Prevalence of Mycoplasma IgM in children with lower respiratory tract illness

Background:  Few data are available for the recent occurrence of Mycoplasma infections in children in Japan. The purpose of the present study was therefore to identify the prevalence of Mycoplasma infections in children in Japan.
Methods:  IgM antibodies to M. pneumoniae were prospectively determined using the Meridian ImmunoCard Mycoplasma test in hospitalized patients with lower respiratory tract infections between January 2004 and June 2007. A total of 858 hospitalized patients aged 0–15 years (445 male, 413 female), diagnosed as having acute pneumonia or bronchitis, were enrolled. The number of patients with pneumonia or bronchitis was 331 (male/female, 167/164) and 527 (male/female/ 278/249), respectively. Two hundred and five of the 858 patients (23.9%) were ImmunoCard positive. Of the 205 patients, 121 children and 84 children were diagnosed as having pneumonia and bronchitis, respectively. One hundred and forty-three of the 727 patients (19.7%) <5 years of age were ImmunoCard test positive.
Conclusions:  M. pneumoniae infection is not rare in children aged <5 years in Japan.     

Comparison of polymerase chain reaction and the indirect particle agglutination antibody test for the diagnosis of Mycoplasma pneumoniae pneumonia in children during two outbreaks

BACKGROUND: Diagnosis of Mycoplasma pneumoniae pneumonia is challenging because of the lack of standardized rapid tests. Many serologic tests and polymerase chain reaction (PCR) based methods are used with different diagnostic criteria. METHODS: This retrospective study was conducted to compare the diagnostic values of the indirect particle agglutination test and nested PCR of nasopharyngeal aspirates for the diagnosis of M. pneumoniae pneumonia in children. These assays were evaluated in 234 hospitalized children with community-acquired lower respiratory tract infections during 2 outbreaks of M. pneumoniae pneumonia in 2000 and 2003. RESULTS: The cumulative PCR positive rate was 26.7% in patients with maximum antibody titers of < or =1:320 and 78.2% in those with titers of > or =1:640. Based on these data, a positive PCR, a 4-fold increase in antibody titer, or a single titer > or =1:640 were considered to indicate acute M. pneumoniae infection. Overall, 152 children were diagnosed to have M. pneumoniae pneumonia; 27 (18%) by serology only, 26 (17%) by PCR only, and 99 (65%) by both methods. Children who were diagnosed by PCR only were significantly younger (P = 0.003) and were more often immunocompromised (P = 0.019) than those that were PCR negative. Duration of cough before PCR diagnosis was shorter in cases diagnosed by PCR only than those that were PCR negative (P = 0.045). CONCLUSIONS: In conclusion, during the 2 outbreaks of M. pneumoniae infection, we found that the PCR test may be useful for the rapid diagnosis of M. pneumoniae pneumonia, particularly in young children and in immunocompromised patients and in early stage disease.     

Mycoplasma pneumoniae infection in a clinical setting

Background: Mycoplasma pneumoniae infection predominantly affects the respiratory tract, although the other organs may also be involved. Previous studies compared the clinical features of patients with M. pneumonia pneumonia to other pathogens and these studies were predominantly adult case series rather than involving children. The objectives of the present study were to compare the clinical features, laboratory, and radiographic findings in children seropositive for M. pneumoniae infection with children tested for suspected M. pneumoniae infection who were seronegative. Methods: Using a retrospective review of children who had complement fixation test (CFT) performed for suspected M. pneumoniae infection, children were classified as seropositive if the acute phase serum titer was ≥64, or paired samples taken 2–4 weeks apart showed a fourfold or greater rise in serum titer. In contrast, a patient with an antibody titer <64 or with paired sera showing less than a fourfold rise in titer was considered seronegative. Results: One hundred and fifty‐one children were included. Seventy‐six children had serological evidence of M. pneumoniae infection and the remaining 75 were seronegative. Children with M. pneumoniae infection were more likely to have fever >6 days duration prior to admission, crackles on auscultation, radiographic consolidation and thrombocytosis at presentation. In addition, M. pneumoniae infection was associated with pneumonia whereas seronegative children were more likely to have upper respiratory tract infection or asthma. Conclusions: Certain clinical parameters could assist in gauging the likelihood of M. pneumoniae infection in children, and thus direct whether antibiotic treatment is needed.     

