[Incidence of Neisseria gonorrhoeae infections in Belgium: trends 2000-2006]

In Belgium, three registration systems collect epidemiological information on N. gonorrhoeae infections. The descriptive analysis of the data presented in this article allows describing the epidemiology of N. gonorrhoeae infections in Belgium in terms of trends in time, describing the characteristics of the patients, and providing information on resistance to antibiotics. The results on the incidence of N. gonorrhoeae infections show an important increase since the year 2000, and this increase is even more pronounced between 2005 and 2006. The majority of the patients reside in big cities, mainly in the district of Antwerp and in the Brussels-Capital region. Among the N. gonorrhoeae specimens that were sent to the reference laboratory, the proportion of specimens resistant to ciprofloxacine increases each year; this proportion reaches 61.4% in 2006. The increase in the incidence of N. gonorrhoeae infections and in antimicrobial resistance is also observed in other European countries. The increase in incidence may be partly related to the important increase of resistance to ciprofloxacine. It is very important to continue the surveillance of antimicrobial resistance, to adapt treatment in function of the recent evolutions and to inform physicians at a regular basis. The results show that homo- and bisexual men are most at risk for N. gonorrhoeae infections. The prevention campaigns for sexually transmitted infections and screening policy have to be reinforced, particularly among homo- and bisexual men.

Haemorrhagic Fever with Renal Syndrome: an analysis of the outbreaks in Belgium, France, Germany, the Netherlands and Luxembourg in 2005

This article aims to describe the Haemorrhagic Fever with Renal Syndrome (HFRS) situation in 2005 in five neighbouring countries (Belgium, France, Germany, the Netherlands and Luxembourg) and define the most affected areas. The 2005 HFRS outbreaks in these countries were the most significant in the region since 1990, with a total of 1,114 confirmed cases. The main feature of the epidemic was the extension of the known endemic area in several of the affected countries, with the involvement of urban areas for the first time. A significant increase in the number of cases was noted for the first time in the province of Liège in Belgium and in the Jura department in France.

Recent syphilis trends in Belgium and enhancement of STI surveillance systems

Over the past five years, a series of syphilis outbreaks mainly occurring among gay men have been observed in Europe. One of these outbreaks was reported in the city of Antwerp, Belgium, during the first quarter of 2001. This outbreak is still ongoing in 2004. Furthermore, active syphilis diagnoses reported by the Sentinel Laboratory Network rose by 89% in the country during the fourth quarter of 2003. An increase in Brussels was also observed during the same quarter (+300%; 24 cases reported). Overall, the sentinel network of clinicians reported that 93.4% of patients were male; among them, 79.9% were men having sex with men (MSM). The overall proportion of patients co-infected with HIV was 50.5% (MSM: 58.6%; male heterosexuals: 23.8%; females: 8.3%); 76.1% of co-infected patients were already aware of their HIV infection at the time they were diagnosed with syphilis.

Recent syphilis trends in Belgium and enhancement of STI surveillance systems

Over the past five years, a series of syphilis outbreaks mainly occurring among gay men have been observed in Europe. One of these outbreaks was reported in the city of Antwerp, Belgium, during the first quarter of 2001. This outbreak is still ongoing in 2004. Furthermore, active syphilis diagnoses reported by the Sentinel Laboratory Network rose by 89% in the country during the fourth quarter of 2003. An increase in Brussels was also observed during the same quarter (+300%; 24 cases reported). Overall, the sentinel network of clinicians reported that 93.4% of patients were male; among them, 79.9% were men having sex with men (MSM). The overall proportion of patients co-infected with HIV was 50.5% (MSM: 58.6%; male heterosexuals: 23.8%; females: 8.3%); 76.1% of co-infected patients were already aware of their HIV infection at the time they were diagnosed with syphilis.

