Other official information and services: www.belgium.be 
The new page on vaccine-preventable diseases has been published.
The information on cancer has been updated with 2022 data.
Explore the new section 'Interactive dashboards' for easy access to interactive dashboards in Sciensano.
Please note that there are different definitions and guidelines available to describe long COVID. Based on the definition used, the results may be different.
The COVIMPACT study in Sciensano was developed based on the definition of the National Institute of Health and Care Excellence (NICE): "symptoms persist or develop for more than 3 months after a COVID-19 infection and cannot be explained by another diagnosis” [1].
The coronavirus disease 2019 (COVID-19) pandemic started in December 2019 in the city of Wuhan, China. COVID-19 is caused by the virus SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2). On 11 March 2020, the Director-General of the World Health Organization declared COVID-19 a global pandemic.
The virus is transmitted from human to human by infectious droplets. People can remain asymptomatic or present with a broad spectrum of symptoms. The risk of severe disease increases markedly with age and previous underlying conditions. For the general public, vaccination, handwashing, social distancing, avoiding crowded indoor spaces, and wearing a face mask are the recommended measures to protect oneself. Vaccines are available in Belgium since January 2021; more information on vaccines can be found here.
An overview of the scientific information about COVID-19 based on updated literature monitoring is available in the Sciensano fact sheet.
In Belgium, the first confirmed case was reported on 3 February 2020, in an asymptomatic person repatriated from Wuhan. The second case was registered almost one month later, on 1 March 2020. This case was followed by a rapid growth in the number of cases occurring after the Carnival holidays. Since then, the virus is widely spreading in the country.
The Belgian institute for health, Sciensano, monitors the epidemic based on the data collected by its surveillance networks and reports on the latest figures and trends.
Four key indicators are followed; for the three first ones a moving average is computed on the last 7 days and compared to the average of the 7 previous days:
Moreover, the reproduction rate, that is the average number of people infected by a person carrying the virus, is calculated. If the reproduction rate is over 1, the disease is spreading in the population. Additional indicators are followed as the number of occupied beds in hospitals and ICU, vaccination coverage, the number of tests performed, and the percentage of those that are positive (positivity rate).
More information on COVID-19 mortality can be found on the following pages: ad-hoc surveillance of COVID-19 mortality 2020-2022, causes of death, causes of premature death.
Since the data are in constant evolution, this sheet refers to the main web pages where figures are updated regularly. Data can be consulted in several places and in several forms:
Comparisons among countries should be interpreted with caution due to differences in testing strategy, in laboratory capacities, and in the effectiveness of the surveillance. Comparisons of COVID-19 deaths are also hampered by differences in the methodology of counting COVID-19 deaths.
Epidemiological International data can be consulted on several platforms:
In the COVIMPACT study, the overall occurrence of long COVID was 47% three months after a SARS-CoV-2 infection, and 32% after 6 months. These numbers are in line with the international literature, which reports a prevalence of 47% and 30% for long COVID at 3 and 6 months [3].
Although the proportion of long COVID differs slightly according to age, it is not a significant risk factor. Among participants with an age between 18 and 25 years, 47% reported persistent symptoms 3 months after a SARS-Cov-2 infection. This is similar to participants aged between 26 and 45 years where 51% reported persistent symptoms, but higher compared to the other age categories 46-65 years (42%) and 66+ (36%). At 6 months, the prevalence of long COVID has decreased among all age categories to 27%, 26%, 37%, and 21% respectively [3].
In the COVIMPACT study, 37% of the participants were men and 63% of them were women. The proportion of long COVID at 3 months is higher amongst women (56%) in comparison to men (42%). After 6 months, the proportion decreased in women to 40% and men to 27%. Women are 1.4 times more likely to have long COVID than men at 3 and 6 months.
Among participants with a lower educational status, 56% reported persistent symptoms 3 months after infection, which is slightly higher compared to patients with a higher educational level (47%). After 6 months, these proportions decrease to respectively 41% and 32%.
