Blida Region Research Articles

Seismic risk assessment for the downtown of the city of Blida, Algeria

Blida (Algeria) is characterized by a high level of seismic exposure and vulnerability due to its dense population and the presence of aging buildings. The historical earthquake that occurred in 1825, with a moment magnitude (Mw7.1), underscored the urgent need for a thorough assessment of seismic risk in the area. Here, an extensive study conducted in downtown of the city of Blida to evaluate seismic risk and its consequences is presented. Geounits 141 and 148 emerged as the most severely affected in all the simulated earthquake scenarios indicating severe damage and casualties mainly for closest earthquakes (Blida and Bounaian, both with moment magnitude Mw7.1) but also for furthest earthquakes as Mouzaia El Affroun (Mw6.6), and Hammam Melouane (Mw6.5). The sensitivity analysis demonstrated the importance of the selection of the performance point computation method (improved displacement coefficient method -IDCM, modified capacity spectrum-MADRS, and nonlinear analysis method-N2) and the choice of the ground motion prediction equation. IDCM results are less influenced by the choice of the GMPE, but they provide higher damage results expressed as a mean damage ratio. Moreover, the study estimated potential human impacts in the Blida region, highlighting varying levels of impact on different geounits under different earthquake scenarios. The study's primary findings from seismic risk assessments in the studied region highlight its high susceptibility to earthquakes and can be summarized as follows: The mean damage ratio will be 52.6% ± 1.4%, 50.9% ± 1.6%; 31.8% ± 3.4% and 21.4% ± 3.1% for the Blida, Bounaian, Mouzaia El Affroun and Hammam Melouane earthquakes respectively.

Solar thermal energy to drive ejector HVAC systems: A numerical study under Blida climatic conditions

This paper aims to show factors that have a direct impact on solar air conditioners that use the ejector as an alternative to the compressor to reduce electricity consumption in the refrigeration field. The weather data of the Blida region were selected as the main data for conducting this study. A parabolic trough solar collector has been made as a solar device to provide the thermal energy needed for the generator. All the mathematical equations that dominate the system have been analyzed and then numerically simplified using Engineering Equation Solver software. The optical efficiency of the studied solar collector was 65.02%, while its maximum value of thermal efficiency was only 60.46%. Regarding the thermal ratio of the studied machine, it reached 0.54. Serious exploitation of this technology will help solve the problem of high consumption of electricity in the hot seasons and also contribute to the preservation of the environment by using water (R718) as a refrigerant.

Evaluation of the anti-inflammatory, antispasmodic and healing effects of walnut leaves Juglans regia L. aqueous extract.

As a part of the valorisation of medicinal plants of the Algerian flora, we have undertaken a study of plant extract ( Juglans regia L.) growing in the Blida region, Algeria. The main objective of this work is to evaluate the in vivo pharmacological effects, namely the anti-inflammatory, antispasmodic and healing effects of common walnuts’s leaves aqueous extracts and ointment. The Carrageenan-induced paw edema test is used for screening of anti-inflammatory activity on 4 batches of mice (control batch, treated batch with Diclofenac® , treated batches with the aqueous extract at 5 and 10%), the analgesic effect was conducted using Acetic acid-induced endogenous spasm test, and the healing effect was conducted on rabbits. The anti-inflammatory test performed on laboratory mice, revealed a remarkable anti-inflammatory effect of the aqueous extract comparing with chosen standard pharmaceutical molecule (Diclofenac®), with a reduction percentage of 25 and 31.72 % for the aqueous extract and Diclofenac® respectively. The results for the analgesic effect was revealed to be significant comparing with those obtained with the reference product Spasfon. Finally, the healing effect was performed on rabbits, revealing high healing power comparing with those obtained with pharmaceutical healing paste ‘MADICASSOL” used as a reference. The ointment prepared using walnut leaves has shown more effectiveness with delay of healing less than a week compared to the ointment of reference which took almost 10 days for total healing effect. The obtained results confirm some information obtained during the ethnobotanical survey in a previous study; and that Juglans regia L. is endowed with an anti-inflammatory, antispasmodic and healing properties.

