old and 13% under 1-2 years old. The positive rate increased with age in both tests. Higher positive rates were observed in the IgM test before 3 years of age and in the PCR test after 3 years of age. The agreement rate between the two tests was 77.9% (Cohen's kappa 0.402). Conclusions: As age increased, the rates of M. pneumoniae infection also increased. In patients under 2 years of age, 4¬-14% of infections were confirmed depending on the method used. The moderate agreement between the PCR and IgM tests suggests that the simultaneous use of PCR and the IgM test for the early diagnosis should be approached with caution.

• Pediatric Infection and Vaccine
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• v.16 no.2
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• pp.215-219
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• 2009

Mycoplasma pneumoniae is a common cause of community-acquired pneumonia in children, with a peak incidence at 5-14 years. Extrapulmonary manifestations occur in 20-25% of patients with M. pneumoniae infection. Most auto-antibodies that cause immune hemolytic anemia in humans are cold agglutinins. The formation of cold agglutinins is frequently observed during M. pneumoniae infections, and cold agglutinin disease usually occurs during M. pneumoniae infections. Nevertheless, severe hemolysis is exceptional. If a patient has any underlying disease related to hemolysis, it is possible to accelerate hemolysis. Hereditary spherocytosis is a common cause of hereditary hemolytic anemia resulting from red blood cell membrane defects. Hemolysis of red cells may result from corpuscular abnormalities or extracorpuscular abnormalities, such as immune or non-immune mechanisms. We report a case of hereditary spherocytosis associated with severe hemolytic anemia due to Mycoplasma pneumonia.

• Pediatric Infection and Vaccine
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• v.12 no.2
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• pp.135-139
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• 2005

Purpose : We investigated the clinical manifestations, radiographic and laboratory findings of children with M. pneumoniae pneumonia(MP) according to their age. Methods : A total of 75 children with MP who admitted to The Catholic University, Daejeon St. Mary's Hospital from July 2003 to February 2004, were classified into the three age groups : the ${\leq}2$ years of age(16 children), the children between 3 and 5 years of age(35 children), and the ${\geq}6$ years and older(24 patients). The diagnosis of MP was depended on the titers of anti-mycoplasma antibody that were measured 2 times, at admission and at discharge. Results : The total duration of the fever and the length of hospitalization were not different among the age groups. Although the white blood cell(WBC) value and differential was significantly different between the groups(P<0.01), a similar number in the WBC and reduced lymphocyte proportion was observed in all age groups compared to age-matched references. The patterns of pneumonia were significantly different according to age, i.e. segmental or lobar patterns were observed in 5 cases(31.3%) in the ${\leq}2$ years old group, but 16 cases(66.6%) in the >6 years old group(P<0.01). Conclusion : Although there was no difference in clinical findings according to age in MP, the radiographic finding was more severe in older children.

• Clinical and Experimental Pediatrics
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• v.48 no.2
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• pp.154-157
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• 2005

Purpose : We evaluated the epidemiologic and clinical characteristics of mycoplasma pneumonia. Methods : A total of 559 medical records of children with mycoplasma pneumonia admitted to The Catholic University of Korea, Daejeon St. Mary's Hospital, were retrospectively analyzed. Results : The mean annual number of cases was 51. There was a higher occurrence in autumn (September-November, 41.7%) and in winter(26.7%). Outbreaks of mycoplasma pneumonia were noted in 1993-94, 1997, 2001, and 2003. The age distribution showed a peak frequency of 5-6 years of age and 68.2 percent of patients were in 3-8 years of age. The male-to-female ratio was 1.2 : 1. In comparison between 1994 and 2003, there was a difference in age distribution with a peak frequency of 5-6 years of age in 1994, and of 3-4 years of age in 2003. There were outbreaks during autumn and winter in 1993-94, and during summer and autumn in 2003. Conclusion : Outbreaks of mycoplasma pneumonia occurred every 2-4 years in Daejeon in accordance with nationwide epidemics during 1993-2003. The peak incidence of age in the recent outbreak was younger than in the outbreak which occurred 10 years ago, and in outbreaks in Western countries.