The most prevalent symptoms reported by participants with long COVID at 3 and 6 months post-infection are fatigue and exhaustion (49% and 50%), headache (27% and 32%), memory problems (26% and 32%), respiratory problems (21% and 27%), sleeping problems (19% and 22%), loss of smell (20% and 17%) and taste (14% and 13%).
The health-related quality of life has been assessed with the EQ-5D questionnaire, which contains questions on mobility, autonomy, daily activities, pain/discomfort, and anxiety/depression. After 3 months, 18% of participants with long COVID reported mobility problems, 4% autonomy problems, 30% had problems with daily activities, 48% had pain and 40% of them reported anxiety and depression. After 6 months, these proportions were respectively 21% (mobility), 5% (autonomy), 33% (daily activities), 56% (pain), and 49% (anxiety and depression).
The mean score of health-related quality of life was assessed among COVIMPACT participants before their SARS-CoV-2 infection, at the time of infection, and after 3 and 6 months. Before infection, the average quality of life score was 92.6/100 and it significantly decreased at the time of infection to 81.7/100. For the scores 3 and 6 months after infection, a comparison was made between people who recovered from their infection and those who had long COVID. People who recovered from the infection had a higher quality of life score 3 and 6 months after infection (95.7/100 and 95.8/100) than people with long COVID (86/100 and 83.6/100).
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Would you like more information about COVID-19?
Besides his mission of surveillance, Sciensano is also involved in scientific research projects on COVID-19. In collaboration with partners, Sciensano coordinates and participates in projects aiming to better understand the virus and its effects on population health. Here is an overview of the existing projects.
Specific aspects of COVID-19 monitoring, prevention, and control are competencies of the regions. Further information on these aspects is available via the following websites:
We invite you to consult the following links: latest news, current measures taken by the Belgian government, guidelines to follow when COVID-19 symptoms appear.
If you are a professional, you can find the procedures for managing COVID cases on the Sciensano website.
In Belgium and worldwide, at the beginning of the COVID-19 pandemic, the focus was on managing the acute phase of the disease. However, some people continue to experience symptoms beyond the acute phase of infection [4] [5]. This phenomenon is referred to as "long COVID" or "Post COVID-19 condition" [6].
There is currently no consensus on the definition of long COVID. Still, many studies apply the definition proposed by the National Institute of Health and Care Excellence: "symptoms persist or develop for more than 3 months after a COVID-19 infection and cannot be explained by another diagnosis [1].
In the COVIMPACT study, the two definitions used to describe long COVID 3 and 6 months after acute infection are (1) having at least one symptom related to the SARS-CoV-2 infection three months after it, (2) still have at least one persistent symptom related to the SARS-CoV-2 infection six months after it. The objective of the COVIMPACT project is to constitute a cohort of people who test positive for COVID-19 in order to:
COVIMPACT is a prospective online observational cohort study. The target group is people who have had a COVID-19 infection confirmed by a laboratory test. When a COVID-19 test is positive, the lab sends the information to a central database that is used by call centers to contact COVID-19 cases and trace their contacts. At the end of the call, the call center agents inform people aged 18 and over about our online survey and ask if they agree to receive a link by SMS for more information on the study, and potentially participate in the study and complete the first questionnaire. Follow-up questionnaires are sent by Sciensano every 3 months until the end of the study in April 2023. Depending on when participants entered the study, the follow-up varies from 3 months to 2 years. Between 29 April 2021 and 1 May 2022, 2092 people completed the first questionnaire and the two follow-up questionnaires (3 and 6 months after infection). Full details on the sample and design are described in the latest COVIMPACT study report. The following topics were assessed in the study: COVID-19, quality of life, breathing difficulties, fatigue, functional limitations, mental health, physical activity, employment, and economic status.
All these results can be found on the COVIMPACT website.