Heat transfer, entropy generation, economic and environmental analyses of linear fresnel reflector using novel rGO-Co3O4 hybrid nanofluids

This work aims to enhance the heat transfer of a small prototype linear Fresnel reflector by using rGO-Co3O4/water hybrid nanofluids at a location in Blida region, in Algeria. Hybrid nanofluids, with varying concentrations (0.05, 0.10, and 0.20 wt%) and temperatures (20–60 °C), are prepared. For 0.2 wt % of rGO-Co3O4 nanofluids, the viscosity and density increased by 70.83%, and 0.47%, respectively, while the specific heat decreased by 0.17% at a temperature of 60 °C over the base fluid data. The receiver pipe energy balance equations are solved using MATLAB software. With the use of 0.2 wt% of hybrid nanofluid, the mean thermal efficiency enhanced by 2.75%–31.95%, the mean exergy efficiency improved by 23.67%–2.27%, and the mean temperature increased by 9.42 °C, while, the receiver pipe temperature decreased by 2.69 °C. In addition, the mean heat transfer coefficient, mean thermal conductivity, Nusselt number, and the performance evaluation criteria were improved by using rGO-Co3O4/water nanofluid at 0.2 wt % by 309.67%, 19.31%, 254.75%, and 240.92%, respectively, while the mean entropy generation and electrical energy consumption decreased by 59.48% and 20.30%, respectively, as the CO2 emission mitigation was 253.94 kg.

Acute coronary syndrome, profile of latecomers in the region of Blida (Algeria) and the implication of the medical staff

Acute coronary syndrome (ACS) management responds to the imperatives of time, this is articulated around clear deadlines whose reduction is a challenge of which will depend the prognosis, we aimed by this work to evaluate ACS management and its delays in the region of blida and its surroundings. We conducted a prospective, descriptive, single-center study of 222 patients admitted to the cardiovascular intensive care unit of Blida University hospital for the management of ACS over a four-month period (10/2018–02//2019). We mainly studied the delays and factors involved in their lengthening before and after appearance of the pathology. 76% of our patients were males (sex ratio 3.1), 47% were hypertensive, 39% were diabetic and 38% were smokers. Nearly 55% live in Blida, the rest came frome farther (50 to 450 km). 43% were hospitalized for STEMI and 57% NSTEMI. The average time for reperfusion (chest pain-reperfusion) was at 1536 min in NSTEMI while 58% of patients received for STEMI were reperfused within 6 hours. The average system delay (1st medical contact-reperfusion) was at 314 minutes for STEMI and 890 minutes for NSTEMI. Only 18% of the patients came directly to our level, 82% were viewed at least by one other center (non-capable of primary PCI or thrombolysis). An under equipated ambulance (45%) and the private vehicle (38%) were the main means of transport, only 01% of patients were transfered by medical emergency transport (SAMU). despite 52% of previous follow-ups in medical consultations, only 15% of the patients had a good knowledge of their cardiovascular pathology and only 18% were sensibilized to the risk of occurrence of ACS. We have relatively long delays in ACS management in our region, this work identify certain factors affecting directly this delay; in addition to a poorly organized network, there is a real inertia in the sensiblization of these patients despite their previous follow in consultation.

Integration of a solar cooling and heating system. Case of a residential building located in Blida region

The object of the present study is the integration of a solar cooling and heating system of a residential building (4-flour) located in Blida region in Algeria. The system consists of a set of solar collectors that supply energy to a balloon through an external heat exchanger. The solar and auxiliary tanks are connected by a heat exchanger immersed in the bottom of the auxiliary tank. In the distribution loop, a recirculation can make possible to obtain the domestic hot water set point temperature. A cold production system is directly connected to the solar tank and a regulation system ensures the control of the installation. We have used the TRANSOL software under TRANSYS to calculate the heating and cooling load. Several parameters are then introduced to size and evaluate the performance of our installation. The results obtained are satisfactory .

