Molecular Detection of Enterovirus D68 in Cases of Acute Respiratory Infection Occurring in the State of Acre

Enterovirus D68 (EV-D68) is an emerging virus of the Enterovirus genus, mainly associated with acute respiratory infections (ARI) and, less frequently, with neurological manifestations such as acute flaccid myelitis. Since its reemergence in the United States in 2014, it has been identified in several countries, with potential for respiratory outbreaks, especially among children and individuals with comorbidities. In Brazil, data on its circulation are still scarce, particularly in the Northern region. Thus, this study aims to describe the clinical and epidemiological profile of ARI cases associated with EV-D68 in the state of Acre from January to May 2025. Materials and methods: A total of 552 respiratory secretion samples from individuals with influenza-like illness, of both sexes and different ages, collected at health units in the state of Acre, were analyzed. Molecular detection was performed by real-time RT-PCR using probes and oligonucleotides specific for EV-D68. Among the 552 samples analyzed, 3.44% (19/552) were positive for Enterovirus D68. Of these, 52.6% (10/19) were classified as influenza-like illness and 47.4% (9/19) as severe acute respiratory syndrome, requiring hospitalization. Regarding sex, most cases occurred in males, 57.9% (11/19), and 42.1% (8/19) in females. A higher prevalence was observed in children aged zero to five years. The most frequent symptoms were cough 84.2% (16/19), fever 78.9% (15/19), headache 47.4% (9/19), respiratory distress and myalgia 42.1% (8/19), dyspnea and sore throat 36.8% (7/19), rhinorrhea 31.6% (6/19), fatigue 5.3% (1/19), and three patients 15.8% (3/19) presented oxygen saturation below 95%. Comorbidities were observed in 21.1% (4/19), including asthma, hypertension, and tracheostomy. The detection of EV-D68 in Acre demonstrates the circulation of this emerging virus in Northern Brazil, as well as its association with severe ARI cases. These results reinforce the importance of molecular surveillance of other respiratory viruses and differential diagnosis of acute respiratory syndromes, especially in vulnerable populations. Furthermore, expanded monitoring is essential to anticipate outbreaks, guide prevention strategies, and improve ARI control in the region.