Survey of Mycoplasma pneumoniae in Iranian children with acute lower respiratory tract infections

Clinical and Epidemiological Determinants of Lower Respiratory Tract Infections in Hospitalized Pediatric Patients

Background

Lower respiratory tract infection (LRTI) is the main cause of pediatric mortality and morbidity in low- and middle-income countries.

Purpose

This study was carried out to determine the clinical and epidemiological characteristics of children with LRTI.

Method

A retrospective study was conducted on all pediatric patients who were hospitalized due to LRTI in Abuzar Hospital (Ahvaz, Iran) during one year. Incomplete medical records and children who were treated on an outpatient basis, as well as infants younger than 1 month of age, were excluded. The patients were evaluated in terms of epidemiological, clinical, and paraclinical characteristics.

Results

A total of 303 hospitalized children and infants were identified. Their mean age was 29.09 ± 38.96 months (range 1 month-15 years), and 59.4% of them were males. The highest frequency of patients was at the age below one year (50.8%, n = 154). Pneumonia and bronchitis were the most common LRTIs. Respiratory (54.6%) and neurological (21.6%) diseases were the most prevalent underlying medical conditions. Admission was more common in winter (n = 120, 39.6%) and spring (n = 79, 26.1%). The mean length of stay (LOS) in the hospital was 8.2 ± 5.5 days, and the overall mortality rate was 11.6%. In addition, 65 patients were severely underweight and 271 patients were malnourished. Moreover, there was a significant association between mortality and disease diagnosis (p < 0.05). Furthermore, there was a significant association between having an underlying disease and consanguineous parents (p < 0.01), as well as the frequency of hospitalization (p < 0.001).

Conclusion

Additional studies are required to determine factors contributing to disease severity among children with LRTI to develop appropriate preventive and therapeutic strategies.

First Detection and Characterization of Macrolide-Resistant Mycoplasma pneumoniae from People with Community-Acquired Pneumonia in Iran

Objectives: Increasing macrolide resistance of Mycoplasma pneumoniae strains is becoming a public health concern worldwide. Nevertheless, no comprehensive genomic background of circulating isolates is available in our region. We aimed to study the genetic diversity of this microorganism using the multiple-locus variable-number tandem-repeat analysis method and to investigate the relationships between MLVA types and macrolide susceptibility profiles of the isolates. Materials and Methods: A total of 270 patients attending Tehran general university hospitals were included in this study. One throat swab was taken from each patient. M. pneumoniae was identified using culture and PCR assay. Macrolide resistance was determined using the broth microdilution method. The MLVA was performed by amplification of four variable-number tandem-repeat loci. Results: Of 270 specimens, M. pneumoniae was detected in 25.2% (n = 68) and 21.8% (n = 59) samples using PCR and culture, respectively. Approximately 56.9% of isolates were resistant to macrolides. Fifty-one of 59 M. pneumoniae isolates were divided into 6 distinct MLVA types. Conclusion: The macrolide-resistant M. pneumoniae (MRMP) rate in this study was relatively high and most of the MRMP isolates were assigned into the type 4/5/7/2. Since a significant association between MLVA type 4/5/7/2 and macrolide resistance of M. pneumoniae isolates was observed, further monitoring of genetic diversity of MRMP isolates might facilitate better understanding of epidemiology of this microorganism. Besides surveillance of the antibiotic susceptibility might be helpful to make necessary reconsiderations on guidelines for treatment of M. pneumoniae infection.

Epidemiology of Mycoplasma pneumoniae prevalence in Iranian patients: a systematic review and meta-analysis

Introduction. Mycoplasma pneumoniae is regarded as the important infectious agent of acute respiratory infections (ARIs) in the world. However, there is little knowledge about the prevalence of M. pneumoniae in Iran. Therefore, the aim of this study was to investigate the prevalence of M. pneumoniae in Iran through a meta-analysis of included studies.Methods. A systematic search was done by using electronic databases from papers that were published by Iranian authors to the end of February 2019. Then, 12 publications, which met our inclusion criteria, were enrolled for data extraction and analysis by using the 'metaprop program' in stata version 14.0.Results. The pooled prevalence of M. pneumoniae was 9 % (95 % confidence intervals: 5-16 %) ranging from 1 to 26 %. There was a significant heterogeneity among the 12 studies (X²=128.29; P<0.001; I ²=91.43 %). The funnel plot for publication bias showed no evidence of asymmetry.Conclusions. The frequency of M. pneumoniae in Iran is comparable with other parts of the world. Although the overall prevalence of M. pneumoniae was low, awareness about the distribution of these agent is very important because of higher infection rates in susceptible groups. In addition, these results showed the rates of M. pneumoniae had variation based on location, type of infection and sample, gender and detection rate and there was evidence of publication bias.