Impact of vitamin D supplementation model on the circulating levels of 25 (OH) D in Algerian children aged 1–23 months

Vitamin D deficiency is a public health problem around the world. In Algeria, the nutritional situation is still subject to uncertainties. In order to evaluate the vitamin D status and to know the impact of the current vitamin D supplementation model on the circulating levels of 25 (OH) D, an investigation was conducted on a group of Algerian children. The study was conducted in the Blida region (Northern Algeria). Sampling focused on 150 healthy children, aged between 1 and 23 months old, recruited from Ben Boulaïd hospital pediatric ward. 83% of children (n = 125) have been supplemented with vitamin D (D3 B.O.N®) according to a scheme currently designed in Algeria (the first intake of 200 000 IU at 1 month and the second intake of 200 000 IU at 6 months). 17% of children (n = 25) have escaped from a supplementation. The average values of 25(OH) D are respectively: 51 ± 20 μg/L for 103 supplement children with vitamin D (25 (OH)D ≤ 100 μg/L), 222 ± 106 μg/L for 22 supplement children with vitamin D (25(OH) D > 100 μg/L) and 30 ± 16 μg/L for 25 non-supplement children with vitamin D. The prevalence of vitamin D deficiency is lower (4%) among the children group with vitamin D supplement. These results show that the vitamin D supplementation model seems entirely efficient on the improvement of vitamin D status.

Seismic vulnerability assessment at urban scale: Case of Algerian buildings

The main purpose of risk reduction methodological and operational approaches is to protect lives and properties against the impact of natural or industrial disaster. Although it is unrealistic to expect to live in a risk free environment, it is possible to reduce this risk through appropriate prediction and management strategies.This work presents an integrated framework for seismic damage assessment at urban scale in Algeria. Its main objective is the proposal of simplified methodological and operational approaches to assess urban vulnerability and socio-economic losses. It relies on the performance of probable seismic scenarios in urban areas exposed to earthquakes. This will enable decision makers to take adequate preventive measures and develop appropriate mitigation strategies, i.e. crisis prevention and management plans to reduce the losses.It deals with the assessment of building seismic risk of urban areas in Algeria by using the RADIUS Model (Risk Assessment Tools for Diagnosis of Urban Areas against Seismic Disaster) after a prior adaptation to the Algerian context. It estimates also the expected number of victims and their spatial distributions.This concept is adopted to estimate the urban seismic risk of the Great-Blida region (consisting of 4 cities, namely Blida, Ouled-Yaïch, Bouarfa and Beni-Mered), west of Algiers region, by performing an earthquake scenario. The region of Blida has experienced strong earthquakes during the last centuries generating seismic intensities ranging between X and XI, of which that most significant, occurred on Mars 2, 1825. It represents an important administrative, military, economic and scientific pole, and features a high concentration of population (1390 inhabitants/km2). In order to draw reliable results, an extensive survey was carried out concerning the buildings (approximately 46,000 units). The data were mapped and stored in databases using GIS tools. The results of this earthquake scenario show that serious damages would be observed in the studied area.The results reported in this study will drive the decision-making, by the local authorities, adapted to the specific socio-environmental vulnerability context at the Great-Blida urban scale. For this purpose, the paper proposes a list of operational measures contributing to the seismic risk reduction, relying on the resilience-building demand.A complementary study, i.e. a separate paper (second part), deals about assessment of seismic risk related to road infrastructures and lifelines devoted to the Algerian urban context.

Prevalence of diabetes and dyslipidemia in hypertensive patients in the area of Blida (Algeria)

PurposeDiabetes mellitus (DM) and lipid disorders (LD) in hypertensive patients are associated with an increased risk of cardiovascular complications requiring follow-up and more aggressive therapeutic strategies. The main objective of this study was to describe the prevalence of DM and LD in adult hypertensive patients followed in specialized consultation of hypertension in the region of Blida (North Algeria) during the period from January 2013 to June 2017. Materials and methodsWe included 3268 hypertensive patients (1453 men and 1815 women), mean age of 58.3±13.8years. Descriptive statistics were used to estimate means by sex and age for subgroups [under 30, 30–39, 40–49, 50–60, over 70]. A linear regression was used to determine annual trends. The age and sex specific results were adjusted to the general population data of the city of Blida for a period of 4years and each year studied. ResultsThe mean prevalence of diabetes was 21.8% and glucose tolerance was 10.9% without significant trend of increase during the study period in the overall population and according to sex, while in the subgroup of hypertensive patients over 60, there has been an increase in the prevalence of diabetes and a decrease in glucose tolerance over the 4 years (R2=0.78, P=0.05 and R2=0.95, P=0.005, respectively). The mean prevalence of LD for the study period was 16.1% without significant trend at 4years. The increase in total cholesterol combined with the increase in low-density lipoprotein (LDL) levels was the most common disorder (32.2%). There was no significant difference in LD prevalence and characteristics in subgroups by sex. Age group analysis showed a greater increase in the frequency of lipid disorders in patients over 60years of age (R2=0.80, P=0.001). ConclusionsOver the 4years of study, age over 60 was associated with an increase in the prevalence of metabolic disorders in hypertensive patients. This trend may explain the poor control of BP. Above all, it must be taken into account for the requirement to achieve therapeutic objectives that effectively reduce the risk of cardiovascular complications occurring in these high-risk patients whose number is becoming increasingly important.

