The Effectiveness of Asian Bush Mosquito (Aedes japonicus japonicus) Control Actions in Colonised Peri-urban Areas in the Netherlands.

The Asian bush mosquito (Aedes japonicus japonicus (Theobald)) is an invasive mosquito species in Europe. In 2012, it was for the first time detected in the Netherlands, in the municipality of Lelystad. After further research, thousands of specimens were found in the surrounding peri-urban areas of the city. A targeted mosquito control campaign began in 2015 with the objective of reducing populations in locations with the highest concentrations of Ae. japonicus breeding sites: allotment garden complexes. Mosquito control consisted of source reduction combined with application of the larvicide Vectomax in breeding sites. At eight complexes, mosquito control effectiveness has been systematically measured by sampling larvae from breeding sites. Six measurements were performed between 2015 and 2016. Results show that the effectiveness of mosquito control actions was similar in all treated allotment gardens and resulted in a significant reduction in Ae. japonicus larval abundance. Rain barrels at the allotments represent the most frequent breeding site in Lelystad, but every water filled artificial container is a potential breeding site for the species. Ae. japonicus was not found in the samples taken in other allotment gardens in the province of Flevoland; however, the collection methodology used proven to be effective in detecting this species when it has newly colonized surrounding areas. Targeted mosquito control actions at the breeding sites are crucial for successful reduction of populations of an invasive mosquito species, and systematic measurements of the effectiveness, is in this case, the base to understand the dynamics of Ae. japonicus populations after mosquito control.

The first detected airline introductions of yellow fever mosquitoes (Aedes aegypti) to Europe, at Schiphol International airport, the Netherlands.

BACKGROUND: Air-borne introduction of exotic mosquitoes to Schiphol airport in the Netherlands has been considered plausible based upon findings of mosquitoes in aircraft cabins during 2008, 2010 and 2011. Beginning in 2013, surveillance efforts at Schiphol had focused on promptly detecting accidental introductions at the airport facilities in order to quickly react and avoid temporary proliferation or establishment of mosquito populations, identify the origin of the introductions, and avoid potential transmission of vector-borne diseases. METHODS: BG-Mosquitaire mosquito traps were set at the most likely locations for arrival of the invasive Aedes mosquitoes as part of the mosquito monitoring program at Schiphol airport. Samples were collected bi-weekly. Upon detection of exotic specimens, information about the origin of the flights arriving to the particular location at the airport where specimens were captured was requested from airport authorities. The GIS tool Intersect was then used to identify airports of origin common to positive trapping locations during the specific trapping period. Captured Aedes aegypti mosquitoes were subsequently genotyped at 12 highly polymorphic microsatellite markers and compared to a reference database of 79 populations around the world to further narrow down their location of origin. RESULTS: In 2016, six adult yellow fever mosquitoes were captured indoors and outdoors at the airport of Schiphol in the Netherlands confirming, for the first time, air-borne transport of this mosquito vector species into Europe. Mosquitoes were captured during three time periods: June, September and October. Containers carried by aircrafts are considered the most likely pathway for this introduction. GIS analysis and genetic assignment tests on these mosquitoes point to North America or the Middle East as possible origins, but the small sample size prevents us from reliably identifying the geographic origin of this introduction. CONCLUSIONS: The arrival of Ae. aegypti mosquitoes to Schiphol airport from flights arriving from overseas, demonstrates the potential risk of international flights to public health as carriers of arthropod vectors of disease. The results strongly suggest that disinsection of containers and their storage compartments inside the aircrafts could contribute to preventing future introductions of mosquito vectors. Invasive mosquito species introduced by aircrafts from overseas could become seasonally established during the warmer months in Europe, or permanently in certain climatically suitable areas for the species, with major consequences for human health.

National Mosquito (Diptera: Culicidae) Survey in The Netherlands 2010-2013.

