Tuberculosis Transmission in a Primary School and a Private Language School. An Estimation of Infectivity

Introduction: Belgium is a country with low incidence of tuberculosis (TB) and a very low number of TB cases in children. Children in contact with an adult smear-positive TB case are at high risk of transmission. Early diagnosis is important as young children have a significant predisposition of developing TB disease. In this paper, we describe two outbreaks after exposure to, respectively, two teachers with smear-positive pulmonary TB: one in a primary school, a nursery teacher, and another in a private language school. Methods: An exposure investigation was carried out in both index cases household and school, according to the stone-in-the-pond principle. The tuberculin skin test (TST) was used a screening tool. The time elapsed between TB diagnosis in the index case and contact investigation was, respectively, 1 and 3 weeks. If this initial test was negative, it was repeated after a "window period" of ≥8 weeks. Results: Index cases showed a transmission rate of, respectively, 13 and 40% in their classes at school, defined as casual contacts. The proximity of contact increased the risk of infection. TB disease was observed in, respectively, 4 and 11% of all the casual contacts; all of them were children younger than 5 years old. TB-infected and children with active TB disease had good compliance with recommended treatment. Uptake of chemoprophylaxis during the "window period" was poor, respectively, only 32-42%, in children under 5 years with an initially negative TST. Discussion: The World Health Organization recommends to screen all young children (<5 years old) who have close contact with a person affected by pulmonary TB and to initiate Latent tuberculosis infection treatment even before infection can be demonstrated, after ruling out active TB disease. Despite this knowledge, a small percentage of the children younger than 5 years with no proof of infection was treated with the proposed chemoprophylactic treatment, in both cases. Conclusion: This exposure investigation of two teachers detects high transmission among family contacts and school casual contacts. Recommendations for chemoprophylactic treatment in children <5 years showed low compliance, reflecting the difficulty of communication to staff, parents, and children in a school outbreak. It is essential to develop a new approach for this vulnerable group of patients. This approach could be improved, applied, and evaluated by National TB Control Programs, involving public and private health services. Public health authorities play a role in raising public awareness about the risks of TB for young children.

2018 Belgian guidelines for the screening for latent tuberculosis in HIV-infected patients

Objectives: To review the current knowledge on screening for latent tuberculosis infection (LTBI) in HIV-infected adults and provide specific guidelines for Belgium. Focus is given to who to test, which testing method to use, timing of screening and choice of LTBI treatment. Methods: Expert review by the members of the Belgian LTBI group, in consultancy with the ARC College. Results: Target population, timing of screening, testing method, active TB exclusion, treatment of LTBI and guideline implementation are all reviewed. Conclusions: The principal changes include a selective approach to screen for LTBI (screening only of the HIV-infected patients at highest risk of active TB) as well as the timing of screening (testing for LTBI performed only after immune-restauration by antiretroviral therapy).

Nontuberculous mycobacteria among pulmonary tuberculosis patients: a retrospective Belgian multicenter study

OBJECTIVES

Currently, there are no European data about the frequency and clinical significance of nontuberculous mycobacteria (NTM) grown from respiratory samples during the treatment of tuberculosis (TB). We determined the frequency and clinical significance of NTM isolated before or during pulmonary tuberculosis treatment in Belgian laboratories.

METHODS

We conducted a nationwide retrospective multicenter cohort study on the co-isolation of TB and NTM in Belgium. Starting from laboratory data between 2006 and 2013, possible TB-NTM co-isolations were searched for.

RESULTS

A total of 2569 unique culture-positive pulmonary tuberculosis cases were included in the study. Only 35 (1.4%) of these TB cases had an NTM co-isolated, and two of these 35 fulfilled the ATS criteria for NTM lung disease.

CONCLUSION

A very low prevalence of 1.4% NTM co-isolations was found in Belgian patients with culture-proven pulmonary TB.

