Radiological findings of community-acquired methicillin-resistant and methicillin-susceptible Staphylococcus aureus pediatric pneumonia in Hawaii

High-Resolution Computed Tomography of Cystic Lung Disease

The cystic lung diseases (CLD) are characterized by the presence of multiple, thin-walled, air-filled spaces in the pulmonary parenchyma. Cyst formation may occur with congenital, autoimmune, inflammatory, infectious, or neoplastic processes. Recognition of cyst mimics such as emphysema and bronchiectasis is important to prevent diagnostic confusion and unnecessary evaluation. Chest CT can be diagnostic or may guide the workup based on cyst number, distribution, morphology, and associated lung, and extrapulmonary findings. Diffuse CLD (DCLDs) are often considered those presenting with 10 or more cysts. The more commonly encountered DCLDs include lymphangioleiomyomatosis, pulmonary Langerhans' cell histiocytosis, lymphoid interstitial pneumonia, Birt-Hogg-Dubé syndrome, and amyloidosis/light chain deposition disease.

Differences Between Methicillin-susceptible Versus Methicillin-resistant Staphylococcus aureus Infections in Pediatrics: Multicenter Cohort Study Conducted in Bogotá, Colombia, 2014-2018

BACKGROUND

The epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-susceptible S. aureus (MSSA) has changed in recent years. The present article is intended to establish differences between clinical, laboratory and imaging findings and outcomes of MSSA and MRSA infections, as well as among subgroups of infection such as skin and soft tissue infection, osteoarticular, bacteremia or pneumonia in a pediatric population from Bogota, Colombia.

METHODS

Retrospective cohort study using clinical records of patients under 18 years of age treated at the participating centers in Bogota, Colombia, between 2014 and 2018. The first positive S. aureus culture was studied. MSSA and MRSA were compared. The χ2 test, Fisher exact test, and Kruskal-Wallis test were calculated, and the statistical significance was presented using the difference and its 95% CI.

RESULTS

Five hundred fifty-one patients were included; 211 (38%) corresponded to MRSA and 340 (62%) to MSSA for a total of 703 cultures. A significantly higher probability of having an MSSA infection than MRSA was found in patients with previous heart disease (3.3% vs. 0.5%), neurologic disease (5.9% vs. 2.5%), recent major surgeries (11% vs. 5%) or who has an implanted device (11% vs. 4%). In contrast, in severe MRSA infections (bacteremia, osteoarticular infections and pneumonia), a higher rate of complications was seen (admission to the pediatric intensive care unit, mechanical ventilation and vasoactive support), and in osteoarticular MRSA, more than 1 surgery per case was seen (89% vs. 61%). Laboratory results and mortality were similar.

CONCLUSIONS

MRSA was associated with a more severe course in bacteremia, osteoarticular infections and pneumonia. Some classical risk factors associated with MRSA infections were found to be related to MSSA. In general, with the exception of skin and soft tissue infection, there was an increased risk of pediatric intensive care unit admission and mechanical and inotropic support with MRSA in a pediatric population.

Diffuse Cystic Lung Disease. Part I

The diffuse cystic lung diseases (DCLDs) are a group of pathophysiologically heterogenous processes that are characterized by the presence of multiple spherical or irregularly shaped, thin-walled, air-filled spaces within the pulmonary parenchyma. Although the mechanisms of cyst formation remain incompletely defined for all DCLDs, in most cases lung remodeling associated with inflammatory or infiltrative processes results in displacement, destruction, or replacement of alveolar septa, distal airways, and small vessels within the secondary lobules of the lung. The DCLDs can be broadly classified according to underlying etiology as those caused by low-grade or high-grade metastasizing neoplasms, polyclonal or monoclonal lymphoproliferative disorders, infections, interstitial lung diseases, smoking, and congenital or developmental defects. In the first of a two-part series, we present an overview of the cystic lung diseases caused by neoplasms, infections, smoking-related diseases, and interstitial lung diseases, with a focus on lymphangioleiomyomatosis and pulmonary Langerhans cell histiocytosis.

Clinical outcomes of children with acute asthma and pneumonia in Mulago hospital, Uganda: a prospective study

BACKGROUND

Little attention has been paid to asthma in 'under-fives' in Sub-Saharan Africa. In 'under-fives', acute asthma and pneumonia have similar clinical presentation and most children with acute respiratory symptoms are diagnosed with pneumonia according to the WHO criteria. The mortality associated with acute respiratory diseases in Uganda is high but improving, dropping from 24% in 2004 to 11.9% in 2012. We describe the immediate clinical outcomes of children with acute asthma and pneumonia and document the factors associated with prolonged hospitalization and mortality.

METHODS

We enrolled 614 children aged 2 to 59 months with acute respiratory symptoms presenting at the emergency paediatric unit of Mulago hospital. Clinical histories, physical examination, blood and radiological tests were done. Children with asthma and bronchiolitis were collectively referred to as 'Asthma syndrome'. Hospitalized children were monitored every 12 hours for a maximum of 7 days. Survival analysis was done to compare outcome of children with asthma and pneumonia. Cox regression analysis was done to determine factors associated with prolonged hospitalization and mortality.

