scholarly journals Seroprevalence and prevalence of Babesia vogeli in clinically healthy dogs and their ticks in Costa Rica

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Andrea García-Quesada ◽  
Ana Jiménez-Rocha ◽  
Juan José Romero-Zuñiga ◽  
Gaby Dolz

AbstractCanine babesiosis is a disease caused by a parasite of the genus Babesia which destroys red blood cells. Previous studies have shown the presence of Babesia vogeli in rural areas in Costa Rica using molecular techniques. The objective of the present study was to determine the seroprevalence and prevalence of B. vogeli in clinically healthy dogs and their ticks at the national level, both within and outside the Central Valley. Blood samples and ticks from 482 dogs were collected between June 2011 and May 2014, and analyzed by immunofluorescence assay (IFA) and real-time polymerase chain reaction (qPCR); two protocols of endpoint PCR and sequencing were used to confirm qPCR-positive samples. Seroprevalence of canine babesiosis of 5.3% (24/453) was determined at the national level, specifically 2.0% (5/253) within and 9.5% (19/200) outside the Central Valley, respectively. Real-time PCR determined a global prevalence of B. vogeli of 31.3% (125/400): 21.4% (47/220) within the Central Valley and 43.3% (78/180) outside the Central Valley. The endpoint PCR amplified only 10 of the 125 blood samples identified as positive in qPCR. One sample amplified by endpoint PCR was sequenced and identified as B. vogeli. Twelve canines were identified with past infections, seven canines with active infection, and 111 canines with early infection. Two species of ticks were found with B. vogeli: Rhipicephalus sanguineus sensu lato (n = 40) and Amblyomma ovale (n = 1). The prevalence of canine babesiosis at the national level, both within and outside the Central Valley, is reported here for the first time, determining the presence of the piroplasmid throughout the country, with a higher circulation of the agent outside the Central Valley. Only one species, B. vogeli, was detected in the blood of dogs and their ticks. Therefore, veterinarians should consider using qPCR to determine the presence of the parasite in blood donors and before starting treatment of vector-borne disease in dogs.

2020 ◽  
Vol 13 (7) ◽  
pp. 1294-1302
Author(s):  
Thanakorn Rawangchue ◽  
Sivapong Sungpradit

Background and Aim: Canine babesiosis, a tick-borne parasitic disease, is caused by the hemoprotozoa, Babesia vogeli, and Babesia gibsoni. Infection with these parasites, which is endemic globally, leads to life-threatening immunosuppression in dogs. The merozoites invade the red blood cells (RBCs) of infected dogs. Ehrlichia canis, an intracellular bacterium that infects monocytes, is transmitted by the same tick species (Rhipicephalus sanguineus) during blood consumption and coinfection with B. vogeli and E. canis has been reported. Although the hematology and biochemistry of canine babesiosis have been studied, more studies are needed to develop a better understanding of the hematobiochemical and molecular profiles associated with cases of single infection and coinfection of canine babesiosis in Thailand. This study aimed to investigate the hematological, biochemical, and molecular profiles of B. vogeli infection and E. canis coinfection. Materials and Methods: The study included 33 B. vogeli–positive blood samples and 11 E. canis–coinfected blood samples. To exclude coinfection with Hepatozoon canis and Anaplasma platys, only dogs with B. vogeli infection and B. vogeli–E. canis coinfection were included in the study. A multiplex polymerase chain reaction (PCR) assay was conducted to detect B. vogeli, E. canis, and H. canis, and a conventional PCR assay was conducted for the detection of A. platys. Besides, the PCR assay and sequencing, comprehensive data analysis was conducted, including a microscopic blood parasite examination and hematological and biochemical data analysis. Results: The comparison of the hematobiochemical data between the B. vogeli–positive and E. canis coinfection groups identified that there were statistically significant differences in the RBC parameters, including RBC count, hemoglobin concentration, hematocrit, and RBC distribution width (p=0.001). Neither B. vogeli infection nor coinfection with E. canis was associated with the sex, breed, recorded clinical signs, geographic origin of the dog and also B. vogeli 18S rRNA gene sequencing results. Conclusion: Coinfection with E. canis increased the severity of babesiosis. The pathogenic mechanisms underlying this infection, such as destruction of RBCs, require further investigation. This study may enhance diagnosis, treatment, and prevention of canine babesiosis.


2020 ◽  
pp. 2143-2152
Author(s):  
Aline Ticiani Pereira Paschoal ◽  
Ana Clécia dos Santos Silva ◽  
Juliana Correa Bernardes ◽  
Eloiza Teles Caldart ◽  
Fernanda Pinto-Ferreira ◽  
...  

