Tuberculosis incidence in foreign-born people residing in European countries in 2020

BackgroundEuropean-specific policies for tuberculosis (TB) elimination require identification of key populations that benefit from TB screening.AimWe aimed to identify groups of foreign-born individuals residing in European countries that benefit most from targeted TB prevention screening.MethodsThe Tuberculosis Network European Trials group collected, by cross-sectional survey, numbers of foreign-born TB patients residing in European Union (EU) countries, Iceland, Norway, Switzerland and the United Kingdom (UK) in 2020 from the 10 highest ranked countries of origin in terms of TB cases in each country of residence. Tuberculosis incidence rates (IRs) in countries of residence were compared with countries of origin.ResultsData on 9,116 foreign-born TB patients in 30 countries of residence were collected. Main countries of origin were Eritrea, India, Pakistan, Morocco, Romania and Somalia. Tuberculosis IRs were highest in patients of Eritrean and Somali origin in Greece and Malta (both > 1,000/100,000) and lowest among Ukrainian patients in Poland (3.6/100,000). They were mainly lower in countries of residence than countries of origin. However, IRs among Eritreans and Somalis in Greece and Malta were five times higher than in Eritrea and Somalia. Similarly, IRs among Eritreans in Germany, the Netherlands and the UK were four times higher than in Eritrea.ConclusionsCountry of origin TB IR is an insufficient indicator when targeting foreign-born populations for active case finding or TB prevention policies in the countries covered here. Elimination strategies should be informed by regularly collected country-specific data to address rapidly changing epidemiology and associated risks.

Outcomes in children treated for tuberculosis with the new dispersible fixed-dose combinations in Port Moresby

Setting

The new child-friendly fixed dose combinations (FDCs) were introduced at Port Moresby General Hospital, Papua New Guinea, in 2016 for the first-line treatment of children (aged <15 years) with tuberculosis (TB) who weighed <25 kg.

Objective

To describe the characteristics and outcomes for children treated with the new FDCs, and to identify risk factors for unfavourable treatment outcomes.

Design

This was a retrospective cohort study of all children treated for TB with the FDCs from August 2016 to August 2017.

Results

Of 713 children included, 488 (68%) were diagnosed with pulmonary TB. Only 6 (0.8%) TB cases were bacteriologically confirmed and human immunodeficiency virus (HIV) status was known in 50%. Treatment outcomes were favourable in 425 (60%) children. Of 288 children with unfavourable outcomes, there were 242 (84%) with loss to follow-up (LTFU) and 25 (8.4%) were known to have died. Children who were severely underweight (weight-for-age Z score <-3) on presentation were at greater risk of LTFU compared to children of normal weight on multivariable analysis (aRR 1.3, 95%CI 1.0-1.6, P < 0.05).

Conclusion

Alternative models of care to decrease LTFU during treatment are needed, including integration with nutritional support. Improving diagnosis through microbiological confirmation of TB and HIV are major challenges to be addressed.

Novel application of NIH case definitions in a paediatric tuberculosis contact investigation study

BACKGROUND

International (National Institutes of Health [NIH]) case definitions have been proposed for paediatric tuberculosis (TB) diagnostic studies. The relevance of these definitions for contact tracing studies is unknown.

METHODS

We developed case definitions for a community-based contact tracing diagnostic study. We compare disease certainty using protocol-defined and NIH case definitions and describe TB disease spectrum and severity.

RESULTS

There were 111 potential disease episodes in 109 (21% human immunodeficiency virus [HIV] infected) of 1093 children enrolled. Based on NIH definitions, there were 8 confirmed, 12 probable, 17 possible and 3 unlikely TB and 2 non-TB episodes. Using protocol case definitions, there were 23 episodes of confirmed, 36 probable, 27 possible and 0 unlikely TB and 21 non-TB. Of 111 potential episodes, 69 were unclassifiable using the NIH definition, while 4 were unclassifiable using the protocol definition. Agreement between definitions was 0.30 (95%CI 0.23-0.38). There were 62 episodes (72%) of non-severe and 24 (28%) of severe TB.

CONCLUSIONS

The NIH definition had limited applicability to household contact studies, despite the wide spectrum of disease observed. Further research is needed to develop case definitions relevant to different research settings, including contact investigation to capture the wide spectrum of paediatric TB in clinical research.

