JCV seroconversion rate during the SARS COVID-19 pandemic.

Area of Science:

• Virology
• Epidemiology
• Neuroimmunology

Background:

• John Cunningham virus (JCV) transmission routes remain unclear, with potential oral transmission via contaminated sources.
• Natalizumab-treated Multiple Sclerosis (MS) patients are monitored for JCV serology due to Progressive Multifocal Leukoencephalopathy (PML) risk.
• COVID-19 pandemic restrictions impacted communicable disease transmission patterns.

Purpose of the Study:

• To evaluate JCV seroconversion rates in Natalizumab-treated MS patients before and during the COVID-19 pandemic.
• To investigate the potential impact of pandemic-related behavioral changes on JCV transmission.
• To infer JCV transmission routes based on seroconversion trends.

Main Methods:

• Retrospective analysis of clinical records for JCV serology status.
• Comparison of seroconversion rates in a single-center cohort of MS patients.
• Assessment of seroconversion prevalence pre-pandemic versus during the COVID-19 pandemic.

Main Results:

• JCV seroconversion rates remained stable during the COVID-19 pandemic compared to pre-pandemic levels.
• Contrary to hypothesis, no significant decrease in seroconversion was observed despite social restrictions.
• Findings indicate consistent JCV exposure patterns irrespective of pandemic-related behavioral shifts.

Conclusions:

• The stability of JCV seroconversion rates during the pandemic supports transmission via the gastrointestinal (GI) tract.
• JCV is unlikely to be transmitted via the respiratory system, as initially hypothesized by some.
• Further research into oral/fecal transmission routes of JCV is warranted.