Evaluation of tuberculosis screening of immigrants in the Netherlands

Reply: Tuberculosis screening in migrants to the EU/EEA and UK

We would like to thank N. Köhler and co-workers for their correspondence regarding our recent paper [1], comparing and contrasting it with their large pan-European study. Their study collected aggregate country-specific tuberculosis (TB) incidence rates as measured by infectious disease surveillance systems in the country of arrival (CoA) [2] and compared these to World Health Organization (WHO) TB incidence estimates from their respective country of origin (CoO). The authors found considerable differences between these incidence rates and conclude that there are many factors, other than incidence in the CoO, which determine TB risk. The authors therefore call for more granular screening policies which consider a wider range of factors including country-specific incidence as measured in CoAs.

Tuberculosis incidence estimates from countries of origin alone are often insufficient to predict TB prevalence among migrants https://bit.ly/3PDc35g

Drivers determining tuberculosis disease screening yield in four European screening programmes: a comparative analysis

BACKGROUND

The World Health Organization End TB Strategy emphasises screening for early diagnosis of tuberculosis (TB) in high-risk groups, including migrants. We analysed key drivers of TB yield differences in four large migrant TB screening programmes to inform TB control planning and feasibility of a European approach.

METHODS

We pooled individual TB screening episode data from Italy, the Netherlands, Sweden and the UK, and analysed predictors and interactions for TB case yield using multivariable logistic regression models.

RESULTS

Between 2005 and 2018 in 2 302 260 screening episodes among 2 107 016 migrants to four countries, the programmes identified 1658 TB cases (yield 72.0 (95% CI 68.6-75.6) per 100 000). In logistic regression analysis, we found associations between TB screening yield and age (≥55 years: OR 2.91 (95% CI 2.24-3.78)), being an asylum seeker (OR 3.19 (95% CI 1.03-9.83)) or on a settlement visa (OR 1.78 (95% CI 1.57-2.01)), close TB contact (OR 12.25 (95% CI 11.73-12.79)) and higher TB incidence in the country of origin. We demonstrated interactions between migrant typology and age, as well as country of origin. For asylum seekers, the elevated TB risk remained similar above country of origin incidence thresholds of 100 per 100 000.

CONCLUSIONS

Key determinants of TB yield included close contact, increasing age, incidence in country of origin and specific migrant groups, including asylum seekers and refugees. For most migrants such as UK students and workers, TB yield significantly increased with levels of incidence in the country of origin. The high, country of origin-independent TB risk in asylum seekers above a 100 per 100 000 threshold could reflect higher transmission and re-activation risk of migration routes, with implications for selecting populations for TB screening.

Mandatory, voluntary, repetitive, or one-off post-migration follow-up for tuberculosis prevention and control: A systematic review

BACKGROUND

Post-migration follow-up of migrants identified to be at-risk of developing tuberculosis during the initial screening is effective, but programmes vary across countries. We aimed to review main strategies applied to design follow-up programmes and analyse the effect of key programme characteristics on reported coverage (i.e., proportion of migrants screened among those eligible for screening) or yields (i.e., proportion of active tuberculosis among those identified as eligible for follow-up screening).

METHODS AND FINDINGS

We performed a systematic review and meta-analysis of studies reporting yields of follow-up screening programmes. Studies were included if they reported the rate of tuberculosis disease detected in international migrants through active case finding strategies and applied a post-migration follow-up (defined as one or more additional rounds of screening after finalising the initial round). For this, we retrieved all studies identified by Chan and colleagues for their systematic review (in their search until January 12, 2017) and included those reporting from active follow-up programmes. We then updated the search (from January 12, 2017 to September 30, 2022) using Medline and Embase via Ovid. Data were extracted on reported coverage, yields, and key programme characteristics, including eligible population, mode of screening, time intervals for screening, programme providers, and legal frameworks. Differences in follow-up programmes were tabulated and synthesised narratively. Meta-analyses in random effect models and exploratory analysis of subgroups showed high heterogeneity (I2 statistic > 95.0%). We hence refrained from pooling, and estimated yields and coverage with corresponding 95% confidence intervals (CIs), stratified by country, legal character (mandatory versus voluntary screening), and follow-up scheme (one-off versus repetitive screening) using forest plots for comparison and synthesis. Of 1,170 articles, 24 reports on screening programmes from 7 countries were included, with considerable variation in eligible populations, time intervals of screening, and diagnostic protocols. Coverage varied, but was higher than 60% in 15 studies, and tended to be lower in voluntary compared to compulsory programmes, and higher in studies from the United States of America, Israel, and Australia. Yield varied within and between countries and ranged between 53.05 (31.94 to 82.84) in a Dutch study and 5,927.05 (4,248.29 to 8,013.71) in a study from the United States. Of 15 estimates with narrow 95% CIs for yields, 12 were below 1,500 cases per 100,000 eligible migrants. Estimates of yields in one-off follow-up programmes tended to be higher and were surrounded by less uncertainty, compared to those in repetitive follow-up programmes. Yields in voluntary and mandatory programmes were comparable in magnitude and uncertainty. The study is limited by the heterogeneity in the design of the identified screening programmes as effectiveness, coverage and yields also depend on factors often underreported or not known, such as baseline incidence in the respective population, reactivation rate, educative and administrative processes, and consequences of not complying with obligatory measures.

CONCLUSION

Programme characteristics of post-migration follow-up screening for prevention and control of tuberculosis as well as coverage and yield vary considerably. Voluntary programmes appear to have similar yields compared with mandatory programmes and repetitive screening apparently did not lead to higher yields compared with one-off screening. Screening strategies should consider marginal costs for each additional round of screening.

