Differences in subtype distribution of Haemophilus influenzae type b from carriers in the general population and patients with meningitis.

Twenty-four Haemophilus influenzae type b strains from 836 children and young adults in an open population were subtyped by outer-membrane-protein (OMP) analysis on sodium dodecyl sulphate-polyacrylamide gels, lipopolysaccharide serotyping and biotyping. The results were compared with those obtained with H. influenzae type b strains from 97 patients with meningitis in the same city (Amsterdam). OMP subtype 1 was significantly more common among the CSF isolates than in carrier strains (82% vs 50%; p less than 0.002). The other OMP subtypes found among carriers were rarely isolated from patients. The lipopolysaccharide serotype and biotype distribution did not differ between the two groups. The combination of OMP subtype 1, lipopolysaccharide 1, biotype I was much more common in isolates from patients than in those from carriers (71% vs 42%; p less than 0.01). The data suggest that various H. influenzae type b subtypes are less virulent than those commonly isolated from invasive infections.

Meningitis and the evolution of dominance of righthandedness.

In bacterial meningitis, forced deviation of the head and/or the eyes towards either the left or the right side reflects an ipsilateral focal inflammation of the brain. Also, the symptom of forced deviation is associated with a high fatality and sequelae rate. In this study it was observed that, among 2124 Dutch patients with bacterial meningitis, forced deviation was significantly more often to the right than to the left. Because the right hemisphere is dominant for motor functions in natural lefthanders, it was concluded that bacterial meningitis might have been a selection mechanism favouring the evolution of a dominance of righthandedness.

Epidemiology of Haemophilus influenzae meningitis in patients more than 6 years of age.

Haemophilus meningitis was found to be rare in those more than 6 years of age in The Netherlands (incidence: 1/10(6)/year). Persons of this age account for only 6-7% of all cases. The histories of a representative sample of 35 of 73 patients over the age of 6 years with Haemophilus influenzae meningitis were reviewed and correlated with the characteristics of the causal strains. Altogether, these patients had suffered 51 episodes of purulent meningitis. Sequelae were found after five of the 35 H. influenzae episodes studied (14%) but none of the patients died during one of these episodes. Of all the patients, 54% had severe predisposing factors, mainly CSF leaks following road traffic accidents or operations, which often led to recurrent bouts of meningitis; these patients were predominantly males. In the patients aged 15-64 years, predisposing factors were present in 74%. Predisposed patients were infected mainly by unencapsulated strains and, as far as type b strains were involved, by uncommon subtypes. Unencapsulated strains were hardly ever able to invade the bloodstream, primarily or secondarily. Careful review of the patient's history is important in this rare disease, because, in many patients, the presence of a CSF fistula may become evident and surgery is likely to prevent recurrences.

The incidence of bacterial meningitis in the Netherlands--a comparison of three registration systems, 1977-1982.

Data on the incidence of bacterial meningitis (BM) in the Netherlands are important for a cost-benefit analysis of new effective vaccines. During the period 1977-1982 we compared the notifications of meningococcal meningitis, diagnoses on discharge from hospital of all causes of BM (Stichting Medische Registratie, Medical Registration Foundation; SMR) and bacteriological data (Netherlands Reference Laboratory for Bacterial Meningitis; RBM). Notifications of meningococcal meningitis were 42% lower than SMR-data. RBM-registration of meningococcal, haemophilus and pneumococcal meningitis was 20% lower than SMR. Reviewing patient-records we found that these diseases had not been reported in 16% (RBM) and 11% (SMR) of cases. We estimate the incidence of BM during an endemic period at 8.0 per 100 000 population per year, to which the meningococcus contributes 20-25%. In children under 5 years of age the age-specific incidence of haemophilus meningitis is 22/100 000.

Types and subtypes of 73 strains of Haemophilus influenzae isolated from patients more than 6 years of age with meningitis in The Netherlands.

