High Prevalence of Mycoplasma pneumoniae and Chlamydia pneumoniae in Children with Acute Respiratory Infections from Lima, Peru

Chlamydophila pneumoniae-associated community-acquired pneumonia in paediatric patients of a tertiary care hospital in Mexico: molecular diagnostic and clinical insights

Chlamydophila pneumoniae is a cause of community-acquired pneumonia (CAP) and responsible for 1-2% of cases in paediatric patients. In Mexico, information on this microorganism is limited. The aim of this study was to detect C. pneumoniae using two genomic targets in a real-time PCR and IgM/IgG serology assays in paediatric patients with CAP at a tertiary care hospital in Mexico City and to describe their clinical characteristics, radiological features, and outcomes. A total of 154 hospitalized patients with diagnosis of CAP were included. Detection of C. pneumoniae was performed by real-time PCR of the pst and arg genes. Complete blood cell count, C-reactive protein measurement and IgM and IgG detection were performed. Clinical-epidemiological and radiological data from the patients were collected. C. pneumoniae was detected in 25 patients (16%), of whom 88% had underlying disease (P = 0.014). Forty-eight percent of the cases occurred in spring, 36% in girls, and 40% in children older than 6 years. All patients had cough, and 88% had fever. Interstitial pattern on chest-X-ray was the most frequent (68%), consolidation was observed in 32% (P = 0.002). IgM was positive in 7% and IgG in 28.6%. Thirty-six percent presented complications. Four percent died. A high proportion showed co-infection with Mycoplasma pneumoniae (64%). This is the first clinical report of C. pneumoniae as a cause of CAP in Mexican paediatric patients, using two genomic target strategy and serology. We found a frequency of 16.2% with predominance in children under 6 years of age. In addition; cough and fever were the most common symptoms. Early detection of this pathogen allows timely initiation of specific antimicrobial therapy to reduce development of complications. This study is one of the few to describe the presence of C. pneumoniae in patients with underlying diseases.

Identification of Mycoplasma pneumoniae-associated pneumonia cases among hospitalized patients using CLART® microarray technology

Objectives

Community-acquired pneumonia (CAP) is a global health condition that affects populations from all age groups. The laboratory identification of Mycoplasma pneumoniae as a causative agent of CAP is challenging because of its atypical and fastidious nature. Therefore, this study assessed the diagnostic potential of PneumoCLART bacteria® in identifying M. pneumoniae as a causative agent of pneumonia in hospitalized adults.

Methods

This prospective study used a cross-sectional approach to assess the diagnostic potential of PneumoCLART bacteria® for detecting M. pneumoniae in sputum samples procured from 27 patients with pneumonia who required hospitalization.

Results

The PneumoCLART bacteria® results illustrated that 7 of 27 patients with pneumonia were positive for M. pneumoniae (26%). However, the quality of sputum varied among the M. pneumoniae-positive and M. pneumoniae-negative samples. Fifty percent of the specimens obtained from patients positive for M. pneumoniae were saliva-contaminated and unsuitable for analysis.

Conclusions

Because the leukocyte count was low and sputum specimens were saliva-contaminated, these findings require further validation to prove the utility of CLART® microarray technology for the identification of M. pneumoniae in pneumonia-positive patients. Conclusively, this prospective study included a small number of clinical samples, which likely affected its outcomes.

Mycoplasma pneumoniae among Hospitalized Patients with Acute Respiratory Tract Infections in an Indian Tertiary Care Hospital: an Underreported Health Problem