80例大叶性肺炎患儿肺泡灌洗液病原及临床分析

目的了解儿童大叶性肺炎的主要病原及临床特点。方法选择2013年4月—2015年5月确诊为大叶性肺炎的患儿80例,应用纤维支气管镜行温盐水灌洗,收集肺泡灌洗液(BALF),采用荧光定量PCR(FQ-PCR)法检测并分析患儿BALF中的病原。结果 80例患儿的BALF中检出肺炎支原体(MP)59例,肺炎衣原体(CP)2例,肺炎链球菌(SP)12例,肺炎克雷伯杆菌(KP)1例,腺病毒(ADV)8例,呼吸道合胞病毒(RSV)1例,其中混合感染14例;MP大叶性肺炎儿童7~14岁年龄组多于其他年龄组。结论儿童大叶性肺炎的病原多样,MP是最多见的病原体。     

Role of Mycoplasma pneumoniae and Chlamydia pneumoniae in children with community-acquired pneumonia in Istanbul, Turkey

BACKGROUND: To investigate the role of Mycoplasma pneumoniae and Chlamydia pneumoniae infection in pediatric pneumonia, in Istanbul, Turkey, we conducted a prospective study covering all the children between 2 months and 15 years hospitalized for community-acquired pneumonia. METHODS: A total of 140 children (85 males, median age 2.5 years) with community-acquired pneumonia were enrolled. Acute and convalescent sera were tested for IgM and IgG antibodies to M. pneumoniae (enzyme-linked immunosorbent assay, Serion ELISA classic) and for IgM and IgG antibodies to C. pneumoniae (microimmunofluorescence, Savyon, Israel). RESULTS: Mycoplasma pneumoniae infection was diagnosed in 38 patients (27%) and C. pneumoniae infection in 7 (5%). In 2 children M. pneumoniae and C. pneumoniae co infection was observed. The average age of the M. pneumoniae cases was 5.3 years and that of the C. pneumoniae was 1.5 years. The average age of pneumonia cases caused by other pathogens was 3.4 years (p<0.05). No significant difference was observed in clinical onset, signs, symptoms and laboratory parameters in children with M. pneumoniae and C. pneumoniae infection and in those without M. pneumoniae and C. pneumoniae infection. CONCLUSIONS: The results of this study suggest a remarkable role for M. pneumoniae and C. pneumoniae in childhood community-acquired pneumonia, and the knowledge of the true prevalence of these two types of infections discovered in the community might lead to modifications in the present empirical treatment of bacterial pneumonia.     

Clinical assessment of Mycoplasma pneumoniae-associated hemophagocytic lymphohistiocytosis

Background: Mycoplasma pneumoniae has been reported to be an etiologic pathogen of infection-associated hemophagocytic lymphohistiocytosis (HLH), but few case reports have been available to date.
Methods: The clinical features of four childhood cases of M. pneumoniae -associated hemophagocytic lymphohistiocytosis (Mp-HLH) were retrospectively assessed to obtain data that might be useful for early diagnosis and effective management. The previous English-language literature pertaining to Mp-HLH was also reviewed.
Results: The patients were two boys and two girls, aged between 1 and 11 years of age. One patient was demonstrated to have concurrent infection with rubella. All the patients had typical radiographic features of M. pneumoniae pneumonia, and one patient also had encephalopathy as a complication. All the children underwent bone marrow examination because of antibiotic-refractory fever, mild hepatosplenomegaly, cytopenia, hyperferritinemia and elevated levels of urine β2-microglobulin. Cytopenia and hepatosplenomegaly in the present patients were relatively mild as compared to those in cases of other infection-associated HLH such as Epstein–Barr virus infection-associated HLH. Treatment with corticosteroids resulted in prompt and complete resolution in two cases, and i.v. high-dose gammaglobulin therapy achieved a complete response in another child. Spontaneous resolution under treatment with antibiotics alone was observed in one case.
Conclusion: Although Mp-HLH is a rare complication of M. pneumoniae infection, it should always be considered in patients with antibiotic-refractory M. pneumoniae infections with cytopenia. Mp-HLH might be effectively treated by corticosteroids or high-dose gammaglobulin. To clarify the diverse clinical manifestations of M. pneumoniae infections, immunological interactions between M. pneumoniae and the host immune system should be further investigated.     

