Background: Trachoma is the leading cause of infectious blindness worldwide. Trachoma is endemic in parts of Africa, the middle east, and India. The disease is particularly problematic in particular Ethiopia and Sudan regions.

Objectives :To detect Chlamydia trachomatis among active trachoma children using molecular technique in -Gadarif State- Sudan

Methodology: A population-based prevalence study was conducted during the period from Nov 2016 to Nov 2017. A total of 318 children were surveyed; their ages range between 1 to 9 years old. The children's eyes were examined for trachoma follicles and trachoma inflammatory intense (TF, and TI). Samples were collected on Swabs from children clinically diagnosed as active trachoma for the DNA analysis, and collection was done from the tarsal conjunctival surface with a dacron polyester swab and with UTM media, DNA was extracted and amplified by molecular technique with Touchdown protocol and primers for C. trachomatis outer membrane protein complex B ( omcB). Data was collected by direct interviewing questionnaire; ethical approval was obtained from Ethical Research Committee -Al Neelain University

Result: Out of the total 318 children, 83(26.1%) children were positive for the

C trachomatis omc B gene; Sequencing was performed for both strands of omc B genes, found that the circulating strain in Sudan Gdarif state is similar genetically to the classical one registered in NCBI

Conclusion: Chlamydia trachomatis is one of the causative agents of trachoma in Sudan, the circulating strain in Sudan Gdarif state is similar genetically to the classical one registered in NCBI

Keywords: Chlamydia trachomatis- omc B genes- PCR- Trachoma- Sudan