Tuberculosis infection risk, preventive therapy care cascade and incidence of tuberculosis disease in healthcare workers at Maputo Central Hospital

Abstract

Background Mozambican healthcare workers have high rates of latent and active tuberculosis, but occupational screening for tuberculosis is not routine in this setting. Furthermore, the specificity of tuberculin skin testing in this population compared with interferon gamma release assay testing has not been established. Methods This study was conducted among healthcare workers at Maputo Central Hospital, a public teaching quaternary care hospital in Mozambique. With a cross sectional study design, risk factors for tuberculosis were assessed using multivariable logistic regression. The care cascade is reported for participants who were prescribed six months of isoniazid preventive therapy for HIV or highly reactive testing for latent tuberculosis infection. The agreement of interferon-gamma release assay results with positive tuberculin skin testing was calculated. Results Of 690 screened healthcare workers, three (0.4%) had active tuberculosis and 426 (61.7%) had latent tuberculosis infection. Less education, age 35–49, longer hospital service, and work in the surgery department were associated with increased likelihood of being tuberculosis infected at baseline ( p < 0.05). Sex, Bacillus Calmette-Guerin vaccination, HIV, outside tuberculosis contacts, and professional category were not. Three new cases of active tuberculosis developed during the follow-up period, two while on preventive therapy. Among 333 participants offered isoniazid preventive therapy, five stopped due to gastrointestinal side effects and 181 completed treatment. For HIV seropositive individuals, the agreement of interferon gamma release assay positivity with positive tuberculin skin testing was 50% among those with a quantitative skin test result of 5-10 mm, and among those with a skin test result ≥10 mm it was 87.5%. For HIV seronegative individuals, the agreement of interferon gamma release assay positivity with a tuberculin skin test result of 10-14 mm was 63.6%, and for those with a quantitative skin test result ≥15 mm it was 82.2%. Conclusions There is a high prevalence of tuberculosis infected healthcare workers at Maputo Central Hospital. The surgery department was most heavily affected, suggesting occupational risk. Isoniazid preventive therapy initiation was high and just over half completed therapy. An interferon gamma release assay was useful to discern LTBI from false positives among those with lower quantitative tuberculin skin test results. Electronic supplementary material The online version of this article (10.1186/s12879-019-3966-7) contains supplementary material, which is available to authorized users.

Preventing Occupational Tuberculosis in Health Workers: An Analysis of State Responsibilities and Worker Rights in Mozambique

“…Mozambique lacks nationally representative data on TB rates among health workers [ 8 , 9 , 10 ]. However, a recent study conducted at Maputo Central Hospital, a public teaching quaternary care hospital, identified an annual incidence rate among health workers of 1676 per 100,000, consistent with the median incidence rate of 1180 per 100,000 reported in a meta-analysis of active TB among health workers in high-TB incidence countries [ 11 ]. Effective implementation of a workplace TB policy for health workers is thus urgently needed in Mozambique [ 11 , 12 , 13 ].…”

Risk factors of delayed isolation of patients with pulmonary tuberculosis

“…Although a high number of TB exposures occurred, most were concentrated in specific units or departments, such as the ICU, the department of infectious diseases, or pulmonology. In previous studies that examined the mechanisms underlying exposure to TB and the risks to healthcare personnel with respect to developing LTBI [7,12,13], the prevalence of LTBI was high among HCWs working in situations with a higher inherent risk of TB exposure, such as working in high-risk departments or having a longer duration of working hours. Therefore, although it is difficult to confirm that the cases of LTBI identified in this study among HCWs was caused by exposure to the 222 patients included in the study, exposure to TB patients while working in a medical institution is likely.…”

Large gap between attitude and action in tuberculosis preventive treatment among tuberculosis-related healthcare workers in eastern China

“…TB healthcare workers (HCWs) are one of the populations most likely to develop LTBI, as they are those with frequent direct or indirect exposure to M. tuberculosis. Multiple studies have shown a significant correlation between TB infection and occupational exposure (Zhang et al, 2013;Shi et al, 2018;Graves et al, 2019). The prevalence of TB among nurses working in TB-related departments is 5.1 times higher than in the general population, and the incidence of LTBI among HCWs is 17-36% (Jo et al, 2008;Mok, 2016).…”