• Proceedings of the Korean Society of Veterinary Service Conference
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• 1995.04a
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• pp.81.2-82
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• 1995

• Pediatric Infection and Vaccine
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• v.12 no.2
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• pp.114-123
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• 2005

Purpose : A wide, epidemic outbreak of M. pneumoniae pneumonia occurred throughout Korea in late 2003. Compared with previous years, the 2003 outbreak resulted in more severe cases and in an increased incidence of extrapulmonary symptoms and/or complications. We compared the clinical characteristics for M. pneumoniae pneumonia of 2003 to those of the past years. Methods : One hundred six children diagnosed with M. pneumoniae pneumonia by serologic tests at Bundang Cha General Hospital between Aug 2003 to April 2004 were enrolled. Medical records were reviewed retrospectively, for clinical, laboratory and radiological aspect as well as complications. The pleural effusions of 3 patients who underwent thoracentesis were also analyzed. Results : The duration of fever, cough, rhinorrhea, and sore throat was $8.2{\pm}4.7$, $22.1{\pm}4.8$, $8.4{\pm}2.1$, $4.3{\pm}1.2$ days, respectively. The incidence (percentage) and duration of abdominal pain, vomiting, diarrhea, headache, skin rash, arthralgia was $5.1{\pm}2.5$ (21.9%), $3.4{\pm}2.1$ (17.1%), $4.3{\pm}1.8$ (16.2%), $3.5{\pm}2.1$ (14.4%), $5.5{\pm}0.7$ (5.9%) and $4.6{\pm}1.3$ days (4.9%), respectively. The mean duration of admission and treatment were $7.4{\pm}4.3$ days and $21.6{\pm}11.1$ days. Higher values of CRP and ESR on admission were positively correlated with the duration of fever and length of admission. The findings of pleural effusion were similar to those seen in TB pleurisy. Complications, including myocarditis (2 cases), arthritis (3 cases), vasculitis (5 cases), asthma (3 cases), ARDS (1 case), and DIC (2 cases) were observed in 14.1% of patients. Conclusion : We found a number of characteristics of M. pneumoniae pneumonia among cases from late 2003 that were different from those of previous years. This outbreak resulted in more severe cases and in an increased incidence of extrapulmonary symptoms and/or complications. A multicenter study is needed to verify the changes in clinical characteristics observed during the 2003 outbreak from previous ones.

• Tuberculosis and Respiratory Diseases
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• v.63 no.6
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• pp.511-514
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• 2007

Mycoplasma pneumoniae is a common pathogen of community-acquired pneumonia. Mycoplasma pneumonia causes upper and lower respiratory tract symptoms in all age groups, with the highest attack rates in subjects 5 to 20 years old. In patients with mycoplasma pneumonia, the most common radiographic findings may be reticulonodular or interstitial infiltration, which have a predilection for the lower lobes. Findings that show lung collapse on a chest X-ray are very rare. We report a case of mycoplasma pneumonia that showed right upper lobe collapse.

• Pediatric Infection and Vaccine
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• v.31 no.1
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• pp.37-45
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• 2024

Purpose: This study aimed to examine the clinical features and determinants of macrolide-unresponsive Mycoplasma pneumoniae pneumonia (MUMP) and to assess the differences in the time to fever resolution between doxycycline (DXC), tosufloxacin (TFX) and corticosteroid (CST) as second-line treatment. Methods: We retrospectively analyzed the medical records of patients under the age of 18 who were admitted to Nowon Eulji University Hospital between July 2018 and February 2020, diagnosed with mycoplasma pneumonia. Macrolide resistance was confirmed by detecting point mutations in the 23S rRNA gene. MUMP was clinically defined by persistent fever (≥38.0℃) lasting for 72 hours or more after the initiation of macrolide treatment. In cases of MUMP, patients were treated with an addition of CST, or the initial macrolide was replaced either DXC or TFX. Results: Out of 157 cases of mycoplasma pneumonia, 83 cases (52.9%) did not respond to macrolides. Patients with MUMP exhibited significantly higher C-reactive protein (CRP) levels (3.2±3.0 vs. 2.4±2.2 mg/dL, P=0.047), more frequent lobar/segmental infiltrations or pleural effusions (56.6% vs. 27.0%, P<0.001; 6.0% vs. 0.0%, P=0.032), and a higher prevalence of 23S rRNA gene mutations (96.4% vs. 64.6%, P<0.001) when compared to those with macrolide-susceptible M. pneumoniae pneumonia. In terms of second-line treatment, 15 patients (18.1%) responded to CST, 30 (36.1%) to DXC, and 38 (45.8%) to TFX. The time to defervescence (TTD) after initiation second-line treatment was significantly shorter in the CST group compared to the DXC (10.3±12.7 vs. 19.4±17.2 hours, P=0.003) and TFX groups (10.3±12.7 vs. 25.0±20.1 hours, P=0.043), with no significant difference observed between the DXC and TFX groups (19.4±17.2 vs. 25.0±20.1 hours, P=0.262). Conclusions: High CRP levels, the presence of positive 23S rRNA gene mutation, lobar or segmental lung infiltration, and pleural effusion observed in chest X-ray findings were significant factors associated with macrolide unresponsiveness. In this study, CST demonstrated a shorter TTD compared to DXC or TFX. Further, larger-scale prospective studies are needed to determine the optimal second-line treatment for MUMP.