Children who contract pneumonia have a greater risk of poor outcomes—including persistent pneumonia, secondary infections, organ failure or death—if they have anemia and live at high altitudes, according to research online ahead of print in the journal Pediatrics.

Investigators analyzed data collected in the World Health Organization-sponsored SPEAR (Severe Pneumonia Evaluation Antimicrobial Research) study, finding that while neither anemia nor high altitude alone increased the risk of treatment failure, the combination of both factors caused a 4-fold increase in failure risk. High altitudes were defined as those above 6,500 ft.

Investigators believe the findings indicate that the prevention and treatment of anemia should be a priority in children living at high altitude, as it could improve outcomes of pneumonia. They also believe that, given the high global prevalence of both anemia and pneumonia, continuing research about the intersection of disease with environmental factors is “critically important.”

“Our results raise the possibility that preventing the development of anemia in children through community-based efforts—such as access to clean water, better nutrition and treating intestinal parasites—and treating anemia when it does occur could have an important impact on pneumonia outcomes,” said Peter Moschovis, MD, MPH, of the divisions of Global Health at MassGeneral Hospital for Children and Pulmonary/Critical Care Medicine at Massachusetts General Hospital, corresponding author of the report.

“While we saw no effect at low altitudes, this study did not include many children who were severely anemic, who may be at risk of poor pneumonia outcomes even at low altitudes. Those questions and better strategies for treating and preventing anemia need to be addressed in future studies.”