Please cite this page as: Sciensano. Communicable Diseases: COVID-19, Health Status Report, 26 Oct 2022, Brussels, Belgium, https://www.healthybelgium.be/en/health-status/communicable-diseases/covid-19
In 2022, 852 new cases of tuberculosis were reported in Belgium (7.4 cases/100,000 inhabitants). Men were approximately 2 times more often affected by the disease than women, with 68% of new cases occurring among men in 2022 in Belgium. Of all cases, 39% of the tuberculosis patients diagnosed in 2022 were aged 25-44 years.
Of the total number of new registered cases, 44% of tuberculosis cases were registered in the Flemish Region (n=371), 32% in the Brussels Capital Region (n=272) and 25% in the Walloon Region (n=209). Considering the number of inhabitants in each region, the incidence rate was four times higher in the Brussels Capital Region (22.2 cases/100,000) as compared to the Walloon Region (5.7 cases/100,000) and the Flemish Region (5.5 cases/100,000). The incidence rates in the Flemish Region and the Walloon Region were similar, with slightly higher rates in the Walloon Region.
In 2022, 62% of the new tuberculosis cases occurred among people with a foreign nationality in Belgium. This proportion was higher in the Brussels Capital Region (70%) compared to the Walloon Region and the Flemish Region (respectively 54% and 62%). Among Belgians, the incidence rate was 4.3 times higher in the Brussels Capital Region (10.3/100,000) compared to the Flemish Region (2.4/100,000), and 3.4 times higher compared to the Walloon Region (3.0/100,000). Among non-Belgians, the incidence rate was 1.5 times higher in the Brussels Capital Region (43.5/100,000) compared to the Flemish Region (29/100,000), and 1.2 times higher compared to the Walloon Region (34.8/100,000).
Tuberculosis incidence per 100,000 by nationality and by region, Belgium, 2022
Source: Belgian tuberculosis registry, FARES/VRGT [2,3]
New cases of tuberculosis by nationality and by region, Belgium, 2022
Source: Belgian tuberculosis registry, FARES/VRGT [2,3]
The distribution of the incidence by age and sex varied according to nationality in 2022. Among Belgians, the incidence increased with age in men, peaking in the 60-74 years group. Incidence was higher in men than in women across all age categories, except for children (0-14 years). The overall male-female ratio tended to increase with age, with incidence rates being 4.0 times higher in men among those over 75 years.
Among non-Belgians, the highest incidence was observed in the 15-29 years age group, with particularly high rates in men. The lowest incidence rates among non-Belgians were seen in women aged 60-74 and in boys (0-14 years). Excluding children (0-14 years), the incidence rate was 1.6 to 4.3 times higher in men compared to women across the all age groups, with the highest male-to-female ratios in the 60-74 years and 15-29 years age groups.
Tuberculosis incidence per 100,000 by age and sex, Belgian people, 2022
Source: Belgian tuberculosis registry, FARES/VRGT [2,3]
Tuberculosis incidence per 100,000 by age and sex, non-Belgian people, 2022
Source: Belgian tuberculosis registry, FARES/VRGT [2,3]
In 2022, tuberculosis occurred more frequently in big cities where more people at risk are living:
The number of new cases of tuberculosis is decreasing for more than 40 years, although the diminution is slowing down since the nineties and tends to stagnate over the last few years. The incidence rate dropped below the level of 10 cases/100,000 for the first time in 2007, ranking the country among low-incidence countries. In 2022, the incidence rate (7.4 cases/100,000; n=852) remained low and was even slightly lower compared to the incidence rate of 2021 (7.6 cases/100,000; n=875). It is slightly higher than in 2020 (7.2/100,000), which was the lowest incidence ever observed in Belgium, probably due to the context of the COVID-19 pandemic (including difficulty accessing healthcare, more complex data collection, under-reporting, containment measures, barrier measures, provision of emergency housing for vulnerable populations, border closures, etc.,). While the lower incidences in 2020 and 2021 could be explained by COVID-19, this is no longer the case for the low incidence in 2022.
