DNA identification of species of the Anopheles maculipennis complex and first record of An. daciae in Belgium.

The present study aimed at identifying the members of the Anopheles maculipennis complex (Diptera: Culicidae) occurring in Belgium. Therefore, the second internal transcribed spacer of nuclear ribosomal DNA (ITS2) and the mitochondrial cytochrome oxidase subunit I (COI) loci were sequenced in 175 and 111 specimens, respectively, collected between 2007 and 2019. In parallel, the suitability of two species-diagnostic PCR-RFLP assays was tested. The identified specimens included: An. maculipennis s.s. (N = 105), An. daciae (N = 62), An. atroparvus (N = 6) and An. messeae (N = 2). Each species was characterized by unique ITS2 haplotypes, whereas COI only supported the monophyly of An. atroparvus, a historical malaria vector in Belgium. Species identification results were further supported by unique PCR-RFLP banding patterns. We report for the first time An. daciae in Belgium, where it was found to co-occur with An. maculipennis s.s. The latter was the most prevalent in the collection studied (60%) and appears to have the widest distribution in Belgium. As in other studies, An. daciae and An. messeae appeared the most closely related species, up to the point that their species status remains debatable, while their ecological differences, including vector competences, need further study.

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.

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.

Nationwide inventory of mosquito biodiversity (Diptera: Culicidae) in Belgium, Europe.

To advance our restricted knowledge on mosquito biodiversity and distribution in Belgium, a national inventory started in 2007 (MODIRISK) based on a random selection of 936 collection points in three main environmental types: urban, rural and natural areas. Additionally, 64 sites were selected because of the risk of importing a vector or pathogen in these sites. Each site was sampled once between May and October 2007 and once in 2008 using Mosquito Magnet Liberty Plus traps. Diversity in pre-defined habitat types was calculated using three indices. The association between species and environmental types was assessed using a correspondence analysis. Twenty-three mosquito species belonging to traditionally recognized genera were found, including 21 indigenous and two exotic species. Highest species diversity (Simpson 0.765) and species richness (20 species) was observed in natural areas, although urban sites scored also well (Simpson 0.476, 16 species). Four clusters could be distinguished based on the correspondence analysis. The first one is related to human modified landscapes (such as urban, rural and industrial sites). A second is composed of species not associated with a specific habitat type, including the now widely distributed Anopheles plumbeus. A third group includes species commonly found in restored natural or bird migration areas, and a fourth cluster is composed of forest species. Outcomes of this study demonstrate the effectiveness of the designed sampling scheme and support the choice of the trap type. Obtained results of this first country-wide inventory of the Culicidae in Belgium may serve as a basis for risk assessment of emerging mosquito-borne diseases.

Human-induced expanded distribution of Anopheles plumbeus, experimental vector of West Nile virus and a potential vector of human malaria in Belgium.

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.

Introduction and establishment of the exotic mosquito species Aedes japonicus japonicus (Diptera: Culicidae) in Belgium.

The establishment of the potential vector species Aedes (Finlaya) japonicusjaponicus (Theobald) (Diptera: Culicidae) in southern Belgium is reported. The species was most likely introduced through the international trade in used tires. It was first collected in 2002 on the premises of a second-hand tire company and was sampled using different sampling methods in the two consecutive years (2003-2004). It was only in 2007 and 2008, during a national mosquito survey (MODIRISK), that its presence as adults and larvae at the above-mentioned site and at another tire company in the area was confirmed based on morphological and molecular identification. This discovery is the first record for Belgium of an exotic mosquito species that established successfully and raises the question on the need for monitoring and control. Considering the accompanying species found during the surveys, we also report here the first observation of Culex (Maillotia) hortensis hortensis (Ficalbi) in Belgium.

Identification of Belgian mosquito species (Diptera: Culicidae) by DNA barcoding.

