L. Isao "L.I." Telaka was a human Starfleet officer in the mid 24th century. He was approximately the same age as USS Enterprise first officer William T. Riker. By 2365 he was the CO of the USS Lantree.
In 2365 his first officer caught a mild case of Thelusian flu. Afterwards the Lantree visited the Darwin Genetic Research Station. Still carrying the flu virus, the first officer was exposed to the genetically modified children living on the planet. Their modified immune systems created an antibody to attack the virus, which had the deadly side effect of modifying human genes responsible for aging. The Lantree took the antibody back to the ship when they left.
Six days later the disease triggered by the antibody caused the crew to rapidly age and die. Telaka had his crew set course for the nearest Federation outpost as well as issuing a distress call which the Enterprise picked up. All of the crew died shortly before the Enterprise arrived. Using sensors Enterprise CMO Doctor Katherine Pulaski determined that the crew apparently died of natural causes.
In his final log Captain Telaka noted that over the past few days he had watched his friends on the Lantree rapidly grow old and die. He also noted that all attempts to analyze what was happening to them had failed.
Captain Jean-Luc Picard and Dr. Pulaski declared a quarantine on the Lantree and the Enterprise departed to Darwin Genetic Research Station. After determining that the exposure to the genetically enhanced children was deadly to normal humans, and that normal medical methods could not stop this disease. The Enterprise crew was able to cure all the other adults infected by the antibody by using their transporter to restore their DNA to a healthy condition.
After leaving the research station Captain Picard decided that the Lantree had to be destroyed in order to prevent any further transmission of the antibody the station had accidentally created. The bodies of Telaka and his crew were destroyed along with the Lantree by a single photon torpedo fired by the Enterprise.
Dr. Pulaski made sure to note the sacrifice of Captain Telaka and his 25 fellow crew members in her official log. Starfleet Intelligence soon classified the details of the Lantree's final mission. (TNG episode: "Unnatural Selection", Decipher RPG module: Starfleet Operations Manual)