Importance of Tuberculosis Screening of Resident Visa Applicants in Low TB Incidence Settings: Experience from Oman

Abstract

Introduction For Oman, a country targeting tuberculosis (TB) elimination, TB among expatriates is a major challenge. Thus, screening for active TB using chest X-ray was made mandatory for expatriates’ residency renewals. Objective To estimate the incidence of bacteriologically confirmed TB and assess impact of chest X-ray based TB screening among expatriates in Muscat Governorate. Methods Applicants for residency and renewals were mandated for chest X-ray-based TB screening in 2018. We collected data of screened subjects with radiological suspicion of TB who were subjected to further bacteriological evaluation. Results Of 501,290 applicants screened during the study period, 436 (0.09%) had X-ray findings suggestive of TB. Among the 436, TB was confirmed in 53 (12.2%; 95% CI 9.2–15.6), giving an overall prevalence of 10.6 (95% CI 8–13.9) per 100,000 applicants (number needed to be screened 9458). Among renewals, the point prevalence of TB was 10.5 per 100,000 expatriates screened (95% CI 6.9–14.04 per 100,000), with a mean follow-up period of 11.8 years. Conclusion Our findings are consistent with the recommendation for utilization of chest X-ray as a preferred tool for active case finding in the setting of expatriate screening. Our findings are also suggestive of the need for latent TB screening and ruling out TB prior to latent TB treatment.

Mycobacterium tuberculosis epidemiology in Oman: whole-genome sequencing uncovers transmission pathways

“…Testing for interferon-gamma release assay among 1,042 applicants for visa renewal in 2019, in Sohar governorate, showed a high prevalence of positive cases among expatriates from Asia (21%) and Africa (31%), indicative of LTB ( 38 ). Similarly, a survey of 501,290 expatriates, for visa renewal in 2018–2020, in Muscat governorate, revealed an LTB rate of 10.6 per 100,000 applicants ( 4 ). This is consistent with the findings of 158 out of 97,100 X-ray results of expatriates in Oman, with presumptive pulmonary TB, in 2018 ( 38 ).…”

“…This is consistent with the findings of 158 out of 97,100 X-ray results of expatriates in Oman, with presumptive pulmonary TB, in 2018 ( 38 ). Thus, the diagnosed TB cases in Oman among the expatriate community are most probably a result of the reactivation of LTB acquired in their country of origin ( 4 , 38 ).…”

“…Around 400 cases are reported every year, with a larger proportion seen among expatriates ( 3 ), who represent over 40% of the population. The majority of expatriates in Oman originate from high TB-burden countries with a TB incidence greater than 100 cases per 100,000 population ( 4 ).…”

Technical Quality and Diagnostic Impact of Chest X-rays in Tuberculosis Screening: Insights From a Saudi Teleradiology Cohort

“…When combined with the clinical picture, radiographic chest assessment has high sensitivity in detecting TB [6,7]. Thus, it is standard practice to utilize chest X-rays as part of the formal TB screening for new immigrant workers across various primary healthcare facilities in Saudi Arabia and the Gulf region [8,9].…”

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“…TB data is sparse from Oman (33-36). The rates of all forms of TB notification have steadily decreased to <100 cases per million since 1991 (37). One study conducted in 2022 found that from 501,290 visa applicants screened, 436 (0.09%) had X-ray findings suggestive of TB.…”