Since 1981, the incidence rate is decreasing in all three regions, with more variations in Brussels:
In 2022, according to World Health Organization (WHO) [4], the estimated incidence rate in Belgium was above the EU-14 average, ranking the country 3rd in the EU-14 after Portugal and Luxembourg.
International comparisons made on reported data must be interpreted with caution, since methods for collecting data are different depending on the country. That is why the WHO Global Task Force on TB Impact Measurement [1] has developed a methodology to take into account under reporting, over and under-diagnosis in tuberculosis estimates. This explains why the incidence rate in Belgium presented in this international comparison (7.8 new cases per 100,000) is different compared to the incidence rate extracted from the Belgian tuberculosis registry publication (7.4 cases per 100,000).
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Fonds des affections respiratoires (FARES)
Vereniging voor Respiratoire Gezondheid (VRGT)
Tuberculosis is a disease caused by a bacterium called Mycobacterium tuberculosis that usually affects the lungs.
According to the World Health Organization (WHO), more than 10 million new cases of tuberculosisoccur every year. The disease is one of the top 10 causes of death worldwide, and the second leading cause of death from a single infectious agent after COVID-19 in 2022. 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 81% in 2021 in Belgium. In Belgium, treatment is free of charge for the entire population, also for people without health insurance. However, 7.4% of tuberculosis patients still die before the end of treatment [2].
The main risk factors for tuberculosis are contacts with 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 2022 report written by the Fonds des Affections Respiratoires (FARES) [2] and the Vereniging voor Respiratoire Gezondheid (VRGT) [3].
The incidence rate is calculated as the number of new cases divided by the number of people registered at the National registry. Incidence rate in non-Belgians is slightly overestimated, as cases in unregistered migrants are counted in the numerator, while the denominator could only include the registered migrants.
Please cite this page as: Sciensano. Communicable Diseases: Tuberculosis, Health Status Report, 29 July 2024, Brussels, Belgium, https://www.healthybelgium.be/en/health-status/communicable-diseases/tuberculosis
Poliomyelitis is a highly infectious viral disease. It causes mild or no symptoms in most people, but in some people it can cause total paralysis or death. After the introduction of the polio vaccination in 1956, the incidence of polio sharply declined and cases have been rare following the introduction of mandatory vaccination in 1967. Since 2002, the European region has been considered polio-free by the World Health Organization (WHO). Currently, the risk of an epidemic in Belgium is low thanks to the high vaccination coverage.
Similarly, Belgium was certified by WHO as having eliminated rubella, thanks to vaccination. This virus can have severe consequences during pregnancy leading to stillbirth, congenital malformations and congenital rubella syndrome (CRS). The last autochthonous case of CRS in Belgium dates from 2007 and the last imported case from 2012. However, as long as these viruses are still circulating elsewhere, vaccination and surveillance remain necessary due to the risk of importation.
For most diseases targeted by vaccination, incidence has dropped drastically since the start of routine vaccination, but outbreaks still occur. Under-immunisation of certain groups or geographical regions significantly increases the risk of outbreaks. There was, for example, a diphtheria outbreak among asylum seekers in 2022, a group where vaccination remains difficult and coverage is too low [2].
In 2024, an important measles outbreak occurred, affecting mostly unvaccinated schoolchildren in Brussels. This highlights the importance of high vaccination coverage throughout the entire population.
For invasive diseases like meningo- and pneumococcal disease, current vaccines protect against certain serogroups/serotypes, but not all. Since the introduction of these vaccines in Belgium, circulation of strains included in the vaccine has dropped significantly. However, other strains not covered by the vaccine in the schedule are on the rise. This changing epidemiology does not indicate a failure of the vaccination policy—total incidence remains lower than before vaccination programs were introduced. It does however highlight the need for development of new vaccines and adjustments in vaccination schedules. For example, the meningococcal vaccine was changed from MenC to MenACWY in 2023 to include three additional serogroups, after an increase in serogroups W and Y was observed.