From 2010 onwards, a nationwide mosquito monitoring scheme has been conducted in The Netherlands with the aim of gaining crucial information about mosquito (Diptera: Culicidae) species composition, geographical distributions, biodiversity, and habitat preferences. The results of this study are based on 778 randomly sampled mosquito locations. These are divided into three main habitat types: urban, rural-agricultural, and natural areas. Twenty-seven mosquito species were found: 26 indigenous and 1 exotic, Aedes japonicus japonicus (Theobald, 1901). The preliminary results are presented here, with details of their species distribution and seasonality. Monitoring the temporal and spatial distribution of mosquitoes is an essential step in the risk analysis of emerging mosquito-borne diseases.

The Mondrian matrix: Culicoides biting midge abundance and seasonal incidence during the 2006-2008 epidemic of bluetongue in the Netherlands.

During the northern Europe epidemic of bluetongue (BT), Onderstepoort-type blacklight traps were used to capture Culicoides Latreille (Diptera: Ceratopogonidae) biting midges weekly between November 2006 and December 2008 on 21 livestock farms in the Netherlands. Proven and potential vectors for the bluetongue virus (BTV) comprised almost 80% of the midges collected: the Obsoletus complex, constituting C. obsoletus (Meigen) and C. scoticus Downes & Kettle (44.2%), C. dewulfi Goetghebuer (16.4%), C. chiopterus (Meigen) (16.3%) and C. pulicaris (Linnaeus) (0.1%). Half of the 24 commonest species of Culicoides captured completed only one (univoltine) or two (bivoltine) generations annually, whereas multivoltine species (including all BTV vectors) cycled through five to six generations (exceeding the one to four generations calculated in earlier decades). Whether this increment signals a change in the phenology of northern Europe Culicoides or simply is an adaptive response that manifests during warmer episodes, thus heightening periodically the incursive potential of midge-borne arboviruses, remains to be clarified. Culicoides duddingstoni Kettle & Lawson, C. grisescens Edwards, C. maritimus Kieffer, C. pallidicornis Kieffer and C. riethi Kieffer are new records for the biting midge fauna of the Netherlands. It is suggested that C. punctatus (Meigen) be added to the European list of vector Culicoides.

Introduction and control of three invasive mosquito species in the Netherlands, July-October 2010.

In July 2010, during routine mosquito surveillance inspections at companies that import used tires, three invasive species were found at five locations in the Netherlands: the yellow fever mosquito (Aedes aegypti), the Asian tiger mosquito (Ae. albopictus), and the American rock-pool mosquito (Ae. atropalpus). This is the first time that Ae. aegypti is reported from the Netherlands. Mosquito control was initiated one week after the first invasive mosquito was found, using adulticides and larvicides. The available data suggest that the implemented control measures have been effective for this season.

Homocysteine and inflammation: predictors of cognitive decline in older persons?

The aim of the current study was to examine the association between homocysteine and 6-year cognitive decline, and the modifying role of the inflammatory markers Interleukin-6 (IL-6), C-reactive protein (CRP) and alpha-1-antichymotrypsin (ACT). Data were collected within the Longitudinal Aging Study Amsterdam (ages >or=65 years) and analyzed using multiple longitudinal regression models (N=1257 of whom N=1076 had longitudinal data). Cognition was measured with the Mini-Mental State Examination (general cognition), Auditory Verbal Learning Test (memory), Coding Task (information processing speed) and Raven Coloured Progressive Matrices (fluid intelligence). Higher homocysteine at baseline was negatively associated with prolonged lower cognitive functioning and a faster rate of decline in information processing speed and fluid intelligence. The negative association between higher homocysteine and immediate recall was strongest in persons with a high level of IL-6. Only in the highest tertile of CRP, higher homocysteine was negatively associated with retention. In the middle tertile of ACT, higher homocysteine was associated with lower information processing speed and faster decline. Both in the lower and middle tertile of CRP, higher homocysteine was associated with a faster rate of decline in information processing speed. The results implicate that a combination of both risk factors may be used as a marker for cognitive impairment.

First report of a North American invasive mosquito species Ochlerotatus atropalpus (Coquillett) in the Netherlands, 2009.

