Incidence of pneumonia in nursing home residents with dementia in the Netherlands: an estimation based on three differently designed studies.

Pneumonia leads to considerable morbidity and mortality in nursing home residents with dementia. We assessed pneumonia incidence based on data from three different studies: (1) real-time national surveillance of healthcare-associated infections in nursing home residents in 2009-2015; (2) a randomized controlled trial in 2012-2015 to assess effects of a practical guideline in nursing home residents with dementia and pneumonia; and (3) a study in 2007-2010 to assess quality of dying in newly admitted nursing home residents with dementia. In national surveillance data, pneumonia incidence was calculated separately for psychogeriatric and somatic beds, as a proxy for residents with and without dementia. Weekly pneumonia incidence was significantly lower per 1000 psychogeriatric beds (3·9; 95% confidence interval (CI) 3·2-4·6) compared with 1000 somatic beds (5·7; 95% CI 5·1-6·3). Annual incidence per 1000 psychogeriatric beds was similar in national surveillance (range 78·9-117·1) and the trial (range 71·0-94·3), and significantly higher in newly admitted dementia residents (range 267·3-363·2). The incidence was highest during the first months after admission when compared with residents with longer stay. In conclusion, follow-up of pneumonia in newly admitted dementia residents may result in higher incidence, possibly due to higher risk in this population.

Extent and origin of resistance to antituberculosis drugs in the Netherlands, 1993 to 2011.

The elimination of tuberculosis (TB) is threatened by an apparent increase in the level of resistance in Mycobacterium tuberculosis. In the Netherlands, where the majority of TB patients are migrants, resistance may also be increasing. We conducted a retrospective study, using 18,294 M. tuberculosis isolates from TB cases notified between 1993 and 2011. We investigated the trends in antituberculosis drug resistance, focusing on the country of birth of the patients and whether resistance had developed during treatment or was the result of transmission of resistant M. tuberculosis strains. For both scenarios, we determined whether this had happened in or outside the Netherlands. Antituberculosis drug resistance was found in 13% of all cases analysed and showed an increasing trend among patients who had been born in the Netherlands (p<0.001) and a decreasing trend among foreign-born (p=0.02) over the study period. Since 2005, the proportion of M. tuberculosis resistant strains among all strains tested has increased in both groups (p=0.03 and p=0.01, respectively). Overall, we found a significantly increasing trend when excluding streptomycin resistance (p<0.001). The trend was most markedly increased for isoniazid resistance (p = 0.01). Although resistance was mainly due to transmission of resistant strains, mostly outside the Netherlands or before 1993 (when DNA fingerprinting was not systematically performed), in some cases (n=45), resistance was acquired in the Netherlands. We conclude that antituberculosis drug resistance is increasing in the Netherlands, mostly related to migration from high TB-incidence countries, but also to domestic acquisition.

The burden of 2009 pandemic influenza A(H1N1) in the Netherlands.

BACKGROUND: The disease burden of the 2009 influenza pandemic has been debated but reliable estimates are lacking. To guide future policy and control, these estimates are necessary. This study uses burden of disease measurements to assess the contribution of the pandemic influenza A(H1N1) virus to the overall burden of disease in the Netherlands. METHODS: The burden of disease caused by 2009 pandemic influenza was estimated by calculating Disability Adjusted Life Years (DALY), a composite measure that combines incidence, sequelae and mortality associated with a disease, taking duration and severity into account. Available influenza surveillance data sources (primary care sentinel surveillance, notification data on hospitalizations and deaths and death registries) were used. Besides a baseline scenario, five alternative scenarios were used to assess effects of changing values of input parameters. RESULTS: The baseline scenario showed a loss of 5800 DALY for the Netherlands (35 DALY per 100 000 population). This corresponds to 0.13% of the estimated annual disease burden in the Netherlands and is comparable to the estimated disease burden of seasonal influenza, despite a different age distribution in incidence and mortality of the pandemic compared to seasonal influenza. CONCLUSIONS: This disease burden estimate confirmed that, although there was a higher mortality observed among young people, the 2009 pandemic was overall a mild influenza epidemic. The disease burden of this pandemic was comparable to the burden of seasonal influenza in the Netherlands.

TB in migrants residing in the Netherlands for at least 5 years at diagnosis, 2003-2018.

