1
|
Pelgrims I, Bastiaens H, Devleesschauwer B, Keune H, Nawrot T, Remmen R, Saenen N, Guyot M, De Clercq EM. Validity of air pollution annoyance to assess long-term exposure to air pollution in Belgium. Eur J Public Health 2020. [DOI: 10.1093/eurpub/ckaa166.088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Background
In environmental epidemiology, air pollution exposure is often estimated at the population level. To avoid the risk of exposure misclassification, one possibility is to interpolate air pollution measures at the residence through Geographical Information Systems. However, this might imply cumbersome administrative procedures. Data on air pollution annoyance from surveys can be an alternative to assess individual exposure to air pollution. This study investigates the association between air pollution annoyance and individual air pollution exposure.
Methods
Analyses were carried out based on a linkage of data from the Belgian Health Interview Survey (HIS 2008 and 2013; >15 years; n = 9347) and annual means of air pollution concentration at the residence. Self-reported air pollution annoyance was assessed through a five-point Likert scale. Statistical analyses included Spearman correlation coefficient, analysis of variance and multivariable ordinal logistic regressions (OLR).
Results
A significant exposure-response relationship was observed between long-term air pollution exposure and self-reported air pollution annoyance. However, Spearman coefficients were low (0.18-0.24), meaning a high heterogeneity of annoyance levels for a given exposure. In multivariable OLR, the odds of being annoyed by air pollution was 2.10 (95% CI: 1.86-2.67) times higher for each Interquartile range (IQR) increase in NO2 concentration (PM2.5: 1.77 [95% CI: 1.53-2.07], PM10: 1.61 [95% CI: 1.33-1.67], black carbon: 1.45 [95% CI: 1.27-1.67]). Air pollution annoyance depended largely on individual factors especially health status.
Conclusions
Air pollution exposure has a significant influence on self-reported air pollution annoyance. However, many other factors were found to influence annoyance, independently of the exposure. We found a limited validity of self-reported air pollution annoyance to assess individual long-term exposure to air pollution.
Key messages
Significant exposure-response relationship between individual long-term air pollution exposure and self-reported air pollution annoyance. Limited validity of self-reported air pollution annoyance for assessing individual long term exposure to air pollution.
Collapse
Affiliation(s)
- I Pelgrims
- Department of Risk and Health Impact Assessment, Sciensano, Brussels, Belgium
- Applied Mathematics, Computer Science and Statistics, Ghent University, Ghent, Belgium
| | - H Bastiaens
- Primary and Interdisciplinary Care, University of Antwerp, Antwerp, Belgium
| | - B Devleesschauwer
- Department of Epidemiology and Public health, Sciensano, Brussels, Belgium
- Department of Veterinary Public Health and Food Safety, Ghent University, Merelbeke, Belgium
| | - H Keune
- Nature and Society, Own-Capital Research Institute for Nature and Forest, Brussels, Belgium
- Primary and Interdisciplinary Care, University of Antwerp, Antwerp, Belgium
| | - T Nawrot
- Center for Environmental Sciences, University of Hasselt, Hasselt, Belgium
| | - R Remmen
- Primary and Interdisciplinary Care, University of Antwerp, Antwerp, Belgium
| | - N Saenen
- Center for Environmental Sciences, University of Hasselt, Hasselt, Belgium
| | - M Guyot
- Center for Operations Research and Econometrics, University of Louvain, Louvain La Neuve, Belgium
| | - E M De Clercq
- Department of Risk and Health Impact Assessment, Sciensano, Brussels, Belgium
| |
Collapse
|
2
|
Vial L, Ducheyne E, Filatov S, Gerilovych A, McVey DS, Sindryakova I, Morgunov S, Pérez de León AA, Kolbasov D, De Clercq EM. Spatial multi-criteria decision analysis for modelling suitable habitats of Ornithodoros soft ticks in the Western Palearctic region. Vet Parasitol 2017; 249:2-16. [PMID: 29279082 DOI: 10.1016/j.vetpar.2017.10.022] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Revised: 10/09/2017] [Accepted: 10/30/2017] [Indexed: 11/19/2022]
