By Andres Schipani
BBC News, La Paz
The virus is passed to humans when mosquitoes carrying it feed on blood
Bolivia has sounded the alarm about the country's worst outbreak of dengue fever for 22 years.
The outbreak has already killed five people in the east of the country and infected more than 7,000.
Bolivia is facing an epidemic in its tropical lowlands and its strained health system appears unable to cope.
Authorities have declared a health emergency. Worst hit is the region of Santa Cruz, bordering the Amazon and neighbouring Paraguay.
More than a dozen of the reported cases have been of dengue haemorrhagic fever or DHF, which if left untreated has a high mortality rate.
Bolivia's medical resources are already stretched to the limit, so a number of military facilities, especially in the city of Santa Cruz, have been turned into temporary hospitals.
Thousands of soldiers and medical workers have been enlisted to help.
The government has allocated funds to supply the hospitals and step up fumigation, but many accuse the authorities of being slow to take action.