In Belgium, the 90% coverage threshold set out in the WHO's Global Vaccine Action Plan (GVAP) [3] has been reached for full primary vaccination (1-4 doses depending on the vaccine) for all vaccines included in the recommended basic vaccination schedule, except for the rotavirus vaccine. The rotavirus vaccine is the only one that is recommended for children but not provided in the free-of-charge vaccination program.
Vaccination coverage for vaccines in the basic vaccination programs for children is consistently high across all Belgian regions. National vaccination coverage for the full schedule (4 doses) of the hexavalent vaccine is 94%, with comparable coverage rates in all regions. The hexavalent vaccine is a vaccine that combines vaccination against six diseases in 1 shot (diphtheria-tetanus-pertussis (DTP), hepatitis B (HebB), Haemophilus Influenza type b (Hib), and poliomyelitis (polio)). Similarly, coverage for meningococcal (92%) and pneumococcal (94%) vaccines, as well as the first dose of measles-mumps-rubella (MMR1), show minimal regional differences.
The rotavirus vaccine is recommended by the Superior Health Council (SHC) but is not included in the free vaccination programs by the regions. It is partially reimbursed by the RIZIV-INAMI, but you still have to pay about €7-12 per dose yourself. As a result, vaccination rates were lower than for the free vaccines in the basic vaccination program, especially in Brussels (70%) and Wallonia (81%). In Flanders, on the other hand, the vaccination coverage rate was 92%.
The WHO targets of 95% for 2 documented doses of mumps, measles and rubella (MMR) and ≥ 90% for human papillomavirus (HPV) coverage have not been reached in Belgium. Based on the latest available surveys, the weighted national average coverage for MMR2 was 83% and has remained stable over time.
The national coverage for full HPV vaccination (2 doses) is 72% for girls, 65% for boys and 68% for girls and boys together. HPV vaccination has slowly been increasing over the years for girls. In 2019, vaccination for boys was introduced. Coverage in boys is currently lagging behind that of girls.
Following the advice from the Superior Health Council to lower the age for the second dose of MMR2, the French Community (FWB) and German-speaking Community lowered the age to 7-8 years old and the Flemish Community to 9-10 years old. In Flanders, the latest survey was performed in 2020, reporting coverage of 89%. FWB performed a new coverage survey in 2021-2022 that indicated a 73% coverage in the whole French Community and 70% for Brussels specifically. There is a likely under-reporting of full vaccination (MMR1+2) due to lost or missing documentation for the first dose in all the regions.
For HPV, the weighted national average hides important regional differences. In 2019-2020, Flanders had a full HPV vaccination coverage rate of 81% for both girls and boys, while the French Community had a coverage of 48%. In a new survey by FWB in 2022-2023, coverage in the French Community increased to 52%. Coverage in Brussels specifically increased from 39% to 41%.
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The Belgian Superior Health Council decides, on a scientific basis, about the recommended vaccination schedule for children. This schedule currently includes vaccines for thirteen infectious diseases. Of these, the polio vaccine is the only one that is mandatory in Belgium. The different communities (Flemish, French and German-speaking Community) are then responsible for the implementation of the guidelines and practical organization of the vaccination campaigns. As a result, there are some regional differences in the age of administration of certain vaccines for children (see schedules for Flanders and Fédération Wallonie-Bruxelles) and in the vaccine brands that are being used. Extensive information can be found in the report “Vaccination policy and advice in Belgium” (available in Dutch and French).
In Belgium, vaccination coverage is monitored by coverage surveys organized and financed by the relevant regions/communities. These surveys take place approximately every four to five years. An estimate of national vaccination coverage in Belgium is calculated each year by Sciensano's Epidemiology of Infectious Diseases Department on the basis of the most recent vaccine coverage studies and weighted by population size. To study infant vaccination coverage, the same methodology is used in all three regions, with a sample drawn from the general population. The method used to study adolescent vaccination coverage differs from region to region. In Flanders, adolescent vaccination coverage studies are carried out on a general population sample. In Brussels and Wallonia, vaccination coverage surveys have been carried out every year on a sample of pupils in French-speaking schools [4]. In Flanders, an electronic vaccination registry, Vaccinet, has existed since 2006 and is being routinely used by all vaccinators. For the French community, new vaccination registries are currently under development. In the future, registry-based vaccination coverage estimates might replace the periodical surveys.