Abstract
Ticks are economically and medically important ectoparasites due to the injuries inflicted through their bite, and their ability to transmit pathogens to humans, livestock, and wildlife. Whereas hard ticks have been intensively studied, little is known about soft ticks, even though they can also transmit pathogens, including African Swine Fever Virus (ASFV) affecting domestic and wild suids or Borrelia bacteria causing tick-borne relapsing fever (TBRF) in humans. We thus developed a regional model to identify suitable spatial areas for a community of nine Ornithodoros tick species (O. erraticus, O. sonrai, O. alactagalis, O. nereensis, O. tholozani, O. papillipes, O. tartakovskyi, O. asperus, O. verrucosus), which may be of medical and veterinary importance in the Western Palearctic region. Multi-Criteria Decision Analysis was used due to the relative scarcity of high-quality occurrence data. After an in-depth literature review on the ecological requirements of the selected tick community, five climate-related factors appeared critical for feeding activity and tick development: (i) a spring temperature exceeding 10°C to induce the end of winter soft tick quiescent period, (ii) a three-months summer temperature above 20°C to allow tick physiological activities, (iii) annual precipitation ranging from 60mm to 750mm and, in very arid areas, (iv) dry seasons interrupted by small rain showers to maintain minimum moisture inside their habitat along the year or (v) residual water provided by perennial rivers near habitats. We deliberately chose not to include biological factors such as host availability or vegetation patterns. A sensitivity analysis was done by performing multiple runs of the model altering the environmental variables, their suitability function, and their attributed weights. To validate the models, we used 355 occurrence data points, complemented by random points within sampled ecoregions. All models indicated suitable areas in the Mediterranean Basin and semi-desert areas in South-West and Central Asia. Most variability between models was observed along northern and southern edges of highly suitable areas. The predictions featured a relatively good accuracy with an average Area Under Curve (AUC) of 0.779. These first models provide a useful tool for estimating the global distribution of Ornithodoros ticks and targeting their surveillance in the Western Palearctic region.
Collapse
Affiliation(s)
- L Vial
- Centre of International Cooperation for Research in Agriculture Development (CIRAD), UMR ASTRE, F-34398 Montpellier, France; UMR ASTRE, Montpellier University, CIRAD, INRA, Montpellier, France.
| | | | - S Filatov
- National Scientific Center Institute of Experimental and Clinical Veterinary Medicine, Kharkiv, Ukraine.
| | - A Gerilovych
- National Scientific Center Institute of Experimental and Clinical Veterinary Medicine, Kharkiv, Ukraine.
| | - D S McVey
- Arthropod-borne Animal Diseases Research Unit, Center for Grain and Animal Health Research, United States; Department of Agriculture- Agricultural Research Service (USDA-ARS), Manhattan, Kansas, United States.
| | - I Sindryakova
- National Research Institute for Veterinary Virology and Microbiology (VNIIVViM), Pokrov, Russia.
| | - S Morgunov
- National Research Institute for Veterinary Virology and Microbiology (VNIIVViM), Pokrov, Russia.
| | - A A Pérez de León
- Knipling-Bushland U.S. Livestock Insects Research Laboratory and Veterinary Pest Genomics Center, United States; Department of Agriculture-Agricultural Research Service (USDA-ARS), Kerrville, Texas, United States.
| | - D Kolbasov
- National Research Institute for Veterinary Virology and Microbiology (VNIIVViM), Pokrov, Russia.
| | - E M De Clercq
- Georges Lemaitre Earth and Climate Research Centre, Earth and Life Institute, Université Catholique de Louvain (UCL), Louvain-La-Neuve, Belgium; Fonds de la Recherche Scientifique F.R.S. (FNRS), Brussels, Belgium.