The epidemiology of Mycoplasma pneumoniae (Mp) is poorly understood in India. The present study was conducted to identify the prevalence of Mp in a large set of patients with acute respiratory tract infections (ARI) in an Indian tertiary hospital. During 2015-2020, we tested throat swab specimens from patients with the clinical diagnosis of ARI (n = 1,098) by a real-time PCR and compared the demographic, clinical, laboratory, and outcome data of Mp-positive and Mp-negative patients. During the study period, 5% (55/1,098) of the tested samples were positive for Mp by PCR. School-aged children and young adults represented 36% (20/55) of the cases and 47.3% (26/55) of the cases were registered during the summer and monsoon. Among the Mp-positive patients, 61.8% (34/55) had underlying conditions; the most common were malignancy (n = 12; 21.8%) and hypertension (n = 6; 10.9%). Fever (98.2% versus 84.9%; P = 0.006), and pharyngitis (27.3% versus 16.3%; P = 0.034) were significantly common in the Mp-positive group than Mp-negative group. Among the Mp-positive group, 20% (11/55) of patients were admitted to an intensive care unit and a total of 7/55 (12.7%) patients received ventilatory support. The mortality in the Mp-positive cohort was 13.3%. The study provides baseline data regarding Mp prevalence and clinical characteristics. The application of molecular assays for diagnosing this pathogen among hospitalized patients with ARI could reduce inappropriate empirical antibiotic treatment and improve patient outcomes. Further large-scale studies are required to avoid the underdiagnosis of Mp infections in India and such studies should address some research gaps, such as macrolide resistance and molecular typing. IMPORTANCE M. pneumoniae (Mp) is a significant pathogen causing atypical pneumonia but by far these infections are underreported clinical entities in India. In the present study, we report the prevalence of Mp and describe the demographic and baseline clinical data of Mp-positive cases in an Indian tertiary care hospital. Our study may improve the clinician's awareness of this important agent of respiratory infection therefore timely and accurate diagnostic tools can be applied for patient management decisions and outcomes.

Epidemiological Study on Mycoplasma pneumoniae and Chlamydia pneumoniae Infection of Hospitalized Children in a Single Center During the COVID-19 Pandemic

Background

Since the outbreak of COVID-19, a series of preventive and control measures in China have been used to effectively curb the spread of COVID-19. This study aimed to analyze the epidemiological characteristics of Mycoplasma pneumoniae (MP) and Chlamydia pneumoniae (CP) in hospitalized children with acute respiratory tract infection during the COVID-19 pandemic.

Methods

MP IgM antibody and CP IgM antibody were detected in all hospitalized children due to acute respiratory tract infection in the Children’s Hospital Affiliated to Zhejiang University from January 2019 to December 2020. These data were compared between 2019 and 2020 based on age and month.

Results

The overall detection rate of MP and CP in 2020 was significantly lower than that in 2019 (MP: 21.5% vs 32.9%, P<0.001; CP: 0.3% vs 0.9%, P<0.001). This study found a 4-fold reduction in the number of children positive for MP and a 7.5-fold reduction in the number of children positive for CP from 2019 to 2020. The positive cases were concentrated in children aged >1 year old. In 2019, the positive rate of MP was detected more commonly in children 3 years of age or older than in younger children. In 2020, the higher positive rate of MP reached a peak in the 3- to 6-year age group (35.3%). CP was detected predominantly in children aged 6 years older in 2019 and 2020, with positive rates of 4.8% and 2.6%, respectively. Meanwhile, the positive rates of MP in 2019 were detected more commonly in July, August and September, with 47.2%, 46.7% and 46.3%, respectively. Nevertheless, the positive rates of MP from February to December 2020 apparently decreased compared to those in 2019. The positive rates of CP were evenly distributed throughout the year, with 0.5%-1.6% in 2019 and 0.0%-2.1% in 2020.

Conclusions

A series of preventive and control measures for SARS-CoV-2 during the COVID-19 pandemic can not only contain the spread of SARS-CoV-2 but also sharply improve the infection of other atypical pathogens, including MP and CP.

Community acquired Acinetobacter baumannii in pediatric patients under 1 year old with a clinical diagnosis of whooping cough in Lima, Peru

Objective

This study aimed to determine the prevalence of A. baumannii in children aged less than 1 year admitted with a clinical diagnosis of whooping cough.

