Unveiling viral pathogens in acute respiratory disease: Insights from viral metagenomics in patients from the State of Alagoas, Brazil.

Background: Respiratory illness affects individuals across all age demographics on a global scale, often precipitated by viral infections. The symptomatic manifestations of these diseases bear clinical resemblance, complicating the accurate determination of their etiological origins. Furthermore, the diagnostic panels for respiratory pathogens used within local medical practices, may not encompass the full spectrum of viral agents responsible for such ailments. Consequently, a significant number of clinically important viral pathogens may remain undetected. Methods and findings: In the light of this, we conducted a metagenomic examination of 66 nasopharyngeal swab specimens, obtained from patients presenting with acute respiratory conditions yet tested negative by the standard diagnostic panels available locally. These specimens were obtained from the Public Health Laboratory, Maceio, State of Alagoas. Our findings indicate a predominant diagnostic escape of rhinoviruses and notably enterovirus D68. Moreover, our study identified a substantial quantity of sequence reads attributed to human respirovirus 3 (human parainfluenza 3) along with various herpresviruses including human herpesvirus-1, Epstein-Barr virus (Human herpesvirus-4), Human herpesviruses 6 and 7 and human parvovirus B19 (B19V). Notably, the metagenomic analysis uncovered a widespread presence of the emerging human vientovirus FB in most of sample pools, though its clinical importance remains to be elucidated. Conclusions: The obtained results in this study underscore the invaluable role of viral metagenomics in the identification of underrecognized viruses bearing clinical relevance. Furthermore, it offers insights into the dissemination of these pathogens within the studied area, thereby informing public health strategies aimed at enhancing diagnostic accuracy and improving patient care. Author summary: The emergence of SARS-CoV-2 has reshaped our understanding of respiratory viruses, highlighting the challenges in etiological diagnosis due to symptom similarities. Metagenomics, an innovative approach, has revolutionized respiratory infection diagnosis by unbiasedly sequencing all genetic material in a sample, enabling the identification of previously unknown or unsuspected viruses where traditional methods often fail. In a study conducted in Alagoas, a Northeast Brazilian state with low human development indexes, samples obtained from patients with flu-like symptoms negative for locally applied diagnostic kits revealed diagnostic escape of rhinoviruses and a notably prevalent enterovirus D68. Additionally, substantial reads attributed to human respirovirus 3 (parainfluenza virus 3) and various herpesviruses, including human herpesvirus-1, Epstein-Barr virus, human herpesviruses 6 and 7, and human parvovirus B19, were identified. These findings are pivotal for differentiating viruses not detected by routinely implemented diagnostic procedures. Metagenomics shows great promise in diagnosing and surveilling respiratory viruses, providing insights into their epidemiology, evolution, and public health impact. [ABSTRACT FROM AUTHOR]