Towards tuberculosis elimination: an action framework for low-incidence countries

This paper describes an action framework for countries with low tuberculosis (TB) incidence (<100 TB cases per million population) that are striving for TB elimination. The framework sets out priority interventions required for these countries to progress first towards "pre-elimination" (<10 cases per million) and eventually the elimination of TB as a public health problem (less than one case per million). TB epidemiology in most low-incidence countries is characterised by a low rate of transmission in the general population, occasional outbreaks, a majority of TB cases generated from progression of latent TB infection (LTBI) rather than local transmission, concentration to certain vulnerable and hard-to-reach risk groups, and challenges posed by cross-border migration. Common health system challenges are that political commitment, funding, clinical expertise and general awareness of TB diminishes as TB incidence falls. The framework presents a tailored response to these challenges, grouped into eight priority action areas: 1) ensure political commitment, funding and stewardship for planning and essential services; 2) address the most vulnerable and hard-to-reach groups; 3) address special needs of migrants and cross-border issues; 4) undertake screening for active TB and LTBI in TB contacts and selected high-risk groups, and provide appropriate treatment; 5) optimise the prevention and care of drug-resistant TB; 6) ensure continued surveillance, programme monitoring and evaluation and case-based data management; 7) invest in research and new tools; and 8) support global TB prevention, care and control. The overall approach needs to be multisectorial, focusing on equitable access to high-quality diagnosis and care, and on addressing the social determinants of TB. Because of increasing globalisation and population mobility, the response needs to have both national and global dimensions.

Tuberculosis in Healthcare Workers Caring for a Congenitally Infected Infant

Objective:

To assess the extent of nosocomial transmission of tuberculosis among infants, family members, and healthcare workers (HCWs) who were exposed to a 29-week-old premature infant with congenital tuberculosis, diagnosed at 102 days of age.

Design:

A prospective exposure investigation using tuberculin skin test (TST) conversion was conducted. Contacts underwent two skin tests 10 to 12 weeks apart. Clinical examination and chest radiographs were performed to rule out disease. Isoniazid prophylaxis was administered to exposed infants at higher risk.

Setting:

A neonatal intensive care unit in an urban hospital in Brussels, Belgium.

Participants:

Ninety-seven infants, 139 HCWs, and 180 visitors.

Results:

Newly positive TST results occurred in HCWs who had been in close contact with the infant. Six (19%) of 32 primary care nurses and physicians had TST conversions and received treatment. Among the 97 exposed infants, 85 were screened and 34 were identified as at higher risk of infection. Of these, 27 received preventive isoniazid. None of the infants and none of the 93 other infants' family members evaluated were infected.

Conclusions:

Congenital tuberculosis in an infant poses a risk for nosocomial transmission to HCWs. Delayed diagnosis of this rare disease and close proximity are the most important factors related to transmission.

Tuberculosis control in big cities and urban risk groups in the European Union: a consensus statement

In low-incidence countries in the European Union (EU), tuberculosis (TB) is concentrated in big cities, especially among certain urban high-risk groups including immigrants from TB high-incidence countries, homeless people, and those with a history of drug and alcohol misuse. Elimination of TB in European big cities requires control measures focused on multiple layers of the urban population. The particular complexities of major EU metropolises, for example high population density and social structure, create specific opportunities for transmission, but also enable targeted TB control interventions, not efficient in the general population, to be effective or cost effective. Lessons can be learnt from across the EU and this consensus statement on TB control in big cities and urban risk groups was prepared by a working group representing various EU big cities, brought together on the initiative of the European Centre for Disease Prevention and Control. The consensus statement describes general and specific social, educational, operational, organisational, legal and monitoring TB control interventions in EU big cities, as well as providing recommendations for big city TB control, based upon a conceptual TB transmission and control model.

European union standards for tuberculosis care

The European Centre for Disease Prevention and Control (ECDC) and the European Respiratory Society (ERS) jointly developed European Union Standards for Tuberculosis Care (ESTC) aimed at providing European Union (EU)-tailored standards for the diagnosis, treatment and prevention of tuberculosis (TB). The International Standards for TB Care (ISTC) were developed in the global context and are not always adapted to the EU setting and practices. The majority of EU countries have the resources and capacity to implement higher standards to further secure quality TB diagnosis, treatment and prevention. On this basis, the ESTC were developed as standards specifically tailored to the EU setting. A panel of 30 international experts, led by a writing group and the ERS and ECDC, identified and developed the 21 ESTC in the areas of diagnosis, treatment, HIV and comorbid conditions, and public health and prevention. The ISTCs formed the basis for the 21 standards, upon which additional EU adaptations and supplements were developed. These patient-centred standards are targeted to clinicians and public health workers, providing an easy-to-use resource, guiding through all required activities to ensure optimal diagnosis, treatment and prevention of TB. These will support EU health programmes to identify and develop optimal procedures for TB care, control and elimination.