Analysis of foodborne disease in Belgium in 1997

Foodborne disease represents a major problem for public health in industrialized countries, albeit with a low lethality. Foodborne diseases are defined as a group of viral, bacterial or parasitic gastrointestinal infections transmitted by means of food. Proper food-hygiene practices and surveillance of individual diseases and in particular outbreaks are the first steps in targeting their prevention. The incidence of this illness is difficult to estimate. In the Netherlands a yearly incidence of gastrointestinal infections of 500 per 1,000 inhabitants is estimated, of which most are foodborne. To set up priorities in the actions to undertake, to establish the most frequent risks, to develop preventive efforts and to answer to international requirements, accurate data on foodborne disease from Belgium are required. In order to co-ordinate the initiatives in the Belgian context, a working group was set up in 1995. In 1997 a total of 2,013 persons with foodborne disease were identified as part of 140 outbreaks, 22 of which occurred with 10 cases or more. Salmonella Enteritidis (88 outbreaks) was identified as the main pathogen in foodborne disease, followed by S. Typhimurium (11), S. Hadar (4). Eggs and meat products were identified as the main food-items involved, although it remains difficult to obtain proper intervention studies allowing to identify the specific cause(s). In 1997, a total of 12,732 human Salmonella isolates and 5,617 Campylobacter isolates were identified by the respective national reference laboratories. Salmonella isolates from Belgium accounted in 1997 for more than a fifth of all Salmonella isolates in the EU. The final objective of the working group is the implementation of a surveillance system for all risk factors concerned with the development of food-related illness, including an early warning system and an efficient analysis of microbiological criteria relating to human health, food and food production, including livestock. An essential element of this surveillance is communication of the results, risks and measures for prevention between all the departments, institutions and public health authorities concerned.

Pharmacoeconomics of immunisation: a review

The effects of immunisation programmes that have existed for several decades in developed countries are demonstrated by the decrease and even eradication of smallpox, poliomyelitis, measles, mumps and hepatitis B. Cost, health policy and spontaneous evolution in the incidence of communicable diseases have a decisive influence on the use of a vaccine. Investment in vaccination policy has to be encouraged to maintain this progress made in the control of infectious diseases and to meet new challenges. Studies re-evaluating ongoing immunisation programmes are scarce. Nevertheless, it can be concluded that for vaccination against hepatitis B in professionally exposed at-risk populations, arguments for positive returns are consistent. The same holds for vaccination against S. pneumoniae and for influenza virus in the elderly. The results of the economic evaluation of revaccination against measles, when insufficient coverage exists, are inconclusive. Universal vaccination of children against Haemophilus influenzae type b (Hib) and of children of hepatitis B-positive mothers against hepatitis may require costs to be paid in order to gain extra health benefits.

[Trends in pneumococcal infections in Belgium from 1986 to 1991]

Streptococcus pneumoniae is one of the most frequent causes of pneumonia, meningitis, and otitis media. Persons at high risk are young children, elderly, and individuals with immunodeficiency or with an underlying disease. Thanks to a network ot 111 laboratories spread all over Belgium, the evolution of the number of deep isolates of S. pneumoniae has been followed from 1986 to 1991: the recorded frequency increased with a mean number of isolations per laboratory and per year rising from 3.6 in 1986 to 6.2 in 1991. The objectives of this paper are to study the evolution of age and sex distribution of the patients, and of the origin of the isolates, and to propose solutions for slowing down this evolution.

Determinants of serum zinc in a random population sample of four Belgian towns with different degrees of environmental exposure to cadmium

This report investigated the distribution of serum zinc and the factors determining serum zinc concentration in a large random population sample. The 1977 participants (959 men and 1018 women), 20-80 years old, constituted a stratified random sample of the population of four Belgian districts, representing two areas with low and two with high environmental exposure to cadmium. For each exposure level, a rural and an urban area were selected. The serum concentration of zinc, frequently used as an index for zinc status in human subjects, was higher in men (13.1 mumole/L, range 6.5-23.0 mumole/L) than in women (12.6 mumole/L, range 6.3-23.2 mumole/L). In men, 20% of the variance of serum zinc was explained by age (linear and squared term, R = 0.29), diurnal variation (r = 0.29), and total cholesterol (r = 0.16). After adjustment for these covariates, a negative relationship was observed between serum zinc and both blood (r = -0.10) and urinary cadmium (r = -0.14). In women, 11% of the variance could be explained by age (linear and squared term, R = 0.15), diurnal variation in serum zinc (r = 0.27), creatinine clearance (r = -0.11), log gamma-glutamyltranspeptidase (r = 0.08), cholesterol (r = 0.07), contraceptive pill intake (r = -0.07), and log serum ferritin (r = 0.06). Before and after adjustment for significant covariates, serum zinc was, on average, lowest in the two districts where the body burden of cadmium, as assessed by urinary cadmium excretion, was highest. These results were not altered when subjects exposed to heavy metals at work were excluded from analysis.

Decrease in blood cadmium levels over time in Belgium

During the time period from 1984 to 1988, blood cadmium concentration decreased by 56% in 31 males who were not occupationally exposed to cadmium and who lived in a Belgian urban area where there existed nonferrous industries. A 40% decrease in blood cadmium concentration was also observed in an independent cross-sectional survey conducted in 1985 and 1988 among 412 subjects who lived in a rural area. This latter decrease persisted when the main determinants of blood cadmium concentration--gender, age, and tobacco--were allowed for. The results presented are consistent with a decrease in environmental cadmium exposure in Belgium.