Development of tuberculosis infection control guidelines in a pediatric HIV clinic in sub-Saharan Africa

SETTING

A well-established pediatric human immunodeficiency virus (HIV) clinic in Lesotho with initial infection control (IC) measures prioritizing blood-borne disease. In line with international recommendations, services have been expanded to include the management of patients with tuberculosis (TB). The creation of comprehensive IC guidelines with an emphasis on TB has become a priority.

OBJECTIVE

To provide a model for developing and implementing IC guidelines in ambulatory care facilities in limited-resource settings with high HIV and TB prevalence. Activities: An IC plan that includes guidance covering both general IC measures and TB-specific guidelines was created by integrating local and international recommendations and emphasizing the importance of administrative measures, environmental controls, and disease-specific precautions. An interdisciplinary committee was established to oversee its implementation, monitoring, and evaluation.

DISCUSSION

Development and implementation of IC guidelines in resource-limited settings are feasible and should be a priority in high HIV and TB prevalence areas. Education should be the cornerstone of such endeavors. Many interventions can be implemented with minimal expertise and material resources. Administrative support and institutional investment are essential to the sustainability of an effective IC program.

It's hard work, but it's worth it: the task of keeping children adherent to isoniazid preventive therapy

SETTING

Isoniazid preventive therapy (IPT) offers children protection against tuberculosis (TB), but it has been difficult to implement, particularly in developing countries.

OBJECTIVE

To understand what encourages or inhibits children from adhering to IPT.

DESIGN

In-depth interviews were conducted with two parents of children adherent to IPT and two staff members from three primary health care clinics in high TB prevalence communities. Themes explored were knowledge and attitudes towards IPT, problems in accessing and adhering to treatment, and community responses.

RESULTS

Parents administering treatment valued it positively, realised their children's risk of TB, and were positive about the clinic. Nurses acknowledged that resistance to treatment remained, with some parents not wanting to acknowledge risk nor willing to make the effort for their children; there was also considerable misinformation about IPT. Clinic nurses acknowledged problems of staff shortages, lengthy waiting times and conflict between staff and community members. Adherence was affected by social problems, stigma about TB and its link to the human immunodeficiency virus, and the extended treatment period.

CONCLUSION

Parents who maintained adherence to the IPT regimen showed that it was possible even in very difficult circumstances. Further effort is required to improve some of the clinic services, correct misinformation, reduce stigma and provide support to parents.

Pasting together the preventive therapy puzzle

In children, the effectiveness of preventive therapy (PT) for tuberculosis (TB) will always be dependent upon the care giver's behaviour, as this determines adherence. We briefly describe the knowledge, attitudes and intended behaviours in care givers of young children referred for PT in a resource-constrained setting with high TB rates. These early efforts describe one critical piece of the PT puzzle: uptake. More behavioural research is needed to understand how the many pieces of this puzzle should be assembled to improve PT usage in children.

Well-quantified tuberculosis exposure is a reliable surrogate measure of tuberculosis infection

SETTING

Cape Town, South Africa.

OBJECTIVE

To develop a standardized, reliable measure of household tuberculosis (TB) exposure that considers child-specific risk factors.

DESIGN

We assessed TB exposure in 536 children. Children were considered Mycobacterium tuberculosis infected if two of three tests of infection were positive. Principal component analysis identified a discrete set of components that collectively described exposure and contributed to a composite contact score. Logistic regression assessed the odds of having M. tuberculosis infection given increasing contact score while controlling for age and past TB treatment.

RESULTS

Four components described 68% of data variance: 1) maternal TB and sleep proximity, 2) index case infectivity, 3) duration of exposure, and 4) exposure to multiple index cases. Components were derived from 10 binary questions that contributed to a contact score (range 1-10, median 5, 25th-75th interquartile range [IQR] 4-7). Among children aged 3 months to 6 years with household exposure, the odds of being M. tuberculosis-infected increased by 74% (OR 1.74, 95%CI 1.42-2.12) with each 1-point increase in the contact score.

CONCLUSIONS

Well-quantified TB exposure is a good surrogate measure of M. tuberculosis infection in child household contacts in a high-burden setting, and could guide targeted preventive treatment in children at highest risk of M. tuberculosis infection.

Tuberculosis contact investigation in a high-burden setting: house or household?

SETTING

A high tuberculosis (TB) burden setting, South Africa. Two frequently used definitions for 'household' are 1) 'all dwellings on the same plot of land that share the same residential address'; and 2) 'a group of persons who live together in the same dwelling unit and who have the same eating arrangements'.