Epidemiology of tuberculosis in foreign students in Japan, 2015–2019: a comparison with the notification rates in their countries of origin

Tuberculosis (TB) in immigrants is becoming a challenge in eliminating TB in Japan. We investigated the epidemiology of TB in foreign students in Japan in 2015–2019. A total of 2007 foreign students with TB whose median age was 22.5 years (1243 (61.9%) were males) were registered. The notification rates peaked in 2016 at 164.0 per 100 000 population and decreased towards 2019. Of the 2007, 535 were from Vietnam, 444 from China and 395 from Nepal. The notification rates were 596.6 per 100 000 person-years (PYs) for Myanmar, 595.4 for the Philippines and 438.6 for Cambodia. The rates were much higher than those of the general populations in their countries of origin for Myanmar, the Philippines, Cambodia, Indonesia, Nepal, Mongolia, Vietnam and China. In comparison with the years 2010–2014, the notification rates for foreign students decreased for the students from Nepal, Vietnam and China. The TB notification rate of the foreign students in Japan can be a good surrogate indicator for the risk of TB among the immigrant subpopulation in Japan and should continuously be monitored. Those who are at higher risk of TB may be annually screened for TB to prevent TB outbreaks.

Tools to implement the World Health Organization End TB Strategy: Addressing common challenges in high and low endemic countries

AIM

The purpose of this viewpoint is to summarize the advantages and constraints of the tools and strategies available for reducing the annual incidence of tuberculosis (TB) by implementing the World Health Organization (WHO) End TB Strategy and the linked WHO TB Elimination Framework, with special reference to Oman.

METHODS

The case-study was built based on the presentations and discussions at an international workshop on TB elimination in low incidence countries organized by the Ministry of Health, Oman, which took place from September 5 to September 7, 2019, and supported by the WHO and European Society of Clinical Microbiology and Infectious Diseases (ESCMID).

RESULTS

Existing tools were reviewed, including the screening of migrants for latent TB infection (LTBI) with interferon-gamma release assays, clinical examination for active pulmonary TB (APTB) including chest X-rays, organization of laboratory services, and the existing centres for mandatory health examination of pre-arrival or arriving migrants, including examination for APTB. The need for public-private partnerships to handle the burden of screening arriving migrants for active TB was discussed at length and different models for financing were reviewed.

CONCLUSIONS

In a country with a high proportion of migrants from high endemic countries, screening for LTBI is of high priority. Molecular typing and the development of public-private partnerships are needed.

Implementation of latent tuberculosis infection screening and treatment among newly arriving immigrants in the Netherlands: A mixed methods pilot evaluation

INTRODUCTION

To reach pre-elimination levels of tuberculosis (TB) incidence in the Netherlands, prevention of TB among immigrants through diagnosis and treatment of latent TB infection (LTBI) is needed. We studied the feasibility of a LTBI screening and treatment program among newly arriving immigrants for national implementation.

METHODS

We used mixed methods to evaluate the implementation of LTBI screening and treatment in five Public Health Services (PHS) among immigrants from countries with a TB incidence >50/100,000 population. We used Poisson regression models with robust variance estimators to assess factors associated with LTBI diagnosis and LTBI treatment initiation and reported reasons for not initiating or completing LTBI treatment. We interviewed five PHS teams using a semi-structured method to identify enhancing and impeding factors for LTBI screening and treatment.

RESULTS

We screened 566 immigrants; 94 (17%) were diagnosed with LTBI, of whom 49 (52%) initiated and 34 (69%) completed LTBI treatment. LTBI diagnosis was associated with male gender, higher age group, higher TB incidence in the country of origin and lower level of education. Treatment initiation was associated with PHS (ranging from 29% to 86%), lower age group, longer intended duration of stay in the Netherlands, and lower level of education. According to TB physicians, clients and their consulted physicians in the home country lacked awareness about benefits of LTBI treatment. Furthermore, TB physicians questioned the individual and public health benefit of clients who return to their country of origin within the foreseeable future.

CONCLUSIONS

Doubt of physicians in both host country and country of origin about individual and public health benefits of LTBI screening and treatment of immigrants hampered treatment initiation: the high initiation proportion in one PHS shows that if TB physicians are committed, the LTBI treatment uptake can be higher.

Effectiveness of interventions for reducing TB incidence in countries with low TB incidence: a systematic review of reviews

AIMS

What is the evidence base for the effectiveness of interventions to reduce tuberculosis (TB) incidence in countries which have low TB incidence?

METHODS

We conducted a systematic review of interventions for TB control and prevention relevant to low TB incidence settings (<10 cases per 100 000 population). Our analysis was stratified according to "direct" or "indirect" effects on TB incidence. Review quality was assessed using AMSTAR2 criteria. We summarised the strength of review level evidence for interventions as "sufficient", "tentative", "insufficient" or "no" using a framework based on the consistency of evidence within and between reviews.

RESULTS

We found sufficient review level evidence for direct effects on TB incidence/case prevention of vaccination and treatment of latent TB infection. We also found sufficient evidence of beneficial indirect effects attributable to drug susceptibility testing and adverse indirect effects (measured as sub-optimal treatment outcomes) in relation to use of standardised first-line drug regimens for isoniazid-resistant TB and intermittent dosing regimens. We found insufficient review level evidence for direct or indirect effects of interventions in other areas, including screening, adherence, multidrug-resistant TB, and healthcare-associated infection.

DISCUSSION

Our review has shown a need for stronger evidence to support expert opinion and country experience when formulating TB control policy.