| |
Collapse
|
3
|
van Schalkwyk OL, Knobel DL, De Clercq EM, De Pus C, Hendrickx G, Van den Bossche P. Description of Events Where African Buffaloes (Syncerus caffer) Strayed from the Endemic Foot-and-Mouth Disease Zone in South Africa, 1998-2008. Transbound Emerg Dis 2014; 63:333-47. [PMID: 25377758 DOI: 10.1111/tbed.12280] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2014] [Indexed: 11/29/2022]
Abstract
African buffaloes (Syncerus caffer) are reservoir hosts of Southern African Territories (SAT) foot-and-mouth disease (FMD) virus strains. In South Africa, infected buffaloes are found in the FMD-infected zone comprising the Kruger National Park (KNP) and its adjoining reserves. When these buffaloes stray into livestock areas, they pose a risk of FMD transmission to livestock. We assessed 645 records of stray buffalo events (3124 animals) from the FMD infected zone during 1998-2008 for (i) their temporal distribution, (ii) group size, (iii) age and gender composition, (iv) distance from the infected zone fence and (v) outcome reported for each event. A maximum entropy model was developed to evaluate spatial predictors of stray buffalo events and assess current disease control zones. Out of all buffaloes recorded straying, 38.5% escaped from the FMD infected zone during 2000/2001, following floods that caused extensive damage to wildlife fences. Escape patterns were not apparently influenced by season. The median size of stray groups was a single animal (IQR [1-2]). Adult animals predominated, comprising 90.4% (620/686) of the animals for which age was recorded. Of the 315 events with accurate spatial information, 204 (64.8%) were recorded within 1 km from the FMD infected zone. During late winter/spring (June-October), stray buffaloes were found significantly closer to the FMD infected zone (median = 0.3 km, IQR [0.1-0.6]). Less than 13% (40/315) of stray groups reached the FMD protection zone without vaccination, posing a higher risk of spreading FMD to these more susceptible livestock. Model outputs suggest that distance from the FMD infected zone, urban areas and permanent water sources contributed almost 85% to the spatial probability of stray buffalo events. Areas with a high probability for stray buffalo events were well covered by current disease control zones, although FMD risk mitigation could be improved by expanding the vaccination zone in certain areas.
Collapse
Affiliation(s)
- O L van Schalkwyk
- Centre for Veterinary Wildlife Studies, University of Pretoria, Onderstepoort, South Africa
| | - D L Knobel
- Department of Veterinary Tropical Diseases, University of Pretoria, Onderstepoort, South Africa
| | | | - C De Pus
- Institute of Tropical Medicine, Antwerpen, Belgium
| | | | | |
Collapse
|
4
|
De Clercq EM, Leta S, Estrada-Peña A, Madder M, Adehan S, Vanwambeke SO. Species distribution modelling for Rhipicephalus microplus (Acari: Ixodidae) in Benin, West Africa: comparing datasets and modelling algorithms. Prev Vet Med 2014; 118:8-21. [PMID: 25466219 DOI: 10.1016/j.prevetmed.2014.10.015] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2013] [Revised: 10/21/2014] [Accepted: 10/25/2014] [Indexed: 10/24/2022]
Abstract
Rhipicephalus microplus is one of the most widely distributed and economically important ticks, transmitting Babesia bigemina, B. bovis and Anaplasma marginale. It was recently introduced to West Africa on live animals originating from Brazil. Knowing the precise environmental suitability for the tick would allow veterinary health officials to draft vector control strategies for different regions of the country. To test the performance of modelling algorithms and different sets of environmental explanatory variables, species distribution models for this tick species in Benin were developed using generalized linear models, linear discriminant analysis and random forests. The training data for these models were a dataset containing reported absence or presence in 104 farms, randomly selected across Benin. These farms were sampled at the end of the rainy season, which corresponds with an annual peak in tick abundance. Two environmental datasets for the country of Benin were compared: one based on interpolated climate data (WorldClim) and one based on remotely sensed images (MODIS). The pixel size for both environmental datasets was 1 km. Highly suitable areas occurred mainly along the warmer and humid coast extending northwards to central Benin. The northern hot and drier areas were found to be unsuitable. The models developed and tested on data from the entire country were generally found to perform well, having an AUC value greater than 0.92. Although statistically significant, only small differences in accuracy measures were found between the modelling algorithms, or between the environmental datasets. The resulting risk maps differed nonetheless. Models based on interpolated climate suggested gradual variations in habitat suitability, while those based on remotely sensed data indicated a sharper contrast between suitable and unsuitable areas, and a patchy distribution of the suitable areas. Remotely sensed data yielded more spatial detail in the predictions. When computing accuracy measures on a subset of data along the invasion front, the modelling technique Random Forest outperformed the other modelling approaches, and results with MODIS-derived variables were better than those using WorldClim data. The high environmental suitability for R. microplus in the southern half of Benin raises concern at the regional level for animal health, including its potential to substantially alter transmission risk of Babesia bovis. The northern part of Benin appeared overall of low environmental suitability. Continuous surveillance in the transition zone however remains relevant, in relation to important cattle movements in the region, and to the invasive character of R. microplus.