Strains of Haemophilus influenzae isolated in The Netherlands between 1975 and 1984 from patients with meningitis were analysed in order to determine whether older patients are infected with particular types or subtypes of the organism. Of 1154 patients with H. influenzae meningitis 73 (6.3%) were more than 6 years of age. Thirty-one strains (42%) were of serotype b, one strain was of serotyped, one strain was of serotype f and 40 strains (55%) were non-typable. Twenty-eight type b strains were available for subtyping by analysis of the major outer-membrane proteins by sodium dodecylsulphate (SDS)-polyacrylamide gel electrophoresis (PAGE), by serotyping of their lipopolysaccharides and by biotyping. Twenty-one strains were outer-membrane protein subtype 1,24-lipopolysaccharide serotype 1 and 24 biotype I. Seventeen strains (61%) combined these characteristics. This percentage did not differ significantly from the percentage found for strains isolated from patients of all age groups (80%). The 32 non-typable H. influenzae strains analysed had different outer-membrane protein patterns as seen by SDS-PAGE. Five biotypes were found, among which biotype II was predominant (21/32). The results indicated that (i) patients more than 6 years of age were infected by subtypes of H. influenzae b strains which were not significantly different from the strains isolated from younger patients, (ii) non-typable strains of H. influenzae were much more common (55%) in the older age group than in the younger (1.2%) and (iii) that these non-typable strains were not of a particular subtype.

Meningococcal disease in The Netherlands, 1959-1981: the occurrence of serogroups and serotypes 2a and 2b of Neisseria meningitidis.

By means of a filter radioimmunoassay and the use of monoclonal anti-2a and anti-2b antibodies, we have serotyped 3164 of 3688 strains of Neisseria meningitidis isolated from patients in The Netherlands between 1959 and 1981. Serotypes 2a and 2b were distributed differently among the major serogroups A, B, C, and W-135. Neither of the types was found among group A strains. Type 2b strains of serogroup B emerged in 1965, causing a country-wide epidemic which reached a peak incidence in March and April of 1966 and continued to predominate within group B until 1979. Type 2a strains of serogroup C were responsible for a substantial number of sporadic cases over a long period without any association with outbreaks or with a shift in the pattern of the serogroup. After the appearance of group W-135 in 1971, W-135 strains caused a small non-focal epidemic wave. The upsurge of disease due to virulent sub-populations of strains B:2b and C:2a appeared to be closely related to a basic pattern of regular cyclical waves with peak intervals which differed for serogroups A, B, and C. In recent years both serotype 2a and 2b strains within the different serogroups fell to insignificant numbers. Our results show that retrospective large-scale serotyping of collected strains provides insight into the epidemiological patterns of endemic meningococcal disease.

[Two chapters from the medical history of this century: antibacterial therapy]. / Twee hoofdstukken uit de medische geschiedenis van de afgelopen eeuw: antibacteriële therapie.

The antibiotic era brought adequate therapies for bacterial infections and began with the introduction of sulphonamides (discovered earlier by Domagk) in 1935 and penicillins (discovered earlier by Fleming) in the course of World War II. Notwithstanding the usual description as 'discoveries', they were the fruits of systematic investigations for chemicals with antibacterial properties and little or no toxicity for the host. Despite the role of serendipity in the discovery of penicillin, the bactericidal moulds that Fleming observed had fallen on fertile soil: a laboratory where the search for antibacterial drugs had been going on for years.

[Costs and benefits of vaccination against Haemophilus influenzae type b]. / De kosten en baten van vaccinatie tegen Haemophilus influenzae type b.

In the Netherlands, Haemophilus influenzae type b (Hib) causes invasive disease in hundreds of children every year; meningitis is the most frequent and most severe infection. Children from the age of 6 months can be protected against Hib-diseases by conjugated vaccines. The financial consequences of the introduction of such vaccine into the state vaccination programme are considered in a cost-effectiveness analysis. Some elements in the analysis are still uncertain, such as the price and the schedule and method of administration of the vaccine. Presumably, the costs and benefits will be in balance, if one vaccine dose will cost about 7 US $+ and if the administration can be combined with the present programme of vaccinations against diphtheria, whooping cough, poliomyelitis and tetanus.