Seismic hazard assessment in the megacity of Blida (Algeria) and its surrounding regions using parametric-historic procedure

The region of Blida is characterized by a relatively high seismic activity, pointed especially during the past two centuries. Indeed, it experienced a significant number of destructive earthquakes such as the earthquakes of March 2, 1825 and January 2, 1867, with intensity of X and IX, respectively. This study aims to investigate potential seismic hazard in Blida city and its surrounding regions. For this purpose, a typical seismic catalog was compiled using historical macroseismic events that occurred over a period of a few hundred years, and the recent instrumental seismicity dating back to 1900. The parametric-historic procedure introduced by Kijko and Graham (1998, 1999) was applied to assess seismic hazard in the study region. It is adapted to deal with incomplete catalogs and does not use any subjective delineation of active seismic zones. Because of the lack of recorded strong motion data, three ground prediction models have been considered, as they seem the most adapted to the seismicity of the study region. Results are presented as peak ground acceleration (PGA) seismic hazard maps, showing expected peak accelerations with 10% probability of exceedance in 50-year period. As the most significant result, hot spot regions with high PGA values are mapped. For example, a PGA of 0.44 g has been found in a small geographical area centered on Blida city.

The Miocene Roof Mapping Using Microtremor Recording and Electrical Survey Method in Blida City, Algeria

Bedrock depths in the Mitidja basin in general and in the Blida region in particular are still poorly known despite, the existence of some relatively deep hydraulic boreholes that intersect only superficial alluvial formations. To assess the seismic risk of Blida town, knowledge of soil amplification requires the thickness and properties of sedimentary formations that cover the substratum. For the purposes of our study, the thicknesses obtained by the vertical electric soundings, carried out in the hydrogeological study of the basin, were combined with horizontal-to-vertical spectral ratio (HVSR) microtremor recordings. This combination made it possible to determine an empirical relationship between frequency and thickness specific to the Blida site area, which enabled the roof of the Miocene to be mapped and shows slight undulations with directions compatible with the tectonic constraints of the region. The boundaries between the low and high frequencies obtained by HVSR are well materialized, at south by Sidi El Kebir river, at west by Chiffa river and in the central part by a line of direction SE–NW corresponding to the old passage of Sidi El Kebir river. The presence of low frequencies attributed to the old alluvial deposits with significant thicknesses that originate just after Sidi El Kebir river confirms that the South Mitidjian contact is subvertical.

Contribution to the Ethnobotanical, Phytochemical, Antimicrobial and Antioxidant Study of the Leaves’ Aqueous Extract of the Common Walnut "<i>Juglans regia</i> L."

This work has focused on phytochemical screening of the Common WalnutJuglans regiaL. leaves, and biological tests: antioxidant and antimicrobial effects of the aqueous extracts (infusion, crude) of the common walnuts leaves that we’ve picked, dried and preserved. An ethnobotanical survey in Blida region has been achieved, where it has been concluded that the inhabitants of this region use the common walnuts leaves in their daily care, and the various organs of the Common walnut are widely used as well. The phytochemical screening based on specific tests helped to highlight the presence of the main secondary metabolites such as tannins, flavonoids, alkaloids, free quinones, anthocyanins and saponins, which could be responsible for the biological properties. The antimicrobial study was conducted on bacterial strains and a yeast showed that both aqueous (infusion, crude) extracts have antibacterial effect against certain bacterial strains:Staphylococcus aureus(40.43 mm),Staphylococcus epidermidis(35.36 mm),Sarcina lutea(31, 17 mm), respectively, and an inhibitory effect only for the crude aqueous extract ofEschirichia coli(12 mm),Klebsiella pneumoniae(12 mm), for against these two extracts were proved to be inactive forCandida albicans.In addition, the study of antioxidant activity by the method of reduction of iron (FRAP) and the method of reduction of free radical (DPPH) has revealed an average rate of aqueous extract (infusion) compared with that of ascorbic acid and rutin respectively. With an EC50 of the aqueous extract and rutin which equal to 0.18 and 0.017 mg/ml respectively. According to these results we confirm some information obtained during the ethnobotanical survey and thatJuglans regiaL. is endowed with an antimicrobial and antioxidant power.