OBJECTIVE

To characterise a household and the outcome of investigations in household child contacts using definition 1 compared to definition 2 during a TB contact investigation.

DESIGN

Access to a household (definition 1) was gained via an adult TB case. Children were assessed for TB infection and disease.

RESULTS

Household enumeration indicated 25 members of three families living in a main house and a fourth family living in an adjacent structure. Three children were diagnosed with TB and two referred for isoniazid preventive therapy. Families living in the main house shared the main kitchen, while the yard house family used its own kitchen. This household would have been classified as two separate households if definition 2 had been used, and children with TB disease and infection would have been missed.

CONCLUSION

The definition of household in TB contact investigation should provide a framework that is broad enough to capture the majority of children at risk.

Opportunities for chemoprophylaxis in children with culture-confirmed tuberculosis

BACKGROUND AND OBJECTIVES

Chemoprophylaxis is an effective strategy to prevent progression of tuberculosis (TB) in vulnerable children who have had contact with an infectious source of TB. However, many operational gaps prevent implementation of routine chemoprophylaxis in high-burden settings. The TB exposure status and disease spectrum in children diagnosed with culture-confirmed TB are described and missed opportunities for chemoprophylaxis are highlighted.

METHODS

All children <13 years of age diagnosed with culture-confirmed TB at a tertiary referral hospital between March 2003 and February 2007 were included. Clinical data were collected from retrospective review of files. TB was classified as pulmonary and extra-pulmonary; disseminated TB included miliary disease and TB meningitis.

RESULTS

During the study period, 614 children (327, 53·3% boys, median age 32 months) were diagnosed with culture-confirmed TB. Contact with an infectious adult source case was documented in 333 (54·2%), 237 (71·2%) of whom were <5 years of age, and 24 (7·2%) were HIV-infected and ≥5 years of age. Of those eligible for chemoprophylaxis, missed opportunities were identified in 156/221 (70·6%) children; 127 (81·4%) were <3 years of age, 39 (25%) had disseminated TB and 8 (5·1%) died. The TB source case was the mother or father in 74/156 (47·4%) children.

CONCLUSION

Opportunities for initiation of chemoprophylaxis in vulnerable children following TB exposure are often missed. Awareness should be increased among health-care workers and in the community at large regarding the importance of chemoprophylaxis in young and HIV-infected children. Health system strengthening is required to improve delivery of chemoprophylaxis to vulnerable children in close contact with newly diagnosed infectious TB cases.

Environmental tobacco smoke exposure increases Mycobacterium tuberculosis infection risk in children

BACKGROUND

Data on the association between exposure to environmental tobacco smoke (ETS) and Mycobacterium tuberculosis infection in children are limited.

OBJECTIVE

To examine the dose-response effect of ETS exposure on the risk of M. tuberculosis infection in children in a high tuberculosis (TB) burden setting.

METHODS

This cross-sectional study included healthy South African children from impoverished urban communities. Data were collected on household ETS and M. tuberculosis exposure, demographics, socio-economic and anthropometric data, M. tuberculosis infection, human immunodeficiency virus and TB disease status.

RESULTS

Among 196 children (median age 6.8 years, range 0.3-15.9), 97 (49.5%) were M. tuberculosis - i nfected (tuberculin skin test [TST] ≥ 10 mm) and 128 (65.3%) reported ETS exposure; of these, 81/128 (63.3%) were exposed to ≥ 2 household smokers. The presence of ≥ 2 household smokers was associated with M. tuberculosis infection in univariate analysis, irrespective of TST cut-off point. In analysis adjusting for M. tuberculosis exposure, socio-economic status, age and previous TB treatment, ETS exposure remained associated with M. tuberculosis infection. In univariate and multivariate analysis, pack-years of exposure were associated with risk of TB infection.

DISCUSSION

Exposure to ETS is associated with M. tuberculosis infection in children after adjustment for multiple variables, with a dose-response relationship between the degree of ETS exposure and risk of infection. Public health interventions to reduce exposure to tobacco smoke among children in high TB burden settings are urgently needed.

Interferon-gamma release assays and childhood tuberculosis: systematic review and meta-analysis

BACKGROUND

Children infected with Mycobacterium tuberculosis have significant risk of developing tuberculosis(TB) and can therefore benefit from preventive therapy.