Results

A total of 225 nasopharyngeal samples from children under 1 year old hospitalized with clinical diagnosis of whooping cough were studied from January 2010 to July 2012. The presence of A. baumannii was detected in 20.89% (47/225) of the nasopharyngeal swab samples. Among the 47 patients with A. baumannii: 5 were diagnosed with A. baumannii monoinfection, 17 co-infection with bacteria, 7 co-infection with virus and 18 co-infection with bacteria + virus. It was observed that 51.6% (116/225) were children between 29 days and 3 months old, this same group had the highest overall prevalence with 53.3%. The most common co-infecting pathogens were Bordetella pertussis in 55.3%, Adenovirus in 42.6% and Mycoplasma pneumoniae in 23.4%.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13104-021-05826-y.

Identification of Coinfections by Viral and Bacterial Pathogens in COVID-19 Hospitalized Patients in Peru: Molecular Diagnosis and Clinical Characteristics

The impact of respiratory coinfections in COVID-19 is still not well understood despite the growing evidence that consider coinfections greater than expected. A total of 295 patients older than 18 years of age, hospitalized with a confirmed diagnosis of moderate/severe pneumonia due to SARS-CoV-2 infection (according to definitions established by the Ministry of Health of Peru) were enrolled during the study period. A coinfection with one or more respiratory pathogens was detected in 154 (52.2%) patients at hospital admission. The most common coinfections were Mycoplasma pneumoniae (28.1%), Chlamydia pneumoniae (8.8%) and with both bacteria (11.5%); followed by Adenovirus (1.7%), Mycoplasma pneumoniae/Adenovirus (0.7%), Chlamydia pneumoniae/Adenovirus (0.7%), RSV-B/Chlamydia pneumoniae (0.3%) and Mycoplasma pneumoniae/Chlamydia pneumoniae/Adenovirus (0.3%). Expectoration was less frequent in coinfected individuals compared to non-coinfected (5.8% vs. 12.8%). Sepsis was more frequent among coinfected patients than non-coinfected individuals (33.1% vs. 20.6%) and 41% of the patients who received macrolides empirically were PCR-positive for Mycoplasma pneumoniae and Chlamydia pneumoniae.

Analysis of mycoplasma pneumoniae infection among children with respiratory tract infections in hospital in Chengdu from 2014 to 2020

BACKGROUND

Respiratory tract infection (RTIs) is one of common diseases among the children. In recent years, the incidence of mycoplasma pneumoniae (M. pneumoniae) infection rate has been increasing, which cause respiratory tract infection. This study sought to analyze the epidemiological characteristics of M. pneumoniae hospitalized children with RTIs to provide a theoretical basis for clinical diagnosis and treatments in Chengdu, China.

METHODS

The data of 22,882 cases of children who had been hospitalized for RTIs were collected. M. pneumoniae immunoglobulin M (IgM) antibody was detected using the indirect immunofluorescence method and passive agglutination method. The demographic features of patients, clinical diagnoses and laboratory data were also analyzed.

RESULTS

A total of 4,213 children tested positive for M. pneumoniae. The total positive rate was 18.41% (18.30% for males and 22.72% for females). Female children had statistically significant higher positive rates than male children (χ²=198.078, P<0.01). The positive rates of M. pneumoniae differed significantly among children of different ages (F=162.7532, P<0.01). The incidence rate of M. pneumoniae in 2017 and 2019 was significantly higher than the average (F=538.95, P<0.01). There were higher M. pneumoniae positive rates from April to May, and September to October (P<0.05) in 2016, 2017, 2018, and 2019. There was no correlation between M. pneumoniae infection and temperature and humidity (P>0.05). There was negative correlation with PM_2.5 (particulate matter in the air <2.5 µm) (R=-0.293, P<0.01) and PM₁₀ (particulate matter in the air <10 µm). (R=-0.285, P<0.01). There were significant differences in the constituent ratios of cases of M. pneumoniae infection between in 2020 and other years (F=159.35, P<0.01). Bronchopneumonia accounted for the highest proportion of cases, followed by acute bronchitis and the exacerbation of asthma in 2020.

CONCLUSIONS

The epidemiological distribution of M. pneumoniae in children with RTIs in Chengdu was found to be related to gender, age, year and month; however, no relationship was found to temperature and humidity. There was a higher M. pneumoniae positive rate in children with bronchial pneumonia and asthma in cases. The prevention measures used to control Coronavirus Disease 2019 (COVID-19) also effectively controlled the M. pneumoniae infection rate.