In late August and early September 2009, numerous larvae, pupae, and actively flying adult specimens of Ochlerotatus atropalpus were discovered in the Province of Brabant, southern Netherlands, during surveillance activities for Aedes albopictus at two trading companies that import used tires. No Ae. albopictus were found. Both companies mainly import used tires from countries in Europe, but also from North America. Oc. atropalpus is endemic to North America and has so far only been found outside of its endemic range in Europe, namely France and Italy, where it was subsequently eradicated. A preliminary modelling study shows that the weather conditions in the Netherlands are unlikely to prevent establishment of Oc. atropalpus. This species has so far only been shown to serve as a vector for virus transmission under laboratory conditions. Studies on potential human and veterinary health risks, as well as possible control strategies are currently ongoing.

Total cholesterol and oxysterols: early markers for cognitive decline in elderly?

In this prospective study we examined whether total cholesterol and the oxysterols 24S- and 27-hydroxycholesterol were related to cognitive performance and rate of cognitive decline in elderly, and whether these associations were modified by ApoE epsilon 4. Data were collected during 6 years of follow-up as part of the Longitudinal Aging Study Amsterdam (N=1181, age >or=65 years), and analyzed using generalized estimating equations. Cognitive performance was measured with the mini-mental state examination (general cognition), the auditory verbal learning test (memory) and the coding task (information processing speed). Lower cholesterol at baseline was negatively associated with both general cognition (p=.012) and information processing speed (p=.045). ApoE modified the association between cholesterol and cognitive decline, and the association between the ratio of 27-hydroxycholesterol to cholesterol and cognitive functioning. In ApoE epsilon 4 carriers, lower cholesterol was related to a higher rate of decline on information processing speed (p=.006), and a higher ratio of 27-hydroxycholesterol to cholesterol was related to a lower level of general performance (p=.002) and memory functioning (p=.045). The results implicate that lower total cholesterol may be considered as a frailty marker, predictive of lower cognitive functioning in elderly.

[Stroke patients in need of long-term nursing home care. Who are they? What are their problems? Which care do they receive?]. / CVA-patiënten die aangewezen zijn op langdurige verpleeghuiszorg. Wie zijn ze? Met welke problemen kampen zij? Welke zorg ontvangen ze?

BACKGROUND AND OBJECTIVE: Many patients who suffer from an acute stroke, will need long-term nursing home care. We are poorly informed about the demographic and clinical characteristics and about the care problems and received care of these patients. This study aims to provide a first description of these characteristics in this group of patients. METHODS: Data on demographic and health-related characteristics, social participation and received care were collected with the Minimum Data Set of the Resident Assessment Instrument, from january 2004-march 2007, in patients who needed long-term nursing home care. Data were collected in eight nursing homes at admission and six months after admission. RESULTS: Many patients were functionally impaired, suffered from depressive symptoms and pain, and were cognitively impaired. In addition, decisional capacity was frequently diminished. The majority of patients were residing at somatic wards, even when severe cognitive impairment was present, such as dementia. Several forms of restraints were frequently used, also at somatic wards. About 40% of the patients, mostly residing at somatic wards, received paramedical treatment. Social engagement was low and was correlated with functional impairment. CONCLUSIONS: Stroke patients who need long-term nursing home care suffer from problems in several domains. The high prevalence of cognitive impairment in stroke patients residing at somatic wards, combined with the ample use of restraints on these wards, raises questions about the appropriateness of the currently delivered care to these patients, considering the problems they have.

Development of classification models for early identification of persons at risk for persistent cognitive decline.

OBJECTIVE: To develop two classification models for use in primary care to aid early identification of persons at risk for persistent cognitive decline. METHODS: Data were used from the Longitudinal Aging Study Amsterdam (LASA), an ongoing populationbased study. The study sample consisted of 2,021 non-demented men and women aged 58-88 years. Data on relevant predictors of persistent cognitive decline were collected at baseline. RESULTS: The incidence of persistent cognitive decline after three years of follow-up was 4.0 %. In the first model, in which predictors already known or otherwise easily assessed (first set) were included, age was the strongest predictor of persistent cognitive decline, with an increased risk for persons > 75. In addition, having memory problems, low education, and a MMSE score of < or = 24, resulted in a predictive value for persistent cognitive decline of 43.5 %. In the second classification model, in addition to the first set, predictors requiring additional measurement (e.g. markers determined in blood) were included in the analyses. Age was again the strongest predictor of persistent cognitive decline. In persons > 75 years, having a low total cholesterol level (< 5.0 mmol/L) and a MMSE score of < or = 24 resulted in a predictive value of 30.0 %. CONCLUSIONS: Both models lead to a substantial increase of the predictive value for persistent cognitive decline, that is from 4.0 % to 43.5 % and 30.0 %, and may identify to a large extent a different subsample of persons who are at risk for persistent cognitive decline. The developed classification trees could be useful for case-finding of persons at risk for future persistent cognitive decline who are therefore at risk for dementia, in a feasible and cost-effective manner.

