Tuberculosis

1. Key messages

In 2017, 972 new cases of tuberculosis were reported in Belgium.
Belgium is a low-incidence country with 8.6 new cases of tuberculosis per 100,000 inhabitants. There are however important geographical differences: the incidence is 3.9 and 4.7 times higher in the Brussels-Capital Region (27.8 cases/100,000), when compared with Wallonia (7.1 cases/100,000) and Flanders (5.9 cases/100,000). Big cities report more cases since there is a higher concentration of risk groups. Brussels is the city with the highest incidence.
The incidence of tuberculosis is higher in men, whatever the age, region or nationality.
In Belgium, in 2017, 52.1% of the tuberculosis cases occurred among people who did not have a Belgian nationality. This proportion was higher in Brussels (63.8%) than in the two other regions.

2. Background

Tuberculosis is a disease caused by a bacterium called Mycobacterium tuberculosis that usually affects the lungs.

According to the World Health Organization (WHO), there were 10 million new cases of tuberculosis in 2017. This disease is one of the top 10 causes of death worldwide. Belgium is situated among the “low-incidence countries” with less than 10 new cases of tuberculosis per 100,000 inhabitants per year [1].

Tuberculosis can nowadays be effectively treated with a success rate of 83.7% in 2016. In Belgium, treatment is free of charge for the entire population (even for people without health insurance). However, 8.7% of tuberculosis patients still die before the end of treatment (half of these deaths are due to comorbidity) [2].

The main risk factors for tuberculosis are contacts of infected people, poverty, poor nutritional status and immunodeficiency. Some people are more likely to get infected with tuberculosis since they are more exposed to the risk factors, like health care professionals and vulnerable populations such as homeless people, prisoners and migrants originating from countries with high tuberculosis prevalence.

Data presented in this chapter are extracted from the Belgian tuberculosis registry 2017 report written by the Fonds des Affections Respiratoires (FARES) [2] and the Vlaamse Vereniging voor Respiratoire Gezondheidszorg en Tuberculosebestrijding (VRGT) [3].

3. Tuberculosis incidence

Belgium

  • In 2017, 972 new cases of tuberculosis were reported in Belgium (8.6 cases/100,000 inhabitants).
  • Men are more often affected by the disease than women, with 65.5% of new cases occurring among men in 2017 in Belgium. The sex ratio is 1.9.
  • 40% of the tuberculosis patients diagnosed in 2017 were aged 25-44 years.

Trends and regional differences

40% of tuberculosis cases are registered in Flanders (n=386), 34% in Brussels (n=331) and 26% in Wallonia (n=255). When related to the number of inhabitants, the incidence rate is 3.9 times higher in Brussels (27.8 cases/100,000) as compared to Wallonia (7.1 cases/100,000) and 4.7 times higher as compared to Flanders (5.9 cases/100,000).

The number of new cases of tuberculosis is decreasing since more than 30 years, although the diminution is slowing down since the nineties and tends to stagnate the last few years. The incidence rate dropped below the level of 10 cases/100,000 inhabitants for the first time in 2007, ranking the country among low-incidence countries.

Since 1981, the incidence rate is decreasing in all three regions, with more variations in Brussels due to migration flows. In Wallonia, the incidence rate has decreased below the national average since 1987, except in 1991 and 1999. The incidence rate in Flanders is slightly lower than in Wallonia.

Tuberculosis incidence per 100,000, Belgium and regions, 1981-2017
Source: Belgian tuberculosis registry 2017, VRGT/FARES asbl, march 2019

Incidence in big cities

Tuberculosis occurs more frequently in big cities where people at risk are over-represented:

  • the incidence in Brussels is the highest (27.8/100,000 in 2017); it is more than 3 times higher than in Belgium as a whole (8.6 /100,000).
  • the incidence is also quite high in Antwerp and Liege (more than 20 new cases/100,000 in 2017), followed by Charleroi and Namur (more than 15 new cases/100,000).

At the opposite, the tuberculosis incidence is lower in the cities of Ghent and Bruges where the rates are below the national average (respectively 8.5 and 5.1 new cases/100,000 in 2017).

Tuberculosis incidence per 100,000 in cities >100,000 inhabitants, Belgium, 2017
Source: Belgian tuberculosis registry 2017, VRGT/FARES asbl, march 2019

Tuberculosis distribution by nationality

In 2017, in Belgium, 52.1% of new tuberculosis cases occurred among people with a foreign nationality: 91.5% of those come from countries with high prevalence of the disease (mostly from Eastern Europe, Africa and South Asia countries). This proportion is higher in Brussels (63.8% of the new tuberculosis cases among people with foreign origin) than in Wallonia and Flanders (respectively 47.5% and 45.1%).