More detailed information on the epidemiology and surveillance of vaccine-preventable diseases can be found in the yearly reports on the specific health topic pages on Sciensano website:
Please cite this page as: Sciensano. Communicable Diseases: Vaccine-preventable diseases, Health Status Report, 18 March 2025, Brussels, Belgium, https://www.healthybelgium.be/en/health-status/communicable-diseases/vaccine preventable diseases
In 2023, 665 new diagnoses of HIV infections were made in Belgium (5.7 new diagnoses per 100.000 inhabitants, or on average 1.8 cases a day). Among those, 70% were men. 76% of the HIV infections were diagnosed in people aged 20-49.
The number of new HIV diagnoses has increased by 13% in 2023 compared to 2022. The total number of new HIV diagnoses is now similar to the last pre-Covid year (-1.3% compared to 2019).
Between the start of the epidemic in the early 80s and the end of 2023, a total of 31,770 persons were diagnosed with HIV, and a total of 5,656 cases of AIDS were reported.
In 2023, of the 665 newly diagnosed persons, 220 were resident in the Brussels-Capital Region, 283 in the Flemish Region, 153 in the Walloon Region, and 9 were residing abroad.
When accounting for the number of inhabitants, the incidence rates in the Flemish Region (max 8 for 100,000 inhabitants in Antwerp district) and in the Walloon Region (max 9/100,000 in Arlon district) are comparable, while the rate in the Brussels Capital Region is much higher (18/100,000). This difference is not surprising since a higher HIV prevalence is a common phenomenon in a big city. The Brussels Capital Region can indeed be considered a big city - with the socio-cultural characteristics of an urban context – while the two other regions mix rural, semi-urban, and urban contexts.
The increase in newly diagnosed people from 2021 onwards observed at national level is mirrored in all three regions, following a decline over the previous decade. This recent increase is particularly marked in the Brussels-Capital Region.
The HIV epidemic in Belgium mainly affects two populations: men who have sex with men (MSM), mostly of Belgian nationality, and men and women who have contracted the virus through heterosexual relations, mainly from sub-Saharan Africa.
However, among both MSM and heterosexuals, the distribution of nationalities changes significantly over time. Among people infected through heterosexual contact, the share of people of sub-Saharan nationality is declining (49% in 2014 to 43% in 2023). The number of diagnoses among heterosexuals has risen by 13% in 2023 compared with 2022. This increase is greater among women of Belgian and other European nationalities (+19% and +23% respectively vs. 2022), as well as men from sub-Saharan Africa and Europe (+33% and +49% vs. 2022).
In 2023, 297 new HIV diagnoses were made among MSM; this represents a 16% increase on 2022. Although the number of new diagnoses is finally declining in the 20-29 age group after a significant rise (+34% between 2021 and 2022), there has been a particularly sharp increase in the 30-39 age group over the past 2 years. An increase of 14% is also observed among MSM of Belgian nationality compared with 2022; they accounted for 48% of HIV diagnoses among MSM in 2023; 18% had another European nationality and 13% had a Latin American nationality.
Number of new HIV diagnoses in MSM by nationality, Belgium, 1995-2023
Source: Epidémiologie du SIDA et de l’infection à VIH en Belgique, Sciensano, 2024 [1]
Number of new HIV diagnoses in heterosexuals by nationality, Belgium, 1995-2023
Source: Epidémiologie du SIDA et de l’infection à VIH en Belgique, Sciensano, 2024 [1]
By the end of 2023, an estimated 18,690 individuals were living with HIV in Belgium. Among them, 93% had received a diagnosis, and of those diagnosed, 95% were undergoing antiretroviral treatment.