Frequency of Chlamydia pneumoniae and Mycoplasma pneumoniae infections in children

OBJECTIVE: Chlamydia pneumoniae and Mycoplasma pneumoniae are among the most important pathogens of acute respiratory infections in children between the ages of 5 and 15 years. We aimed to investigate seasonal frequency of respiratory infections caused by C. pneumoniae and M. pneumoniae, frequency of coinfection, clinical findings and to determine relationship between clinical findings and laboratory results. MATERIAL AND METHODS: Total of 284 patients (ranging 5-15 years of age), admitted to out-patient clinic with symptoms of respiratory tract infections between January 2004 and June 2005, were enrolled in the study. IgA, IgG and IgM antibodies against C. pneumoniae were quantitatively detected in all serum samples by using microimmunofluorescence (MIF). For the M. pneumoniae infection an IgM titer in the ELISA test were analyzed. Nasopharyngeal smear samples were collected for PCR detection. RESULTS: Mean age was 8 +/- 2.2 (range 5-14) years. Mycoplasma pneumoniae IgM in 86 (30.2%) cases, C. pneumoniae IgM in one (0.3%) case, IgA in six (2.1%) cases and IgG in 10 (3.5%) cases were found positive. In 10 (3.5%) cases, both C. pneumoniae IgG (a titer of >1/216) and M. pneumoniae IgM were found positive concomitantly. The M. pneumoniae IgM in winter was found significantly higher compared to other seasons. Mycoplasma pneumoniae PCR method was performed on a total of 203 samples in 33 (16.2%) of which M. pneumoniae was found positive. The false positive ratio of PCR technique was found 16.2%. In a total of 217 examined samples by PCR method, the DNA of C. pneumoniae was found positive in two patients. CONCLUSION: Mycoplasma pneumoniae was a common pathogen in respiratory infections. The otherwise C. pneumoniae infections were rarely seen in children. A Comparison of serology diagnostic tests for M. pneumoniae infections was found more sensitive and specific than PCR.     

The role of Mycoplasma pneumoniae in acute pneumopathies in children

Among 199 cases of bronchopulmonary infection in children observed over a 2-year period, 22 cases (11%) were due to Mycoplasma pneumoniae. The diagnosis was based upon the complement fixation test on whole serum in half of the children and the research of specific IgM by complement fixation test on fractioned serum and/or indirect immunofluorescence on the others. The mean age of children with Mycoplasma pneumoniae was 6 years. The clinical and radiographic appearance of the affection was non specific, often similar to pneumococcal pneumonia.     

Myositis caused by a mycoplasma infection

Mycoplasma pneumonia infection can be associated with neurological manifestations such as meningoencephalitis, cerebellitis, aseptic meningoitis, polyradiculopathy, transverse myelitis, cranial nerve palsies and myositis [4, 5]. We report a case of a white female 11 years, 2 months old child, who presented with a 3 day history of pain in the left leg. The electromyograpy showed pathological signs. We found a serological titer of IgM antibodies for Mycoplasma pneumoniae. By treatment with erythromycin the complaints improved quickly. CONCLUSION: A myositis can be caused with an infection with Mycoplasma pneumoniae. The differential diagnosis is essential.     

儿童肺炎支原体肺炎治疗的研究进展

肺炎支原体(Mycoplasmal pneumonia,MP)感染可引起包括上呼吸道感染、气管支气管炎、肺炎等临床疾病.学龄期前后的儿童肺炎支原体感染多见为肺炎支原体肺炎(Mycoplasma pneumoniae pneumonia,MPP).因此,有效治疗肺炎支原体肺炎,包括由肺炎支原体感染引起的肺炎支原体血症及重症、难治性肺炎支原体肺炎对儿童健康的恢复具有重要意义.MPP的治疗宜采用综合治疗措施,包括合理、联合、足量、足疗程使用抗肺炎支原体的有效抗生素.同时,根据患儿不同的病情进展情况采取相应的特异性及非特异性免疫治疗等达到理想的治疗目的.     