The use of multiplex PCR for the detection of atypical pathogens in Egyptian children with CAP: a high rate of Bordetella pertussis in early infancy

Background

Atypical pathogen infections played an important role in community-acquired pneumonia (CAP) in children. Pathogen-specific clinical symptoms are often lacking, and it is difficult to detect atypical pathogens by culture methods. The use of multiplex polymerase chain reaction (PCR) methods enables testing for many pathogens simultaneously in a single analysis.

Aim

To determine the role of atypical pathogens in children hospitalized with CAP.

Patients and methods

This cross-sectional study was conducted throughout a 2-year period from August 2015 to September 2017. It included 400 Egyptian children hospitalized with clinical diagnosis of CAP at a tertiary hospital in Cairo, Egypt. Sputum samples were collected from lower respiratory tract of all enrolled patients by mucus trap catheter for identification of Bordetella pertussis, Mycoplasma pneumoniae, Chlamydia pneumoniae, and Legionella pneumophilia by using multiplex real-time PCR.

Results

Among the 400 CAP patients enrolled in this study, atypical pathogens were detected in 12/400 (3%) patients. Bordetella pertussis was detected in 2% of cases, and it was responsible for CAP in 8/104 (7.69%) infants in the age stratum ≤ 4 months; compared with pertussis-negative cases, pertussis-positive cases were younger and incompletely vaccinated (P values were 0.001 and 0.007, respectively). Mycoplasma pneumoniae was detected in 1% of cases, all were among the age stratum > 4 months ≤ 59 months in 4/272 (1.47%) children.

Conclusion

In early infancy, Bordetella pertussis causes a significant proportion of hospitalized CAP cases; all were ≤ 4 months old and incompletely vaccinated. This finding could suggest the role of maternal immunization in developing countries.

Mycoplasma pneumoniae in Community-Acquired Lower Respiratory Tract Infections

OBJECTIVE

To determine the role of Mycoplasma pneumoniae (M. pneumoniae) in pediatric lower respiratory tract infections (LRTIs) employing serological tests and polymerase chain reaction (PCR) analysis.

METHODS

In this prospective study, 200 children aged 6 mo to 12 y hospitalized with acute LRTIs were investigated for M. pneumoniae. Serum samples were collected for serological analysis of M. pneumoniae. Throat swab samples were obtained on admission to amplify 277-base pair region of 16S rDNA gene of M. pneumoniae by PCR.

RESULTS

In the present study, 40(26.1%) children <5 y and 28(59.5%) children ≥5 y age group were positive for M. pneumoniae infection and this difference was statistically significant (P < 0.001). M. pneumoniae was positive in 32(41%) female and 36(29.5%) male children though this difference was statistically insignificant (P = 0.12). The clinical profile across M. pneumoniae positive and negative cases were comparable except for presence of chest pain which was statistically significant (P = 0.023). None of the radiological findings was statistically associated with incidence of M. pneumoniae infection. Serological evidence of acute M. pneumoniae infection was observed in 64(32%) patients with sensitivity 66.6% and specificity 70.1% while PCR positivity in 12(6%) patients with sensitivity 12.5% and specificity 97%. Together, serology and PCR detected M.pneumoniae infection in 68(34%) patients.

CONCLUSIONS

The present study underlines the role of M. pneumoniae in children with community- acquired LRTIs and more particularly in ≥5 y of age.

Bronchiolitis associated with Mycoplasma pneumoniae in infants in Suzhou China between 2010 and 2012

Viruses cause most cases of bronchiolitis in infants; consequently the importance of other agents such as Mycoplasma pneumoniae (MP) in the etiology of bronchiolitis may not be fully recognized. We investigated the prevalence and seasonal distribution of bronchiolitis caused by MP in 674 children admitted to the Children's Hospital affiliated with Soochow University from January 2010 to December 2012. The presence of MP was confirmed by real-time PCR. During the 3 years, we identified MP in 17.2% of the children with bronchiolitis. The annual MP detection rates were 16.6% in 2010, 17.8% in 2011, and 17.2% in 2012. MP was detected throughout the year, with a peak from July to September. The median age of MP-positive children was 10 months. Common clinical manifestations included cough, wheezing, and high fever. Moist and/or wheezing rales were frequent, and pulmonary interstitial infiltration was seen in 66.4% of chest X-rays. Patients with MP infection were older, were more likely to have pulmonary interstitial infiltration, and had shorter hospital stays than those with respiratory syncytial virus infection. Our study revealed MP as an important cause of bronchiolitis, with peaks of occurrence during the summer and early autumn. Pulmonary interstitial infiltrations were a common event.