Reappraisal of the Seismicity of the Southern Edge of the Mitidja Basin (Blida Region, North‐Central Algeria)

The recent seismicity of the Blida region could not be assessed without due consideration to its earthquake history. We reexamine the 1867 Mouzaia–El Affroun earthquake, which is one of the largest historical earthquakes that occurred in the region, and use the earthquake history of the last 250 yrs to help decipher the complexity of the active deformation of the Mitidja basin (MB). Newly discovered contemporary accounts are used to assess and discuss the extent and intensity of events considered of particular interest and which occurred before the installation of the Algerian seismic network. The 78 significant earthquakes tabulated with comments, among which are 27 events that were not reported in any previous work or catalog, make it clear that the southern border of the MB has long been markedly more active than the northern border. A main objective of this article is to make available the historical data that can be used in further investigations.

Chemical Composition and Antioxidant Activity of Essential Oils from Umbels of Algerian Ammi visnaga (L.)

Two samples of essential oils from the umbels of wild Ammi visnaga L. from two different sites in Algeria, Tessala El Merdja (Blida region) and Arbatache (Boumerdes region) were isolated by hydro-distillation (HD) and investigated by capillary GC-FID and GC-MS. Two columns of different polarities CP SIL-5CB and DB wax have been used. The best separation of the major compounds was achieved in this case on the polar one. A total of 34 compounds were identified representing 76.2–76.8 % of the oils. The main components of the volatile oils were 2-methylbutyl-2- methylbutyrate (16.7–27.4 %), linalool (24.8–41.2 %), limonene (6.8–9.9 %) and isoamylisovalerate (7.3–7.4 %). The antioxidant efficiency was tested using the 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging method. In comparison with butylated hydroxytoluene (BHT), which was used as positive control, all samples showed a weak activity . However, the essential oil from Arbatache site showed a relatively better antioxidant power (6.45 ± 0.74 to ± 9.16 0.53) in comparison with that of Tessala El Merdja (3.8 ± 0.13 to 6.65 ± 0.49) for the concentration range of 600 to 1000 mg/l.

P1-06: The characteristics of hypertension in postmenopausal women in specialized consultation in the region of Blida (Algeria)

Objectifs Evaluer la prevalence, le degre de controle et les comorbidites de l'hypertension arterielle (HTA) chez les femmes menopausees. Methodes C'est une etude transversale, retrospective et descriptive realisee entre juin 2013 et juin 2015, sur une population hypertendue, suivie en consultation specialisee d'HTA du Centre Hospitalo-Universitaire de Blida (Algerie) et ayant inclus 1 721 femmes menopausees, presentant une amenorrhee de plus de 12 mois consecutifs. Toutes les donnees anthropometriques ont ete notees (âge, pression arterielle (PA), tour de taille, poids, taille, index de masse corporelle). Un examen clinique complet, ainsi qu'un bilan biologique ont ete realises. Toutes les complications cardiovasculaires, neurologiques et renales documentees ont ete recherchees. Tous les calculs et analyses statistiques sont traites par le logiciel SPSS 17.0. Resultats La moyenne d'âge de notre population d'etude est de 65,3 ± 9,5 ans. L'âge moyen de survenue de la menopause est de 50,7 ± 6,2 ans. La prevalence de l'HTA est de 71 %, significativement plus elevee chez les femmes menopausees âgees de 65 ans et plus. 90,1 % de l'echantillon avaient une PA superieure ou egale a 140/90 mmHg ou recevaient deja un traitement antihypertenseur. 82,3 % des femmes avaient une PAS > 150 mmHg et 42,2 % une PAD > 90 mmHg. La prevalence du diabete est de 34,8 % dont 88,4 % ont un diabete de type 2. La prevalence du tabac est de 1,3 %. La prevalence de l'hypoHDLemie est de 52 %. La prevalence de l'hypertriglyceridemie est de 43,5 %. La prevalence du surpoids est de 48,2 %, celle de l'obesite est de 31,7 %. La prevalence du syndrome metabolique dans la population feminine menopausee est de 57,8 %. Les principales complications cardiovasculaires constatees sont : l'accident vasculaire cerebral (AVC) dans 26,4 %, l'insuffisance cardiaque dans 14,8 %, l'infarctus du myocarde dans 13,2 %, l'insuffisance renale dans 10,1 %. Le controle de l'HTA n'est atteint que dans 33,6 %. Conclusion Chez la femme hypertendue menopausee, la prevalence de l'HTA systolique est plus importante que la diastolique. L'AVC reste la complication la plus redoutable. Le controle de l'HTA demeure insuffisant et l'equilibre des chiffres de la PA est recommande.