Seasonality in testing and positive respiratory bacterial infections in the Australian Capital Territory, 1997-2007

Background

Chlamydia pneumoniae (Cp) and Mycoplasma pneumoniae (Myco) bacteria are atypical pathogens that can cause pneumonia and exacerbate underlying conditions such as asthma and chronic obstructive pulmonary disease. In the Australian Capital Territory, there is limited information on how seasonal patterns for positive infections and testing may vary, a gap that has implications for control strategies.

Methods

We examined seasonal patterns of immunoassay results of patients from Canberra Hospital, Australia, who were tested for Cp and/or Myco. Pathology data, collected from August 1997 to March 2007 from 7,275 patients, were analysed with time series additive decomposition and time series regression.

Results

The proportion of positive Cp infections was highest in March and April (autumn) and lowest in June and August (winter). The proportion of positive Myco infections was highest in December and January (summer) and lowest in August (winter), even though testing for the pathogen peaked in winter with a low in summer. Models with a long-term trend and a variable for month were a better fit for the data than the null models for both infections.

Conclusion

We found differences in seasonal patterns of testing and in the proportion of positive infections. These findings suggest that preventative measures for common infections need to account for seasonal testing practices so as to build an accurate picture of temporal changes in these infections.

Viral and bacterial coinfection among hospitalized children with respiratory tract infections

BACKGROUND

The epidemiology of Mycoplasma pneumoniae (MP) and local dominant etiologies of pathogens that cause respiratory tract infections (RTIs) among central China children (≤14 years old) hospitalized are poorly understood.

METHODS

A total of 10,429 specimens were analyzed, and IgM antibodies against 9 respiratory pathogens including MP were detected using indirect immunofluorescence assay from serum.

RESULTS

It showed that 59.3% of the enrolled children were positive for at least 1 pathogen; highest detection rates included those between 3 and <6 years of age (70.4%), female (63.2%), and who were hospitalized in 2014 (80.9%). The most predominant pathogen was MP (45.6%), followed by Parainfluenza viruses (PIVs) (22.6%) and influenza B viruses (IFVB) (14.7%). Coinfection was observed in 2,907 specimens (27.9%); the coinfection combination containing MP and PIVs had the highest detection rate of 15%, followed by MP and IFVB as well as IFVB and PIVs.

CONCLUSIONS

MP was the most commonly detected bacteria among hospitalized children, which should be included in the differential diagnosis for hospitalized children with RTI. These findings will contribute to the effective prevention and therapeutic approaches of pathogens among local children suffering from RTI.

Community acquired paediatric pneumonia; experience from a pneumococcal vaccine- naive population

BACKGROUND

Childhood pneumonia continues to be a disease that causes severe morbidity and mortality among children mainly in South-East Asia and Africa though it is not so in the developed world. Pneumonia accounts for 16% of all deaths of children under 5 years old in the world, killing nearly one million children in 2015. In Sri Lanka, there were 21,000 reported cases of pneumonia in 2006, 40% were in the age group of less than 4 years.

METHODS

This was a retrospective study done on the children aged 1 month to 14 years who were admitted to the Professorial Paediatric unit of Teaching Hospital, Peradeniya between 1st of March 2016 and 30th of July 2017 fulfilling diagnostic criteria for community-acquired pneumonia. Data including diagnosis, clinical details, management details and other relevant data were collected from patient records by using a data collection sheet.

RESULTS

In this study, 48% of 127 patients admitted with community-acquired pneumonia had bronchopneumonia. About 2/3 of the patients neededa secondline of intravenous antibiotics while 51/ 127 needed care in the high dependency unit with supplemental oxygen. No mortality was observed in the group.

CONCLUSIONS

Community- acquired paediatric pneumonia has a significant associated morbidity but not mortality in the studied population. The need for the second-line treatment with intravenous antibiotics in a significant proportion of patients may indicate a high degree of antibiotic resistance. Introduction of national antibiotic policy will help the cause.