Bacterial meningitis in 366 children in the Netherlands, 1982-1983. Epidemiology and antibiotic therapy.

Records of 366 children 0-15 years with bacterial meningitis (April 1982-March 1983) were reviewed in the framework of a medical audit. The general epidemiological pattern and the antibiotics administered are described and the patients in general hospitals are compared with those in academic hospitals. H. influenzae has been isolated from 31% of patients, N. meningitidis from 23% and S. pneumoniae from 10%. Case-fatality ratio was 6.6% overall, but it was higher in disease due to rare pathogens like E. coli and group B-Streptococcus (up to 25%). These rare pathogens were more common among patients in academic than in general hospitals. However, this difference was not significant, nor were differences in age distribution or case-fatality ratio between the two hospital categories. As initial therapy chloramphenicol plus a penicillin were administered to 30% of patients. On the fifth day of treatment ampicillin was the most frequently used antibiotic in general hospitals (31%), but in academic centres the above-mentioned combination (27%) and penicillin alone (24%) were most popular. It is argued that new antibiotics need to be evaluated carefully. Because this necessitates several hundreds of patients, multi-centered randomised trials should be carried out.

[The plague]. / Pest.

The word plague evokes associations with old times, but plague actually does still occur all over the world. The survival chances are at the moment much better (antibiotics) than formerly, when half of the patients died; now this figure is 15%. The causal organism is Yersinia pestis, a bacterium in fleas on rodents. This bug is a plausible candidate for attacks by bioterrosists. So, in this time, there is good reason to pay attention to it, as well as to to smallpox and anthrax and their causal organisms.

[Anthrax]. / Miltvuur (anthrax).

Anthrax is a severe infectious disease by Bacillus anthracis. It can cause massacres among large herbivores, but means also a threat to humans. The latter develop mainly cutaneous anthrax, which they mostly survive. Inhalation can lead to more severe infections which, without medical intervention, are virtually always lethal. At the moment the disease draws much attention since it is thought to be a potential weapon in the hands of bioterrorists.

[Cataract]. / Cataract.

Cataract is an opacity of the ocular lens, often occurring at mature age. Apart from ageing it can be caused by--among other things--metabolical disorders, trauma, and infrared or ultraviolet light. Globally, cataract is one of the main causes of blindness. Already for more than 2500 years cataract operations have been performed. During the last 25 years both the operation and the implantation of artificial lenses have been brought to great perfection. This means that one of the prominent spoilers of a good old age is to a large degree controllable.

[Sarcoidosis]. / Sarcoïdose.

Sarcoidosis is a chronic generalized benign granulomatous disorder of perhaps an autoimmune character which can afflict many organs. The insidious form prevails, a (sub)acute onset covers about one third of cases. In most patients the lungs are involved; tissue damage by granulomas and inflammatory cells causes a reduction of respiratory capacity, with dyspnoea as a result. Other often-affected organs are larger joints, skin and eyes. The diagnosis is based on the symptoms, thoracic x-ray and histology. In most cases prednisone is the drug of first choice. It is tantalizing to have to decide whether to treat or not. The decision is based on the severity of the process in vital organs.

[Fifty years of dissertations by dentists]. / Vijftig jaar promoveren door tandartsen.

From 1947 the faculties of dentistry of the Dutch universities are entitled to grant Ph.D. grades for dental theses. In the fifty years that have elapsed since, about 500 dentists defended their thesis; the vast majority (6/7) during the second half of the period. This article describes the first thesis (dating from 1956-1973) of each of the five dental faculties that have existed in the Netherlands, followed by a short analysis of the entire group of 500 dissertations. In recent years dissertations are hardly ever written in Dutch, English taking over nearly entirely. Subjects in the field of social dentistry seem to loose foot. The increase in numbers of dental dissertations is stagnating (at a level of 20-30/year), just as is the case for medical theses (600-700/year).

[Severe acute respiratory syndrome (SARS)]. / Severe acute respiratory syndrome (SARS).