Since its introduction in 2003, DNA barcoding has proven to be a promising method for the identification of many taxa, including mosquitoes (Diptera: Culicidae). Many mosquito species are potential vectors of pathogens, and correct identification in all life stages is essential for effective mosquito monitoring and control. To use DNA barcoding for species identification, a reliable and comprehensive reference database of verified DNA sequences is required. Hence, DNA sequence diversity of mosquitoes in Belgium was assessed using a 658 bp fragment of the mitochondrial cytochrome oxidase I (COI) gene, and a reference data set was established. Most species appeared as well-supported clusters. Intraspecific Kimura 2-parameter (K2P) distances averaged 0.7%, and the maximum observed K2P distance was 6.2% for Aedes koreicus. A small overlap between intra- and interspecific K2P distances for congeneric sequences was observed. Overall, the identification success using best match and the best close match criteria were high, that is above 98%. No clear genetic division was found between the closely related species Aedes annulipes and Aedes cantans, which can be confused using morphological identification only. The members of the Anopheles maculipennis complex, that is Anopheles maculipennis s.s. and An. messeae, were weakly supported as monophyletic taxa. This study showed that DNA barcoding offers a reliable framework for mosquito species identification in Belgium except for some closely related species.

Further observations showing the impact of the probenecid test in movement disorders.

Two patients with movement disorders are described and neurochemically studied. The first subject concerns a central anticholinergic syndrome in a 83 years old man treated with l-dopa and amantadine for red nucleus tremor. The second one is an association of parkinsonism and chorea in a 76 years old woman presenting with FAHR's syndrome. In both cases, CSF HVA levels were measured before and after oral probenecid load. The observations confirm the usefulness of this neurochemical strategy in order to classify aging patients with parkinsonism into dopasensitive and doparesistant groups.

[Quantitative rheoencephalographu in normal and pathological ageing (author's transl)]. / La rhéoencéphalographie quantitative dans le vieillissement normal et pathologique

A method of quantitative rheoencephalography estimating the rapid cerebral blood flow, defined by the clearance of Xe 133 is applied to normal, hemiplegic and demented subjects. In the normal child the flow is twice that of the elderly. In adults a decrease of 13% is observed in the fifties. The flow is decreased in both hemispheres of the hemiplegics. The cerebral flow is decreased in the two clinical groups of demented patients (vascular and non-vascular); different values of flow are obtained in these two groups.

[Use of the probenecid test for the diagnosis and treatment of Parkinsonism. Review of the literature and personal experience (author's transl)]. / Apports du test au probénécide au diagnostic et à la thérapeutique des parkinsoniens. Revue de la littérature et études personnelles.

After describing the clinical picture of Parkinsonism, other Parkinson and depressive syndromes, the authors clarify ascending dopaminergic and serotoninergic pathways in the central nervous system as well as current knowledge on the nigro-striatal pathway. They also underline the interest of the probenecid test in the diagnosis of Parkinsonsism with or without depression. Neurochemical criteria of dopa-sensititivy and dopa-resistance are proposed as well as criteria aimed at serotoninergic therapy. Finally, the use of this neurochemical test in treatment and follow up is illustrated by a clinical case report.

[Emphysematous pyelitis and pyelonephritis: unrecognized clinical entities]. / Pyélite et pyélonéphrite emphysémateuses: entités cliniques méconnues.

A case of emphysematous pyelitis occurring in an old diabetic woman is described. The data of the literature about the pathologic agents, the epidemiology and the physiopathology of the disease are reviewed. The approach for diagnosis and the therapy are discussed.

[Ageing and cerebral vascular sclerosis: myth or reality? (author's transl)]. / Viellissement et sclérose vascularie cérébrale: réalité ou utopie?

The most important aspects of normal and pathological brain ageing are considered from a structural, cellular, hemodynamical, chemical and clinical point of view. It seems admitted that cerebral blood flow and cerebral consumption for oxygen decrease with age but when severe health criteria are used to select normal old subjects, no significant differences exist between normal young and optimally healthy elderly. The question arises whether the blood flow reductions are responsible for the alterations in metabolism, or whether it is simply an auto-regulatory response to the lesser metabolic demands of the tissue. The part of cerebral arteriosclerosis is questioned on cerebral flow drop accompanying clinical signs in senile mental impairment. Among some cardiovascular risk factors, hypertension seems to play a leading part in acute and chronic neurological diseases associated with age and with certain types of senile dementia (multi-infarct). However in all other cases, hypertension and cerebral vascular insufficiency, for all that this syndrome exists, seem to have been overestimated to explain chronic senile brain deterioration.

[Aging and cerebral vascular sclerosis: myth or reality?]. / Vieillissement et sclérose vasculaire cérébrale: réalité ou utopie?

