Eurosurveillance - Volume 11, Issue 3, 01 March 2006

This special issue of Eurosurveillance is dedicated to the memory of Andrea Infuso, a dear and respected colleague and friend, who died suddenly on 20 September 2005 at the age of 44. Andrea was actively involved in the preparation of this special issue on vaccination and tuberculosis. As EuroTB coordinator since 2000, his knowledge of and contacts with all European experts involved in tuberculosis surveillance in Europe were very valuable in conceiving this thematic issue. The Euroroundup published in this issue, European survey of BCG vaccination policies and surveillance in children, 2005, written by Andrea as first author, is a posthumous publication.

BCG (Bacillus Calmette-Guerin) vaccine was developed from an attenuated strain of Mycobacterium bovis at the beginning of the twentieth century. Its widespread use as a vaccine against tuberculosis spread in Europe, and subsequently globally, over the next 50 years. It remains one of the most frequently administered vaccines in the world. It has also been one of the most controversial. Widely differing estimates of the effectiveness of BCG at protecting against different forms of tuberculosis in different population subgroups in different settings have been published [1]. Some countries, with a low incidence of tuberculosis, did not adopt the use of BCG vaccine at all and some others abandoned its use at a later stage. In addition, great variation developed in national programmes for the administration of BCG including the age(s) at which it should be given, whether or not its administration should be preceded by tuberculin sensitivity testing, and whether repeat vaccinations with BCG should be given.

In 2005, all 25 EU countries, as well as Andorra, Bulgaria, Norway, Romania and Switzerland, participated in a survey on BCG vaccination in children. BCG was recommended nationally for children under 12 months in 12 countries, in older children in five countries and in children at risk (from origin, contact or travel) in 10 countries. Seven countries did not use BCG systematically. Revaccination was practised in four countries. In countries with universal vaccination, BCG coverage was high (83.0% to 99.8%). TB cases commonly occurred in vaccinated children (at least 30%-98% in five countries using universal or high-risk approach). Disseminated infection due to BCG was rarely reported in recent years (0-1/100 000 vaccinated). There is a wide variation among BCG recommendations in Europe, and nearly half the countries surveyed were considering revisions, at a time when the European Centre for Disease Prevention and Control (ECDC) is advocating for harmonised vaccine strategies. Data on monitoring of BCG coverage in target groups is important but often lacking in Europe. Information on BCG status and eligibility should be collected routinely through TB case notification. The incidence of severe adverse effects of BCG in children should be monitored. Given lack of evidence to its efficacy, revaccination should be discontinued.

Until recently, the French BCG vaccination programme consisted of a mandatory BCG vaccination before children started at daycare centres, and of re-vaccination of tuberculin-negative children. A re-assessment of this programme has been undertaken in recent years. It has led to the discontinuation of all revaccinations and post-vaccination tuberculin tests except those post-vaccination tuberculin tests performed as part of a diagnosis of tuberculosis infection or disease or of the follow-up of health or social workers for whom BCG vaccination remains mandatory. Based on an estimate of the epidemiological impact of either selective vaccination of high risk children or discontinuation of BCG vaccination, and taking into account the risk-benefit balance that can be made of the two options, the Conseil Supérieur d’Hygiène Publique de France (CSHPF, national high council of public hygiene) has recommended a change to selective vaccination. However, the committee has proposed the strengthening of other control measures aimed at decreasing the risk of infection for children, as a pre-requisite to the implementation of this strategy. This position is made more complex by the withdrawal of the multipuncture technique in early 2006, previously used in France in more than 90% of BCG primary vaccinations.

In 1975 the BCG vaccination policy in Sweden changed from routine vaccination of all newborn infants to selective vaccination of groups at higher risk. This report aims to evaluate the present BCG policy, with focus on the tuberculosis situation in Sweden during the period from 1989 to 2005. The population structure in Sweden has changed, with increasing numbers and proportions of people who were born outside Sweden, especially in countries with high prevalence of tuberculosis. BCG vaccination coverage fell from more than 95% before 1975 to less than 2% in 1976 to 1980, and then again increased to around 16 % (corresponding to about 88% of the risk group recommended for vaccination). The increasing proportion of foreign born tuberculosis patients among all tuberculosis cases of illness in Sweden, and the high age-specific incidence of tuberculosis in the childbearing age groups in the foreign-born population, indicate the need to continue selective vaccination of children in families originating from countries with high tuberculosis incidence. The cumulative incidence of tuberculosis in the 30 cohorts born in Sweden after 1974 and observed to the end of 2004 was estimated at 0.5 cases per 100 000 person-years. Sweden still has one of the lowest incidences of tuberculosis in the world, which means a minimal average risk of infection for the majority of children born to Swedish parents. The observed increase of tuberculosis in 2005, partly attributed to an outbreak at a day nursery, is a reminder of the serious consequences of delayed diagnosis. Intensified active case finding is the most important action to prevent childhood tuberculosis, by means of eliminating the sources of infection to prevent transmission to the child population. Early detection and treatment of infected children is necessary to prevent development of serious disseminated tuberculosis.

