Ongoing monitoring of COVID-19 risk in individuals with cystic fibrosis required

Although individuals with cystic fibrosis have increased risk for respiratory tract viral infections, this population does not appear to have a higher risk for SARS-CoV-2 infection based on published evidence to date.

Researchers used EMBASE and Medline to perform a systematic review between April and December 2020 to assess whether individuals with cystic fibrosis are at elevated risk for SARS-COV-2 infection and development of COVID-19. Their review identified six studies that described outcomes of patients with COVID-19 with exposure constituting cystic fibrosis history. The six studies that met inclusion criteria reported on 339 individuals with cystic fibrosis who contracted COVID-19.

“It is not clear whether individuals with [cystic fibrosis] are at higher risk of COVID-19 or its adverse consequences,” Hannah R. Mathew, BSc, medical student in the department of biological sciences at the University of Calgary, Calgary, Canada, and colleagues wrote in BMC Pulmonary Medicine. “This topic has been of great concern due to the importance of recurrent respiratory viral infections in disease perturbation and pulmonary exacerbations.”

According to the review, the incidence of COVID-19 among individuals with cystic fibrosis was lower compared with the general population despite those with cystic fibrosis generally experiencing acute lung disease exacerbations from infectious diseases. In a multinational cohort study, the incidence of COVID-19 was 0.07%, which was more than half of the 0.15% rate in the general population. Another study conducted in France reported a incidence of COVID-19 of 0.41%, which represented a 93% reduced incidence compared with the general population.

Researchers also observed an increased risk for more severe COVID-19 infection among subsets of individuals with cystic fibrosis, including those who underwent organ transplants. In one study of 32 lung transplant recipients with COVID-19, 16% had mild COVID-19, 44% had moderate COVID-19 and 41% had severe COVID-19. In addition, 84% of patients were hospitalized and 34% died. These results suggest COVID-19 was associated with significantly higher mortality among lung transplant recipients, according to the researchers.

According to the review, authors of most studies included suggested lower COVID-19 rates among individuals with cystic fibrosis can be linked to their increased awareness of infection prevention and control, such as hand hygiene and wearing facial masks. In addition, other potential protective mechanisms among individuals with cystic fibrosis include pre-pandemic social isolation practices, an altered expression of angiotensin-converting enzyme and certain medication use.

“The limited cases of SARS-CoV-2 infection among the [cystic fibrosis] population is likely due to several factors that include effective physical and social distancing and the effective use of learned principles and practices of infection control stressed as parts of routine [cystic fibrosis] care,” Mathew and colleagues wrote. “Other factors that are likely at play include altered expression of [angiotensin-converting enzyme], [angiotensin-converting enzyme]-2 and CFTR; and the use of medications with anti-viral effects.”

Mathew and colleagues concluded: “As SARS-CoV-2 variants are identified and the pandemic goes through additional waves of disease outbreaks, ongoing monitoring of the risk of COVID-19 in individuals with cystic fibrosis is required.”