Collapse
Affiliation(s)
- E M De Clercq
- Research Fellow FNRS, Georges Lemaître Institute for Earth and Climate Research, Université catholique de Louvain, Place Louis Pasteur 3, 1348 Louvain-la-Neuve, Belgium.
| | - S Leta
- Adami Tullu Agricultural Research Center, P.O.Box 35, Adami Tullu, Ethiopia
| | - A Estrada-Peña
- Dept. of Parasitology, Veterinary Faculty, Miguel Servet 177, 50013 Zaragoza, Spain
| | - M Madder
- Vector Biology Unit, Institute of Tropical Medicine, Nationalestraat 155, 2000 Antwerp, Belgium; Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort 0110, Pretoria, South Africa
| | - S Adehan
- Institut National des Recherches Agricoles du Benin-INRAB, 01 BP 884 Cotonou, Benin
| | - S O Vanwambeke
- Adami Tullu Agricultural Research Center, P.O.Box 35, Adami Tullu, Ethiopia
| |
Collapse
|
5
|
Adakal H, Biguezoton A, Zoungrana S, Courtin F, De Clercq EM, Madder M. Alarming spread of the Asian cattle tick Rhipicephalus microplus in West Africa-another three countries are affected: Burkina Faso, Mali and Togo. Exp Appl Acarol 2013; 61:383-6. [PMID: 23722233 DOI: 10.1007/s10493-013-9706-6] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2013] [Accepted: 05/20/2013] [Indexed: 05/24/2023]
Affiliation(s)
- H Adakal
- Centre international de recherche-développement sur l'élevage en zone subhumide (CIRDES), 01 B.P. 454, Bobo-Dioulasso, Burkina Faso,
| | | | | | | | | | | |
Collapse
|
6
|
Dekoninck W, Hendrickx F, Versteirt V, Coosemans M, De Clercq EM, Hendrickx G, Hance T, Grootaert P. Changes in species richness and spatial distribution of mosquitoes (Diptera: Culicidae) inferred from museum specimen records and a recent inventory: a case study from Belgium suggests recent expanded distribution of arbovirus and malaria vectors. J Med Entomol 2013; 50:237-243. [PMID: 23540109 DOI: 10.1603/me12134] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Mosquito (Diptera: Culicidae) distribution data from a recent inventory of native and invading mosquito species in Belgium were compared with historical data from the period 1900-1960 that were retrieved from a revision of the Belgian Culicidae collection at the Royal Belgian Institute of Natural Sciences. Both data sets were used to investigate trends in mosquito species richness in several regions in Belgium. The relative change in distribution area of mosquito species was particularly important for species that use waste waters and used tires as larval habitats and species that recently shifted their larval habitat to artificial larval habitats. More importantly, several of these species are known as vectors of arboviruses and Plasmodium sp. and the apparent habitat shift of some of them brought these species in proximity to humans. Similar studies comparing current mosquito richness with former distribution data retrieved from voucher specimens from collections is therefore encouraged because they can generate important information concerning health risk assessment at both regional and national scale.
Collapse
Affiliation(s)
- W Dekoninck
- Royal Belgian Institute of Natural Sciences, Department Entomology, Vautierstraat 29, B-1000 Brussels, Belgium.
