Chiungunya fever has affected more than 27,000 people in Puerto Rico since last May and of those, 14 have died, though it has not been determined whether the virus was the direct cause of death.

According to figures released Friday by the Puerto Rico Health Department that go back to Jan. 21, a total of 27,465 cases have been recorded of infection by the virus, which is transmitted by mosquito bites and was detected in this U.S. commonwealth for the first time last May.

Of those cases, just 4,274 samples have been tested by laboratories of the U.S. Centers for Disease Control and Prevention, or CDC, in Atlanta.

No cases have yet been detected of people infected by the chikungunya virus and dengue fever at the same time.

Authorities said that 14 fatalities on the island since May tested positive for the chikungunya virus, though they could not say that the deaths were directly related to that infection.

Chikungunya virus is relatively new in the Americas - the first case was detected just over a year ago - and since then it has spread rapidly.

Symptoms of the virus, whose incubation period is from three to seven days, include fever, skin rash and sharp pain in the joints, head and muscles, and very rarely is it fatal, usually for people already suffering from serious health problems.

Compared with dengue, the chikungunya infection normally causes more intense pain to the joints and tendons, the beginning of the fever is more pronouced but has a shorter duration, and rarely is serious hemorrhaging observed.

Though the symptoms tend to diminish after seven to 10 days, the pain and stiffness in the joints can persist for several months. EFE