Low prevalence of Chlamydia pneumoniae infections during the Mycoplasma pneumoniae epidemic season: Results of nationwide surveillance in Japan

OBJECTIVE

Chlamydia pneumoniae and Mycoplasma pneumoniae are both common causes of atypical pneumonia. We conducted an annual national survey of Japanese children to screen them for C. pneumoniae infections during the M. pneumoniae epidemic season.

METHODS

Nasopharyngeal swab specimens were collected from children aged 0-15 years with suspected acute lower respiratory tract infection due to atypical pathogens, at 85 medical facilities in Japan from June 2008 to March 2018. Specimens were tested for infection using real-time polymerase chain reaction assays.

RESULTS

Of 5002 specimens tested, 1822 (36.5%) were positive for M. pneumoniae alone, 42 (0.8%) were positive for C. pneumoniae alone, and 20 (0.4%) were positive for both organisms. In children with C. pneumoniae infection, the median C. pneumoniae DNA copy number was higher in those with single infections than in those with M. pneumoniae coinfection (p = 0.08); however it did not differ significantly according to whether the children had received antibiotics prior to sample collection (p = 0.34).

CONCLUSIONS

The prevalence of C. pneumoniae infection was substantially lower than that of M. pneumoniae infection during the study period. The change in prevalence of C. pneumoniae was not influenced by that of M. pneumoniae. Children with single C. pneumoniae infection are likely to have had C. pneumoniae infection, while those with coinfection are likely to have been C. pneumoniae carriers.

Analysis of Multiple Factors Involved in Pertussis-Like Coughing

Objectives. To identify risk factors associated with the prognosis of pertussis-like coughing. Methods. A retrospective study on children hospitalized with pertussis-like coughing from 2018 to 2019. We collected all the case data from medical records including age, gender, vaccination, clinical symptoms, complication, pathogens, white blood cell (WBC) count, lymphocyte ratio, application of macrolide antibiotics, usage of sulfamethoxazole, and usage of inhaled glucocorticoids. Logistic regression was used in this study. Results. A total of 213 hospitalized children with pertussis-like coughing were included in this study. About 70 children were cured within 2 weeks. One120 children were cured from 2 weeks to 3 months, including cases of initial attack and relapse. Symptoms lasting longer than 3 months accounts for 10.8%. Bordetella pertussis, WBC count >20 × 10⁹/L and lymphocyte ratio >60% were associated with poor prognosis (P < .05). Conclusions. Bordetella pertussis, WBC count, and lymphocyte ratio are independent risk factors for poor prognosis.

High frequency of Chlamydia pneumoniae and risk factors in children with acute respiratory infection

This study was performed as a contribution for a better understanding of Chlamydia pneumoniae frequency in children with respiratory infections. A total of 416 children were recruited from two clinical centers in Sao Luis, Brazil. Of these patients, 165 children had upper respiratory tract infections (URTI), 150 had community-acquired pneumonia (CAP), and 101 were asymptomatic volunteer children. Clinical and epidemiological data from the participants were recorded. Nasopharyngeal swab samples were collected to extract DNA. C. pneumoniae DNA positivity and copy numbers were obtained by an absolute quantitative real-time PCR method. RESULTS: Positivity for C. pneumoniae DNA was higher in samples from URTI children (38.2%) and from CAP children (18.0%) than in those from the control group (7.9%; p < 0.001). Moreover, C. pneumoniae DNA was denser in children with URTI than in asymptomatic children. Considering the cutoff, the highest value of C. pneumoniae DNA found in asymptomatic children of the 3.98 log10 copies/mL, 8.5% (14/165) of the children with URTI, and 3.3% (5/150) with CAP presented high copy numbers of C. pneumoniae DNA. CONCLUSION: Taken together, these results revealed a high frequency of C. pneumoniae in both children with URTI and CAP.