RESULTS

Overall mortality was 3.6%. The highest case fatality was due to pneumocystis jirovecii pneumonia (2/4) and pulmonary tuberculosis (2/7). None of the children with asthma syndrome died. Children with 'asthma syndrome' had a significantly shorter hospital stay compared to those with pneumonia (p<0.001). Factors independently associated with mortality included hypoxemia (HR = 10.7, 95% CI 1.4- 81.1) and severe malnutrition (HR = 5.7, 95% CI 2.1- 15.8). Factors independently associated with prolonged hospitalization among children with asthma syndrome included age less than 12 months (RR = 1.2, 95% CI 1.0-1.4), hypoxemia (RR = 1.4, 95% CI 1.2-1.7), and severe malnutrition (RR = 1.5 95% CI 1.3-1.8). Similar factors were associated with long duration of hospital stay among children with pneumonia.

CONCLUSION

This study identified a sharp decline in acute respiratory mortality compared to the previous studies in Mulago hospital. This may be related to focus on and treatment of asthma in this study, and will be analysed in a later study. Bacterial pneumonia is still associated with high case fatality. Hypoxemia, severe malnutrition, and being an infant were associated with poor prognosis among children with acute asthma and pneumonia and need to be addressed in the management protocols.

The changing microbiologic epidemiology of community-acquired pneumonia

Community-acquired pneumonia (CAP) is a common infectious disease in the United States and the incidence continues to grow as the aging population increases. Overall, in-hospital patient mortality rates have been reported to be as high as 18%. Management of patients with CAP has been challenged by the evolution of resistant pathogens (particularly Streptococcus pneumoniae and Staphylococcus aureus) that have reduced susceptibility to recommended standard antimicrobial agents. Streptococcus pneumoniae continues to be the most frequently identified pathogen in CAP and recently, S. aureus has been found to be the second most often identified pathogen. Data from the SENTRY Antimicrobial Surveillance Program has shown declining susceptibility of pneumococci to penicillin, amoxicillin/clavulanate, and ceftriaxone from 1998 through 2011. In the Assessing Worldwide Resistance Evaluation (AWARE) surveillance program, > 50% of all S. aureus isolates from patient bloodstream infections, skin and skin structure infections, and pneumonia were methicillin-resistant. Stratifying risk factors to identify patients at risk for community-acquired multidrug-resistant pathogens should be considered when selecting therapy. Differences in microbiology and outcomes have been noted in patients presenting from the community with recent exposure to the health care system (eg, nursing home residents, patients with a recent hospital admission). These patients are at an increased risk of an infection caused by a multidrug-resistant pathogen. Understanding a patient's risk for drug-resistant pathogens will allow the physician to choose an appropriate empiric treatment regimen to optimize clinical outcomes.

Asthma and pneumonia among children less than five years with acute respiratory symptoms in Mulago Hospital, Uganda: evidence of under-diagnosis of asthma

Background

Pneumonia is considered the major cause of mortality among children with acute respiratory disease in low-income countries but may be over-diagnosed at the cost of under-diagnosing asthma. We report the magnitude of asthma and pneumonia among “under-fives” with cough and difficulty breathing, based on stringent clinical criteria. We also describe the treatment for children with acute respiratory symptoms in Mulago Hospital.

Methods

We enrolled 614 children aged 2–59 months with cough and difficulty breathing. Interviews, physical examination, blood and radiological investigations were done. We defined asthma according to Global Initiative for Asthma guidelines. Pneumonia was defined according to World Health Organization guidelines, which were modified by including fever and white cell count, C-reactive protein, blood culture and chest x-ray. Children with asthma or bronchiolitis were collectively referred to as “asthma syndrome” due to challenges of differentiating the two conditions in young children. Three pediatricians reviewed each participant’s case report post hoc and made a diagnosis according to the study criteria.

Results

Of the 614 children, 41.2% (95% CI: 37.3–45.2) had asthma syndrome, 27.2% (95% CI: 23.7–30.9) had bacterial pneumonia, 26.5% (95% CI: 23.1–30.2) had viral pneumonia, while 5.1% (95% CI: 3.5–7.1) had other diagnoses including tuberculosis. Only 9.5% of the children with asthma syndrome had been previously diagnosed as asthma. Of the 253 children with asthma syndrome, 95.3% (95% CI: 91.9–97.5) had a prescription for antibiotics, 87.7% (95% CI: 83.1–91.5) for bronchodilators and 43.1% (95% CI: 36.9–49.4) for steroids.

Conclusion

Although reports indicate that acute respiratory symptoms in children are predominantly due to pneumonia, asthma syndrome contributes a significant proportion. Antibiotics are used irrationally due to misdiagnosis of asthma as pneumonia. There is need for better diagnostic tools for childhood asthma and pneumonia in Uganda.

Emergency management of community-acquired bacterial pneumonia: what is new since the 2007 Infectious Diseases Society of America/American Thoracic Society guidelines

Community-acquired pneumonia (CAP) is a major health problem in the United States and is associated with substantial morbidity, mortality, and health care costs. Patients with CAP commonly present to emergency departments where physicians must make critical decisions regarding diagnosis and management of pneumonia in a timely fashion, with emphasis on efficient and cost-effective diagnostic choices, consideration of emerging antimicrobial resistance, timely initiation of antibiotics, and appropriate site-of-care decisions. In light of the burden that pneumonia places on health care systems and the emergency department in particular, this article reviews significant developments in the management of CAP in the United States 5 years since the publication of the 2007 Infectious Diseases Society of America/American Thoracic Society consensus guidelines on the management of CAP in adults, focusing on recent studies and recommendations for managing CAP, the primary bacterial pathogens responsible for CAP, and trends in resistance, new diagnostic technologies, and newer antimicrobials approved for the treatment of CAP. These new data and additional guidelines pertaining to the treatment of CAP further our knowledge and understanding of this challenging infection. Furthermore, appreciation of the availability of new diagnostic testing and therapeutic options will help meet the demand for improved management of CAP.