By Daniela Desantis

ASUNCION (Reuters) – The death toll from a dengue fever outbreak in Paraguay rose to 34, the Public Health Ministry said on Friday, warning that the virus is spreading beyond the capital Asuncion.

The number of fatalities was up from 20 last week, officials said. Confirmed cases spiked to 137,000 from 100,000 in the South American country of 6.8 million people.

On Wednesday, a 5-year-old girl with dengue symptoms died in the northern city of Concepcion.

Her death shocked the country because fatalities from the disease – also known as “breakbone fever” due to its severe muscle aches – are typically elderly people suffering from other ailments and because most of the cases have been concentrated around Asuncion to the south.

Another 90 deaths were under investigation to determine whether they were due to dengue fever.

However, Health Minister Julio Mazzoleni said dengue fever cases in the capital were in “a gradual decline.”

“We can confirm the trend that there is a significant decrease in Asuncion and the surrounding area,” Mazzoleni said at a news conference.

“The number of cases is relatively small in the rest of the country, but … the proportion may be important based on the populations of those districts,” Mazzoleni added.

Cases of dengue fever, caused by a virus transmitted by mosquitoes, typically increase in the summer months between January and March, when mosquito activity peaks. The number of cases tends to gradually decrease toward the end of March.

The number of dengue cases registered in Paraguay in the first two months of the year is the highest in the last decade. The death toll, however, is lower than in 2013, when there were 250 dengue fever deaths.

(Reporting by Daniela Desantis; writing by Cassandra Garrison; editing by Jonathan Oatis)