| | | | | | | | | | | | | | | |
Collapse
|
7
|
De Clercq EM, Vanwambeke SO, Sungirai M, Adehan S, Lokossou R, Madder M. Geographic distribution of the invasive cattle tick Rhipicephalus microplus, a country-wide survey in Benin. Exp Appl Acarol 2012; 58:441-452. [PMID: 22689006 DOI: 10.1007/s10493-012-9587-0] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2012] [Accepted: 05/26/2012] [Indexed: 06/01/2023]
Abstract
The cattle tick Rhipicephalus microplus is currently invading the West African region, and little information is available on the spread of this exotic tick in this region. We set out a country-wide field survey to determine its current distribution in Benin. Ticks were collected on cattle from 106 farms selected by random sampling covering all regions of the country. Rhipicephalus annulatus was found on 70 % of all farms, R. decoloratus on 42 %, R. geigyi on 58 %, and R. microplus on 49 %. There is a clear geographic separation between the indigenous Rhipicephalus species and R. microplus. Rhipicephalus annulatus occurs mainly in the northern departments, but it was also observed in lower numbers in locations in the south. The presence of R. decoloratus is limited to the northern region, and in most locations, this tick makes up a small proportion of the collected ticks. The tick R. geigyi tends to be dominant, but occurs only in the four northern departments. The observations concerning R. microplus are entirely different, this species occurs in the southern and central region. The results of this survey confirm the invasive character and displacement properties of R. microplus, since in less than a decade it has colonized more than half of the country and has displaced indigenous ticks of the same genus in many of the sampled locations.
Collapse
Affiliation(s)
- E M De Clercq
- Georges Lemaître Institute for Earth and Climate Research, Université catholique de Louvain, Place Louis Pasteur 3, 1348 Louvain-la-Neuve, Belgium.
| | | | | | | | | | | |
Collapse
|
8
|
De Clercq EM, Vanwambeke SO, Sungirai M, Adehan S, Lokossou R, Madder M. Geographic distribution of the invasive cattle tick Rhipicephalus microplus, a country-wide survey in Benin. Exp Appl Acarol 2012; 58:441-452. [PMID: 22689006 DOI: 10.1007/s10493-012-9587-0/tables/2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Received: 04/27/2012] [Accepted: 05/26/2012] [Indexed: 05/24/2023]
Abstract
The cattle tick Rhipicephalus microplus is currently invading the West African region, and little information is available on the spread of this exotic tick in this region. We set out a country-wide field survey to determine its current distribution in Benin. Ticks were collected on cattle from 106 farms selected by random sampling covering all regions of the country. Rhipicephalus annulatus was found on 70 % of all farms, R. decoloratus on 42 %, R. geigyi on 58 %, and R. microplus on 49 %. There is a clear geographic separation between the indigenous Rhipicephalus species and R. microplus. Rhipicephalus annulatus occurs mainly in the northern departments, but it was also observed in lower numbers in locations in the south. The presence of R. decoloratus is limited to the northern region, and in most locations, this tick makes up a small proportion of the collected ticks. The tick R. geigyi tends to be dominant, but occurs only in the four northern departments. The observations concerning R. microplus are entirely different, this species occurs in the southern and central region. The results of this survey confirm the invasive character and displacement properties of R. microplus, since in less than a decade it has colonized more than half of the country and has displaced indigenous ticks of the same genus in many of the sampled locations.
Collapse
Affiliation(s)
- E M De Clercq
- Georges Lemaître Institute for Earth and Climate Research, Université catholique de Louvain, Place Louis Pasteur 3, 1348 Louvain-la-Neuve, Belgium.
| | | | | | | | | | | |
Collapse
|
9
|
Versteirt V, De Clercq EM, Fonseca DM, Pecor J, Schaffner F, Coosemans M, Van Bortel W. Bionomics of the established exotic mosquito species Aedes koreicus in Belgium, Europe. J Med Entomol 2012; 49:1226-1232. [PMID: 23270149 DOI: 10.1603/me11170] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Adults of an exotic mosquito, Aedes (Finlaya) koreicus (Edwards) (Diptera: Culicidae) were identified by morphology and genotyping from one site in Belgium in 2008. In late summer of that year, the occurrence of adults and immature stages reconfirmed its presence. This is the first record of this species outside its native range and in particular in Europe. Two subsites of the original location were prospected from April until October 2009 with different traps to evaluate the extent of its presence and establishment in the area and to understand the dynamics of the species' population. Next to Ae. koreicus, 15 other mosquito species were collected. Adult individuals of Ae. koreicus were found from May to September and larvae were still found early October. Larvae were mainly retrieved from artificial containers both in 2008 as in 2009. Containers with eggs and/or larvae were found up to 4 km away from the initial location, indicating the species is spreading locally. Though the introduction route is unknown, it may have occurred via international trade as a large industrial center was located nearby. A comparison of different climatic variables between locations in Belgium with Ae. koreicus and putative source locations in South Korea, revealed similarities between winter temperatures and the number of freezing days and nights in four consecutive years (2004-2008), while humidity and precipitation values differed strongly. The introduction of a new potential disease vector into Europe seems to be a result of proper entrance points, created by intense worldwide trade and suitable environmental conditions.
