[National Immunisation Programme: is vaccinating less an option?] / Rijksvaccinatieprogramma: is minder vaccineren een optie?

Many people are no longer familiar with the diseases that are part of the Dutch National Immunisation Programme (NIP). The protection given by the NIP has ensured that these diseases, most of them serious, have largely disappeared. The NIP has developed gradually, but in retrospect it was in 1957 that what we now know as the NIP started. Over the years, the NIP has gradually expanded to include various vaccines such as live attenuated vaccines, conjugate vaccines and vaccines that offer protection against chronic viral infections. Currently, the NIP offers protection against twelve different diseases. Occasionally the Netherlands still sees minor outbreaks of those diseases included in the NIP programme, generally among non-vaccinated people. It is important that the NIP is retained; stopping vaccination always leads to the return of the disease. The question is: can good protection be maintained with fewer injections? This subject is on the agenda of the Health Council Of The Netherlands for discussion in 2022.

[No scientific lower threshold for compulsory vaccination]. / Geen wetenschappelijke ondergrens voor verplicht vaccineren.

The national vaccination rate in young children in the Netherlands has decreased in recent years. This has led to social and political discussions, for instance about compulsory vaccination for children in child-care. The national commission on child-care and vaccination has advised that vaccination should be made compulsory when the rate of vaccination has declined to a pre-determined lower threshold, to be determined by the government. A frequently quoted lower threshold is 95%. The idea behind this is the concept of a critical vaccination rate, a threshold needed for elimination of an infection in a large, well-mixed population. In this article we argue why the critical vaccination rate does not offer a scientific basis for a lower threshold to the national vaccination rate.

No evidence found for an increased risk of long-term fatigue following human papillomavirus vaccination of adolescent girls.

INTRODUCTION: In 2013, the Netherlands Pharmacovigilance Center Lareb published an overview of reports of long-lasting fatigue following bivalent HPV-vaccination (2vHPV). After an update of this overview in 2015, concerns regarding the safety of 2vHPV was picked up by the media, which led to further reports of long-lasting fatigue. Therefore, the Dutch National Institute for Public Health and the Environment (RIVM) investigated a possible association between HPV-vaccination and long-term fatigue. METHODS: In this retrospective cohort study conducted in the Integrated Primary Care Information database, we investigated the occurrence of chronic fatigue syndrome (CFS), fatigue ≥6 months and 3-6 months in all girls born in 1991-2000 during the follow-up period January 1st 2007-December 31st 2014 (2007-2008 pre-vaccination and 2009-2014 post-vaccination). Patients with certain fatigue ≥6 m were asked for consent to link their primary care information with vaccination data. Incidence rates per 10,000 person years (PY) for 12-16-year-old girls were compared between pre- and post-HPV-vaccine era. A self-controlled case series (SCCS) analysis was performed using consenting vaccinated cases. A primary high-risk period of 12 months after each dose was defined. RESULTS: The cohort consisted of 69,429 12-16-year-old girls accounting for 2758 PY pre-vaccination and 57,214 PY post-vaccination. Differences between pre- and post-vaccination incidences (CFS: 3.6 (95% CI 0.5-25.7)/10,000 PY and 0.9 (0.4-2.1); certain fatigue ≥6 m: 7.3 (1.8-29.0) and 19.4 (16.1-23.4); certain fatigue 3-6 m: 0.0 and 16.6 (13.6-20.3), respectively) were not statistically significant. SCCS analyses in 16 consenting vaccinated cases resulted in an age-adjusted RR of 0.62 (95%CI 0.07-5.49). CONCLUSIONS: Fatigue ≥6 m and 3-6 m was frequently found among adolescent girls, but CFS was rarely diagnosed. No statistically significant increased incidence rates were found post-vaccination compared to similar age groups of girls pre-vaccination. The SCCS analysis included a low number of cases but revealed no elevated risk of certain fatigue ≥6 m in the high-risk period.

Recurrent coma and fever in familial hemiplegic migraine type 2. A prospective 15-year follow-up of a large family with a novel ATP1A2 mutation.

