South Korea plans to carry out massive free tests for latent tuberculosis this year as part of efforts to cut the high incidence rate of the infectious disease in the country, officials said Wednesday.

Starting in April, some 600,000 high school freshmen, teachers and other school employees will be tested for latent TB -- a condition in which the TB bacteria is in the body but inactive with no symptoms, according to the Ministry of Health and Welfare.
 

TB patients are said to increase considerably around the age of 15. Without treatment, about 5 to 10 percent of latent TB patients are known to develop TB at some time in their lives, usually between 15 and 40.

About 850,000 South Koreans aged 40 will also get tested for latent TB during their annual mandatory medical checkups from July this year.

In January, the ministry required all possible military conscripts and employees of postpartum centers to receive a mandatory test for latent TB. The compulsory tests will be expanded to workers at daycare centers, hospitals and welfare facilities in March, and to prison inmates in May.

The move comes as South Korea has the highest prevalence rate of TB among members of the Organization for Economic Cooperation and Development. The country had 63 patients per 100,000 people in 2015. Portugal ranks second with 25 patients, followed by Poland with 21.

Yet South Korea's TB incidence rate has been on the decline.

The country's new TB patients stood at 32,181 in 2015, down 2,688 from the previous year.

In March last year, the ministry unveiled a package of measures to counter TB, which calls for lowering the country's incidence rate for the disease to 12 patients per 100,000 people by 2025. (Yonhap)