Severe Acute Respiratory Syndrome (SARS) is a disease caused by a corona-virus. These viruses are long known to be human pathogens but this form is new and more virulent. It emerged in March this year in China and seemed to be apt to sweep over the world as a kind of Spanish Flu. Forunately, this didn't happen and at the moment the emerging pandemic seems to be contained. This offers hope in case a more virulent pandemic would suddenly strike in the next future. A world prepared is a difficult prey, even for a surprise virus.

[Glaucoma]. / Glaucoom.

Glaucoma is a group of afflictions that have loss of eyesight in common. This impairment of vision is caused by damage to the optic nerve as a result of high intraocular pressure. The patient's optical fields narrow and at last only a tiny rest is left. The mechanisms of the disease are well known but it is in most cases unexplained why a person develops glaucoma. This review discusses the several forms of glaucoma, the diagnosis and therapy, and the epidemiology and prevention.

[Considerations on vaccinations for the dental staff]. / Overwegingen inzake vaccinaties voor tandartsen.

In this article the available vaccinations in the Netherlands that might be of value to dentistry are discussed. This in view of protection of both the patient and the medical worker. Furthermore vaccines that are necessary but do not exist or have not been developed yet, are mentioned. Of the available vaccinations, the one against hepatitis B is of the utmost importance. This has been stressed in the Netherlands from all sides for a long time already; nonetheless not all dental workers have been vaccinated up until now. The vaccines against human immunodeficiency virus (HIV) and viral hepatitis C rank high on the list of medical achievements most wanted.

[Smoking and pregnancy]. / Roken en zwangerschap.

Smoking is disadvantageous for health in every respect. This is a fortiori the case during pregnancy. Pregnant women who smoke burden their unborn child with a mixture of hundreds of tobacco combustion products, dozens of which have been proved to be harmful, apart from the negative influence of the smoke induced blockade of the haemoglobin by carbon monoxide. Since the embryonic and foetal tissues which are formed in a short period, are particularly vulnerable, many detrimental effects can be observed. The fertility rate of women who smoke is reduced and their risk of abortion, miscarriage and preterm delivery is increased. Babies born to women who smoked during pregnancy have lower birth weights and are less developed. They run an increased risk of many disorders including asthma and even cancer. Their cancer risk seems even to be increased in adulthood. Smoking fathers also damage the development of their unborn child.

[Considerations for dental care during pregnancy]. / Overwegingen bij tandheelkundige behandeling van zwangeren.

Traditionally, general dentists have been reluctant to treat pregnant patients due to uncertainty of the risks that might be imposed on both the mother and the fetus. However, preventive, emergency, and routine dental procedures are all suitable during various phases of a pregnancy, with some treatment modifications and initial planning. This article will review some of the physiologic changes and oral pathology associated with pregnancy, and how these alterations affect dental care for the patient. A brief discussion concerning the risks and benefits of radiation, certain medications, and pre-natal fluoride is also given. Additionally, an overview of possible obstetric emergencies that may arise during a general dental appointment is presented with treatment options outlined.

[The competence of a female. Battle against the rise of the female dentist]. / De geschiktheid der vrouw. Strijd tegen opkomst van de vrouwelijke tandarts.

The refusal of the Dutch Dental Society in 1898 to admit three female dentists to their ranks, was the reason for a polemic. Two important male dentists both wrote a pamphlet considering the competence of women for the study and the practice of learned professions like dentistry. Moreover, they deliberated the value of study and practice for both women and society. The authors are strongly influenced by Social Darwinism and their arguments would now be described as male chauvinism. They admit that women could do the job as well as men, if only after a long evolution. But that evolution is not to be welcomed at all: the best attribute of woman (maternal love) would be frustrated and her highest task (child care) would not be fulfilled. Her femininity would disappear and the new 'man-woman' would not be desired by men, which would be detrimental to the institution of marriage. Already now, they argue, marriages are diminishing, lose quality and divorces are on the increase. They know the cause of all evil: feminism and the women's rights movements.