Background Familial hemiplegic migraine (FHM) is a rare monogenic migraine subtype characterised by attacks associated with transient motor weakness. Clinical information is mainly based on reports of small families with only short follow-up. Here, we document a prospective 15-year follow-up of an extended family with FHM type 2. Patients and methods After diagnosing FHM in a patient with severe attacks associated with coma and fever, we identified eight more family members with FHM and one with possible FHM. All family members were prospectively followed for 15 years. In total 13 clinically affected and 21 clinically non-affected family members were genetically tested and repeatedly investigated. Results A novel p.Arg348Pro ATP1A2 mutation was found in 14 family members: 12 with clinical FHM, one with psychomotor retardation and possible FHM, and one without FHM features. In 9/12 (75%) family members with genetically confirmed FHM, attacks were severe, long-lasting, and often associated with impaired consciousness and fever. Such attacks were frequently misdiagnosed and treated as viral meningitis or stroke. Epilepsy was reported in three family members with FHM and in the one with psychomotor retardation and possible FHM. Ataxia was not observed. Conclusion FHM should be considered in patients with recurrent coma and fever.

[Effects of ageing on infectious disease]. / Effecten van vergrijzing op infectieziekten.

Expectations are that 25% of the Dutch population will be aged 65 years or older in 2050 whilst in 2008 this proportion was only 15%. As a consequence the annual absolute number of new cases of specific infectious diseases will increase. Elderly people often have less clear symptoms of infection, making it harder for clinicians to recognize the disease. Morbidity and mortality caused by infections increase with age. Ageing will possibly cause an increase in levels of antibiotic resistance. There will be more elderly people in hospitals and nursing homes, where more antibiotics are used. This development will come in addition to other developments in the field of antibiotic resistance. There will be more elderly people with chronic HIV and viral hepatitis B and C infection and their complications because patients who are presently infected with those pathogens are ageing. Policy makers should more often consider introducing vaccination of older age groups against certain infectious diseases.

[Changes in the duty of notification of infectious diseases via the Dutch Public Health Act]. / Veranderingen in de meldingsplicht voor infectieziekten door de Wet Publieke Gezondheid.

The Dutch Public Health Act, which came into force on 1 December 2008, replaces the existing laws concerning the combating of infectious diseases. Important changes have been incorporated in the new Public Health Act in comparison with the previous law on infectious diseases. Diseases which are probably infectious in nature and caused by as yet unknown pathogens are now notifiable, laboratories also have a nominal duty of notification and the list of notifiable diseases has been extended with 10 new infectious diseases. The provisions in the law comply with the International Health Regulations of the World Health Organization. The Centre for Infectious Disease Control Netherlands at the Dutch National Institute for Public Health and the Environment (RIVM) has issued a booklet for all Dutch physicians and laboratories providing background information on notifiable diseases. This can be useful in daily practice for helping to decide whether a disorder or cluster of infections is notifiable.

Reflections on an evaluation of the Dutch Infectious diseases Surveillance Information System.

The Netherlands' Infectious diseases Surveillance Information System (ISIS) was developed 12 years ago as an early warning system for the country. The initial objective was to establish a surveillance system that gathered the test results of all microorganisms from all medical microbiology laboratories (MMLs) in the Netherlands on a daily basis in order to create an early warning system. This paper analyses the most important results of a recent evaluation of the system. The evaluation was based on an analysis of early warning signals to detect outbreaks, number of visits to the ISIS website, and interviews with stakeholders, documentation on the ISIS system, and analyses of the ISIS MML database. While the daily collection of data on all micro-organisms for early warning has been achieved, the connection of all 85 MMLs in the Netherlands to the central ISIS MML database has not been achieved - only 18 MMLs have been connected. This has resulted in a low coverage and non-representative selection of MMLs for the Netherlands and therefore national outbreaks were missed. Data were used to determine trends in antimicrobial resistance over time. The ISIS system was not found suitable for early warning since outbreaks were detected via other systems. However, with some adaptations the ISIS system could be suitable for the surveillance of antimicrobial resistance. Furthermore, the discontinuation of this network would cause the loss of the most important data system for antimicrobial resistance in the Netherlands, since there is no other national system that gathers data on this topic. This evaluation resulted in a restart of the network.

[Climate change influences the incidence of arthropod-borne diseases in the Netherlands]. / Klimaatverandering beïnvloedt het vóórkomen in Nederland van ziekten overgebracht door teken, muggen en zandvliegen.

