Over the last few decades, wild boar populations have increased in the urban areas of Barcelona and in other parts of Catalonia. This wild animal is an important reservoir of the hepatitis E virus, the disease causative agent that affects more than 20 million people every year, according to the World Health Organization (WHO). Over the last few decades, wild boar populations have increased in the urban areas of Barcelona and in other parts of Catalonia. This wild animal is an important reservoir of the hepatitis E virus, the disease causative agent that affects more than 20 million people every year, according to the World Health Organization (WHO). Ecology Veterinary medicine Phys.org – latest science and technology news stories