Distribution of APOE genotypes in a memory clinic cohort.

AIM: To describe the distribution of apolipoprotein E (APOE) genotypes in a cohort of memory clinic patients. METHODS: We included 749 memory clinic patients. Diagnoses were made in a multidisciplinary consensus meeting and the APOE genotype was determined. The community-based cohort of the Longitudinal Aging Study Amsterdam was used as control population (n = 2,233). RESULTS: In the memory clinic sample, there were 173 patients with subjective complaints, 125 patients with mild cognitive impairment (MCI), 251 patients with Alzheimer disease (AD), 107 patients with another type of dementia, and 93 patients with another neurologic or psychiatric diagnosis. The APOE allele distribution differed among groups. There was no difference in the prevalence of the epsilon2 allele, but there were differences in distribution of the epsilon3 and epsilon4 alleles. Compared with the control population (15%), the prevalence of APOE epsilon4 was increased among patients with subjective complaints (22%), MCI (36%), AD (42%) and other types of dementia (25%). CONCLUSION: We observed an increased prevalence of APOE epsilon4 in patients with MCI and subjective complaints. This finding is of great clinical importance as nondemented patients positive for APOE epsilon4 could be identified as being at genetic risk of AD, and for that reason monitored more closely.

Inflammatory markers in late-life depression: results from a population-based study.

BACKGROUND: Previous studies have reported conflicting results concerning the association between several inflammatory markers and depression. The association between inflammation and depression may depend on the presence of specific chronic diseases or be relevant in specific sub-groups of depressed patients only. OBJECTIVE: To assess associations between inflammatory markers and depression in older people, taking account of confounding and effect-modifying factors. METHOD: Population-based study of 1285 participants of the Longitudinal Aging Study Amsterdam, aged 65 and over. Plasma concentrations of Interleukin-6 (IL-6) and C-reactive protein (CRP) were measured. Major depression (first- or recurrent episode) and sub-threshold depression were assessed. Associations were adjusted for confounding variables. Associations with inflammatory markers were further studied with regard to severity and duration of depression, and with regard to specific depressive symptoms. RESULTS: High levels of IL-6 (above 5 pg/mL) were associated with major depression (odds ratio 2.49 (1.07-5.80), both in recurrent and first episodes. No significant effect of either one of the markers on specific symptom dimensions of depression was found. Mildly elevated plasma levels of CRP (above 3.2 mg/L) were associated with higher CES-D scores, but not after correction for the confounding effect of age and chronic diseases. LIMITATIONS: The cross-sectional design limits conclusions regarding causality. CONCLUSIONS: A high plasma level of IL-6, but not CRP, is associated with an increased prevalence of major depression in older people, independent of age, chronic diseases, cognitive functioning and anti-depressants. Present results suggest new directions for clinical research into the prevention of physical consequences of depression.

[Unhealthy lifestyles during the life course: association with physical decline in late life]. / Ongezonde leefstijl in de loop van het leven: samenhang met lichamelijke achteruitgang op oudere leeftijd.

