Madrid, Aug 22 (IANS): Spain has reported this year's first death due to the West Nile virus, a mosquito-borne infection, officials said.

Spanish TV network Telecinco said in a report on Friday that the victim, a 77-year-old man from the town of La Puebla del Rio, died on Thursday night, reports Xinhua news agency.

According to the report, the patient had been in intensive care in a hospital near the town, where he was receiving treatment for several days.

A total of 35 people have so far been infected in the biggest West Nile outbreak ever detected in the country's southern region of Andalusia, according to the El Pais newspaper.

The outbreak mainly affected two towns in Andalusia -- La Puebla del Rio and Coria del Rio -- both located on the banks of the Guadalquivir River.

The average age of those infected in the outbreak is 60, and 71 per cent of the victims are men, said El Pais.

The virus is spread by mosquitoes, which are common in the area given the proximity to the river.

Transmitted by the common Culex mosquito, the virus causes a death rate of 0.1 per cent among those infected.

According to the World Health Organization, approximately 80 per cent of people who are infected will not show any symptoms.