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Pathogens associated with acute lower respiratory tract infection in young children
Insights
Viruses, particularly respiratory syncytial virus, are common causes of acute lower respiratory infections in young children. Bacterial infections, often with multiple pathogens, are associated with more severe symptoms.
Area of Science:
- Pediatrics
- Infectious Diseases
- Microbiology
Background:
- Acute lower respiratory infection (ALRI) is a significant cause of morbidity and mortality in young children globally.
- Identifying causative agents is crucial for effective treatment and prevention strategies.
Purpose of the Study:
- To identify the specific infectious agents associated with ALRI in hospitalized children under five years old.
- To compare the detection rates of different pathogens using various diagnostic methods.
Main Methods:
- A cohort of 102 hospitalized children (<5 years) was studied.
- Diagnostic methods included culture, serology, fluorescent antibody testing, blood cultures, and counterimmunoelectrophoresis.
- Tests targeted common viruses, Chlamydia trachomatis, Streptococcus pneumoniae, and Haemophilus influenzae type b.
Main Results:
- At least one pathogen was detected in 87% of children; 33% had multiple infections.
- Viruses were most common (80 detections), with respiratory syncytial virus (RSV) being predominant (61 cases).
- Bacteria (23 cases of pneumococcus, 5 of H. influenzae) were detected more often by counterimmunoelectrophoresis than blood culture and were associated with more severe symptoms.
Conclusions:
- Viruses are the most frequent agents in pediatric ALRI, with RSV being the most common.
- While Chlamydia trachomatis was detected in infants <4 months, it was not a significant factor in older children.
- Bacterial co-infections were associated with increased severity of ALRI.
Abstract:
To determine the agents associated with acute lower respiratory infection in young children, we studied 102 hospitalized children less than 5 years old using culture and serology for viruses and Chlamydia trachomatis, fluorescent antibody testing for pertussis and respiratory syncytial virus, blood cultures and counterimmunoelectrophoresis of nasopharyngeal secretions and urine for pneumococcal and Haemophilus influenzae type b antigens. At least one agent was detected in 87 children and multiple agents were found in 33. Viruses were detected 80 times; respiratory syncytial virus was most common (61 cases) and was detected as often by fluorescent antibody testing as by culture. C. trachomatis was detected in 10 children; all were less than 4 months old and 9 had mixed infections. Bacteria were detected 32 times, were usually pneumococcus (23) or H. influenzae (5) and were detected more often by counterimmunoelectrophoresis than by blood culture. Compared with children yielding only C. trachomatis or viruses, those with bacteria were significantly more likely to have fever, a band count over 2000/mm3 and radiographic consolidation. In this study acute lower respiratory infection was associated commonly with viruses, often with multiple pathogens but not with C. trachomatis after 4 months of age.