This study aimed to examine the association between unhealthy lifestyle in young age, midlife and/or old age and physical decline in old age, and to examine the association between chronic exposure to an unhealthy lifestyle throughout life and physical decline in old age. The study sample included 1297 respondents of the Longitudinal Aging Study Amsterdam (LASA). Lifestyle in old age (55-85 y) was assessed at baseline, while lifestyle in young age (around 25 y) and midlife (around 40 y) were assessed retrospectively. Lifestyle factors included physical activity, body mass index (BMI), number of alcohol drinks per week and smoking. Physical decline was calculated as change in physical performance score between baseline and six-year follow-up. Of the lifestyle factors present in old age, a BMI of 25-29 vs. BMI <25 kg/m2 (odds ratio (OR) 1.6; 95% confidence interval (CI) 1.1-2.2) and a BMI of > or =30 vs. BMI <25 kg/m2 (OR 1.8; 95% CI 1.2-2.7) were associated with physical decline in old age. Being physically inactive in old age was not significantly associated with an increased risk of physical decline, however, being physically inactive both in midlife and in old age increased the odds of physical decline in old age to 1.6 (95% CI 1.1-2.4) as compared to respondents who were physically inactive in midlife and physically active in old age. Being overweight in both age periods was associated with an OR of 1.5 (95% CI 1.1-2.2). These data suggest that overweight in old age, and chronic exposure to physical inactivity or overweight throughout life increases the risk of physical decline in old age. Therefore, physical activity and prevention of overweight at all ages should be stimulated to prevent physical decline in old age.

[Predictors of dementia, the construction of classification trees]. / Vroege predictoren van dementie, de constructie van beslisbomen.

In order to identify persons who are at risk for dementia in an early phase, two classification trees were developed. Data were used from the Longitudinal Aging Study Amsterdam (LASA). The prevalence of dementia in the whole sample was 4.0%. In the first tree age seemed to be the strongest predictor, with an increased risk for persons older than 75. In this group the positive predictive value reached a maximum of 33.3% when the persons had memory complaints and a score on the Mini Mental State Examination (MMSE) <24. In a second classification tree, age was excluded as a predictor because of high association with the other potential predictors. In this tree functional limitations seemed the strongest predictor. In the group of persons with at least one functional limitations, the positive predictive value reached a maximum of 28.8% when the persons had memory complaints and a score <24 on the MMSE. In persons without memory complaints, persons with cardiovascular diseases or diabetes were at increased risk of dementia. Further research is necessary before these classification trees can be implemented in general health care.

The apolipoprotein E e4 polymorphism is strongly associated with poor mobility performance test results but not self-reported limitation in older people.

BACKGROUND: The apolipoprotein E (ApoE) e4 polymorphism is linked to increased mortality rates, Alzheimer's disease, and cardiovascular disease in older people, but previous studies have largely failed to detect an effect on self-reported mobility disability. We hypothesized that poor performance on mobility-related tests may provide a better measure of effects, and we aimed to estimate the extent to which the ApoE e4 allele increases risks of poor performance on measured mobility and self-reported mobility disability compared to e3/3, in a medium-sized population cohort. METHODS: Data were from 1262 people at baseline older than 65 years from the Longitudinal Aging Study Amsterdam (LASA), followed up for 6 years. Age- and sex-adjusted logistic regression models were used to explore associations. RESULTS: At baseline, those individuals with an e4 allele had an odds ratio of 2.26 (95% confidence interval, 1.31-3.90) for poor performance on gait speed testing (<0.4 m/s) and 1.94 (95% confidence interval, 1.19-3.16) for five chair stands (> or =20 s), compared to those with e3/3 status. At follow-up, associations between e4 status and incident poor performance on the chair stand test was significant. Associations with self-reported inability or need for help walking for 5 minutes or for climbing 15 steps were nonsignificant throughout. CONCLUSIONS: The ApoE e4 polymorphism is associated with a substantial excess of mobility limitation. The impact is detectable by performance testing, but not by self-reports. Poor results on mobility performance tests may provide a phenotype of ageing.

Serum inflammatory proteins and cognitive decline in older persons.