OBJECTIVE

To assess the value of interferon-gamma release assays (IGRAs) and the tuberculin skin test (TST)in the diagnosis of TB infection and disease in children.

METHODS

Thirty-three studies were included, assessing commercial IGRAs (QuantiFERON®-TB [QFT] andT-SPOT.®TB) and TST. Reference standards for infection were incident TB or TB exposure. Test performance for disease diagnosis was evaluated in studies assessing children with confirmed and/or clinically diagnosed TB,compared to children where TB was excluded.

RESULTS

Two small studies measured incident TB in children tested with QFT and found weak positive predictive value. Association of test response with exposure-categorized dichotomously or as a gradient-was similar for all tests. The sensitivity and specificity of all tests were similar in diagnosing the disease. Stratified analysis suggested lower sensitivity for all tests in young or human immuno deficiency virus infected children.

CONCLUSIONS

Available data suggest that TST and IGRAs have similar accuracy for the detection of TB infection or the diagnosis of disease in children. Heterogeneous methodology limited the comparability of studies and the interpretation of results. A rigorous, standardized approach to evaluate TB diagnostic tests in children is needed.

Mycobacterial genotype is associated with disease phenotype in children

OBJECTIVE

To investigate the association between mycobacterial genotype and disease phenotype in children.

METHODS

We describe hospitalised children diagnosed with culture-confirmed tuberculosis (TB) in South Africa, a high TB burden setting. Disease phenotype was classified as intrathoracic or extrathoracic based on mycobacterial culture site. Mycobacterial genotyping was completed using spoligotyping.

RESULTS

We analysed 421 isolates from 392 children (median age 2 years, range 0.1-12). Intrathoracic disease was present in 294 (75%) children and extrathoracic disease in 98 (25%). The Beijing genotype was the most prevalent (32.9%), followed by the Latin American Mediterranean (LAM, 28.8%), and S genotypes (6.4%). Age was significantly associated with genotype. Children with the Beijing (OR = 2.36, 95%CI 1.21- 4.60) and S genotypes (OR = 3.47, 95%CI 1.26-9.56) were more likely to have extrathoracic disease compared to children infected with the LAM genotype, in analyses adjusted for age and drug resistance.

CONCLUSIONS

TB genotype and disease phenotype in children were associated. Beijing and S genotypes were more frequently cultured from extrathoracic cultures, indicating potential improved ability to disseminate. Strain-related phenotypes could explain different disease spectra in geographic settings where certain strains are successful. Studies of mycobacterial human interaction should consider host immune responses, clinical and epidemiological factors.

Recording isoniazid preventive therapy delivery to children: operational challenges

Despite recommendations to provide isoniazid preventive therapy (IPT) to eligible children aged <5 years who are in close contact with an infectious tuberculosis (TB) case, IPT delivery in high-burden settings remains poor. To evaluate the current system supporting IPT delivery to children in an urban community, South Africa, we reviewed the recording practices of a local clinic regarding management of children exposed to a current adult TB case. No standardised IPT management tools existed. Only 21% of children eligible for IPT had documentation of IPT delivery. There is a need to implement systems that support IPT recommendations in high-burden settings.

Highly discordant T cell responses in individuals with recent exposure to household tuberculosis

BACKGROUND

There are limited data comparing interferon-gamma release assays (IGRAs) for the detection of Mycobacterium tuberculosis infection in highly endemic settings.

METHODS

A cross-sectional household contact study was conducted to measure the agreement of two IGRAs in relation to the tuberculin skin test (TST) to detect M tuberculosis infection and to assess the influence of M tuberculosis exposure and age.

RESULTS

In 82 individuals in household contact, 93% of children and 42% of adults had a high M tuberculosis contact score. The TST was positive in 78% of adults and 54% of children, the T-SPOT.TB was positive in 89% of children and 66% of adults and the QuantiFERON TB Gold (QTF) was positive in a similar proportion of adults and children (38.1% and 39.6%). In children there was poor agreement between the TST and T-SPOT.TB (kappa = -0.15) and the T-SPOT.TB and the QTF (kappa = -0.03), but good agreement between the TST and the QTF (kappa = 0.78) using 10 mm cut-off. In adults there was fair to moderate agreement between the TST and T-SPOT.TB (kappa = 0.38), the TST and QTF (kappa = 0.34) and T-SPOT.TB and QTF (kappa = -0.50). High levels of exposure to M tuberculosis were associated with at least a sevenfold odds of being T-SPOT.TB positive (95% CI 7.67 to 508.69) and a threefold odds of being QTF positive (95% CI 3.02 to 30.54). There was a significant difference in the magnitude of T-SPOT.TB early secretory antigenic target (ESAT)-6 and culture filtrate protein 10 kD (CFP-10) spot counts between adults and children.