Among Belgians, the incidence rate is more than 4 times higher in Brussels compared to Flanders, and 3.8 times higher than in Wallonia.

Among non-Belgians, the incidence rate of tuberculosis is also higher in Brussels when compared with the two other Regions but the difference is less pronounced than for Belgian people: the incidence rate is respectively 1.6 and 1.5 times higher than in Flanders and in Wallonia.

Flanders has the lowest incidence rate, regardless of nationalities.

  • Crude rate
  • Number of cases

Tuberculosis incidence per 100,000 by nationality and by region, Belgium, 2017
Source: Belgian tuberculosis registry 2017, VRGT/FARES asbl, march 2019

New cases of tuberculosis by nationality and by region, Belgium, 2017
Source: Belgian tuberculosis registry 2017, VRGT/FARES asbl, march 2019

The distribution of the incidence by age and sex is different according to nationality:

  • among Belgians, the incidence is higher in age groups 30-44 years and 60-74 years.
  • among non-Belgians, the incidence is higher in age group 15-29 years and lower in upper age groups.

Among Belgians, the sex ratio is 1.7. It tends to increase with age: the incidence rate is 4 times higher in men among people over 75 years.

If the number of new cases increases with age among men, it is not the case among women: the incidence is higher in age group 15-29 years and gradually decreases after 29 years.

Among non-Belgians, the sex ratio is 2. The incidence rate is more than 2 times higher in men in age groups 15-29 years, 30-44 years and over 75 years.

  • Belgians
  • Non-Belgians

Tuberculosis incidence per 100,000 by age and sex, Belgian people, 2017
Source: Belgian tuberculosis registry 2017, VRGT/FARES asbl, march 2019

Tuberculosis incidence per 100,000 by age and sex, non-Belgian people, 2017
Source: Belgian tuberculosis registry 2017, VRGT/FARES asbl, march 2019

International comparison

In 2017, according to WHO [4], estimated incidence rate in Belgium is above the EU-15 mean, ranking the country third among the countries with the highest incidence rate after Portugal and Spain.

International comparisons made on reported data must be interpreted with caution, since methods for collecting data can be very different depending the country. That is why the WHO Global Task Force on TB Impact Measurement [1] has developed a methodology to take into account underreporting, over and under-diagnosis in tuberculosis estimates. This explains why the incidence rate in Belgium presented in this international comparison is different compared to the incidence rate extracted from the Belgian tuberculosis registry publication.

Tuberculosis incidence per 100,000, EU-15 countries, 2017
Source: WHO/ECDC 2019

4. Read more

View the metadata for this indicator

Vlaamse Vereniging voor Respiratoire Gezondheidszorg en Tuberculosebestrijding (VRGT)

Definitions

Tuberculosis case
According to the WHO-recommended definitions [5], a tuberculosis case is defined by a case of active tuberculosis clinically diagnosed by a clinician or other medical practitioner or bacteriologically confirmed. Clinically diagnosed cases include “cases diagnosed on the basis of X-ray abnormalities or suggestive histology and extrapulmonary cases without laboratory confirmation” [5].
EU-15
The EU-15 corresponds to all countries that belonged to the European Union between 1995 and 2004: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Ireland, Italy, Luxembourg, the Netherlands, Portugal, Spain, Sweden and the United Kingdom. We compare the Belgian health status to that of the EU-15 because these countries have similar socioeconomic conditions.

References

  1. Global tuberculosis report 2018. Geneva: World Health Organization; 2018. https://www.who.int/tb/publications/global_report/en/
  2. Registre belge de la tuberculose 2017, FARES asbl, mars 2019. https://www.fares.be/static/front/upload/1/upload/files/tuberculose/registres/Regtbc2017.pdf
  3. Tuberculoseregister België 2017, Vlaamse Vereniging voor Respiratoire Gezondheidszorg en Tuberculosebestrijding VRGT vzw. https://tuberculose.vrgt.be/sites/default/files/Tuberculoseregister%20België%202017.pdf
  4. WHO Regional Office for Europe/European Centre for Disease Prevention and Control.
    Tuberculosis surveillance and monitoring in Europe 2019 – 2017 data. Copenhagen: WHO Regional Office for Europe; 2019. https://ecdc.europa.eu/sites/portal/files/documents/tuberculosis-surveillance-monitoring-Europe-2019-20_Mar_2019.pdf
  5. Definitions and reporting framework for tuberculosis – 2013 revision, updated December 2014. Geneva: World Health Organization; 2015. https://www.who.int/tb/publications/definitions/en/