BACKGROUND: One of the challenges of TB elimination in low-incidence countries is the relatively high incidence of TB in migrants in these countries, even after multiple years of residence.OBJECTIVE: To describe and compare TB incidence and characteristics of migrant TB patients residing in the Netherlands for at least (≥)5 years at diagnosis with non-foreign-born TB patients in order to identify additional strategies that could reduce TB incidence in the former group.METHODS: A retrospective cohort study was conducted in migrants from Somalia, Morocco, Suriname, Turkey and Indonesia who were diagnosed with TB in the Netherlands in 2003-2018. TB incidences were calculated and multivariate logistic regression was used to identify differences in characteristics of TB patients per country of birth compared to non-foreign-born patients.RESULTS: TB incidence was highest in individuals from Somalia (162.5/100,000 population in 2018), followed by individuals from Morocco (37.1/100,000). In the non-foreign-born population, TB incidence was 1.2/100,000. Differences in characteristics of TB patients compared to non-foreign-born patients varied by country of birth.CONCLUSION: Our findings underline the importance of being aware of the heterogeneity of TB incidence and characteristics of patients in the migrant population residing ≥5 years in the Netherlands.

Risk of hospitalization and death for healthcare workers with COVID-19 in nine European countries, January 2020-January 2021.

This article presents and compares coronavirus disease 2019 attack rates for infection, hospitalization, intensive care unit (ICU) admission and death in healthcare workers (HCWs) and non-HCWs in nine European countries from 31st January 2020 to 13th January 2021. Adjusted attack rate ratios in HCWs (compared with non-HCWs) were 3.0 [95% confidence interval (CI) 2.2-4.0] for infection, 1.8 (95% CI 1.2-2.7) for hospitalization, 1.9 (95% CI 1.1-3.2) for ICU admission and 0.9 (95% CI 0.4-2.0) for death. Among hospitalized cases, the case-fatality ratio was 1.8% in HCWs and 8.2% in non-HCWs. Differences may be due to better/earlier access to treatment, differential underascertainment and the healthy worker effect.

Experience of establishing severe acute respiratory surveillance in the Netherlands: Evaluation and challenges.

The 2009 influenza A (H1N1) pandemic prompted the World Health Organization (WHO) to recommend countries to establish a national severe acute respiratory infections (SARI) surveillance system for preparedness and emergency response. However, setting up or maintaining a robust SARI surveillance system has been challenging. Similar to other countries, surveillance data on hospitalisations for SARI in the Netherlands are still limited, in contrast to the robust surveillance data in primary care. The objective of this narrative review is to provide an overview, evaluation, and challenges of already available surveillance systems or datasets in the Netherlands, which might be used for near real-time surveillance of severe respiratory infections. Seven available surveillance systems or datasets in the Netherlands were reviewed. The evaluation criteria, including data quality, timeliness, representativeness, simplicity, flexibility, acceptability and stability were based on United States Centers for Disease Control and Prevention (CDC) and European Centre for Disease Prevention and Control (ECDC) guidelines for public health surveillance. We added sustainability as additional evaluation criterion. The best evaluated surveillance system or dataset currently available for SARI surveillance is crude mortality monitoring, although it lacks specificity. In contrast to influenza-like illness (ILI) in primary care, there is currently no gold standard for SARI surveillance in the Netherlands. Based on our experience with sentinel SARI surveillance, a fully or semi-automated, passive surveillance system seems most suited for a sustainable SARI surveillance system. An important future challenge remains integrating SARI surveillance into existing hospital programs in order to make surveillance data valuable for public health, as well as hospital quality of care management and individual patient care.

Severe acute respiratory infections surveillance for early signals in the community.

BACKGROUND: Surveillance of acute respiratory infections (ARI) in the Netherlands and other European countries is based mostly on primary care data, with little insight into the severe spectrum of the disease. We compared time-trends for ARI in secondary care with influenza-like illness (ILI), ARI and pneumonia in primary care, and crude mortality, in order to assess the value of routinely collected data on respiratory infections in hospitals and the added value of severe acute respiratory infections (SARI) surveillance. METHODS: We calculated incidence of ARI in secondary care, ILI, ARI, and pneumonia in primary care, and crude mortality using five historical databases (2008-2016). RESULTS: Over eight years, seasonal incidence peaks of ARI in secondary care occurred earlier than ILI and ARI incidence peaks in primary care, except during the 2009 influenza A(H1N1) pandemic and post-pandemic season. The median time-lag between ARI in secondary care and ILI, ARI and pneumonia in primary care was 6.5 weeks, 7 weeks, and 1 week, respectively. Crude mortality lagged a median 5 weeks behind ARI in secondary care. CONCLUSION: This observational study demonstrates that routinely collected data can be used for describing trends of ARI in secondary care and may be suitable for near real-time SARI surveillance. In most seasons, the incidence peaks for ARI in secondary care preceded the peaks in primary care and crude mortality with a considerable time-lag. It would be of great value to add microbiological test results to the incidence data to better explain the difference in time-lag between these surveillance systems.

[The role of children in the transmission of SARS-CoV-2]. / De rol van kinderen in de transmissie van SARS-CoV-2.

