High number of hospitalisations and non-classical presentations: lessons learned from a measles outbreak in 2017, Belgium.

We describe and analyse an outbreak of measles that affected Belgium early 2017. In total, 289 cases were reported, mostly (53%) in people 15 years or older. For 133 (46%) vaccination status was unknown and a further 117 (41%) were not vaccinated. According to national guidelines, 83 of the unvaccinated cases (29% of total cases) should have received minimum one dose of vaccine, but did not. One in five cases (21%) did not present with the classical triad of fever, rash and any of coryza, conjunctivitis or cough. Rash was the most sensitive symptom, being absent in only six cases. A large proportion of cases (125/289, 43%) required hospitalisation. In hospitalised patients, the most commonly observed complications were hepatic disorders (present in 58/125 hospitalised patients, 46%). Thirty-six of the cases (12%) were in healthcare workers and nosocomial spread contributed importantly to the outbreak. Older age at presentation, altered clinical presentations and presence of complications like hepatitis can delay the correct diagnosis of measles. Clinicians should maintain a high index of suspicion in any individual presenting with rash. If the elimination target is to be reached, catch-up vaccination campaigns should be intensified and target young adults and health care workers.

[Determinants of breastfeeding in the Brussels Region]. / Facteurs associés à l'allaitement maternel à la maternité en Région bruxelloise.

PURPOSE: The objectives of this paper is to study the prevalence of breastfeeding in Brussels, to assess whether the targets of the Maternal and Child Health program (MCH) were met (prevalence's of breastfeeding of 85 and 75% of exclusive breastfeeding) and finally to identify factors associated with exclusive breastfeeding at the birth. MATERIALS AND METHOD: The cross-sectional survey is representative of children 18 to 24 months living in Brussels. Data on breastfeeding are anamnestic and retrospective. A face to face questionnaire was administered by trained investigators, 16 questions about breastfeeding as well socio-demographic information were collected from 544 mothers. The survey took place in 2012. RESULTS: At the birth, 83.3% (95% CI 80.1-86.4) of mothers exclusively breastfed and 9.7% of the mothers (7.3-12.2) partially. When discharged from maternity unit, 80.9% (77.6-84.2) of mothers breastfed exclusively and 9.7% (7.3-12.2) partially. When fitting a logistic model, predictors associated with exclusive breastfeeding at the birth were gestation, type of birth, father's education level and the main influencing factor was the partner's attitude. DISCUSSION: The targets of the MCH were reached in Brussels. Until now, transversal surveys are the only way of knowing the prevalence and the factors associated with breastfeeding in Brussels. These first representative data on breastfeeding came from the 2012 vaccine coverage survey. Given the primary role of the father in choosing a breastfeeding it is necessary that the father is more often taken into account in regard to the promotion of AM during the prenatal period. A rigorous use of definitions of AM should be systematized.

Breastfeeding duration: a survival analysis-data from a regional immunization survey.

OBJECTIVE: To report the duration of and factors associated with exclusive and any breastfeeding among the French-speaking community of Belgium (Wallonia). MATERIAL AND METHODS: A two-stage cluster sample was drawn from the population of children aged 18-24 months living in the area in 2012. Anamnestic data on breastfeeding and sociodemographic information were collected from 525 mothers. Cox's proportional hazards model was used to identify factors associated with discontinuing breastfeeding. RESULTS AND DISCUSSION: Only 35.1% of the women were satisfied with their duration of any breastfeeding. At 3 months, 54.1% of the infants were breastfed, of which 40.6% exclusively, with these percentages falling to 29.1% and 12.6% at 6 months. Exclusive and any breastfeeding durations were independently positively associated (P < 0.05) with foreign-born mothers, awareness of WHO recommendations, and maternity leave >3 months. Exclusive BF duration was associated with higher parental income and the prenatal decision to breastfeed. The duration of any breastfeeding was associated with the mothers' age of ≥30 years and whether they were exclusively breastfeeding at discharge from the maternity unit. CONCLUSIONS: Programs promoting and supporting BF should concentrate on training prenatal health-care professionals. Prenatal professional advice may promote adherence to WHO BF guidelines. The benefits of exclusive BF should be emphasized. Pregnant women should be discouraged from introducing supplementary feeding in the maternity ward.