The most important aspects of normal and pathological brain ageing are considered from a structural, cellular, hemodynamical, chemical and clinical point of view. It seems admitted that cerebral blood flow and cerebral consumption for oxygen decrease with age but when severe health criteria are used to select normal old subjects, no significant differences exist between normal young and optimally healthy elderly. The question arises whether the blood flow reductions are responsible for the alterations in metabolism, or whether it is simply an autoregulatory response to the lesser metabolic demands of the tissue. The part of cerebral arteriosclerosis is questioned on cerebral flow drop accompanying clinical signs in senile mental impairment. Among some cardiovascular risk factors, hypertension seems to play a leading part in acute and chronic neurological diseases associated with age and with certain types of senile dementia (multi-infarct). However in all other cases, hypertension and cerebral vascular insufficiency, for all that this syndrome exists, seem to have been overestimated to explain chronic senile brain deterioration.

Comparative study of cerebral vasoactivity in vascular sclerosis of the brain in elderly men.

Thirty-five elderly patients underwent a systematic series of cerebrovascular examinations. The patients were divided into three groups on the basis of clinical criteria: normal patients (Group 1), patients with sequelae of a previous stroke or with minor mental disorders (Group 2), and patients with arteriosclerosis dementia (Group 3). The vasomotor reactions of the cerebral arteries were investigated by estimating regional cerebral blood flow (133Xe clearance technique). The authors emphasize the existence of cerebral vasoreactivity in subjects with clinical symptoms of senile dementia. Furthermore, in each of the three groups of elderly patients, there seemed to be a lack of correlation between the clinical symptoms and certain specific vascular examinations.

Cerebral vasoreactivity in senile dementia.

A group of clinical senile dementia patients underwent a series of cerebrovascular examinations. Some of them were standard examinations (fundus oculi, electroencephalogram, rheoencephalogram, cerebral angiogram and pneumonencephalogram) while the others were studying regional cerebral blood flow (rCBF) and modification of flow under fonctional tests (hypercapnia, hypocapnia and intravenous injection of 50 mg chl. papaverine) using the 133Xe clearance technique. The senile dementia group (III) was compared with 'normal' old patients group (I) and with patients suffering from sequelae of a previous stroke or from minor mental disorders (group II). Elderly subjects regarded as 'normal' often present alterations in usual vascular examinations but reveal a relative integrity of cerebral autoregulation. Some patients considered irreversibly 'sclerotic' still have a good grey matter flow (r1CBF) with real vasomotor possibilities. In each of the three groups of elderly subjects, there seemed to be a lack of correlation between the clinical symptoms and certain specific vascular examination.

Comparative study of the clinical effects of vincamine + glycerol versus glycerol + placebo in the acute phase of stroke.

The treatment of the acute phase of stroke creates a difficult problem to the clinician. The presently used drugs lead to controversial results. The progress in knowledge of the pathogenesis of cerebral damage underlines the determinant role of the metabolic deficits in the ischemic areas. The effect on the clinical symptomatology of patients in the acute phase of stroke was studied during a double-blind comparative clinical trial with an alcaloid of Vinca minor (Pervincamine) which acts favorably against disturbances of oxydative glucose metabolism and of cerebral microcirculation. 20 patients divided into two homogeneous groups received during 5 days either Pervincamine (4 ampoules of 3 ml = 60 mg vincamine p.d.) + glycerol, or glycerol + placebo administered by i.v. infusion. Clinically the results indicate a greater improvement of the neurological status (objectivated by a neurological scale) with vincamine treatment than with placebo. Statistically the analysis confirms the highly significant effect of vincamine on motility of lower and upper limbs (p less than 0.02) and the significant effect on cranial nerves (homonymous hemianopsia and conjugated deviation of eyes) (p less than 0.05) and on the sphincter control level (p less than 0.05).

[Comparative study of changes in electroencephalographic and rheoencephalographic recordings with advancing age (author's transl)]. / Etude comparative electroencéphalographique et rhéoencéphalographique dans le vieillissement.

The correlation between the frequency index of the left parietotemporal E.E.G., and cerebral blood flow determined by rheoencephalography, was studied in 20 normal children (aged 8 to 13 years), 24 normal adults (18 to 45 years), 15 normal elderly subjects (78 to 95 years), and 37 patients with pathological disorders. A significant correlation was found in each group between the E.E.G. frequency index and blood flow rate. The occupation times correlating with the flow were: rapid rhythms in children, alpha rhythms (negative correlation) in normal adults, slow rhythms (negative correlations) in elderly subjects, and slow rhythms (negative correlation) in patients with pathological disorders.