Retrospective analysis of Mycoplasma pneumoniae infection in pediatric fatal pneumonia in Guangzhou, South China

The objective of this study is to investigate the infection and distribution of Mycoplasma pneumoniae in autopsied pulmonary tissue of pediatric severe pneumonia. Mycoplasma pneumoniae nested polymerase chain reaction and immunohistochemistry were done on autopsy pulmonary tissue from 173 patients who died of severe pneumonia. Mycoplasma pneumoniae was identified in 135/173 (78.03%) and 114/173 (65.89%) samples of autopsied pulmonary tissue of lethal severe pneumonia via nested polymerase chain reaction and immunohistochemistry, respectively. The coincidence of both assays was 92.4%. Mycoplasma pneumoniae associated fatal pneumonia has showed an increasing trend from 1988 to 2005 in South China, and the fatality rate of Mycoplasma pneumoniae associated fatal pneumonia in infants, 1 to 12 months, has risen to 66.9% (97/145). Mycoplasma pneumoniae is a significant cause of severe pneumonia, it is a universal event in infants, and children have died of severe pneumonia in South China. Mycoplasma pneumoniae might be an important pathogen responsible for fatal pneumonia in Guangzhou area, South China.     

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??Objective To investigate the application of bronchoalveolar lavage of flexible bronchoscopy in diagnosis and treatment of children with Mycoplasma pneumoniae pneumonia??MPP??. Methods Clinical data of 155 pneumonia patients ??57 cases of MPP and 98 cases of non-MPP????who had examination in flexible bronchoscopy, MP-DNA of bronchoalveolar larlavage fluid(BALF),and the traditional blood serological test of Mycoplasma pneumoniae??were retrospectively analyzed from Aug.2011 to Apr.2012 in Anhui Provincial Children’s Hospital. Results Mycoplasma pneumoniae pneumonia often occur red in children over the age of 5 or with lobar pneumonia or atelectasis in the left lung. The accuracy of MP-DNA in BALF was higher than that of the blood serological test. After alveolar wash and administration of medicines, 95.7?? of the atelectasis cases were cured. Conclusions Flexible bronchoscopy and bronchoalveolar lavage should be applied to MPP and atelectasis cases as soon as possible to promote lung recruitment and improve the outcome.     

Etiology of respiratory tract infections in children in Cali, Colombia.

One hundred eighty children hospitalized for acute respiratory disease were studied in Cali, Colombia. In the majority of patients, pneumonia was the reason for hospitalization and remained the final diagnosis. Fifty-one cases of pneumonia of indeterminate etiology comprised the largest single diagnostic category, followed by 38 cases of pneumonia associated with measles, and 22 cases assocaited with serologic evidence of infection with other viral agents or Mycoplasma pneumoniae. Etiologic diagnosis could be assigned with a reasonable degree of confidence in 116 of the 180 patients (64%). The laboratory procedure found most likely to provide the etiologic diagnosis in this series was paired sera specimens for demonstration of rise in antibody titer against the common viral respiratory pathogens. Those most frequently implicated serologically as etiologic agents in the cases studied were, in order of decreasing frequency, measles, influenza, parainfluenza, and adenoviruses.     

Score clínico para el descarte de neumonía por Mycoplasma pneumoniae

IntroductionThe gold standard for the diagnosis of pneumonia secondary to Mycoplasma pneumoniae is the serial measurement of IgM, since an isolated test for IgM has a poor sensitivity of 31.8%. A pneumonia due to Mycoplasma pneumoniae could be of clinically different origins, thus it is possible to perform a clinical score for its early diagnosis.ObjectiveTo develop a clinical score in order to rule out a pneumoniae secondary to Mycoplasma pneumoniae.MethodologyA total of 302 patients from 0 to 18 years-old, with a diagnosis of pneumonia were evaluated and divided into two groups: Mycoplasma positive and Mycoplasma negative. Using different variables in the medical records a clinical score was calculated.ResultsOf the 302 cases studied, 34 were classified as Mycoplasma positive and 268 as Mycoplasma negative. The variables relevant to the calculation of the score were age, days with fever, and days with cough, thus providing the CAF (Cough, Age, Fever) score. Ranges were assigned for each variable and points were given for each range. A value greater than or equal to 5 meant a positive score. The CAF score was applied to the 302 cases, resulting in 164 cases of Mycoplasma positive and 138 cases of Mycoplasma negative. The CAF score had a sensitivity of 85% and specificity of 49%.ConclusionThe CAF score had better sensitivity than other clinical diagnostic tools. With a negative predictive value of 96% it is possible to rule out a pneumonia secondary to M. pneumoniae. The study requires a prospective study to verify the usefulness of our score.     