The association between blood pressure, calcium and other divalent cations: a population study

This report investigated the associations between blood pressure and the levels of various divalent cations in blood and urine in the population at large. The 1,982 participants (963 men and 1019 women; mean age 48 years) constituted a stratified random sample of the population of 4 Belgian districts. Systolic/diastolic pressure averaged 133/78 mmHg in men, and 128/76 mmHg in women. Serum total calcium (2.37 mmol/l), serum magnesium (1.00 mmol/l) and blood cadmium (10.0 nmol/l) were on average similar in the two sexes. By contrast, serum zinc (13.1 and 12.6 mumol/l, respectively), blood lead (0.56 and 0.36 mumol/l) and the urinary excretions of calcium (4.86 and 3.95 mmol/24h), copper (0.16 and 0.13 mumol/24h), and cadmium (9.4 and 7.2 nmol/24h) were significantly higher in men than in women. After adjustment for significant blood pressure covariates (age, body mass index, pulse rate, log gamma-glutamyltranspeptidase, smoking habits, and in women the contraceptive pill), serum total calcium was independently and positively correlated with systolic pressure in both sexes, and with diastolic pressure in women. After similar adjustments systolic pressure was positively correlated with urinary copper in men and women. In addition, systolic pressure and blood lead, and diastolic pressure and urinary cadmium were negatively correlated in men. In conclusion, this population study demonstrated a positive relationship between systolic blood pressure and both serum total calcium and urinary copper.

Effects of exposure to cadmium on calcium metabolism: a population study

The objective was to investigate the hypothesis that environmental exposure to cadmium may affect calcium metabolism in the population at large. The 1987 participants (965 men and 1022 women), from 20 to 80 years old, constituted a random sample of the population of four Belgian districts. The urinary excretion of cadmium, a measure of lifetime exposure, averaged 9.3 nmol/24 h in men (range 0.4-324 nmol/24 h) and 7.1 nmol/24 h (range 0.1-71 nmol/24 h) in women. Serum alkaline phosphatase activity and the urinary excretion of calcium correlated significantly and positively with urinary cadmium excretion in both men and women, and serum total calcium concentration negatively with urinary cadmium excretion in men only. The regression coefficients obtained after adjustment for significant covariates indicated that when urinary cadmium excretion increased twofold, serum alkaline phosphatase activity and urinary calcium excretion rose by 3-4% and 0.25 mmol/24 h respectively, whereas in men serum total calcium concentration fell by 6 mumol/l. After adjustment for significant covariates the relation between serum total calcium concentration and urinary cadmium excretion was not significant in women. The findings suggest that even at environmental exposure levels calcium metabolism is gradually affected, as cadmium accumulates in the body. The morbidity associated with this phenomenon in industrialised countries remains presently unknown and requires further investigation.

Blood pressure, the prevalence of cardiovascular diseases, and exposure to cadmium: a population study

In a population study conducted from 1985 to 1989 in Belgium, the authors investigated whether exposure to cadmium is associated with blood pressure elevation and with an increased prevalence of cardiovascular diseases. The participants, aged 20-88 years, constituted a random sample of the households living in two low exposure areas (n = 803) and two high exposure areas (n = 1,283). For each exposure level, a rural and an urban district were selected. The cadmium levels in blood (8.5 vs. 11.0 nmol/liter) and urine (7.2 vs. 8.7 nmol/24 hours) were significantly (p less than 0.001) raised in the two high exposure areas compared with the two low exposure areas (p less than 0.001). Systolic pressure was similar in both rural areas, but in the urban area with high exposure systolic pressure was 5 mmHg (p less than 0.001) higher than in the control town. Diastolic pressure was similar in the four districts and the same was true for the prevalence of hypertension and of other cardiovascular diseases. Adjustment of systolic pressure for blood and urinary cadmium did not remove the difference in systolic pressure between both urban areas, suggesting that it was not related to the cadmium burden on the environment. Further analyses in individual subjects showed that neither blood pressure nor the presence of cardiovascular diseases were significantly and positively correlated with blood and urinary cadmium. Thus, the present population study did not confirm the hypothesis that increased exposure of the population to cadmium is associated with blood pressure elevation and with a higher prevalence of cardiovascular diseases.