[Breastfeeding in the French-speaking community of Belgium (2009)]. / Estimation de la prévalence de l'allaitement maternel au travers d'une enquête en population de couverture vaccinale en Belgique francophone en 2009.

PURPOSE: The objectives of this paper were to study the prevalence of breastfeeding in the French-speaking community of Belgium, to assess whether the targets of the Maternal and Child Health program (MCH) were met (prevalence of breastfeeding of 85, 70, 50, and 25% at the maternity hospital and at 3, 6, and 12 months of age, respectively), and to identify factors associated with breastfeeding at the maternity hospital and at 6 months of age. MATERIALS AND METHODS: A sample (two-stage cluster sampling) was drawn from the population of children aged 18-24 months living in the area. A face-to-face questionnaire was administered by trained investigators. Anamnestic data on breastfeeding at the maternity hospital and at 3, 6, and 12 months as well sociodemographic information were collected from 522 mothers. The survey took place in 2009. RESULTS: At the maternity hospital, 75.7% (95%CI [72.7-79.5]) of the mothers were breastfeeding: 72.4% among the Belgians (and French) and 89.0% among foreign mothers. At 3 months of age, the breastfeeding prevalence was 48.3% (CI, 44.0-52.6): 42.5% among the Belgians (and French) and 72.0% among foreign mothers (p<0.001). At 6 months of age, 26.0% of the mothers were breastfeeding (CI, 22.3-29.8): 19.3% among the Belgians (and French) and 53.0% among foreign mothers (p<0.001). At 12 months of age, 10.0% (CI, 7.4-12.5) of the mothers were breastfeeding: 4.8% among the Belgians (and French) and 31.0% among the foreign mothers (p<0.001). When fitting a logistic model, the predictors associated with breastfeeding at the maternity hospital were educational level, nationality of birth, and parity. At 6 months, logistic models were fitted separately in the two strata. Among the Belgians, the level of education and attending a MCH consultation were significantly associated with breastfeeding. In the stratum of foreign mothers, the only factor associated with breastfeeding was working time. No association was observed between breastfeeding and the mother's age at the maternity hospital or at 6 months. DISCUSSION: The targets of the MCH were not reached in Belgian and French mothers, while they were in mothers of other nationalities. Until now, transversal surveys have been the only way of knowing the prevalence and the factors associated with breastfeeding in the French-speaking community of Belgium. These first representative data on breastfeeding came from the 2009 vaccine coverage survey.

[Vaccination: cost-effectiveness ratio]. / Les vaccinations: rapport coût-efficacité.

Vaccination is often recognized as having an excellent cost-effectiveness ratio. Economic assessments are more and more important regarding the steadily increasing costs of vaccines. However, vaccine-specific features have to be taken in account and there is scope for improving quality of available economic evaluations of vaccination programmes. To provide clear and concise guidance for improving quality of cost-effectiveness studies in vaccinology, WHO guide has been developed. After presenting this guide, the economic evaluations of the new vaccines introduced in the Belgium calendar are reviewed.

[Vaccine prevention of Rotavirus infection]. / La prévention vaccinale des infections a Rotavirus.

Two new life attenuated vaccines have been granted this year a marketing authorization by European and American regulatory agencies. One, Rotarix, is a monovalent vaccine derived from a human strain and takes advantage of the cross-reactivity between human Rotavirus strains. The other, RotaTeq, is a pentavalent human-bovine reassortant. These 2 vaccines have been shown to have an excellent safety profile in clinical trials and are highly effective in protecting infants against severe manifestations of Rotavirus gastroenteritis. In industrialized countries, the incidence of Rotavirus infection has not been reduced by the improvement of economic and sanitary conditions and are still associated with severe morbidity and an important economic impact. When they are administered at the same time as DTPa-VHB-IPV/Hib and Pn7V vaccines, they do not interfere with the immune response against the 7 valencies included in these vaccines. The widespread use of these vaccines should allow to control Rotavirus infections in the European context.