CONCLUSIONS

The T-SPOT.TB may be more sensitive than the TST or QTF for detecting recent M tuberculosis infection in children. Differences between assays and the predictive utility of these findings for subsequent disease development should be prospectively assessed.

High level of discordant IGRA results in HIV-infected adults and children

SETTING

Tygerberg district, Western Cape Province, South Africa.

OBJECTIVE

To measure the agreement of two interferon-gamma release assays (IGRAs) and the tuberculin skin test (TST) for the detection of Mycobacterium tuberculosis infection in human immunodeficiency virus (HIV) infected adults and children in a setting highly endemic for tuberculosis (TB).

DESIGN

Cross-sectional study.

RESULTS

In HIV-infected adults (n=20) and children (n=23), tests yielded discordant results, with 61% of individuals testing positive with T-SPOT.TB, 41% with TST and 28% with QuantiFERON TB Gold (QTF). In children, there was poor agreement between the TST and T-SPOT.TB (kappa [kappa]=-0.02), but moderate agreement between the TST and QTF (kappa=0.44). In adults, there was moderate agreement between the TST and T-SPOT.TB (kappa=0.43), and the TST and QTF (kappa = 0.46). In children and adults, there was fair agreement between the T-SPOT.TB and QTF (kappa=0.33). Twenty per cent of adults had >or=1 indeterminate IGRA results.

CONCLUSIONS

There is poor to moderate agreement between the TST and IGRAs in HIV-infected adults and children. T-SPOT.TB may have improved sensitivity for detection of M. tuberculosis infection in HIV-infected individuals compared to the QTF and the TST. In HIV-infected individuals, IGRA test properties are affected by test cut-off point and nil control responses.

Human immunodeficiency virus status and delayed-type hypersensitivity skin testing in Ugandan children

BACKGROUND

In previous studies, delayed-type hypersensitivity (DTH) skin testing has been shown to be affected by several factors including nutritional status, intercurrent infection, host immune status, and previous exposure to the antigen being used.

OBJECTIVE

To determine the effect of human immunodeficiency virus type 1 (HIV-1) status on DTH skin testing in a cohort of HIV-1-infected and noninfected Ugandan children followed prospectively from birth.

DESIGN

Nested case-control study.

SETTING

Primary care clinic serving study participants at Mulago Hospital, Makerere University, Kampala, Uganda.

PARTICIPANTS

Thirty HIV-1-infected children and 30 age-matched, HIV-1-noninfected children.

METHODS

After completion of history and physical, each child underwent Mantoux skin testing with both Candida and purified protein derivative (PPD). Results of skin testing were read in 48 to 72 hours. Complete chart reviews were performed on all children. CD4 lymphocyte counts were obtained on all HIV-1-infected children at the time the skin testing was read.

RESULTS

The average age of participants was 67 months (range, 51-92 months). HIV-1-infected children (mean CD4 lymphocyte count, 1069 mL-1; range, 86-3378 mL-1), compared with noninfected, age-matched peers, developed significantly smaller PPD reaction size (mean, 1.18 mm +/- 4.3 vs 3.6 mm +/- 7.6, respectively). Candida responses were not different between the two groups of children. Among HIV-1-infected children, there was a larger Candida reaction size in children who had recently received chloroquine treatment. There was no significant correlation between Candida reactivity and PPD reactivity, progressive HIV-1 disease, or CD4 lymphocyte count. The six children diagnosed clinically with active tuberculosis had lower absolute CD4 lymphocyte counts than children without tuberculosis. Lack of reaction to PPD was associated with lower CD4 lymphocyte counts and progressive HIV-1 disease.

CONCLUSIONS

In HIV-1-infected Ugandan children, DTH skin testing was influenced by the choice of antigen selected, HIV-1 infection, and recent treatment with chloroquine. Based on these findings, we believe that further prospective, longitudinal investigation into the role of chloroquine in HIV-1-infected children is needed. We emphasize the limitations of DTH skin testing in HIV-infected children as an adjunct in the diagnosis of active tuberculosis.