Does environmental exposure to cadmium represent a health risk? Conclusions from the Cadmibel study

Cadmium is a very dispersive pollutant which has progressively accumulated in the environment mainly in the areas where nonferrous smelters have been in operation. An important toxicological feature of cadmium is its exceptionally long biological half-life in the human body. For the general population mainly exposed to cadmium by the diet and smoking, the kidney is the main target organ. Some studies have also suggested that cadmium might play a role in the pathogenesis of hypertension. A cross-sectional study (called Cadmibel) was undertaken to assess whether environmental pollution by cadmium in Belgium might represent a health risk. This paper does not present the detailed results of this study which are published elsewhere but simply report its main conclusions. A total number of 2327 subjects (stratified according to age and sex) was randomly sampled in two urban (Liège and Charleroi) and two rural (Hechtel-Eksel and Noorderkempen) areas, with different environmental pollution by cadmium. After allowing for the various factors known to influence cadmium accumulation, it was estimated that the cadmium body burden of the residents of the most polluted district (Noorderkempen) was 50 to 85% higher than in the less polluted areas. No statistical association was found between environmental exposure to cadmium and blood pressure elevation or the prevalence of cardiovascular diseases. However, the study has shown that the environmental exposure of the general population to cadmium may induce slight renal tubular dysfunction and may probably also affect cadmium homeostasis. The probability of tubular dysfunction (as assessed by sensitive tests) is about 10% when cadmium in urine reaches 2 micrograms/day. The morbidity associated with the changes in the renal proximal tubule and the calcium metabolism observed when the body burden of cadmium exceeds this value remains to be assessed.

Renal effects of cadmium body burden of the general population

In a cross-sectional population study to assess whether environmental exposure to cadmium is associated with renal dysfunction, 1699 subjects aged 20-80 years were studied as a random sample of four areas of Belgium with varying degrees of cadmium pollution. After standardisation for several possible confounding factors, five variables (urinary excretion of retinol-binding protein, N-acetyl-beta-glucosaminidase, beta 2-microglobulin, aminoacids, and calcium) were significantly associated with the urinary excretion of cadmium (as a marker of cadmium body burden), suggesting the presence of tubular dysfunction. There was a 10% probability of values of these variables being abnormal when cadmium excretion exceeded 2-4 micrograms/24 h. Excretion reached this threshold in 10% of non-smokers. There was also evidence that diabetic patients may be more susceptible to the toxic effect of cadmium on the renal proximal tubule.

Health effects of environmental exposure to cadmium: objectives, design and organization of the Cadmibel Study: a cross-sectional morbidity study carried out in Belgium from 1985 to 1989

Cadmium is a cumulative environmental pollutant. For the general population mainly exposed by the oral route and through tobacco smoke inhalation, the kidney is the critical organ. Belgium is the principal producer of cadmium in Europe, and certain areas of the country are polluted by cadmium mainly because of past emissions from nonferrous industries. Preliminary studies carried out in one polluted area have suggested that environmental pollution might lead to an increased uptake of cadmium by the human body and possibly to health effects. Thus, a large-scale morbidity study has been initiated to assess the validity of this hypothesis. The present paper describes the protocol of this study. Its main objectives are to determine to what extent environmental exposure to cadmium resulting from industrial emissions may lead to accumulation of the metal in the human organism; to establish whether or not environmental exposure may induce renal changes and/or influence blood pressure; and to assess the acceptable internal dose of cadmium for the general population. The study design takes advantage of the fact that biological indicators of exposure, body burden, and early nephrotoxic effects of cadmium are available, which increase the likelihood of detecting a cause-effect relationship.

Lowering time trend of blood lead levels in Belgium since 1978

Since 1978, the biological screening of the Belgian population was regularly monitored by measuring blood lead levels. Over 11 years, 6070 samples were analyzed in urban, rural, and industrial areas. The median values of blood lead concentration dropped from 170 to 78 micrograms/liter of blood, i.e., a lowering of about 55%. The trend persists when taking into account some individual characteristics which influence blood lead levels such as gender, age, tobacco, and areas. These influences and the possible environmental causes of the observed trend are discussed.

The relationship between blood pressure and environmental exposure to lead and cadmium in Belgium