The Association Between Mycoplasma pneumoniae and Chlamydia pneumoniae, a Life-Threatening Condition in Small Children-A Case Report and a Review of the Literature

Mycoplasma pneumoniae (MP) and Chlamydia pneumoniae (CP) are two atypical pathogens that may result in mild, moderate or severe acute respiratory infections. We report the case of a 2 years and 9-month-old male child admitted with prolonged fever, dry cough, and shortness of breath for which he underwent symptomatic treatment. The laboratory tests showed leukocytosis with neutrophilia, anemia, and elevated inflammatory biomarkers and the thoracic radiography revealed pleural effusion raising the suspicion of inferior right pneumonia. Although we the initial evolution was favorable being treated with 3rd class cephalosporin and Oxacillin, on the 8th day of admission the fever and the acute phase reactants levels increased as well as the quantity of the pleural effusion, requiring surgical drainage. We ruled out lung tuberculosis, but we identified positive IgM for both MP and CP. Based on these findings we changed the antibiotic therapy on Levofloxacin for 10 days with favorable evolution. MP and CP are two atypical pathogen that are difficult to be diagnosed due to their slow-growing pattern. Despite their self-limiting feature, the association between them might carry a vital risk in small children, especially in the lack of a proper and timely diagnosis.

[Flu-like disease in summer - what do we know about it?]

Durchsucht man die deutschsprachige medizinische Literatur nach dem Begriff „Sommergrippe“, scheitert man kläglich. Jeder glaubt zu wissen, was damit gemeint ist, doch keiner schreibt darüber. Ist das überhaupt ein seriöses Thema?

Detection of Mycoplasma pneumoniae in Mexican children with community-acquired pneumonia: experience in a tertiary care hospital

Purpose: Mycoplasma pneumoniae is an important cause of community-acquired pneumonia (CAP). Information on the prevalence of M. pneumoniae in pediatric patients with CAP in Mexico is limited. The aim of this study was to detect M. pneumoniae in hospitalized pediatric patients with CAP. Patients and methods: We performed a descriptive study in a tertiary-level pediatric reference center, obtaining 154 respiratory samples from patients under 18 years of age and diagnosed with CAP. M. pneumoniae was detected by real-time polymerase chain reaction (PCR) targeting the p1 and CARDS genes. Complete blood cell count, measurement of C-reactive protein and detection of IgM and IgG anti-P1 were performed. Clinical, epidemiological and radiological data of the patients were analyzed. Results: M. pneumoniae was detected by real-time PCR in 26.6% of the samples. 39% of the cases occurred during the spring season. A total of 83% of the patients with M. pneumoniae had some underlying disease; renal disease, autoimmune disease and primary immunodeficiencies had a significant association with M. pneumoniae CAP. Children under 6 years of age represented 53.7% of the cases. Fever and cough were the most frequent symptoms. IgM and IgG were positive in 1.9% and 14% of the patients, respectively. In the chest X-ray, 17.1% of the patients showed multifocal alveolar infiltrates pattern. The complications in this series were 26.8%. The mortality in this study was 4.9%. Conclusion: This is the first report in Mexico about M. pneumoniae as a causal agent of CAP in a tertiary care pediatric hospital using real-time PCR and serology. M. pneumoniae was responsible for 26.6% of the cases and was frequent in children under 6 years of age. In addition, we described the clinical presentation in patients with underlying diseases.

Identfication of viral and bacterial etiologic agents of the pertussis-like syndrome in children under 5 years old hospitalized

BACKGROUND

Acute respiratory infections (ARIs) represent an important cause of morbidity and mortality in children, remaining a major public health concern, especially affecting children under 5 years old from low-income countries. Unfortunately, information regarding their epidemiology is still limited in Peru.

METHODS

A secondary data analysis was performed from a previous cross-sectional study conducted in children with a probable diagnosis of Pertussis from January 2010 to July 2012. All samples were analyzed via Polymerase Chain Reaction (PCR) for the following etiologies: Influenza-A, Influenza-B, RSV-A, RSV-B, Adenovirus, Parainfluenza 1 virus, Parainfluenza 2 virus, Parainfluenza 3 virus, Mycoplasma pneumoniae and Chlamydia pneumoniae.

