To analyze the latent tuberculosis infection and preventive treatment in the school tuberculosis epidemic, so as to provide theoretical and technical support for tuberculosis prevention and control in schools.

Information on latent infection, preventive treatment and tuberculosis incidence were collected from five tuberculosis outbreaks in schools in Hunan Province from January to December 2023. Statistical analysis was conducted by using Chi-square test and Fisher's exact test.

The prevalence of tuberculosis patients in close contacts (7.69%) and the latent infection rate of Mycobacterium tuberculosis (31.87%) were higher than those in non-close contacts (0.12%, 6.29%), and the differences were statistically significant (P < 0.01). The subsequent incidence of close contacts with latent infection was higher (8.62%) than that of non-close contacts (0), the rate of close contacts receiving prophylactic treatment (63.30%) was higher than that of non-close contacts (47.37%), and the proportion of close contacts receiving prophylactic treatment (68.12%) was higher than that of non-close contacts (45.56%), and the differences were statistically significant (P < 0.05). The latent infection rate of Mycobacterium tuberculosis in college students (13.58%) was higher than that in middle school students (7.08%) (χ²=37.77, P < 0.01). The proportion of college students receiving preventive treatment (100.00%) was higher than that of middle school students (40.34%), and the subsequent incidence of latent infection (6.67%) was higher than that of middle school students (0.54%); the rate of middle school students who should receive preventive treatment (70.41%) was higher than that of college students (30.77%), and the rate of middle school students who received preventive treatment (100.00%) was higher than that of college students (62.50%), and the differences were statistically significant (P < 0.01). Among the latent infected persons, 144 who completed preventive treatment did not get sick, and 10 of the 177 who did not complete preventive treatment got sick, with an incidence rate of 5.65%. The incidence rate of close contacts (19.23%) was higher than that of non-close contacts (0) (P < 0.01). There was no significant difference in the incidence of pulmonary tuberculosis between university (8.18%) and middle school (1.49%) among latent infected persons who did not complete preventive treatment (P=0.09).

Actively promoting preventive treatment for latent infections, especially among close contacts, and ensuring that all eligible individuals receive treatment can reduce tuberculosis incidence in schools and help control the scale of school tuberculosis outbreaks.