Recommendations for the use of the 23-valent polysaccharide pneumococcal vaccine in adults: a Belgian consensus report.

A multidisciplinary expert panel, appointed by the High Council for Public Health, evaluated the scientific evidence on which the recommendations for the appropriate use of the pneumococcal vaccine was based and reviewed the studies that became available since previous reports. The conclusions of the working group, presented in this manuscript, resulted in an update of the Belgian recommendations for pneumococcal vaccination.

[Pneumococcal conjugate vaccine in children]. / Le vaccin anti-pneumococcique conjugué chez l'enfant.

Streptococcus pneumoniae is one of the major causes of severe invasive infections in young children. As purified polysaccharide are not immunogenic in infants, vaccines containing the bacterial polysaccharide conjugated to a carrier protein have been developed according to the model that has proved to be effective for Haemophilus influenzae b and group C meningococcus. A conjugate vaccine containing the 7 serotypes responsible for about 90% of the invasive infections occuring in children in the United States has been shown to have a 97% protective efficacy against infections caused by vaccine serotypes. Pneumococcal conjugate vaccines are also protective, although to a lesser extent, against otitis media caused by vaccine serotypes, but the global impact of these vaccines on the total number of otitis media remains limited. The large scale use of this vaccine has demonstrated its epidemiological impact on the burden of invasive pneumococcal disease in the age group targeted by vaccination as well as among the adult contacts of the vaccines. On the basis of these informations, the conjugate pneumococcal vaccine has been included in the recommended vaccination schedule in Belgium. However, repeated vaccine shortages as well as the high cost of the product make the implementation of this recommendation uncertain.

[Hexavalent combined vaccination]. / La vaccination hexavalente.

Since January 2004, hexavalent combined vaccines are available in Belgium. They protect children simultaneously against 6 diseases (poliomyelitis, diphtheria, tetanus, pertussis, invasive infections with Haemophilus influenzae type b and hepatitis B) and reduce the number of needed injections. Acellular pertussis vaccine is the corner-stone of the combination. Theoretically, only 5 visits and 6 injections are needed to complete the vaccination of the children. In addition to the reduction of injections and consequently a better comfort for the child, Hexavalent vaccination favours an increase of immunization coverage, alleviation of the burden of diseases evitable by vaccination, simplification of immunisation programme and diminution of their cost. However an increased surveillance of the incidence of the diseases, particularly for pertussis and invasive Haemophilus influenzae type b disease is needed. As always for a new product, pharmacovigilance has to be able to detect any severe adverse event. Parent's information must be strengthened to maintain confidence in the immunization programme. Medical practice will have to adapt to the new vaccine because it reduces individual flexibility and modifies the catch-up immunization schedule.

[Pertussis vaccine in adolescents and adults]. / La vaccination de l'adolescent et de l'adulte contre la coqueluche.

Despite high immunisation rates in infancy, Bordetella pertussis is still circulating in industrialised countries, causing severe infections in infants too young to be vaccinated, as well as an important number of long lasting cough episodes in older children, adolescents and young adults. The limited duration of the protection resulting from vaccination in the 2 first years of life is probably responsible for the insufficient control of the disease. The development of acellular pertussis vaccines has allowed immunisation of school age children, and an adult formulation is now available. The indications of this vaccine will be discussed.

[Conjugate vaccines]. / Les vaccins conjugués.

Conjugate vaccines extend the vaccinal prevention for children to more diseases. Conjugating the capsular polysaccharide to a carrier protein transforms a T-independent antigen in a T-dependent, allowing protection of the children (before 2 years of age) against Haemophilus influenzae type b, meningococcal C and pneumococcal infections. This article reviews the 3 conjugate vaccines and their results with focus on some questions: antigens interference in the immunological response, serological subrogate for protection, herd immunity and replacement of circulating serotypes.