[Pulmonary tuberculosis]

Tuberculosis (TB) is a global health problem driven by poverty, HIV infection, etc. In Europe, the problem of multidrug resistance (i.e., resistance to at least rifampin and isoniazid) (MR) develops. The cases come essentially from the former U.S.S.R. In Belgium, the incidence of tuberculosis continues to decline to 9.4/100,000 inhabitants in 2008. The percentage of MR germs is 2.8%. The distribution of cases is not uniform across the country. The incidence is much higher among people recently coming from high prevalence countries than among the Belgian native. The pulmonary forms of TB are more contagious and more common. The clinical signs are frequently non specific. The diagnosis is often mentioned up after performing a chest Xray and must always be confirmed by microbiological examination and culture of several sputum or other respiratory specimens. It is very important to identify the germ, M. tuberculosis complex and to test its sensitivity to anti-TB agents. Standard treatment consists of 4 drugs: isoniazid, rifampin, ethambutol and pyrazinamide for 2 months followed by rifampin and isoniazid for at least 4 additional months. In suspected cases of MR, 5 drugs are prescribed at the outset. Treatment and duration will be adjusted according to the results of susceptibility testing. The potential toxicities of second-line drugs should be well known by the physicians. Compliance of the patient is essential. Screening in the entourage is part of the therapeutic process.

Standardised PCR-based molecular epidemiology of tuberculosis

A population-based molecular epidemiology investigation has been undertaken to evaluate tuberculosis transmission and control in the Brussels-Capital Region (Belgium). All tuberculosis cases reported from January 2003 to December 2004 were investigated. In total, 536 Mycobacterium tuberculosis isolates (89% of culture-positive samples) were genotyped by the newly standardised 24 loci-based mycobacterial interspersed repetitive unit-variable number tandem-repeat typing, spoligotyping and IS6110 fingerprinting. Of all the patients, 30% were grouped based on strain clusters, suggesting a transmission index of 20%. An unsuspected outbreak entailing > or = 23 patients was evidenced by molecular typing analysis and confirmed by contact tracing. Foreign-born status accounted for 79% of the studied patients, including 37.9% illegal immigrants and asylum seekers. Among foreign-born patients, asylum seekers and illegal immigrants were significantly less abundant in strain clusters than settled residents. Tuberculosis in the Brussels-Capital Region is a bi-faceted problem, comprising both persisting recent transmission and "imported diseases". Molecular epidemiology based on real-time genotyping techniques has proven invaluable in better understanding tuberculosis transmission. However, it will most efficiently contribute to tuberculosis control when implemented in an integrated public health system.

Tuberculosis and tuberculosis control in European prisons

OBJECTIVE

Correctional facilities have often been cited as reservoirs for tuberculosis (TB), presenting a potential threat to the general population. Although correctional facilities are recognised as ideal settings for interventions, little is known about the TB epidemiology within them. The purpose of our survey was to collect data on TB in prisons of the WHO European Region and on existing control measures.

DESIGN

A questionnaire was sent to 52 EuroTB correspondents asking for 2002 data on the total number of inmates, number of prisoners with TB, resistance rates, screening strategies, monitoring and responsibilities.

RESULTS

Twenty-two (42.3%) countries completed the questionnaire. The median TB notification rate was 232 per 100,000 inmates (0-17,808). Prisoners had up to 83.6 times more TB than civilians. The majority (90.9%) of the participating countries reported performing active screening for TB on entry into prison, with a median detection rate of 393/100,000 (42-2362). Of the respondent countries, 81.8% claimed to perform contact investigations and 86.4% to house infectious TB patients separately.

CONCLUSION

Although response to this survey was only 42.3% and might be biased by a country's engagement in TB control in prisons, the results highlight the vulnerability of prisoners to TB and emphasise the need for adequate case-finding and containment strategies in prison.

