Abstract

Acute respiratory infections (ARI) of viral etiology represent one of the leading causes of morbidity and mortality worldwide. The objective of this research was to determine the circulation of respiratory viruses in the province of Villa Clara, Cuba, during the post-pandemic period. A cross-sectional, descriptive, observational study was conducted in the Molecular Biology Laboratory of the Provincial Center of Hygiene, Epidemiology, and Microbiology (PCHEM) of Villa Clara province, Cuba, from May 2023 to December 2025. The study population consisted of all nasopharyngeal swab samples from primary and secondary care settings with suspected acute respiratory infections (ARIs) or severe ARIs (N=1,206). These collected samples were processed by real-time RT-PCR for SARS-CoV-2 detection using the RIDA®GENE SARS-CoV-2 commercial kit. Nucleotide sequencing was performed to determine circulating variants and subvariants, thus complementing the epidemiological analysis. Influenza virus (FLU B) was the most frequently detected, with 19 confirmed cases (43.2%), followed by CoV-OC43 with 12 cases (27.3%). It should be noted that 6 samples showed coinfection: one of FLU B with CoV-OC43; one of Respiratory Syncytial Virus B (RSV B) with CoV-OC43; two of FLU B with CoV-HKU1; one of CoV-OC43 with CoV-HKU1; and one of Metapneumovirus with CoV-OC43. That of the 44 confirmed samples, a 97.7% concordance rate was obtained with respect to the LNR-IPK. Of the 10% of negative samples submitted, a 100% concordance rate was obtained. It is concluded that there is active and significant circulation of Human Coronavirus OC43, especially in older adults, which was also the most frequent agent and associated with severe forms of the disease.