A modified approach for change detection using change vector analysis in posterior probability space

Abstract. The multispectral and multitemporal data coming from satellites allow us to extract valuable spatiotemporal change. Consequently, Earth surface change detection analysis has been used in the past to monitor land cover changes caused by different reasons. Several techniques have been used for that purpose and change vector analysis (CVA) has been frequently employed to carry out automatic spatiotemporal information extraction. This work describes a modified methodology based on Supervised Change Vector Analysis in Posterior probability Space (SCVAPS) with the final aim of obtaining a change detection map in Blida, Algeria. The proposed technique is a Modified version of Supervised Change Vector Analysis Posterior probability Space (MSCVAPS) and it is applied at the same region that the original technique studied in the literature. The classical Maximum Likelihood classifier is the selected method for supervised classification since it provides good properties in the posterior probability map. An improved method for threshold determination based on Double Flexible Pace Search (DFPS) is proposed in this work and it is employed to obtain the most adequate threshold value. Then, the MSCVAPS approach is evaluated by two cases study of the land cover change detection in the region of Blida, Algeria, and in the region of Shunyi District, Beijing, China, using a pair of Landsat Thematic Mapper images and pair of Landsat Enhanced Thematic Mapper images, respectively. The final evaluation is given by the overall accuracy of changed and unchanged pixels and the kappa coefficient. The results show that the modified approach gives excellent results using the same area of study that was selected in the literature.

Carence en vitamine A chez un groupe d’enfants sains âgés de 1 à 23 mois de la région de Blida, Algérie

The vitamin A deficiency (VAD) is considered as a major public health problem in the world. This phenomenon is still not well known in Algeria. The prevalence of this deficiency is calculated on a group of children in good health, not supplemented with vitamin A, from rural, semi-rural and urban environments in the Blida region (Algeria), aged 1 to 23months and recruited in the pediatric services of Blida area, during the period of November 2007–April 2008. The sample is composed of 150 children (87 boys and 63 girls) who present a concentration of C-reactive protein (CRP)<10mg/L. The mean concentrations of serum retinol are 1.049±0.422μmol/L. The dosages of the serum retinol-binding protein (RBP) and prealbumin revealed the mean values of 0.024±0.009g/L and of 0.152±0.039g/L, respectively for RBP and prealbumin. The prevalence of serum retinol deficiency is 19%; this indicates the presence of a moderate VAD. The prevalence of carrier protein deficiency is 76% for the RBP and 10% for the prealbumin. To remedy the problem of vitamin A deficiency, it is advisable to implement a policy of nutritional education. The supplementation can be interesting only for the children whose nutritional status is defective or living in areas where the food products rich in vitamin A are rare.

Spotted fever group rickettsiae identified in Dermacentor marginatus and Ixodes ricinus ticks in Algeria

Our study was carried out using Ixodes ricinus ticks collected from cattle from Tizi-Ouzou and Dermacentor marginatus ticks collected from the vegetation of the Blida region, a tourist site, both regions situated in northern Algeria. The results of real-time quantitative PCR (qPCR) specific for a partial sequence of the citrate synthase gene (gltA) indicate that Rickettsia spp. were present in 11/23 (48%) and 4/9 (44%) of the examined ticks from Tizi-Ouzou and Blida, respectively. The sequences of Rickettsia helvetica and Ri. monacensis were found in I. ricinus ticks using gltA primers. In addition, Ri. slovaca was detected based on the sequences of the gltA and the outer membrane protein (OmpA) genes in D. marginatus ticks. DNA sequencing to identify the species revealed for the first time the presence of Ri. helvetica in I. ricinus ticks and Ri. slovaca in D. marginatus ticks from Algeria and confirmed the presence of Ri. monacensis.