OBJECTIVE: To determine whether children play a role in the transmission of SARS-CoV-2 to other children and adults, and to gain insight into symptomatic and asymptomatic infections in children. DESIGN: Analysis of national COVID-19 notifications and prospective observational study in families with children. METHOD: Information about COVID-19 patients and their contacts was obtained from the registration systems used by the public health services. In an ongoing study, patients with COVID-19 were asked to participate if they have a family with children. On two occasions nose-throat swabs and blood were collected for PCR analysis and determination of antibodies against SARS-CoV-2. RESULTS: The notifications suggest that transmission finds place mainly between adults and to a lesser extent between parents and children. For the family study, data were available from 54 households with a total of 227 participants. In families of a confirmed COVID-19 patient, children between 1 and 11 years were less often positive in PCR and serology than older children and adults. CONCLUSION: The study gives no indications that children play an important role in the transmission of SARS-CoV-2. Children can indeed become infected, but transmission mainly takes place between adult peers and from adult family members to children. Transmission among children or from children to adults, as is known in influenza, appears to be less common. Ongoing studies should provide important information for further decision-making on control measures, such as closure of schools.

Time trends in primary-care morbidity, hospitalization and mortality due to pneumonia.

Most studies reporting pneumonia morbidity are restricted to hospitalized patients, although only a minority of pneumonia patients are admitted to hospital. To get a better understanding of the burden of disease in the general population, we conducted a population-based retrospective study to examine trends in pneumonia incidence in general practice, hospitalization, and mortality due to pneumonia in The Netherlands between 1997 and 2007. Between 2001/2002 and 2006/2007 there was an adjusted yearly increase of 12% in the clinical diagnosis of pneumonia in patients consulting general practitioners. Hospitalizations increased 5% per year between 1999/2000 and 2006/2007, while mortality annually decreased by 2% between 1997/1998 and 2006/2007. Our study suggests that the morbidity of pneumonia in the Dutch population increased considerably over this period, especially in primary-care settings, and that focusing only on hospitalization might underestimate the increasing public health burden of pneumonia.

Implementation of point-of-care testing and a temporary influenza ward in a Dutch hospital.

BACKGROUND: The seasonal influenza epidemic poses a significant burden on hospitals, both in terms of capacity and costs. Beds that are occupied by isolated influenza patients result in hospitals temporary being closed to admissions and elective operations being cancelled. Improving hospital and emergency department (ED) patient flow during the influenza season could solve these problems. Microbiological point-of-care-testing (POCT) could reduce unnecessary patient isolation by providing a positive/negative result before admission, but has not yet broadly been implemented. METHODS: A clinical pathway for patients with acute respiratory tract infection presenting at the ED was implemented, including a PCR-based POCT for influenza, operated by nurses and receptionists. In parallel, a temporary ward equipped with 15 beds for influenza-positive patients was established. In this retrospective observational study, we describe the results of implementing this pathway by comparison with the previous epidemic. RESULTS: Clinical performance of the POCT within the clinical pathway was good with strongly decreased time from ED presentation to sample collection (194 vs 47 min) and time from sample collection to result (1094 vs 62 min). Hospital patient flow was improved by a decreased percentage of admitted influenza-positive patients (91% vs 73%) and shorter length of subsequent stay (median 5.86 vs 4.61 days) compared to the previous influenza epidemic. In addition, 430 patient-days of unnecessary isolation have been prevented within a time span of 18 weeks. Roughly estimated savings were almost 400,000 euros. CONCLUSION: We recommend that hospitals explore possibilities for improving patient flow during an influenza epidemic.

Impact of infant pneumococcal conjugate vaccination on community acquired pneumonia hospitalization in all ages in the Netherlands.

BACKGROUND: The long-term impact of pneumococcal conjugate vaccines on pneumonia hospitalizations in all age-groups varies between countries. In the Netherlands, the 7-valent pneumococcal conjugate vaccine (PCV7) was implemented for newborns in 2006 and replaced by PCV10 in 2011. We assessed the impact of PCVs on community-acquired pneumonia (CAP) hospitalization rates in all age-groups. METHODS: A time series analysis using Poisson regression was performed on 155,994 CAP hospitalizations. Hospitalization rates were calculated using the total number of hospitalizations as denominator. The time trend in the pre-PCV period (1999-2006) was extrapolated to predict the hospitalization rate in the post-PCV period (2006-2014) if PCV had not been implemented. Rate ratios over time were calculated by comparing observed and predicted time trends. RESULTS: In children <5 years of age, the observed hospitalization rates during the post-PCV period were significantly lower than predicted if PCV had not been implemented (0-6 months: 0.62, 95% CI: 0.41-0.96; 6 months - 1 year: 0.67, 95% CI: 0.50-0.90; 2-4 years: 0.78, 95% CI: 0.61-0.97). In all other age-groups, rate ratios declined over time but did not reach statistical significance. CONCLUSIONS: After introduction of PCV, CAP hospitalizations declined in young children but no clear impact of PCV on CAP hospitalizations was seen in other age-groups.