Physician's involvement in the smoking cessation process of their patients. Results of a 1998 survey among 4,643 Belgian physicians

This report relates to the 1,667 responses to a selfadministered mail-back questionnaire sent by BELTA to a sample of 4,643 physicians (17.3% current smokers) who are in professional contact with patients (response rate: 35.9%). Links between active smoking and disease are considered as well-demonstrated by 98.8% physicians and for passive smoking by 85.3%, for foetal consequences of smoking during pregnancy by 96.4%. Nicotine dependence is admitted by 83.3%. Interaction of smoking with drug metabolism is insufficiently known. Modulation of the specific approach of smoking cessation, according to the various stages of the cessation cycle, to the level of nicotine dependence and to the psychological status of the smoker is not sufficiently perceived by the physicians. Patient's smoking status is systematically determined by less than half the physicians, of whom nearly 90% claim to inform their smoking patients on smoking-related risks, and 84.2% to tackle the problem of cessation. The intervention is mostly limited to a firm advice, completed by nicotine replacement for a maximum of 50% of smokers (especially gum and patch). Referral to specialized structures is unfrequent (between 10 and 20%). Follow up after cessation is clearly deficient. In this retrospective study of their activity patterns, physicians' reports may reflect their intentions rather than their actual practices. We conclude that smoking issues and cessation techniques should be more intensively taught both at graduate and postgraduate levels, in order to obtain a more active behaviour of health professionals against smoking.

Prevention of transmission of tuberculosis in hospitals; a survey of practices in Belgium, 1995

In July 1995, a questionnaire survey was made of nosocomial tuberculosis (TB) prevention practices in Belgian hospitals. Of 122 respondents (response rate: 64%), 93% had hospitalized at least one TB patient, and 11% at least one multi-resistant TB case, during 1994. Effective prevention measures were not uniformly applied: only 96% isolated contagious TB patients, and only 84% isolated patients suspected of contagious T.B. In six hospitals, TB patients and those with human immunodeficiency virus (HIV) were mixed. Wearing of masks by personnel entering a TB patient's room was routine in 96%, but in only 24% of these was the mask adequate for filtering 1 micron particles. Moreover, some centres made use of seemingly unnecessary measures, for example routine use of disposable crockery (50%) and enhanced room cleaning (66%). Expensive prevention measures were rarely applied: UV lamps in 12%; HEPA filters in air conditioning in 2%. Tuberculin skin testing at some stage of employment, was routinely performed by 82% of respondents, but varied according to the type of personnel: doctors and temporary staff were significantly under-assessed. Lowest conversion rates among staff were observed in hospital with the least TB admissions but high rates were observed in hospitals of all sizes. The risk of acquiring TB in Belgian hospitals exists and precautions taken to prevent transmission are not sufficient. The situation could be improved by following national guidelines and a general adoption of proven effective practices, and by abandoning expensive and ineffective measures.

[Tuberculosis: multidrug-resistance in Belgium in 1992 and 1993]

The "Belgian TB Multidrug Resistance Working Group" determined in collaboration with 28 laboratories carrying out antibiograms for mycobacteria, the prevalence and incidence of multidrug resistance in Belgium in 1992-1993. During this period, respectively 14 (1.1%) and 17 (1.3%) cases of multidrug resistance (i.e. resistance to at least isoniazid and rifampicin, according to the W.H.O. definition), were detected by these laboratories. Since 9 new cases of multidrug resistance were detected in 1992 and 10 in 1993, the incidence of multidrug resistance in Belgium can be estimated at 0.1 per 100.000 inhabitants. Among these 19 new cases, 2 are confirmed as primary resistance cases.

[Treatment of tuberculosis with a fixed combination antitubercular drug in a marginal population in Brussels]

Tuberculosis is a world-wide persistent problem. Treatment is usually successful when the bacteria are drug-susceptible and patient compliance ensured. We report our results of treatment of high-risk patients without social security coverage in Brussels. Double and triple fixed antituberculous agents in combined tablets were used. Cure was obtained without drug toxicity in all patients who completed therapy. Only 19.5% of patients failed to complete therapy.