In 2023, Sciensano estimated the number of people living with undiagnosed HIV [1] based on a tool developed by ECDC [2]. It is estimated that 1325 people living with HIV in Belgium were unaware of their HIV status. However, these estimates should be interpreted with caution given the significant uncertainty surrounding the estimates for the last 3 years derived from this model. Based on the ECDC tool, the number of people living with undiagnosed HIV in Belgium appears to have been steadily declining since 2011.
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Sexually transmitted infections (STIs) such as human immunodeficiency virus (HIV) are spread primarily through person-to-person sexual contact. Additionally, HIV can be transmitted through blood products and tissue transfer, and from mother to child during pregnancy or breastfeeding.
HIV can be present without symptoms, which can facilitate transmission. It is one of the most serious communicable diseases in Europe. Infection with the virus can, if antiretroviral treatment (ART) is not initiated, lead to serious morbidity (Acquired Immunodeficiency Syndrome (AIDS)) and requires life-long treatment.
HIV is an avoidable infection since the transmission is largely preventable by behavioural measures (safe sex, safe injection). Therefore HIV incidence in a defined population is an indicator of the success/failure of control strategies. Since 2017, the use of pre-exposure prophylaxis to HIV (PrEP) is reimbursed in Belgium.
The epidemiological surveillance of HIV in Belgium dates from 1985 and is carried out by Sciensano on the basis of the registration of new HIV diagnoses. These data are reported by the seven AIDS reference laboratories that perform all confirmations of positive HIV screening tests. In addition to recording the number of newly diagnosed HIV positive persons, the laboratories also collect basic epidemiological data on sex, age, nationality, probable route of infection, and clinical stage at the time of diagnosis. Sciensano also collects data on the people living with HIV (PLWH) in Belgium (HIV cohort data) from the AIDS reference laboratories and the HIV reference centres.
Besides the newly diagnosed cases, Sciensano also estimates the number of people living with HIV: those who have not yet been diagnosed [1] and those living with a diagnosed infection. To estimate the undiagnosed population an instrument developed by the European Center for Disease Prevention and Control (ECDC), called the ECDC HIV Modeling Tool [2] is used. HIV cohort data are used to estimate the number of people living with a diagnosed infection.
ECDC and the WHO Regional Office for Europe jointly coordinate HIV/AIDS surveillance in Europe [3]. The international comparability has some limitations since the national surveillance systems differ in levels of underreporting and reporting delay.
[1] Epidémiologie du VIH en Belgique. Situation au 31 décembre 2023. Bruxelles: Sciensano; 2024. https://www.sciensano.be/en/biblio/epidemiologie-du-vih-en-belgique-situation-au-31-decembre-2023
[2] European Centre for Disease Prevention and Control. HIV Modelling Tool. 2015. https://www.ecdc.europa.eu/en/publications-data/hiv-modelling-tool
[3] European Centre for Disease Prevention and Control/WHO Regional Office for Europe. HIV/AIDS surveillance in Europe 2024 – 2023 data. Stockholm: ECDC; 2024. https://www.who.int/europe/publications/i/item/9789289061551
Please cite this page as: Sciensano. Communicable Diseases: HIV, Health Status Report, 16 Jan 2025, Brussels, Belgium, https://www.healthybelgium.be/en/health-status/communicable-diseases/hiv-and-other-sexually-transmitted-infections
Influenza-like illness (ILI) is a medical diagnosis of possible influenza or other illness causing a set of symptoms. These symptoms commonly include fever, shivering, chills, malaise, dry cough, loss of appetite, body aches, and nausea, typically in connection with a sudden onset of illness. In most cases ILI is a benign illness, but for elderly people, pregnant women and people with chronic diseases, the complications of flu can be dangerous.