No evidence of Legionella infection in general practice patients presenting with acute respiratory infections in The Netherlands.

The role of Legionella spp. in the aetiology of acute respiratory infections (ARIs) is largely unknown. In this case-control study, conducted in a general practitioner setting during 2000 and 2001, nose and throat samples from patients presenting with ARIs (n = 230) and controls (n = 200) were analysed for the presence of Legionella spp. by real-time PCR. Legionella DNA was not detected in any of the cases or controls. Thus, Legionella spp. do not seem to play a role in patients presenting with ARIs, nor were they present in patients who visited their general practitioner for complaints other than ARIs.

The aetiology of community-acquired pneumonia and implications for patient management.

PURPOSE: Understanding which pathogens are associated with clinical manifestation of community-acquired pneumonia (CAP) is important to optimise treatment. We performed a study on the aetiology of CAP and assessed possible implications for patient management in the Netherlands. METHODS: Patients with CAP attending the emergency department of a general hospital were invited to participate in the study. We used an extensive combination of microbiological techniques to determine recent infection with respiratory pathogens. Furthermore, we collected data on clinical parameters and potential risk factors. RESULTS: From November 2007 through January 2010, 339 patients were included. Single bacterial infection was found in 39% of these patients, single viral infection in 12%, and mixed bacterial-viral infection in 11%. Streptococcus pneumoniae was the most frequently identified pathogen (22%; n=74). Infection with atypical bacteria was detected in 69 (20%) of the patients. CONCLUSION: Initial empirical antibiotics should be effective against S. pneumoniae, the most common pathogen identified in CAP patients. The large proportion of patients with infection with atypical bacteria points to the need for improved diagnostic algorithms including atypical bacteria, especially since these atypical bacteria are not covered by the first-choice antibiotic treatment according to the recently revised Dutch guidelines on the management of CAP.

Proton pump inhibitor therapy predisposes to community-acquired Streptococcus pneumoniae pneumonia.

BACKGROUND: The pathophysiological mechanisms which contribute to an increased risk of community-acquired pneumonia (CAP) in patients using proton pump inhibitors are not well established. AIM: To examine differences in microbial etiology in patients with CAP between patients with and without proton pump inhibitor (PPI) therapy and its possible impact on disease severity. METHODS: All individuals consulting the emergency care unit were prospectively registered and underwent chest radiography. Sputum, urine, nose-throat swabs and blood samples were obtained for microbial evaluation. We evaluated the association between use of proton pump inhibitors, etiology of CAP and severity of illness with multivariate regression analysis. RESULTS: The final cohort comprised 463 patients, 29% using proton pump inhibitors (PPIs). Pathogens regarded as oropharyngeal flora were more common in CAP patients using PPI therapy compared to those who did not (adjusted OR: 2.0; 95% CI: 1.22-3.72). Patients using proton pump inhibitors more frequently had an infection with Streptococcus pneumoniae (28% vs. 14%) and less frequently with Coxiella burnetii (8% vs. 19%) compared to nonuser of PPI. Adjusted for baseline differences, the risk of PPI users being infected with S. pneumonia was 2.23 times (95% CI: 1.28-3.75) higher compared to patients without PPI's. No risk between PPI use and any other microbial pathogen was found. There was no difference in severity of CAP between patients with and without using PPI therapy. CONCLUSIONS: Proton pump inhibitor therapy was associated with an approximately 2-fold increased risk to develop community-acquired pneumonia possibly as a result of S. pneumoniae infection.

Long time trends in influenza-like illness and associated determinants in The Netherlands.

We analysed long-term epidemiological trends in influenza-like illness (ILI) in The Netherlands and used an ecological analysis to estimate its relationship with age, influenza vaccination, and virological aspects. This study used data from weekly ILI consultation reports from sentinel general practitioners (1986/1987 to 2006/2007), virological data from sentinel ILI patients (1992/1993 to 2006/2007), and data for influenza vaccine uptake (1991-2005). The incidence of ILI consultations, although varying during the study period, was estimated to decrease in the total population by 12.2/10 000 persons each season (95% CI 8.6-15.9). Uptake of influenza vaccination in people aged > or = 65 years (elderly) increased from 28% in 1991 to >70% since 1997. ILI incidence in the elderly declined by 1.7/10 000 persons (P=0.05) per percentage vaccine uptake per season. The decline in ILI incidence over the last 20 years could be related to the increased vaccine uptake. However, insufficient data were present to assess the impact of other potential contributing factors, such as diminished fitness of influenza viruses and changes in consulting behaviour.