This paper retrospectively analysed the prevalence of macrolide-resistantMycoplasma pneumoniae(MRMP) in some parts of China. Between January 2013 and December 2019, we collected 4,145 respiratory samples, including pharyngeal swabs and alveolar lavage fluid. The highest PCR-positive rate of M. pneumoniae was 74.5% in Beijing, the highest resistance rate was 100% in Shanghai, and Gansu was the lowest with 20%. The highest PCR-positive rate ofM. pneumoniaewas 74.5% in 2013, and the highest MRMP was 97.4% in 2019; the PCR-positive rate ofM. pneumoniaefor adults in Beijing was 17.9% and the MRMP was 10.48%. Among the children diagnosed with community-acquired pneumonia (CAP), the PCR-positive and macrolide-resistant rates ofM. pneumoniaewere both higher in the severe ones. A2063G in domain V of 23S rRNA was the major macrolide-resistant mutation, accounting for more than 90%. The MIC values of all MRMP to erythromycin and azithromycin were ≥ 64 μg/ml, and the MICs of tetracycline and levofloxacin were ≤ 0.5 μg/ml and ≤ 1 μg/ml, respectively. The macrolide resistance varied in different regions and years. Among inpatients, the macrolide-resistant rate was higher in severe pneumonia. A2063G was the common mutation, and we found no resistance to tetracycline and levofloxacin.

To evaluate the relationships between maternal particulate matter exposure and offspring birth weight. Studies were categorized into three subgroups: term low birth weight (TLBW) among full-term births and all births (regardless of gestational age) and low birth weight (LBW) among all births, based on the search results of MEDLINE and the Web of Science from the inception of the database to April 2022. Subgroup analyses were conducted based on the economic status, region, exposure assessment, risk of bias, and adjustment. Sixty-one studies involving 34,506,975 singleton live births in 15 countries were analyzed. Overall, the risk of bias for most studies (75%) was low. In 39 of 47 term birth studies, the pooled odds ratio of TLBW among term births for per interquartile range (IQR) increases throughout the entire pregnancy was 1.02 (1.01 to 1.03) for PM_2.5 and 1.03 (1.01 to 1.05) for PM₁₀ after adjustment for covariates. No significant relevance was detected across each trimester period for PM_2.5. A stronger effect was observed during the second trimester (1.03, 1.01 to 1.06) for PM₁₀. There was no increased risk of TLBW in all births associated with IQR increases in PM_2.5 and PM₁₀. LBW was associated with PM_2.5 exposure in 4 of 7 studies, but statistical heterogeneity was considerable. In the TLBW subgroup analysis, the effects of PM_2.5 and PM₁₀ were both greater in studies conducted in advanced countries, studies with low bias, and studies that adjusted for maternal age, infant sex, and parity. Stronger effects were present for PM_2.5 exposure collected from monitoring stations and PM₁₀ exposure interpolated from the inverse distance weighting model. TLBW may be associated with prenatal exposure to particulate matter, but no critical windows were identified. Stronger associations were observed in advanced countries. Future original study designs need to consider the impact of different exposure assessment modalities and all possible confounding factors.

We assessed the relationship between serum 25-hydroxyvitamin D (25(OH)D) level and community-acquired pneumonia (CAP) among Chinese children. This observational study examined children aged 3 days to 14 years (n = 1582) from the Capital Institute of Pediatrics in 2009 to 2011. There were 797 children in the CAP group and 785 controls. The CAP group was divided into 2 groups: a pneumonia group and pneumonia-induced sepsis group. The serum 25(OH)D level was estimated using micro whole blood chemiluminescence. The average serum 25(OH)D level in all samples was 25.32 ± 14.07 ng/mL, with the CAP group showing a lower value than the control group (P < .001). There were also significant differences between the pneumonia group and pneumonia-induced sepsis group (P < .001). In the pneumonia-induced sepsis group, significant differences in serum 25(OH)D levels were observed in children who received mechanical ventilation or presenting with multiple organ dysfunction (P < .01). All serum 25(OH)D levels in the pneumonia group and pneumonia-induced sepsis group were below normal levels, particularly in the sepsis group. A lower serum 25(OH)D level was associated with more serious symptoms in CAP children. Children with low serum 25(OH)D levels may be at higher risk of receiving mechanical ventilation and presenting with multiple organ dysfunction. These findings suggest that vitamin D supplements are beneficial for the treatment and prevention of CAP.

Background: Post-infectious bronchiolitis obliterans (PIBO) is a long-term sequela after an initial insult to the lower respiratory tract. A comprehensive understanding of the factors that contribute to a high risk of developing PIBO is important to help define therapeutic strategies and improve prognosis.Methods: We performed a systematic review of published literature available in the online databases including PubMed, Embase, Web of Science, CNKI, Wan Fang, and VIP, with the last search updated on 27 January 2022. Observational studies and case-control studies that provide sufficient data to examine associations between potential risk factors and PIBO were included. Pooled odds ratio (OR) or mean difference (MD) with 95% confidence interval (CI) and heterogeneity were calculated.Results: A total of 14 risk factors were selected from 9 studies included in the analysis. The strongest risk factors were hypoxemia, mechanical ventilation, tachypnea, and wheezing. Hypoxemia conferred the greatest risk with pooled OR of 21.54 (95% CI: 10–46.36, p < 0.001). Mechanical ventilation ranked second (pooled OR 14.61, 95% CI: 7.53–28.35, p < 0.001). Use of γ-globulin, use of glucocorticoids, co-infection of bacteria, a history of wheezing, and being male were other prominent risk factors. The effects of premature birth, allergic rhinitis, and imaging finding (pulmonary consolidation, atelectasis, pleural effusion) are less clear and require further confirmation. Cases that developing PIBO had a lower age compared with controls (MD, −8.76 months, 95% CI: −16.50 to −1.02, p = 0.03). No significant differences were observed in the duration of fever (MD, 1.74 days, 95% CI: −0.07 to 3.54, p = 0.06). Children diagnosed with PIBO had higher LDH levels (MD, 264.69 U/L, 95% CI: 67.43 to 461.74, p = 0.008) and duration of hospitalization (MD, 4.50 days, 95% CI: 2.63 to 6.37, p < 0.001).Conclusion: In this study, we found that the strongest risk factors for PIBO were hypoxemia, mechanical ventilation, tachypnea, and wheezing. Use of glucocorticoids, γ-globulin, co-infection of bacteria, a history of wheezing, and being male may also play a role. The factors discussed above can inform the generation of a clinical prediction model for the developing PIBO in children.