Climate change is associated with changes in the occurrence of arthropod-borne diseases. It is difficult to foresee which arthropod-borne diseases will appear in the Netherlands due to climate change. Climate change influences the prevalence of ticks and may lead to a further increase in Lyme disease and an increased risk of the introduction of rickettsioses. With further warming of the climate there is a real possibility of settlement of the mosquito Aedes albopictus and introduction of the sandfly in the Netherlands. Whether this will lead to circulation of micro-organisms transmitted by these vectors (e.g. West Nile virus, Dengue virus, Leishmania) is not clear. Continued vigilance is necessary, even for vector-borne diseases that appear to be less relevant for the Netherlands.

The value of ProMED-mail for the Early Warning Committee in the Netherlands: more specific approach recommended.

This article describes a retrospective and descriptive study into the added value of ProMED-mail--the global electronic reporting system for outbreaks of emerging infectious diseases and toxins maintained by the International Society for Infectious Diseases--as an early warning system for The Netherlands Early Warning Committee (NEWC). Information about infectious disease events in foreign countries originating from ProMED-mail was retrieved from the reports of the NEWC between May 2006 and June 2007. Each event was analysed in depth in order to determine if it could have been a possible threat to public health in The Netherlands. It was determined whether these events were mentioned in other sources of information used by the NEWC besides ProMED-mail. In addition, we assessed the possible consequences of missing an event when not reading ProMED-mail or of being informed of the event with a time delay. Semi-structured interviews with stakeholders were conducted to explore other functions of ProMED-mail besides early warning. Five out of 25 events reported in ProMED-mail were assessed as a potential threat to The Netherlands, mainly because of the known vulnerability of The Netherlands for vaccine preventable diseases: an outbreak of measles in the United Kingdom and Japan, a case of poliomyelitis in Kenya, and two events concerning Highly Pathogenic Avian Influenza (HPAI) H5N1. The outbreak of measles in Japan and one case of HPAI H5N1 infection in a bird in Germany were only reported by ProMED-mail; the other potential threats were mentioned in other sources with a time delay. ProMED-mail has a limited but real added value over other sources in the early warning of threats. A more specific approach of using ProMED-mail by defining vulnerabilities of a country would be useful and efficient. ProMED-mail is appreciated for providing background and preliminary outbreak information.

[Recent changes in the epidemiology of infectious diseases in the Netherlands: the report 'Status of infectious diseases in the Netherlands, 2000-2005']. / Recente veranderingen in de epidemiologie van infectieziekten in Nederland: het rapport 'Staat van infectieziekten in Nederland, 2000-2005'.

Based on the changes in the epidemiology of infectious diseases in the Netherlands in 2000-2005, it is possible to formulate a prediction for the immediate future. Developments that one may expect with a reasonable amount of certainty are a further rise in sexually transmitted diseases, continued vulnerability for infectious diseases for which the State Vaccination Programme distributes vaccines, a slow increase in bacterial resistance, an increase in opportunistic infections, and growing risks for the introduction of new micro-organisms via international travel and trade. Much less certain are the developments surrounding avian influenza A/H5N1, ticks and mosquitoes, the rise and spread of new diseases, and bioterrorism.

Evaluating the IHS criteria for cluster headache--a comparison between patients meeting all criteria and patients failing one criterion.

Cluster headache (CH) is diagnosed according to criteria of the International Headache Society (IHS), but, in clinical practice, these criteria seem too restrictive. As part of a nation-wide study, we identified a group of patients who met all criteria minus one (IHS-CH-1), and assessed in which way they differed from CH patients meeting all criteria (IHS-CH). We performed a nation-wide questionnaire study for CH and CH-like syndromes, including questions based on the IHS criteria, and additional features such as restlessness during attacks, nocturnal onset of attacks, circadian rhythmicity of attacks and response to treatment. IHS-CH and IHS-CH-1 patients were compared. Of 1452 responders to two questionnaires, 1163 were IHS-CH and 289 were IHS-CH-1. The majority of the IHS-CH-1 patients were classified as such because their attacks exceeded 3 h (64%, median attack duration: 5 h), or came in a frequency of less than 1 per 2 days (16%). Age at onset was similar between the groups. The male to female ratio was 3.7 : 1 in the IHS-CH group and around 1.6 : 1 in the IHS-CH-1 groups (P < 0.005). Patients with attacks exceeding 3 h less often reported a circadian rhythmicity (IHS-CH-1: 49%, IHS-CH: 64%), episodic periodicity (IHS-CH-1: 65%, IHS-CH: 78%), nocturnal attacks (IHS-CH-1: 67%, IHS-CH: 78%), smoking (IHS-CH-1: 90%, IHS-CH: 80%) and restlessness during attacks (IHS-CH-1: 64%, IHS-CH: 76%) than IHS-CH patients (P < 0.005). Photo- or phono-phobia (IHS-CH-1: 67%, IHS-CH: 54%) and nausea (IHS-CH-1: 38%, IHS-CH: 27%) were more frequently reported by patients who reported to have attacks exceeding 3 h (P < 0.005). Similar proportions reported effect of verapamil on their attacks (IHS-CH-1: 54%, IHS-CH 61%). We conclude that average attack duration exceeding 3 h was frequently the reason for not fulfilling IHS CH criteria. Symptoms often accompanying CH such as restlessness, nocturnal attacks and an episodic attack pattern were relatively frequently present in IHS-CH-1 patients with longer attacks. These patients may therefore be diagnosed with CH. Attack frequency may not be a useful criterion for the diagnosis of CH. The upper limit of 3 h should be increased in future diagnostic criteria.