In Finland, all newborns are currently offered BCG vaccination, and the national coverage is over 98%. The annual incidence of tuberculosis is low, at 6.6/100 000 in 2004 and has been steadily declining in recent years. Finland differs from the other Nordic countries in that the majority of cases are detected in people aged 65 and over in the indigenous population, and only a smaller proportion (12%) detected in immigrants. The high incidence of TB and MDR TB in neighbouring countries has raised concern, but no increase in TB detected in Finnish-born citizens has been seen. A decision has been made to change from mass BCG vaccination to targeting risk groups.

We discuss tuberculosis treatment outcome monitoring and the adherence of countries in the WHO European Region to modifications introduced in 2001 to enhance inter-country comparability. Outcomes for definite pulmonary tuberculosis cases were compared for cases reported in 2001 and 2000. Reporting was considered complete if 98% or more of cases originally notified had outcome reported. In both years, maximal period of observation was 12 months from start of treatment. In 2000, countries reported outcome as ‘cured’, ‘completed’, ‘died’, ‘failed’, ‘defaulted’, ‘transferred’ and ‘other, not evaluated’ for cohorts of new and retreated cases. In 2001, following changes, countries were also requested to monitor cases with unknown treatment history and two outcome categories were added – ‘still on treatment’ and ‘unknown’. Of 42 countries reporting outcomes in 2001, 74% (31) had nationwide, complete data, up from 50% (19/38) in 2000. Twelve of 21 countries that reported on observation period complied with that recommended. ‘Defaulted’ and ‘transferred’ were applied interchangeably with ‘unknown’. Among new cases, ‘still on treatment’ was used by 15/31 countries (range: 1%-15%). ‘Failed’ was rarely recorded in western European countries (<1%). European tuberculosis outcome monitoring should include all definite pulmonary cases, applying the standard period of observation and revised categories, and preferably reported using individual data.

As in other countries with low tuberculosis incidence, tuberculosis in England and Wales tends to be concentrated in some subgroups of the population, and is mainly a problem in large cities. In 2003, almost half of all tuberculosis cases reported in England and Wales were from London, where the incidence was almost five times higher than in the rest of England and Wales. While the highest proportion of cases occur in foreign born patients, evidence from a large outbreak of drug resistant tuberculosis points to ongoing active transmission among marginalised groups including homeless people, hard drug users, and prisoners. Increasing rates of disease and levels of drug resistance, combined with a concentration of disease in hard-to-reach risk groups now present a major challenge to tuberculosis control in the city. To respond to the changing epidemiology observed in recent years, treatment and control services are being reconfigured, surveillance has been improved with the implementation of the London TB register, and the utility of mobile digital x ray screening for at risk populations such as homeless people and prisoners is being evaluated. However, tuberculosis in London is not yet under control and more needs to be done. Services must adapt to the needs of those groups now most affected. This will require continued improvements to surveillance and monitoring, combined with improved access to care, better case detection, rapid diagnosis and active social support for people undergoing treatment.

From 1991 until the end of 1998, the number of patients with tuberculosis in Latvia increased 2.5 times with a simultaneous increase of drug resistant and multidrug resistant tuberculosis (MDR-TB). Descriptive analysis of different TB programme services, activities and strategies including Directly Observed Therapy Short-course (DOTS) for tuberculosis and treatment of MDR-TB, were performed. Data from the state tuberculosis registry, drug resistance surveillance, and the national MDR-TB database were used. The state-funded national tuberculosis control programme (NTAP, Nacionâlâ Tuberkulozes Apkarodanas Programma), based on WHO recommended DOTS strategy, was introduced in Latvia in 1996. The NTAP includes TB control in prisons. Treatment of MDR-TB using second line drugs was started in 1997. Cure rates for TB patients increased from 59.5% in 1996 to 77.5% in 2003. Between 1996 and 2003, more than 200 patients began MDR-TB treatment each year, and the cure rate was between 66% and 73%. Numbers of MDR-TB patients were reduced by more than half during this period. Treatment results including MDR-TB reached the WHO target, with cure rates 85% of newly diagnosed patients. These results demonstrate that MDR-TB treatment and management using the individualised treatment approach can be effectively provided within the overall TB programme on a national scale, to successfully treat a large number of MDR-TB patients. Rapid diagnostic methods combined with early intensified case finding, isolation and infection control measures could decrease transmission of TB and MDR-TB in hospitals and in the community. Highly important that MDR-TB management follows WHO recommendations in order to stop creating drug resistance to first and to second line drugs.