Collapse
Affiliation(s)
- V Versteirt
- Department of Parasitology, Institute of Tropical Medicine, Nationalestraat 155, B-2000 Antwerp, Belgium
| | | | | | | | | | | | | |
Collapse
|
10
|
Dekoninck W, Hendrickx F, Vasn Bortel W, Versteirt V, Coosemans M, Damiens D, Hance T, De Clercq EM, Hendrickx G, Schaffner F, Grootaert P. Human-induced expanded distribution of Anopheles plumbeus, experimental vector of West Nile virus and a potential vector of human malaria in Belgium. J Med Entomol 2011; 48:924-8. [PMID: 21845955 DOI: 10.1603/me10235] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
For the majority of native species, human-created habitats provide a hostile environment that prevents their colonization. However, if the conditions encountered in this novel environment are part of the fundamental niche of a particular species, these low competitive environments may allow strong population expansion of even rare and stenotopic species. If these species are potentially harmful to humans, such anthropogenic habitat alterations may impose strong risks for human health. Here, we report on a recent and severe outbreak of the viciously biting and day-active mosquito Anopheles plumbeus Stephens, 1828, that is caused by a habitat shift toward human-created habitats. Although historic data indicate that the species was previously reported to be rare in Belgium and confined to natural forest habitats, more recent data indicate a strong population expansion all over Belgium and severe nuisance at a local scale. We show that these outbreaks can be explained by a recent larval habitat shift of this species from tree-holes in forests to large manure collecting pits of abandoned and uncleaned pig stables. Further surveys of the colonization and detection of other potential larval breeding places of this mosquito in this artificial environment are of particular importance for human health because the species is known as a experimental vector of West Nile virus and a potential vector of human malaria.
Collapse
Affiliation(s)
- W Dekoninck
- Department Entomology, Royal Belgian Institute of Natural Sciences, Vautierstraat 29, B-1000 Brussels, Belgium.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Peters J, De Baets B, Van Doninck J, Calvete C, Lucientes J, De Clercq EM, Ducheyne E, Verhoest NEC. Absence reduction in entomological surveillance data to improve niche-based distribution models for Culicoides imicola. Prev Vet Med 2011; 100:15-28. [PMID: 21496932 DOI: 10.1016/j.prevetmed.2011.03.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2010] [Revised: 03/10/2011] [Accepted: 03/10/2011] [Indexed: 11/15/2022]
Abstract
Data-driven models for the prediction of bluetongue vector distributions are valuable tools for the identification of areas at risk for bluetongue outbreaks. Various models have been developed during the last decade, and the majority of them use linear discriminant analysis or logistic regression to infer vector-environment relationships. This study presents a performance assessment of two established models compared to a distribution model based on a promising ensemble learning technique called Random Forests. Additionally, the impact of false absences, i.e. data records of suitable vector habitat that are, for various reasons, incorrectly labelled as absent, on the model outcome was assessed using alternative calibration-validation schemes. Three reduction methods were applied to reduce the number of false absences in the calibration data, without loss of information on the environmental gradient of suitable vector habitat: random reduction and stratified reduction based on the distance between absence and presence records in geographical (Euclidean distance) or environmental space (Mahalanobis distance). The results indicated that the predicted vector distribution by the Random Forest model was significantly more accurate than the vector distributions predicted by the two established models (McNemar test, p<0.01) when the calibration data were not reduced with respect to false absences. The performance of the established models, however, increased considerably by application of stratified false absence reductions. Model validation revealed no significant difference between the performance of the three distinct Culicoides imicola distribution models for the majority of alternative stratified reduction schemes. The main conclusion of this study is that the application of Random Forests, or linear discriminant analysis and logistic regression on the condition that calibration data were first reduced on geographical or environmental information, potentially lead toward better vector distribution models.
Collapse
Affiliation(s)
- J Peters
- KERMIT, Department of Applied Mathematics, Biometrics and Process Control, Ghent University, Coupure Links, Gent, Belgium.
| | | | | | | | | | | | | | | |
Collapse
|