# Persistent Infection in Harbor Seals 12–13 Years after Phocine Distemper Virus Epizootics in 1988 and 2002, North Sea

## TL;DR

Harbor seals in the North Sea showed signs of persistent infection from phocine distemper virus up to 12–13 years after major outbreaks in 1988 and 2002.

## Contribution

The study identifies defective virus variants causing long-term neurological disease in seals, similar to human and canine conditions.

## Key findings

- Defective phocine distemper virus variants were found in seals years after initial outbreaks.
- The neurological disease in old seals resembled subacute sclerosing panencephalitis in humans and old dog encephalitis in canines.
- This suggests long-term persistence and evolution of the virus in the seal population.

## Abstract

Phocine distemper virus caused epizootics of fatal pneumonia in North Sea harbor seals in 1988 and 2002. Two seals that stranded years later were infected with defective phocine distemper virus variants that caused severe encephalomyelitis. Old seal encephalitis resembled subacute sclerosing panencephalitis in humans and old dog encephalitis in canines.