Respiratory syncytial Virus leading cause of pneumonia in Afro Asian Kids: Lancet

Viral pathogen, specifically respiratory syncytial virus (RSV), and not bacterial pathogen is the leading cause of pneumonia that requires hospitalization in children younger than 5 years in low- and middle-income countries throughout Africa and Asia. The findings of the study have been published in the journal The Lancet.

The researchers suggest that widespread uptake of Haemophilus influenzae type b (Hib) vaccine and pneumococcal conjugate vaccine (PCV) in low and middle-income countries, provides protection against major causes of bacterial pneumonia. This makes viruses, particularly, RSV as the leading cause of pneumonia in children aged less than 5 years, in these countries.

Maria Deloria Knoll, PhD, a senior scientist in the department of international health at the Johns Hopkins Bloomberg School of Public Health, and colleagues estimated causes of pneumonia in young African and Asian children, using novel analytical methods applied to clinical and microbiological findings.

According to Dr. Knoll, the viruses that caused pneumonia in the African and Asian sites are also commonly found in the United States and other high-income countries. However, the risk factors for viral pneumonia are more prevalent in low- and middle-income countries, "including living in overcrowded households, poor nutrition, poor indoor air quality due to burning coal and wood, and higher risk for other comorbidities — all of which increase susceptibility to infection."

The researchers conducted a case-control study in nine sites Bangladesh, The Gambia, Kenya, Mali, South Africa, Thailand and Zambia from the Pneumonia Etiology Research for Child Health (PERCH) Study Group. The study that lasted 2 years included more than 1,700 children aged 1 to 59 months who were hospitalized for severe pneumonia. The researchers assessed the prevalence of the organisms causing the children's pneumonia using cultures, multiplex PCR, or both. A group of about 5,100 age-matched controls were randomly selected from communities around the study sites.

• They estimated that 61.4% of pneumonia cases were caused by viruses, whereas 27.3% were caused by bacteria and 5.9% were caused by Mycobacterium tuberculosis.


• Very severe cases of pneumonia were more likely to be caused by bacteria (very severe cases = 33.7%; severe cases = 22.8%) compared with viral infections (very severe cases = 54.5%; severe cases = 68%).


• RSV was identified as the cause of 31.1% (95% CI, 28.4%-34.2%) of all cases, making it the most common cause of pneumonia.


• Several pathogens — human rhinovirus, human metapneumovirus A or B, human parainfluenza virus, Streptococcus pneumoniae, M. tuberculosis and H. influenzae — each contributed to 5% or more of cases.

"In our study, a small set of pathogens accounted for most cases of pneumonia requiring hospital admission. Preventing and treating a subset of pathogens could substantially affect childhood pneumonia outcomes," concluded the authors.

To read the complete study follow the link: https://doi.org/10.1016/S0140-6736(19)30721-4