Role of mycoplasma pneumoniae infection in aetiopathogenesis of juvenile idiopatic arthritis

Although more and more is known about chronic autoimmune diseases, attempts to establish one trigger factor have been unsuccessful. The role of endogenic factors is beyond doubt. But it is emphasized that environmental factors are necessary to cause the disease. Infections are taken under consideration as trigger mechanism in the development of autoimmune diseases including chronic arthritis. Both numerous viruses and bacteria are among the microorganism mentioned. We considered it sensible to conduct research on Mycoplasma pneumoniae infections in a group of patients with juvenile idiopathic arthritis (JIA). MATERIALS: 19 patients diagnosed with JIA aged between 6-17 were investigated for Mycoplasma pneumoniae infection whose blood was examined for antibodies against Mycoplasma pneumoniae in class IgG and IgM. The control group comprised 20 children of similar age admitted to hospital with digestive tract complaints. Methods: Serologic tests were made in serum. Marking of antigens of class IgM and IgG were made by Elisa method using commercial kits produced by Scientific Point. Quantitative calculations of a level of antigens were done using appropriate standards, positive and negative serum of reference standard and calibration curve. RESULTS: In 11 patients positive reaction for Mycoplasma pneumoniae in class IgG was observed and only in 2 in class IgM with low titer. In the control group positive reaction was observed in 3 children (15%). The fact that 58% of patients were infected (contact either with Mycoplasma pneumoniae) indicates that in the group of our patients with JIA, infections with these bacteria might have had a role in triggering the disease.     

北京单中心社区获得性肺炎住院患儿病原学分析

目的 了解住院患儿社区获得性肺炎(CAP)的病原谱及病原流行特点。方法 回顾性收集2012年12月至2013年11月首都医科大学附属北京儿童医院（我院）确诊的CAP患儿,采集性别、年龄、入院前抗病原治疗情况、入院时间、病原学诊断等资料,分析不同年龄、季节病原构成及流行特点。结果 1 853例CAP患儿总体病原检出率为781%,入我院前均有抗生素应用史。细菌检出率270%,前3位依次是肺炎链球菌、流感嗜血杆菌和肺炎克雷伯菌;病毒检出率为225%,以呼吸道合胞病毒（RSV）和腺病毒（ADV）最常见;肺炎支原体检出率为487%;混合感染检出率为230%,以细菌合并病毒感染最多见。②随着年龄增长单一细菌或病毒感染的比例呈明显下降趋势,肺炎支原体感染的比例呈现明显上升趋势,多种病原混合感染或无明确病原感染比例随年龄增长亦有所降低;肺炎链球菌感染多见于3岁以下婴幼儿（759%）;流感嗜血杆菌（750%）和肺炎克雷伯菌感染（684%）多见于婴儿。RSV感染多见于婴儿（762%）,ADV感染多见于3岁以下婴幼儿（822%）。③单一细菌感染春季最多见,冬季次之;单一病毒感染冬季多见;单一肺炎支原体感染秋季最多见,夏季次之;多种病原混合感染以冬春季多见;无明确病原感染在春季最高。肺炎链球菌感染多见于冬春季,流感嗜血杆菌感染多见于春季,肺炎克雷伯菌感染多见于冬春季,RSV感染多见于冬季,ADV感染以冬春季多见。结论 CAP的病原谱构成存在显著的年龄和季节分布特点。细菌、病毒感染多见于婴儿,肺炎支原体感染多见于5岁以上患儿,多种病原混合感染以婴儿最多见。细菌感染冬春季多见,病毒感染冬季多见,肺炎支原体感染多发生于夏秋季;多种病原混合感染多见于冬春季。     

Procalcitonin in children admitted to hospital with community acquired pneumonia.