OBJECTIVE: To assess whether serum levels of the inflammatory proteins alpha(1)-antichymotrypsin (ACT), C-reactive protein (CRP), interleukin-6 (IL-6), and albumin are associated with cognitive decline in older persons. METHODS: The study sample consisted of 1,284 participants in the Longitudinal Aging Study Amsterdam, aged 62 to 85 years. Cognition was assessed on general cognition (Mini-Mental State Examination [MMSE]), memory (Auditory Verbal Learning Test), fluid intelligence (Raven's Colored Progressive Matrices), and information-processing speed (Coding Task) at baseline and at 3-year follow-up. RESULTS: The highest tertile of ACT was associated with an increased risk of decline on the MMSE (age-, sex-, education-adjusted odds ratio [OR] 1.60; 95% CI: 1.05 to 2.43) but not on any other cognitive test score. CRP, IL-6, and albumin were not associated with cognitive decline on any cognitive test in our study. CONCLUSIONS: This population-based study showed that the serum inflammatory protein alpha1-antichymotrypsin is associated with cognitive decline in older persons, whereas C-reactive protein, interleukin-6, and albumin are not.

Memory complaints; the association with psycho-affective and health problems and the role of personality characteristics. A 6-year follow-up study.

BACKGROUND: The objective is to investigate whether memory complaints in older persons without manifest cognitive decline are associated with depressive symptoms, anxiety symptoms, physical health and personality characteristics. Furthermore, it is investigated whether personality characteristics have a modifying effect on the association of memory complaints with depressive and anxiety symptoms and physical health. METHODS: The study was carried out using the Longitudinal Aging Study Amsterdam (LASA). Participants were examined during three observation cycles covering a period of 6 years. They were asked about memory complaints, and were examined on cognitive functioning, physical health, depressive and anxiety symptoms, and the personality characteristics: mastery, perceived self-efficacy and neuroticism. The data were analysed by means of Generalised Estimating Equations (GEE). RESULTS: Memory complaints were associated with physical health problems, depressive and anxiety symptoms, low feelings of mastery, low perceived self-efficacy and high neuroticism. The associations between memory complaints and physical health problems, depressive and anxiety symptoms were significantly stronger in people with high mastery, high perceived self-efficacy and low neuroticism. LIMITATIONS: We used a conservative criterion for cognitive decline and therefore we might have included some people with cognitive decline during our follow-up. In order to minimise selection bias we included actual cognitive performance in our regression models. CONCLUSIONS: Our findings suggest that when older persons complain about their memory and do not show actual cognitive decline, one should be aware that these complaints might reflect psycho-affective or health problems.

Effects of gender and age on the association of apolipoprotein E epsilon4 with bone mineral density, bone turnover and the risk of fractures in older people.

The aim of this study was to examine whether the presence of apolipoprotein E epsilon4 (ApoE epsilon4) is associated with a lower bone mineral density (BMD), lower quantitative ultrasound (QUS) measurements, higher bone turnover and fracture risk, and whether these relations are modified by gender and age. A total of 1406 elderly men and women (> or =65 years) of the Longitudinal Aging Study Amsterdam (LASA) participated in this study. In all participants, QUS measurements were assessed, as well as serum osteocalcin (OC) and urine deoxypyridinolin (DPD/Cr urine). Follow-up of fractures was done each three months. In a subsample ( n = 604), total body bone mineral content (BMC) and BMD of the hip and lumbar spine were measured. In addition, prevalent vertebral deformities were identified on radiographs. In women, the presence of ApoE epsilon4 was associated with significantly lower femoral neck BMD (g/cm(2); mean +/- SEM; epsilon4+, 0.64 +/- 0.01 vs. epsilon4-, 0.67 +/- 0.01; p = 0.04), lower trochanter BMD (g/cm(2); mean +/- SEM; epsilon4+, 0.58 +/- 0.01 vs. epsilon4-, 0.61 +/- 0.01; p = 0.01) and lower total body BMC (g; mean +/- SEM; epsilon4+, 1787 +/- 40.0 vs. epsilon4-, 1863 +/- 23.8; p = 0.04). Women with ApoE epsilon4 also had a higher risk of severe vertebral deformities (OR=2.78; 95%CI: 1.21-6.34). In men, the associations between ApoE status and both hip BMD and QUS depended on age. Only among the younger men (65-69 years) was the presence of ApoE epsilon4 associated with lower BMD values. Bone markers and fractures were not associated with ApoE epsilon4 in either women, or men. In conclusion, this large community-based study confirms the importance of ApoE epsilon4 as a possible genetic risk factor related to BMD and vertebral deformities and demonstrates that its effect is gender related, and depends on age in men only.