An epidemiological study of pneumonia in migrant infants and children on the Thai-Myanmar border

Background: Pneumonia is the leading cause of death in children and the estimated incidence of childhood pneumonia in Myanmar is the third highest in the world. Effective interventions, including case-management and immunisations, have been established.However these focus on bacterial pneumonia and recent advances in molecular diagnostics have highlighted the substantial role played by viruses. An understanding of the local epidemiology and aetiology of childhood pneumonia is vital to ensure that current and future interventions are appropriate to the local population. Objective: To study the severity and aetiology of childhood pneumonia, in migrant infants and children under five years old, presenting to a clinic on the Thai-Myanmar border. Methods: A one-year prospective observational study was conducted in a rural clinic on the Thai-Myanmar border. All children attending the clinic, who were diagnosed with clinical pneumonia according to the World Health Organization definitions, were treated and investigated according to local paediatric guidelines. Results: During the study period 175 episodes of clinical pneumonia were diagnosed. Of these 59% were male and half were infants (48%). The median age at presentation was 7.5 months (IQR 3 to 13). Clinically half (50%) had severe or very severe pneumonia. Using the WHO standardised method for interpretation, 38% of radiographs had primary endpoint pneumonia. At least one virus was identified in 49% of patients. The most commonly identified virus was adenovirus, which was identified in 24% of cases, followed by RSV (22%), then hMPV (6%) and Influenza A (3%). The cases of pneumonia peaked at the end of the rainy season and this closely followed the RSV activity. Conclusion: The majority of children presented with severe or very severe pneumonia, suggesting that in this population patients may present later. The substantial burden in infants suggests that future interventions should focus on this vulnerable age group. Viruses were frequently identified. Adenovirus was commonly identified, however its presence in nasopharyngeal secretions is of uncertain significance, especially in the presence of other viruses. The persistence of adenovirus and its role in acute pneumonia needs further investigation. RSV is an important and commonly found pathogen and prevention of RSV through a safe and effective vaccine could have substantial effect on the reduction of childhood pneumonia on the Thai-Myanmar border.