RESULTS

A total of 288 patients were included. The most common pathogen isolated was Adenovirus (49%), followed by Bordetella pertussis (41%) from our previous investigation, the most prevelant microorganisms were Mycoplasma pneumonia (26%) and Influenza-B (19.8%). Coinfections were reported in 58% of samples and the most common association was found between B. pertussis and Adenovirus (12.2%).

CONCLUSIONS

There was a high prevalence of Adenovirus, Mycoplasma pneumoniae and other etiologies in patients with a probable diagnosis of pertussis. Despite the presence of persistent cough lasting at least two weeks and other clinical characteristics highly suspicious of pertussis, secondary etiologies should be considered in children under 5 years-old in order to give a proper treatment.

Implementation of Point-of-Care Molecular Diagnostics for Mycoplasma pneumoniae Ensures the Correct Antimicrobial Prescription for Pediatric Pneumonia Patients

Mycoplasma pneumoniae is a leading causative pathogen of pneumonia among pediatric patients, and its accurate diagnosis may aid in the selection of appropriate antimicrobial agents. We established a rapid reporting system of a polymerase chain reaction (PCR) examination for M. pneumoniae that enables physicians to obtain test results approximately 90 minutes after ordering the test. In this study, we evaluated the impact of this system on antimicrobial prescriptions for pediatric pneumonia patients after its implementation from May 2016 to April 2017. In total, we identified 375 pediatric pneumonia patients, and the results of the rapid PCR examinations for Mycoplasma pneumoniae were reported immediately in 90.7% of patients (340/375), with physicians able to use these results to decide on patients' management before the prescription of antimicrobial agents. Of the 375 pediatric pneumoniae patients, M. pneumoniae was detected in 223 (59.5%). Among the 223 M. pneumoniae-positive pneumonia cases, antimicrobial agents for atypical pathogens (macrolides, tetracyclines or quinolones) were prescribed in 97.3% (217/223) at the initial evaluation, and their prescription rates increased to 99.1% (221/223) during management. In contrast, antimicrobial agents for atypical pathogens were prescribed only in 10.5% of 152 M. pneumoniae-negative pneumonia cases at the initial evaluations, and only 1 additional case was prescribed clarithromycin for persistent symptoms during management. In conclusion, we show that molecular technology could be applicable in the field of point-of-care testing in infectious disease, and its implementation will ensure the correct antimicrobial prescription for pediatric pneumonia patients.

A retrospective seroepidemiologic survey of Chlamydia pneumoniae infection in patients in Beijing between 2008 and 2017

Background

Chlamydia pneumoniae (C. pneumoniae) is an obligate intracellular bacterium and a human pathogen that causes respiratory infectious diseases. More than 50% of the adult population worldwide was once infected with C. pneumoniae, but investigations into this topic are insufficient in mainland China.

Methods

Anti-C. pneumoniae IgG and IgM antibodies were detected using micro-immunofluorescence test in serum samples of patients visiting Peking Union Medical College Hospital between 2008 and 2017 for routine medical purposes, and the aim of this retrospective study was to analyze the test results.

Results

Among 12,050 serum specimens tested for anti-C. pneumoniae IgG and IgM antibodies, the overall prevalence of anti-C. pneumoniae IgG antibodies was 86.6%, 87.2% for men and 86.0% for women. Adult men (>20 years) were found to have a significantly higher prevalence of anti-C. pneumoniae IgG than women (χ² = 30.32, P = 0.000). 3 to 5 years old patients were observed to have the lowest prevalence of anti-C. pneumoniae IgG, 42.8%, then increased with age, reaching the highest level of 98.6% in patients over 70 years of age. In the 10,434 specimens with C. pneumoniae IgG antibodies, the total geometric mean titer (GMT) for C. pneumoniae IgG was 45.71. Although GMTs were found to be significantly higher among all men than among all women (t = 5.916, P = 0.000), sex difference actually began in patients over 40 years of age and increased in the elderly. In the total 12,050 specimens, 1.2% had anti-C. pneumoniae IgM, 3.3% had anti-C. pneumoniae IgG with titers equal to or greater than 1:512; 0.39% had ≥4-fold increasing titers of antibodies in acute and convalescent phase paired samples, and 4.4% were finally confirmed to have acute antibodies against C. pneumoniae. 6 to 10 years old patients were found to have the highest rate of both IgM antibodies (3.9%) and acute antibodies (6.2%) against C. pneumoniae. Acute antibodies against C. pneumoniae were found to be more frequent in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD, 14.0%, χ² = 20.43, P = 0.000), patients with pneumonia (7.8%, χ² = 51.87, P = 0.000) and patients with acute respiratory tract infection (12.3%, χ² = 60.91, P = 0.000) than among all patients (4.4%). Both anti-C. pneumoniae IgG and IgM antibodies should be tested for acute antibodies against C. pneumoniae as testing for either alone will underestimate by a maximum of two-thirds the incidence of acute antibodies against C. pneumoniae.