Cardiovascular autonomic function tests in cluster headache.

While facial autonomic signs are prominent during cluster headache (CH) attacks, cardiovascular autonomic changes have been described in few CH patients. Cardiovascular autonomic function tests (AFT) can be used to assess general autonomic function in CH patients in different stages of the disease. We aimed to assess whether general autonomic function is changed in CH patients during a cluster period. AFT was performed both during a cluster period, but outside an actual attack, and outside a cluster period in 18 patients. Heart rate variability was studied at rest, during deep breathing, after standing up and during a Valsalva manoeuvre. Blood pressure (BP) changes were recorded at rest, during standing up and during sustained handgrip. Measurements during and outside the cluster period were compared using the paired t-test. AFT measurements revealed no significant differences between the two measurements, except for diastolic BP in rest, which was higher during the cluster period [80.3 (SD 12.2) vs. 74.8 (SD 9.0), P = 0.04]. Autonomic dysfunction during a cluster period, but outside an attack, does not include systemic cardiovascular control.

Cluster headache in women: relation with menstruation, use of oral contraceptives, pregnancy, and menopause.

In contrast with migraine, little is known about the relation between cluster headache and menstrual cycle, oral contraceptives, pregnancy, and menopause. A population based questionnaire study was performed among 224 female cluster headache patients, and the possible effect of hormonal influences on cluster headache attacks studied. For control data, a similar but adjusted questionnaire was sent to healthy volunteers and migraine patients. It was found that menstruation, use of oral contraceptives, pregnancy, and menopause had a much smaller influence on cluster headache attacks than in migraine. Cluster headache can, however, have a large impact on individual women, for example to refrain from having children.

Recognition of threats caused by infectious diseases in the Netherlands: the early warning committee.

The early warning committee was established in order to recognise threats to public health caused by infectious diseases in the Netherlands in a timely and complete fashion. This article describes the outcome of a retrospective and descriptive evaluation into the completeness of the recognitions made by the early warning committee. Information about outbreaks of infectious disease in the Netherlands in 2002 and 2003, as reported in the Nederlands Tijdschrift voor Geneeskunde (Dutch Journal of Medicine), and about infectious disease events in other countries, was compared with reports of the regular weekly meetings of the Dutch early warning committee. If an outbreak or a foreign event was not mentioned in the meetings of the early warning committee, the cause for this was established. For events in other countries, it was established on the basis of whether or not the event could have been a threat to public health in the Netherlands. All outbreaks of infectious disease in the Netherlands, published or mentioned in the Nederlands Tijdschrift voor Geneeskunde were discussed by the early warning committee. Three of the events occurring in other countries in 2002 had not been discussed by the committee although, based on the criteria for a potential threat to the Netherlands, they should have been: the outbreak of avian influenza A/H5N1 in domestic fowl in Hong Kong, the increase among hospitalised patients of carriers of extended-spectrum a-lactamase producing micro-organisms in Scotland, and outbreaks of measles in several countries. In 2003, all events in other countries that could have posed a threat to the Netherlands were discussed by the early warning committee. In 2002 and 2003, the early warning committee recognised nearly all threats due to infectious diseases and outbreaks of infectious diseases which were of national importance and published in various sources of literature.

[Avian influenza H5NI in Europe: little risk as yet to health in the Netherlands]. / Vogelgriep H5NI in Europa: vooralsnog gering gezondheidsrisico voor Nederland.

