An international team led by Dr. Quique Bassat, researcher at ISGlobal, describes the identification of a biomarker signature that accurately classifies pneumonias according to their bacterial, viral or malarial origin. The study, done in collaboration with researchers from Harvard and MIT from the USA and the Manhiça Health Research Centre (CISM) from Mozambique and published in the American Journal of Respiratory and Critical Care Medicine, could contribute to a faster and more accurate diagnosis of pediatric pneumonias, thus reducing disease morbidity and the unnecessary use of antibiotic therapies.
Acute respiratory infections are a leading cause of pediatric hospital admissions globally. These can be caused by virus, bacteria or, in endemic areas, by malaria. Symptoms associated with these three types of pathogens usually overlap and differential diagnosis is difficult since it involves clinical and radiographic tests that are often inaccurate and poorly reproducible. However, a rapid and accurate diagnosis of pediatric pneumonias would ensure that children with bacterial infection receive prompt antibiotic therapy while limiting its overuse in the case of viral and malarial infections.
The goal of the study was to identify proteins and protein combinations that would discriminate bacterial from viral or malarial infections. The authors studied plasma levels for 56 proteins in blood samples obtained from African pediatric patients with clinically diagnosed pneumonia and who met criteria for bacterial, viral or malarial infection. Three proteins were identified that when combined allowed an accurate classification of the type of infection, with a high sensitivity and specificity. The different concentration of proteins depending on the combination is likely explained by the type of immune response triggered by each pathogen, explain the authors. Importantly, the identified biomarker signatures were not altered by co-infections with other virus, such as HIV, a frequent condition in sub-Saharan Africa.
Dr. Bassat points out: "when used together with malaria diagnostic tests, these ‘signatures' could allow the quick identification of those children with bacterial infections that would benefit from immediate antibiotic therapies". He adds: "this type of test could improve the speed and accuracy of the diagnosis and simplify treatment decisions in rural zones of Africa where resources are limited."