ILI is caused by a variety of respiratory pathogens, including, amongst others, influenza virus, parainfluenza virus, adenovirus, RSV, and Mycoplasma pneumoniae. The influenza A(H1N1) and A(H3N2) viruses as well as the influenza B virus are the cause of seasonal influenza epidemics in Belgium and circulate every year to different extents. Vaccination remains the best way of preventing transmission, complications and hospitalization of flu.
Sciensano coordinates sentinel networks of general practitioners and hospitals to ensure the permanent surveillance of ILI and influenza activity, intensity and severity of epidemics and impact on the population. The epidemic threshold is the minimum number of GP consultations for flu-like symptoms per 100,000 inhabitants per week needed to officially speak of an epidemic. This number is calculated by the European Centre for Disease prevention and Control (ECDC), and varied between 135 and 157 GP visits/100,000 inhabitants over the last 5 years. Sciensano also hosts the National Reference Centre (NRC) for influenza virus.
At the international level, influenza surveillance and pandemic preparedness is coordinated by ECDC and the World Health Organization.
More information on COVID-19 surveillance can be found on another page.
The Belgian flu epidemic of the 2018-2019 season lasted 8 weeks, which was average compared to previous seasons. The epidemiological threshold was exceeded from week 4/2019 (January 21 to January 27, 2019) to week 11/2019 (March 11 until March 17, 2019). The epidemic was of medium activity.
From week 40/2018 to week 18/2019, respiratory samples from patients diagnosed with ILI were collected by the sentinel network of general practitioners and analyzed at the National Influenza Center. Of these samples, 53% were positive for influenza viruses.
Based on surveillance through the sentinel network of general practitioners, it was estimated that about 506,000 Belgians consulted their GP for flu-like symptoms and, if they were all systematically tested, about 307,000 of them would actually be infected with the flu virus.
All age groups were affected at the approximately same weeks during the epidemic, with peak incidences in weeks 7/2019 and 8/2019.
Although there were many hospital admissions for a severe acute respiratory tract infection (SARI) during this intense season, the severity indicators of the confirmed flu cases (estimated through the network of 6 sentinel hospitals) indicated that this flu epidemic was relatively no more serious than in previous seasons.
The average length of stay for a serious flu infection during this season was 8.8 days (varying in age from 3.6 days in the age of 0-4 to 13.3 days in persons aged 85 years and older). This is comparable to the other seasons.
About 2% to 3% of people with influenza were hospitalized. Among those, 13% had serious complications, which were fatal in 6% of hospitalized patients; these indicators are however similar to those observed in the previous seasons. The vast majority of patients who suffered from severe complications had pre-existing comorbidity (91%).
Deaths were only observed in people aged 54 and over and 90% of these deaths were in patients with one or more comorbidities. The median age of death of patients without comorbidities was 87 years (range: 71-90 years) and the median age of death of patients with comorbidities was 79 years (range: 54-97 years).
The observations in Belgium were in line with those in the rest of Europe.
At European level, influenza activity started in week 49/2018, peaked in week 7/2019 and returned to baseline levels in week 17/2019. Influenza viruses started circulating at high levels in week 52/2018 until week 12/2019.
Intensive care unit (ICU) cases were mainly aged 65 years and older, but in certain countries there was a substantial number of hospitalizations in persons aged 40–64 years.
Each year, between 300,000 and 900,000 people visit their GP because of influenza-like illness in Belgium. Among these, the annual number of influenza infections is estimated between 116,000 and 472,000.
Since 2012, between 11% and 15% of patient hospitalized with a confirmed influenza infection have developed severe complications, including 4% to 9% who have died in the course of hospital stay.
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Results of the surveillance of influenza and influenza-like illness in Belgium
Laboratory surveillance of influenza in Belgium
Please cite this page as: Sciensano. Communicable Diseases: Influenza and influenza-like illness, Health Status Report, 06 Sept 2020, Brussels, Belgium, https://www.healthybelgium.be/en/health-status/communicable-diseases/influenza-and-influenza-like-illness