[Conjugate vaccines]. / Les vaccins conjugués.

Conjugate vaccines extend the vaccinal prevention for children to more diseases. Conjugating the capsular polysaccharide to a carrier protein transforms a T-independent antigen in a T-dependent, allowing protection of the children (before 2 years of age) against Haemophilus influenzae type b, meningococcal C and pneumococcal infections. This article reviews the 3 conjugate vaccines and their results with focus on some questions: antigens interference in the immunological response, serological subrogate for protection, herd immunity and replacement of circulating serotypes.

[Conjugated vaccines]. / Les vaccins conjugués.

Conjugate vaccines extend the vaccinal prevention for children to more diseases. Conjugating the capsular polysaccharide to a carrier protein transforms a T-independent antigen in a T-dependent, allowing protection of the children (before 2 years of age) against Haemophilus influenzae type b, meningococcal C and pneumococcal infections. This article reviews the 3 conjugate vaccines and their results with focus on some questions: antigens interference in the immunological response, serological subrogate for protection, herd immunity and replacement of circulating serotypes.

Analysis of factors influencing vaccine uptake: perspectives from Belgium.

METHODS AND OBJECTIVES: To estimate the infant vaccination coverage in Belgium, a random cluster sample according to the expanded program on immunization (EPI) cluster sampling technique was performed in 1999 in the Flemish (Flanders) and French (Wallonia) speaking community of Belgium. The objective was to document the infant vaccination coverage retrospectively in 18-24-month-old children. In addition, the study offered the opportunity to assess some factors influencing vaccine uptake in infants. RESULTS: In the Flemish community infant vaccination coverage could not be associated with any of the socio-demographic factors, with two exceptions: the province (county) and the hepatitis B (HepB) vaccination. The main reason for not complying with the vaccination schedule was mainly carelessness on either parent's or physician's side. In the French speaking community parents feel mostly themselves responsible for the non-vaccination or incomplete vaccination of their child, except for pertussis. For all vaccines, the attitude of the physician is mentioned as being very influential in the decision to vaccinate a child. Most of the socio-demographic factors showed no association with the infant vaccination coverage. CONCLUSION: The surveys in Flanders and Wallonia stress the importance of having information made available, and underline the role parents as well as physicians (and nurses) play in the infant immunization coverage.

Oral poliomyelitis vaccine: time to change?

For 3 decades, vaccination against poliomyelitis has rested mainly on the use of the oral attenuated vaccine (OPV). In countries where wild type poliomyelitis has been successfully controlled by OPV, the rare cases of poliomyelitis that can still be identified occur in vaccinees or their contacts and are caused by vaccine related strains. Over years, data indicating that the inactivated vaccine (IPV) also has the potential to control poliomyelitis and that there are no known risks associated with the use of this vaccine have accumulated. The reasons for changes in vaccine policy in industrialised countries and the situation of the global effort of poliomyelitis immunisation are described. Some of the issues and challenges for the future are reviewed.

Epidemiological survey of workers exposed to inorganic germanium compounds.

OBJECTIVES: To assess occupational exposure to inorganic germanium (Ge) in workers from a producing plant, and to assess the health of these workers, with a special focus on respiratory, kidney, and liver functions. METHODS: Cross sectional study of 75 workers exposed to Ge and 79 matched referents. Exposure was characterised by measuring air and urine concentrations of the element during a typical working week, and health was assessed by a questionnaire, clinical examination, lung function testing, chest radiography, and clinical chemistry in serum and urine, including high and low molecular weight urinary proteins. RESULTS: Airborne concentrations of Ge (inhalable fraction) ranged from 0.03 to 300 micrograms/m, which was reflected by increased urinary excretion of Ge (0.12-200 micrograms/g creatinine, after the shift at the end of the working week). Lung, liver, and haematological variables were not significantly different between referents and workers exposed to Ge. A slightly higher urinary concentration of high molecular weight proteins (albumin and transferrin) was found in workers exposed to Ge, possibly reflecting subclinical glomerular changes. No relation was found between the intensity or duration of exposure and the urinary concentration of albumin. No difference between referents and workers exposed to Ge was found for other renal variables. CONCLUSIONS: Measurement of urinary Ge can detect occupational exposure to inorganic Ge and its compounds. It is prudent to recommend the monitoring of renal variables in workers exposed to Ge.