Since 2004, outbreaks of fowl plague caused by a highly pathogenic avian influenza virus of the subtype A/H5NI have been reported from various countries in Southeast Asia. To date, 118 cases with 61 deaths have been documented in humans, due to close contact with infected poultry or raw poultry meat. Although efficient human-to-human transmission has not occurred, in a few cases transmission to blood relatives could not be ruled out. In October 2005, outbreaks of A/H5NI in poultry and wild fowl have been confirmed from Turkey, Romania and Russia, due probably to infection via migratory birds. The direct risk of infection in humans in Europe is very low and is associated with direct exposure to infected poultry. In order to address the long-term risk of a pandemic due to recombination of human and avian viruses or to mutations in the avian virus itself, guidelines for pandemic preparedness have been developed and implemented in the Netherlands.

[Recognition of the threats caused by infectious diseases in The Netherlands in 2002 and 2003 by the weekly meetings of the early warning committee]. / Signalering van bedreigingen door infectieziekten in Nederland in 2002 en 2003 door het wekelijkse signaleringsoverleg.

OBJECTIVE: To establish whether the meetings of the so-called 'early warning committee' recognise all the threats to the public health in the Netherlands caused by infectious diseases. DESIGN: Retrospective and descriptive evaluation. METHOD: The information about the outbreaks of infectious diseases in the Netherlands and about events in the area of infectious diseases in foreign countries was compared with the domestic and foreign reports discussed in the regular weekly meetings of the Dutch early warning committee. For this purpose, the authors summarized the outbreaks of infectious diseases in the Netherlands in 2002 and 2003 as reported in articles in the Nederlands Tijdschrift voor Geneeskunde (Dutch Journal of Medicine). This summary was then compared with the domestic reports discussed in the meetings of the early warning committee. If an outbreak was not mentioned in the meetings of the early warning committee, the cause for this was established. For the same period, a summary was made of the foreign events in the area of infectious diseases and this was also compared with the foreign reports mentioned in the meetings of the early warning committee. When an event had not been discussed in the meetings of the early warning committee, it was established on the basis of criteria whether the event could have been a threat to public health in the Netherlands. RESULTS: All outbreaks of infectious diseases in the Netherlands had been discussed in the early warning committee. Of the foreign events in 2002, 3 had not been discussed in the committee although they should have been, based on the criteria for a potential threat to the Netherlands: the outbreak of avian influenza A/H5NI in domestic fowl in Hong Kong, the increase among hospitalised patients of carriers of extended-spectrum 3-lactamase producing micro-organisms in Scotland, and outbreaks of measles in several countries. In 2003, all foreign events that could have been a threat to the Netherlands were discussed in the early warning committee. CONCLUSION: In 2002 and 2003, the meetings of the early warning committee recognised practically all the outbreaks of and threats due to infectious diseases.

[Syndromic surveillance for the detection of outbreaks of unusual infectious diseases]. / Syndroomsurveillance om uitbraken van ongebruikelijke infectieziekten vroegtijdig te signaleren.

Syndromic surveillance has been developed in order to detect outbreaks of unusual infectious diseases such as severe acute respiratory syndrome (SARS) or anthrax at an early stage. Whereas the usual surveillance systems are based on established diagnoses and emergency department discharge data, syndromic surveillance uses preliminary outcomes and derived data such as absenteeism, prescription medication and requests for laboratory tests. Investigations abroad have indicated the potential ofsyndromic surveillance. In the Netherlands, the National Institute of Public Health and Environment (RIVM) is examining the feasibility of implementing syndromic surveillance.

Verapamil induced gingival enlargement in cluster headache.

Verapamil is an effective prophylactic treatment for cluster headaches and, therefore, is widely used. This report describes four patients with cluster headache who developed gingival enlargement after initiating treatment with verapamil. In two patients, it was possible to control this side effect adequately by optimising oral hygiene and dental plaque control. In the other two patients, lowering of the verapamil dose, in addition to optimal oral hygiene and dental plaque control, was necessary; in one patient verapamil had to be stopped completely to reverse the gingival enlargement. Doctors treating cluster headache with verapamil need to be aware of this side effect, especially as it may be preventable with good dental hygiene and dental plaque control, is reversible with reduction or cessation of verapamil, and can lead to dental loss.