BY CAROL ROSENBERG

                      GUANTANAMO BAY NAVAL BASE, Cuba -- U.S. medical officers met with
                      Cuban doctors earlier this month to reassure the government that
                      suspected terrorist prisoners are not introducing malaria into this
                      island, which has been free of the mosquito-borne disease for 50
                      years.

                      At the same time, Cuban medical personnel used the Feb. 8 session
                      just across the Northeast Gate, on Cuban territory, to brief U.S.
                      authorities on their efforts to control dengue fever, a
                      mosquito-transmitted viral disease that has been detected in nearby
                      Santiago Province.

                      ''We talked about dengue, and they wanted to know what we're doing about malaria,'' said Navy Capt.
                      Al Shimkus, commander of the Naval Hospital at the base. ``I think both sides needed reassurances
                      that we're going by public health standards of the World Health Organization, that we're doing the
                      right thing.''

                      FOUR INFECTED

                      Steps to stop the spread of malaria include impregnating the uniforms of both prisoners and troops
                      who handle prisoners with mefloquin and other agents to kill the parasite that causes the malady.
                      Four of the 300 prisoners at Camp X-Ray have malaria; 40 percent of Afghanistan's population is
                      afflicted with the disease, Shimkus said. They are being treated to make sure they are no longer
                      contagious, although they will suffer the condition for life.

                      The existence of dengue in Cuba is on record with the World Health Organization. So Cuban medical
                      personnel ''discussed the details of their eradication process,'' Shimkus said, including increased
                      sanitation efforts and pest control.

                      Commanders say there is little concern on the American side that dengue will spread to this
                      45-square-mile base that is home to about 4,500 military and civilians. They cite WHO literature that
                      says the range of the mosquito species that carries dengue is 200 to 300 yards; the nearest known
                      cases are more than 10 miles away.

                      Local U.S. and Cuban commanders have held monthly ''fence-line meetings'' since 1995 at the seam
                      between the Navy base and Cuban-controlled territory -- now separated by 17.4 miles of
                      razor-wire-topped fence and a Cuban minefield -- to keep down tensions by alerting the others to
                      unusual activity.

                      21-GUN SALUTE

                      Commanders forewarned the Cuban military, for example, about a Monday lunchtime 21-gun salute in
                      celebration of Presidents Day.

                      But the Feb. 8 session was ''the first time that a real-time public health issue has arisen around the
                      fence-line,'' said Tom Gerth, a State Department official assigned to deal with the Guantánamo issues.

                      As of Thursday, there were 300 prisoners from Afghanistan at Camp X-Ray.

                      ROS-LEHTINEN INQUIRY

                      The officers briefed The Herald on the latest medical exchange after an inquiry from U.S. Rep. Ileana
                      Ros-Lehtinen, the Miami Republican, who had expressed concern about increasing medical contacts in
                      a formal letter.

                      The Feb. 8 discussion between ''technical experts'' lasted about 45 minutes, Shimkus said. It was
                      requested by Cuban commanders. There were three U.S. representatives at the session: a translator,
                      a U.S. public health officer and a preventive medicine physician. Cuba sent three equivalent envoys.