Study On The Latent Tuberculosis Infection And Its Risk Factors Among Healthcare Workers In A Chest Hospital

Tuberculosis(TB), known as "White Plague", is a chronic infection disease which can make serious hazard to human health. China is one of the twenty two counties with high disease burden caused by TB. The amount of TB cases in China is the top two in the world. Healthcare workers (HCWs) are at risk of nosocomial infection with Mycobacterium tuberculosis. The risk for TB among HCWs is higher than the risk among the general population worldwide. Transmission of tuberculosis (TB) in health care settings to both patients and health care workers (HCWs) has been reported from virtually every country of the world, regardless of local TB incidence. TB transmission occurs through droplet nuclei aerosolized by patients with infectious pulmonary TB and inhaled by other persons. Transmission is most likely to occur from unrecognized or inappropriately treated TB. The risk for transmission varies by occupational group, and the use of respirators and masks.This study is to investigate the rate of latent tuberculosis infection (LTBI) among HCWs with two different methods-enzyme-linked immunospot (ELISPOT) and tuberculin skin test (TST), and questionnaires to assess risk factors. We evaluated the prevalence of latent TB infection (LTBI) and TB disease and risk factors in health care workers (HCW) in a chest hospital in Shandong province in China.Results1.80of706HCWs ELISPOT results were positive, the positive rate was 11.33%; the positive rate in those with and without BCG scar was9.20%and6.59%, respectively, and there were no significant differences between them.2.213of440HCWs TST results were positive(TST≥10mm),the positive rate was48.41%.The positive rate in those with and without BCG scar was52.15%and36.84%, respectively, and there were significant differences between them3. The distribution of TST induration diameters:TST<5mm,28.9%;5mm≤TST＜10mm,21.9%;10mm＜TST＜15mm,22.4%;15mm<TST<20mm,20.1%; TST≥20mm,6.7%.4. The median of TST induration diameters with positive ELISPOT results and negative ELISPOT results were10.75mm and9.00mm,respectively, and there was no statistical difference.5.32TB cases occurred among HCWs,46.9%were nurses,37.5%physicians. Administrative staff had the lowest prevalence of TB; The mean age of the32HCW was39.2(21-60) years old,21were female, and11were male. HCW with longer duration of employment seemed at increased risk of active TB;96.9%worked for≥2years in the hospital。 The prevalence rate was associated with job location and longer duration of employment.6. There are76.4%HCWs who had on respirator at work and23.6%HCWs who hadn’t on respirator at work. Among the latter,32.3%were administrative staff,17.2%ancillary staff,13.5%pharmacy staff,3.1%radiology technicians,2.1%physicians,1.0%laboratory staff,30.7%others.7. The kind of the respirators HCWs had on at work were:12.9%were protective face mask,35.9%surgical masks,35.7%one-off masks,6.9%cotton yarn masks.8. On the post evaluation of isolation and protection, that meet the requirements of321people, accounting for39.7%; general enough that260people, accounting for32.1%; considered poor121people, accounting for14.9%; that does not have the conditions of isolation107people, accounting for13.2%.Of. Considered poor and do not have the conditions of isolation section is mainly clinical departments accounted for63.2%especially in internal medicine ward46.4%. Considered poor and do not27.5%College, secondary school20.9%,55.9%others, as the highest, most of them are hospitals temporary employees.Conclusions1. Healthcare workers (HCWs) are at risk of nosocomial infection with Mycobacterium tuberculosis. They are the high-risk population, TST positive judgment standards to more than10mm is appropriate.2. ELISPOT experiment in screening for LTBI, not BCG vaccination effect, strong specificity, no harm to human body, easy to medical personnel to accept, to get the real survey data.3. Worked for≥2years in the TB hospital, medical personnel have a significantly increased risk of tuberculosis.4. Doctors and nurses are tuberculosis infection in two high risk groups, must do a good job of personal protective.5. Internal medicine ward medical staff in close contact with tuberculosis patients, hospitals should strengthen the internal medicine ward isolation protection management.6. Hospitals should increase the temporary employees in biological safety training, and to provide to meet the requirements of protective measures, urge the clinical departments in accordance with the execution.7. Medical institutions should provide protective face masks for medical staff, ensure protective face masks worn for experimental training and the corresponding wear suitable for experiments, to ensure that the tuberculosis infection prevention produce actual effect.