Conclusions

More than 86% of Chinese patients on an average were once infected with C. pneumoniae. Adult men had both a higher prevalence and higher levels of antibodies than women. 6 to10 year old patients were found to have the most frequent acute infection of C. pneumoniae. C. pneumoniae is associated with AECOPD, pneumonia and acute respiratory tract infection. Anti-C. pneumoniae IgG and IgM should be tested simultaneously to avoid underestimation of acute antibodies against C. pneumoniae.

High frequency of Mycoplasma pneumoniae among patients with atypical pneumonia in Tehran, Iran

Introduction

Mycoplasma pneumoniae is a major cause of atypical community-acquired pneumonia (CAP) with a prevalence range of 15-20% and up to 40% in adults and children, respectively. In Iran, the recorded frequency ranges between 1-6.15%. We aimed to investigate the frequency of M. pneumoniae among patients with atypical pneumonia acquired from the community.

Methods

Over a period of 5 months between January and June 2017, 520 patients with suspected CAP, who had been to the hospital outpatient clinics of Tehran University, were enrolled in this study. Throat swab specimens were obtained from 110 outpatients who presented with symptoms of atypical pneumonia. M. pneumoniae was identified via culture and biochemical tests, such as fermentation of glucose and arginine, hemolysis, and hemadsorption. For confirmation, PCR was performed to amplify the gene fragment coding for p1 adhesin.

Results

The major and minor clinical signs of the patients were dyspnea (67.3%) and nausea (15.5%), respectively. Out of 110 specimens, 25 (22.7%) and 29 (26.4%) isolates were identified to be M. pneumoniae via culture and molecular assay, respectively. Comparing the results of the two methods, the PCR showed better sensitivity and rapidity for the detection of M. pneumoniae. There was a high congruence between culture and the PCR assay; kappa level was 'almost perfect' (κ=0.90).

Conclusion

This is the first report of high frequency of M. pneumoniae in our region. This finding can serve as baseline information for further investigation and confirmation of the potential epidemics of M. pneumoniae pneumonia in our community.

Molecular etiological profile of atypical bacterial pathogens, viruses and coinfections among infants and children with community acquired pneumonia admitted to a national hospital in Lima, Peru

OBJECTIVE

The main objective of this study was to detect the presence of 14 respiratory viruses and atypical bacteria (Mycoplasma pneumoniae, Chlamydia pneumoniae), via polymerase chain reaction in patients under 18 years old hospitalized due to community-acquired pneumonia (CAP) from Lima, Peru.

RESULTS

Atypical pathogens were detected in 40% (58/146); viral etiologies in 36% (52/146) and coinfections in 19% (27/146). The most common etiological agent was M. pneumoniae (n = 47), followed by C. pneumoniae (n = 11). The most frequent respiratory viruses detected were: respiratory syncytial virus A (n = 35), influenza virus C (n = 21) and parainfluenza virus (n = 10). Viral-bacterial and bacterium-bacterium coinfections were found in 27 cases. In our study population, atypical bacteria (40%) were detected as frequently as respiratory viruses (36%). The presence of M. pneumoniae and C. pneumoniae should not be underestimated as they can be commonly isolated in Peruvian children with CAP.