The question whether in the general population environmental exposure to lead and cadmium influences blood pressure after controlling for confounding factors remains debated. The environmental exposure of the Belgian population to both lead and cadmium is high as compared with other countries. The Cadmibel Cooperative Study was therefore designed to elucidate whether environmental exposure to lead and cadmium has any effect on blood pressure and renal function in the population at large. Before embarking on the large Cadmibel project, a small study was conducted. Blood pressure and the 24-hr urinary excretion of cadmium (CdU) and lead (PbU) were determined in a random 4% sample of the population of a small Belgian town. CdU averaged 0.27 micrograms/24 hr in 46 youths (mean age 14 +/- 3 years, +/- SD), increased with age, and was higher in 57 adult men (age 41 +/- 14 years), as compared with 59 adult women (age 39 +/- 14 years) (1.05 vs. 0.81 micrograms/24 hr; p less than 0.01). PbU averaged 5.8 micrograms/24 hr in youths and similarly increased with age; adult men excreted more lead than women (13.3 vs. 8.3 micrograms/24 hr; p less than 0.001). Among men, manual workers excreted more cadmium (1.4 vs. 0.8 micrograms/24 hr; p less than 0.05) but a similar amount of lead (7.0 vs. 6.9 micrograms/24 hr) as compared with office workers. In simple regression analysis, CdU was positively correlated with both systolic (r = 0.30; p less than 0.05) and diastolic (r = 0.38; p less than 0.01) blood pressure in women.(ABSTRACT TRUNCATED AT 250 WORDS)

Assessment and comparison of human exposure to lead between Belgium, Malta, Mexico and Sweden

This is a follow-up study of UNEP/WHO Pilot Project on Assessment of Human Exposure to Lead and Cadmium through Biological Monitoring, carried out in 1983/1984. The main objectives of the follow-up study were: to study whether differences in blood-lead levels found between countries in the Biological Monitoring Project were confirmed and were primarily due to exposure via ingested lead (oral intake) or via inhaled lead; to make a preliminary survey, in selected areas, of the possible sources of high exposure (Malta, Belgium). Four countries participated: Belgium, Malta, Mexico, Sweden. To insure comparability between the populations, certain categories were monitored: teachers for socio-economic status, non smoking males, aged between 25 and 50 years old. The blood-lead concentration (PbB) was measured to determine the current exposure and the feces-lead excretion (PbF) was determined to find out the part of the exposure due to ingestion. Blood-lead levels and feces-lead excretion were very different between the four countries. Median values for PbB, in micrograms Pb/1, were, in decreasing values 247 in Malta, 188 in Mexico, 135 in Belgium and 53 in Sweden. Median values for PbF, in micrograms Pb/day, were 361 in Malta, 159 in Mexico, 82 in Belgium and 22 in Sweden. Oral intake seems to be the major exposure route in the four countries. The relationship between PbB and PbF is curvilinear. To investigate the possible source of high exposure, a preliminary survey was made in Malta and Belgium; lead in air suspended and sedimenting particles was monitored as well as the lead concentration in some food and street dust samples. Concerning the comparison of lead concentrations in these environmental samples between Belgium and Malta, no major differences were detected. The high internal exposure to lead in Maltese people, as measured by PbB, is probably due to a combination of several factors.

Exposure to lead and cadmium of the general population of Malta

The blood levels of lead (PbB), cadmium (CdB), and zinc protoporphyrin (ZPP) were determined in 538 Maltese adult subjects. A relatively high level exposure to both metals was discovered. For lead, the median value is 274 micrograms/l with percentile 90 and 98 respectively 564 and 863 micrograms/l. These values are to be compared with the reference values proposed by a directive of the European Community, respectively 200, 300 and 350 micrograms/l. For cadmium, the median value is 2.2 micrograms/l with percentile 90 and 98 respectively 3.8 and 5.7 micrograms/l. These values are compared with those of a Belgian population which are respectively 1.7, 2.6 and 4.3 micrograms/l. The causes of this relatively high exposure are not known. A few tentative hypotheses, which are to be investigated, are made.

Exposure to lead of the Belgian population

According to the Council Directive of 29 March 1977 on biological screening of the population for lead, the blood-lead levels (PbB) were determined in samples of the Belgian population not occupationally exposed to this metal. Two campaigns of sampling were performed: the first one in 1979 (1678 samples analysed) and the second in 1981 (1000 samples analysed). Sampling was done in urban and industrial zones, as well as in areas where lead risk could be present. Concerning the urban and industrial areas, the results obtained seem to indicate that a particular lead risk does not exist for the adult population if we consider the reference levels of the CEE Directive. Moreover, the results of the second campaign of sampling showed a decreasing trend: the median PbB values dropped from 183 to 156 micrograms/l in Brussels and from 192 to 139 micrograms/l in Liège. This could be partly due to the limitation of the lead content of gazoline. On the other hand, the results of the surveys clearly demonstrated the existence of two areas where an obvious lead risk exists. In one of those, the lead risk is of industrial origin (lead smelter) and concerns mainly children: median PbB value 260 micrograms/l, percentile 90 and 98 respectively 390 and 430 micrograms/l. In the other one, the lead risk is from a hydric source and concerns adults and children: median PbB value 258 micrograms/l, percentile 90 and 98 respectively 370 and 520 micrograms/l.