Table 1. Summary of the evolution of TB surveillance, diagnosis, and treatment in Puerto Rico over 3 periods*.

Period	Surveillance	Diagnosis	Treatment
1898–1946	Passive, relying on voluntary reporting; Bureau of TB established in 1924; TB becomes a part of vital statistics centrally compiled by PRDH in 1931	Primarily clinical diagnosis; TST progressively routinized after 1929; chest radiography and limited sputum examination in TB dispensaries since 1935	Pneumothorax procedures, bed rest in sanatorium, and isolation of patients with active TB
1947–1992	TB recording and reporting through PRDH TB centers and centralized at PRDH; private physicians, hospitals, and VA report to PRDH; case-level data collection and reporting to NTSS uses RVCT	TST and chest radiography routine for screening (e.g., medical cards); limited sputum AFB examination and ability to culture	Three-drug regimen of streptomycin, PAS, and isoniazid; free treatment in 3-mo courses for total treatment of >2 y; introduction of short-course regimens using rifampin in the 1970s
1993–2015	RVCT revised and expanded; CDC NTSS electronic registry launched; molecular testing for DST at PRDH laboratory and genotyping and molecular testing through CDC introduced	Diagnosis relies on sputum AFB examination and culture; screening with TST and chest radiography; few cases diagnosed clinically	DOT, 4-drug regimen of isoniazid, rifampin, pyrazinamide, and ethambutol; intensive and continuation phase for 6–8 mo; regimens individualized according to DST results

*AFB, acid-fast bacillus; CDC, Centers for Disease Control and Prevention; DOT, directly observed therapy; DST, drug-sensitivity testing; NTSS, National TB Surveillance System; PAS, para-aminosalicylic acid; PRDH, Puerto Rico Department of Health; RVCT, Report of Verified Case of Tuberculosis; TB, tuberculosis; TST, tuberculin skin testing; VA, Veterans Administration.