A woman as "healthy as could be" has died in southern Spain after contracting a virus spread by mosquitoes.

Granada Romero Ruiz was hospitalised on July 11 after falling ill with the West Nile virus, a disease in the same family as dengue and yellow fever transmitted to humans via mosquito bites.

She died on Friday night aged 86 at Seville’s Virgen del Rio Hospital.

The son of the woman, Antonio Pineda, said she was in perfect health before the mosquito bite.

He said: "She had no underlying health problems, she was healthy as could be, active and with a normal life." His devastating loss, Mr Pineda believes, could have been avoided had areas near his mother's home been properly fumigated.

Ms Romero Ruiz is the second person to have been killed by the virus this year in the Seville area.

The first Spanish victim of the West Nile virus was a 71-year-old woman who lived in the town of Dos Hermanas, a 30 minute drive from La Puebla del Rio where the late 86-year-old was from.

The West Nile fever, which is believed to have first reached Spain in 2004, has also been identified in other European nations including Italy, Portugal, France, and Romania - where the first large outbreak occurred in 1996.

Pablo Barreiro, an expert in infectious diseases, warned the virus can spread easily due to one main trait.

He said: "Only about two to five per cent of the cases present symptoms. It’s an illness that can go unnoticed very easily."

Elderly people and those with underlying conditions including diabetes and cancer are most at risk of falling victim to this virus, which can cause meningitis in children.

Earlier this month, the European Centre for Disease Prevention and Control (ECDC) director Andrea Ammon warned climate change is "creating more favourable conditions for invasive mosquitoes to spread" in European areas previously unaffected and "infect more people with diseases such as dengue".

He added: "Increased international travel from dengue-endemic countries will also increase the risk of imported cases, and inevitably also the risk of local outbreaks."