Risk Factors and Prevalence for Latent Tuberculosis Infection among Health Care Workers in Al-Quwayiyah General Hospital Riyadh, KSA

Background: All health care facilities should intensify TB screening and encourage treatment of latent tuberculosis infection (LTBI) among Healthcare workers (HCWs) to prevent progression to tuberculosis (TB) disease.

Aim: This study was conducted to determine the prevalence and associated risk factors of LTBI among HCWs in Al Quwayiyah General hospital as well as to compare the performance of QuantiFERON-TB Gold Plus (QFT-Plus) to TST in identifying LTBI.

Methods: A cross sectional study and prospective cohort study was performed from January to July 2019 in Al Quwayiyah General hospital involving a total of 718 HCWs. questionnaire with socio-demographic data and work history was filled, and both tests were done TST and QFT test for each Healthcare worker.

Results: The study showed that The prevalence of latent tuberculosis diagnosed was 9.05% and 9.19% using QFT-Plus and TST respectively. Only 26 (3.62%) subjects were positive for both tests whereas 131 (18.25%) were positive by either test. Comparing the results of the QFT-Plus with those of the TST, both tests had a significant total agreement of 88.8. Negative concordance comprised 85.37% of the results, and positive concordance comprised 3.62%. However, positive TST but negative QFT-Plus comprised 5.57% of the results, and negative TST but positive QFT-Plus comprised 5.43%. The association between risk factors and QFT-Plus test results in the studied groups showed that the smoking, health status, immunosuppresion, housing, occupation, contact T.B. at work place, past history of TB and diabetes mellitus appear as significant risk factors. The association between the studied risk factors and TST in the studied groups showed sig­nificant difference noted for smoking, BCG vaccination, immunosuppresion, housing, occupation, contact T.B. at work place, past history of TB and diabetes mellitus.

Conclusion: The prevalence of latent tuberculosis diagnosed was 9.05% and 9.19% using QFT-Plus and TST respectively. Testing of HCWs at hire and periodically can help in the detection of LTBI Large scale study is recommended to confirm such findings in Saudi Arabia, also the use of Quantiferon for detection of LTBI beside using TST is recommended as it reduce the false positive reports by TST and is not affected by prior BCG status.