Safety and immunogenicity of an Haemophilus influenzae type b-tetanus toxoid conjugate (PRP-T) and diphtheria-tetanus-pertussis (DTP) combination vaccine administered in a dual-chamber syringe to infants in Belgium and Chile.

To document any unexpected differences in the immune response between study populations and to evaluate immunogenicity and safety of a simplified presentation (dual-chamber syringe) of an Haemophilus influenzae type b-tetanus toxoid conjugate (PRP-T) and diphtheria-tetanus-pertussis (DTP) combination vaccine, a multicentre, randomized, comparative study was conducted in Belgium and Chile. A total of 537 healthy infants, 270 in Chile and 267 in Belgium, received PRP-T and DTP vaccines combined in a dual-chamber syringe (D-Ch group, DTP/PRP-T, reconstituted by pressing the plunger of the syringe immediately before injection, n = 239) or combined in a single-chamber syringe (C-In group, DTP@PRP-T, reconstituted immediately before injection, n = 61) or in separate injections (S-In group, DTP + PRP-T, simultaneously injected at separate sites, n = 237) at 3, 4, and 5 months of age. Serum samples were collected before vaccination and at 6 months of age. In the D-Ch group, the incidence of adverse events was comparable to administration of DTP vaccine alone. Higher rates of local and systemic reactions were observed in the Chilean population, possibly due to differences in surveillance practice. The immune response to each vaccine component compared well to that of the separate administration of PRP-T and DTP vaccines, except for higher post-immunization anti-PRP geometric mean titre (GMT) values after separate injections (25.6 micrograms mL-1) than after combined injection with the dual-chamber syringe (17.6 micrograms mL-1) (p = 0.001). An unexpected 'syringe' effect was seen: a greater post-immunization anti-PRP GMT was observed in the D-Ch group (17.6 micrograms mL-1) than in the C-In group (7.7 micrograms mL-1) (p = 0.0001). Whereas pre-immunization GMTs of some antibodies were significantly lower in Chilean than in Belgian infants, the post-immunization GMTs of Chilean infants were two to three times greater for all of the antibodies studied (p < 0.005). Differences in reactogenicity and in the immune response between the study populations or the different vaccine presentations were striking, but are probably of no clinical relevance. The convenient dual-chamber syringe presentation of DTP and PRP-T vaccines is safe and highly immunogenic.

Acute and subacute inhalation toxicity of germanium dioxide in rats.

Two acute (4 hr) and one subacute (4 wk) inhalation toxicity studies on germanium dioxide (purity > or = 99%, mean particle size 1.7-2.6 microns) were conducted in young adult Wistar rats. In the acute studies, exposure of two groups of five rats of each sex to maximum attainable concentrations of either 3.10 g amorphous or 1.42 g hexagonal germanium dioxide/m3 for 4 hr was not lethal. In the subacute study, four groups of five rats of each sex were exposed to 0, 16, 72 and 309 mg hexagonal germanium dioxide/m3 for 6 hr/day, 5 days/wk during 4 wk. Two additional groups of 5 rats per sex, exposed either to 0 or to 309 mg/m3, were kept for a 33-day post-exposure period. At the end of the treatment period, changes were observed only in rats of the high concentration group: these changes were decreased body weight gain (both sexes), decreases in haematocrit (females) and thrombocyte count (both sexes), and increases in neutrophil count (both sexes) and white blood cell count (females). On clinical chemistry evaluation, decreased fasting blood glucose (females), decreased total protein concentration (both sexes), increased plasma alanine aminotransferase and aspartate aminotransferase activities (females), increased plasma urea nitrogen (males) and increased plasma bilirubin level (females) were observed. In addition, urinary volume was elevated, and urine density and pH were lowered in both sexes. Relative weights of kidneys, spleen, heart and lungs were higher than in controls. Microscopic examination revealed effects on renal tubular epithelium. Effects on growth, kidneys, and liver were still present at the end of the 33-day recovery period. It was concluded that the 4-hr LC50 value of amorphous germanium dioxide was greater than 3.10 g/m3 and that of the hexagonal form greater than 1.42 g/m3. The no-adverse-effect-level in the 4-wk study using hexagonal germanium dioxide was 72 mg/m3.

