Dear editor,

We would like to share ideas on “Hospital-acquired infections in a tertiary hospital in Iran before and during the coronavirus disease 2019 (COVID-19) pandemic [1].” In their study, Mohammadi et al. examined and compared the incidence of nosocomial infections in a hospital for 9 months during the COVID-19 period to the 8 months in the pre-COVID era [1]. There has been no research on the impact of shifting the entire number of patients from the pre- to postepidemic period, not only instances with nosocomial infections. Enhanced infection prevention methods established in hospitals to limit the spread of a pandemic infection, according to Mohammadi et al., may not always reduce rates of other hospital-acquired infections during a pandemic [1]. Limited resources, personnel transfers, and staff shortages due to quarantine measures, according to Mohammadi et al., may hinder enhanced preventative practices from effectively managing nosocomial infections [1].

We agree that infection control is an important concept regardless the existence of the COVID-19 pandemic. The incidence of hospital-acquired infection might or might not increase during the COVID-19 pandemic period. It is necessary to recognize the effect of increasing number of admitted patients during the outbreak. With a significant increase of hospitalized cases, there might be an increased number of nosocomial infections. In the study by Mohammadi et al., the analysis of an interrelationship with overall number of hospitalizations might give more important observations. Finally, when there is a mass vaccination policy against COVID-19, medical personnel might sometimes neglect the universal prevention concept, which might be a possible cause of disease spreading [2]. For example, a post-vaccination COVID-19 outbreak was reported from a hospital in tropical Asia, and a rooted cause analysis revealed that vaccinated workers may overlook universal precautions, potentially leading to a post-vaccination COVID-19 outbreak [2]. Another study on the prevalence of post-vaccination COVID-19 infection in healthcare workers in the USA found that below-average facemask use was linked to a higher risk of infection for vaccinated healthcare workers [3].

Finally, during the COVID-19 pandemic, there may be a change in the incidence of hospital-acquired infections. It is possible that the situation will be different in different locations. The number of patients in the hospital at different periods during an outbreak in that environment, as well as the intensity with which local healthcare staff undertake universal prevention, are important elements that can affect the prevalence of hospital-acquired infections in any context.