Respiratory virus prevalence among healthcare university students in Ecuador: a multicenter cross-sectional study

Background Respiratory viruses remain a major global public health concern and are among the leading causes of acute respiratory infections worldwide. University students, particularly healthcare students, represent a potentially important group for viral circulation because of frequent social interaction and exposure to clinical environments. Evidence regarding respiratory virus circulation in university populations from Latin America, especially Ecuador, remains limited. Objective To estimate the prevalence of respiratory viruses among 438 healthcare university students in three Ecuadorian cities and to describe the proportion of infections detected in students without symptoms. Methods A multicenter cross-sectional study based on a convenience sample was conducted between January 4 and February 3, 2026, among healthcare university students from universities located in Quito, Guayaquil, and Cuenca, Ecuador. Nasopharyngeal samples were analyzed on site using a combo rapid antigen test for respiratory syncytial virus (RSV), Influenza A, Influenza B, and Adenovirus. Sociodemographic and epidemiological variables were recorded. Exact tests and exploratory Firth penalized logistic regression were used to explore factors associated with positivity. Results Fourteen participants tested positive for at least one respiratory virus, corresponding to an overall prevalence of 3.2% (95% CI: 1.8–5.3). Influenza A virus and respiratory syncytial virus (RSV) were the most frequent single detections ( n = 4 each), followed by adenovirus ( n = 3). Three coinfections were identified. Eight of the 14 positive participants (57.1%) were asymptomatic, whereas six (42.9%) reported respiratory symptoms. A significant association was identified between symptom presence and viral detection ( p < 0.001). Conclusion Respiratory virus detection among healthcare university students in Ecuador was low, and more than half of the positive students reported no symptoms, suggesting that these viruses may circulate unnoticed within university environments. Because rapid antigen tests have limited sensitivity and do not directly measure infectivity, the true prevalence is probably higher, and studies with molecular confirmation, larger samples, and longer sampling periods are needed. Rapid antigen tests were operationally feasible as point-of-care tools for on-site screening in academic environments.