Biological monitoring of workers exposed to cobalt metal, salt, oxides, and hard metal dust.

OBJECTIVE: The aim was to examine the relation between environmental and biological (blood and urine) indices of exposure to different chemical forms of cobalt. METHODS: A cross sectional study was undertaken in workers exposed to cobalt metal, oxides, and salts in a refinery and to a mixture of cobalt and tungsten carbide in a hard metal producing plant. RESULTS AND CONCLUSION: Although biological monitoring of workers exposed to cobalt oxides showed higher blood and urine concentrations than in non-exposed subjects, these indices poorly reflected the recent exposure level. By contrast, when exposure was to soluble cobalt compounds (metal, salts, and hard metals), the measurement of urine or blood cobalt at the end of the workweek could be recommended for the assessment of recent exposure. An eight hour exposure to 20 or 50 micrograms/m3 of a soluble form of cobalt would lead to an average concentration in a postshift urine sample collected at the end of the workweek of 18.2 or 32.4 micrograms of cobalt/g creatinine, respectively.

Epidemiological survey of workers exposed to cobalt oxides, cobalt salts, and cobalt metal.

Several organs (lung, skin, thyroid, heart, bone marrow) are potential targets of cobalt (Co). Whereas there is no doubt that inhalation of Co alone may cause bronchial asthma, its role in the occurrence of hard metal disease is still controversial because most cases were reported in workers exposed not only to Co but also to other substances such as tungsten carbide, titanium carbide, iron, silica and diamond. To assess whether exposure to pure Co dust (metal, oxides, or salts) may lead to adverse health effects a cross sectional study was carried out among 82 workers in a Co refinery. The results were compared with those in a sex and age matched control group. The Co group had been exposed for 8.0 years on average (range 0.3-39.4). The geometric mean time weighted average exposure assessed with personal samplers (n = 82) was about 125 micrograms/m3 and 25% of the values were higher than 500 micrograms/m3. The concentrations of Co in blood and in urine after the shift were significantly correlated with those in air. Concentration of Co in urine increased during the workweek. A slight interference with thyroid metabolism (decreased T3, T4, and increased TSH), a slight reduction of some erythropoietic variables (red blood cells, haemoglobin, packed cell volume) and increased white cell count were found in the exposed workers. The exposed workers complained more often of dyspnoea and wheezing and had significantly more skin lesions (eczema, erythema) than control workers. Within the exposed group a dose-effect relation was found between the reduction of the forced expiratory volume in one second/vital capacity and the intensity of current exposure to Co assessed by the measurement of Co in air or in urine. The prevalence of dyspnoea was related to the dustiness of the workplace as reflected by statistically significant logistic regression between this symptom and the current levels of Co in air and in urine. No difference between lung volumes, ventilatory performances, carbon monoxide diffusing capacity, and serum myocardial creatine kinase and procollagen III peptide was found between the Co and control groups and no lung abnormalities were detected on the chest radiographs in both groups. The results suggest that exposure to high airborne concentrations of Co alone is not sufficient to cause pulmonary fibrosis. This finding is compatible with experimental studies indicating that interaction of other airborne pollutants with Co particles play a part in the pathogenesis of parenchymal lung lesions.