Surveillance and diagnosis of influenza and other seasonal respiratory viruses
Although respiratory diseases are generally not severe, they cause thousands of hospitalizations and deaths worldwide every year, which would increase dramatically if surveillance systems were not in place.

Seasonal influenza is easily spread and rapidly transmitted in settings such as schools, nursing homes, or hospitals. Infected individuals disperse infectious droplets (containing the virus) into the air up to 1 meter away when coughing or sneezing, thus infecting nearby people who inhale these droplets. The virus can also spread through contaminated hands.
During the winter, many other respiratory viruses also circulate, such as SARS-CoV-2, Respiratory Syncytial Virus (RSV), Rhinovirus, Adenovirus, or Metapneumovirus. Like influenza, these viruses spread relatively easily and typically result in mild to moderate, self-limiting respiratory illness, meaning they resolve on their own without special treatment. However, older adults and individuals with underlying illnesses are more likely to develop severe illness. In fact, these respiratory viruses cause millions of illnesses and thousands of hospitalizations and deaths worldwide each year.
In Spain, Influenza surveillance has traditionally relied on various systems and information sources, providing a comprehensive view of the disease’s behaviour and circulating influenza viruses. However, the emergence of COVID-19 during February and March 2020 led to a distortion of these surveillance systems.
Following international recommendations from the European Centre for Disease Prevention and Control (ECDC) and the World Health Organization (WHO), sentinel surveillance systems have been established. These systems aim to monitor influenza and COVID-19 jointly and to remain over time as acute respiratory infection surveillance systems, both mild and severe, capable of monitoring any other respiratory virus or emerging etiological agent in the future.
The emergence of COVID-19 also brought changes in the approach to diagnosing infectious diseases, particularly the implementation of molecular techniques. Real-Time PCR has become the gold standard for identifying infectious agents, primarily viruses. In this context, the technique allows for syndromic diagnosis, meaning the identification of RNA from different respiratory viruses in patients with similar symptoms, a practice that is being carried out in in major hospital worldwide.
In this regard, Certest Biotec, a pioneering biotechnology company based in Aragón for over 20 years, develops and manufactures in vitro diagnostic tests based on Real-Time PCR. These kits can simultaneously identify more than 20 respiratory viruses in less than 2 hours, significantly speeding up diagnosis and contributing the effective functioning of surveillance systems.
The company operates through its network of distributors in over 110 countries, providing its lyophilized and sustainable product format worldwide year-round, addressing seasonal epidemics of respiratory viruses in temperate regions as well as irregular outbreaks in tropical areas.
Cristina Escolar, Product Specialist Manager for Molecular Diagnostic de Certest