AIMS: To assess the sensitivity, specificity, and predictive value of procalcitonin (PCT) in differentiating bacterial and viral causes of pneumonia. METHODS: A total of 72 children with community acquired pneumonia were studied. Ten had positive blood culture for Streptococcus pneumoniae and 15 had bacterial pneumonia according to sputum analysis (S pneumoniae in 15, Haemophilus influenzae b in one). Ten patients had Mycoplasma pneumoniae infection and 37 were infected with viruses, eight of whom had viral infection plus bacterial coinfection. PCT concentration was compared to C reactive protein (CRP) concentration and leucocyte count, and, if samples were available, interleukin 6 (IL-6) concentration. RESULTS: PCT concentration was greater than 2 microg/l in all 10 patients with blood culture positive for S pneumoniae; in eight of these, CRP concentration was above 60 mg/l. PCT concentration was greater than 1 microg/l in 86% of patients with bacterial infection (including Mycoplasma and bacterial superinfection of viral pneumonia). A CRP concentration of 20 mg/l had a similar sensitivity but a much lower specificity than PCT (40% v 86%) for discriminating between bacterial and viral causes of pneumonia. PCT concentration was significantly higher in cases of bacterial pneumonia with positive blood culture whereas CRP concentration was not. Specificity and sensitivity were lower for leucocyte count and IL-6 concentration. CONCLUSIONS: PCT concentration, with a threshold of 1 microg/l is more sensitive and specific and has greater positive and negative predictive values than CRP, IL-6, or white blood cell count for differentiating bacterial and viral causes of community pneumonia in untreated children admitted to hospital as emergency cases.     

苏州地区儿童急性肺炎的病原学研究

目的探讨苏州地区小儿肺炎病原学,为临床诊疗提供依据。方法选取2005年11月～2006年2月苏州大学附属儿童医院呼吸科住院治疗的急性肺炎患儿,用无菌负压吸引法采集其新鲜痰液,直接免疫荧光法检测病毒,细菌培养检测细菌,酶联免疫吸附试验（ELISA）法检测血清支原体、衣原体抗体。结果532例中360例痰标本检测阳性,总检出率为67.7%。其中单纯病毒感染178例（33.5%）,单纯细菌感染23例（4.3%）,单纯支原体感染50例（9.4%）,单纯衣原体感染19例（3.6%）,混合感染90例（16.9%）。病毒以呼吸道合胞病毒为主（44%）;细菌则以肺炎链球菌（4.7%）为主,其次为表皮葡萄球菌（2.8%）和流感嗜血杆菌（1.9%）。结论病毒是苏州地区冬春季小儿急性肺炎的最常见病原,其次是肺炎支原体、细菌、肺炎衣原体。支原体感染多见于3岁以上儿童,肺炎衣原体感染则多见于小于3个月的婴儿。混合感染在3岁以下尤其1岁以下小儿明显。     

Mycoplasma pneumoniae pneumonia in a four-year-old child with transient abscess in the right lower lobe]

The frequency of Mycoplasma pneumoniae infection among community-acquired pneumonia, underestimated for a long time, is now better known. Severe evolution is yet uncommon. Differential diagnosis with Streptococcus pneumoniae is often difficult. CASE REPORT: A 4-year-old child was admitted for a right lower lobe pneumonia, with very high values of white blood cell count and CRP, worsening despite a treatment with high doses of amoxicillin, then with cefotaxime and vancomycin. Diagnosis of M. pneumoniae infection was considered only on the tenth day after admission and confirmed on the thirteenth day. Clinical outcome rapidly improved with macrolide antibiotherapy. Radiologic outcome consisted, two months after the beginning of the pneumonia, in abscess of the right lower lobe, which recovered in one month with continuing oral antibiotherapy. CONCLUSION: Lung abscess is very rare in M. pneumoniae pneumonia, as only two other cases were described in the literature. In all three cases, macrolide therapy was delayed. Those cases highlight the importance of considering M. pneumoniae infection in a beta-lactams-resistant community-acquired pneumonia, whatever its severity may be, and to start macrolide antibiotherapy. Our case also shows the possibility of a conservative treatment in case of pulmonary abscess, if clinical tolerance is good.