There is an increase in tick-borne diseases in dogs in urban and rural areas in Brazil and some of these are of public health importance. Rhipicephalus sanguineus-transmitted hemoparasitoses are the main causes of mortality in dogs. The present study investigated the molecular occurrence of Ehrlichia canis, Babesia vogeli and Anaplasma platys in dogs with clinical sings and hematological abnormalities suggestive of tick-borne diseases. These dogs were seen at a Veterinary Hospital of a Public University between January 2014 and December 2016, and were evaluated through anamnesis, clinical examination and complementary exams. The polymerase chain reaction technique was used to detect the presence of hemoparasites DNA. From the 461 dogs that were tested for B. vogeli, 10.6% (49/461) were positive, the associated variable was age. Regarding the 730 animals screened for E. canis, 15.1% (110/730) were positive, and the infection was associated with hematocrit and number of platelets. Relative to the 86 samples evaluated for A. platys, 15.1% (13/86) were positive, and no variable presented statistical significance. From the animals positive for B. vogeli, no of these showed positivity by qPCR for Rangelia vitalii. It is concluded that the occurrence of hemoparasitosis in dogs from the Londrina region is common. Therefore, it is emphasized that molecular techniques should be used as an auxiliary tool for the differential diagnosis of the different etiological agents causing hemoparasitosis. Additionally, these molecular tools are essential for better investigation and preventive assertiveness because it allows to detect parasite DNA.


Waterlines ◽  
2019 ◽  
Vol 38 (4) ◽  
pp. 286-304
Author(s):  
Róger Madrigal-Ballestero ◽  
Tabaré Capitán ◽  
Ariana Salas ◽  
Daniela Córdoba

Author(s):  
Ricardo Sánchez-Murillo

This study presents a hydrogeochemical analysis of spring responses (2013-2017) in the tropical mountainous region of the Central Valley of Costa Rica. The isotopic distribution of δ18O and δ2H in rainfall resulted in a highly significant meteoric water line: δ2H = 7.93×δ18O + 10.37 (r2=0.97). Rainfall isotope composition exhibited a strong dependent seasonality. The isotopic variation (δ18O) of two springs within the Barva aquifer was simulated using the FlowPC program to determine mean transit times (MTTs). Exponential-piston and dispersion distribution functions provided the best-fit to the observed isotopic composition at Flores and Sacramento springs, respectively. MTTs corresponded to 1.23±0.03 (Sacramento) and 1.42±0.04 (Flores) years. The greater MTT was represented by a homogeneous geochemical composition at Flores, whereas the smaller MTT at Sacramento is reflected in a more variable geochemical response. The results may be used to enhance modelling efforts in central Costa Rica, whereby scarcity of long-term data limits water resources management plans.


2020 ◽  
Vol 14 (2) ◽  
pp. 194-204
Author(s):  
Anuradha Tomar

Background: Despite so many developments, most of the farmers in the rural areas are still dependent on rainwater, rivers or water wells, for irrigation, drinking water etc. The main reason behind such dependency is non-connectivity with the National grid and thus unavailability of electricity. To extract the maximum power from solar photovoltaic (SPV) based system, implementation of Maximum Power Point Tracking (MPPT) is mandatory. PV power is intermittent in nature. Variation in the irradiation level due to partial shading or mismatching phenomena leads to the development of modular DC-DC converters. Methods: A stand-alone Multi-Input Dual-Output (MIDO) DC-DC converter based SPV system, is installed at a farm; surrounded with plants for water pumping with stable flow (not pulsating) along with battery energy storage (BES) for lighting. The proposed work has two main objectives; first to maximize the available PV power under shadowing and mismatching condition in case of series/ parallel connected PV modules and second is to improve the utilization of available PV energy with dual loads connected to it. Implementation of proposed MIDO converter along with BES addresses these objectives. First, MIDO controller ensures the MPPT operation of the SPV system to extract maximum power even under partial shading condition and second, controls the power supplied to the motor-pump system and BES. The proposed system is simulated in MATLAB/ SIMULINK environment. Real-time experimental readings under natural sun irradiance through hardware set-up are also taken under dynamic field conditions to validate the performance. Results and Conclusion: The inherent advantage of individual MPPT of each PV source in MIDO configuration, under varying shadow patterns due to surrounding plants and trees is added to common DC bus and therefore provides a better impact on PV power extraction as compared to conventional PV based water pumping system. Multi-outputs at different supply voltages is another flag of MIDO system. Both these aspects are implemented and working successfully at 92.75% efficiency.


2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Claire Y. T. Wang ◽  
Emma L. Ballard ◽  
Zuleima Pava ◽  
Louise Marquart ◽  
Jane Gaydon ◽  
...  

Abstract Background Volunteer infection studies have become a standard model for evaluating drug efficacy against Plasmodium infections. Molecular techniques such as qPCR are used in these studies due to their ability to provide robust and accurate estimates of parasitaemia at increased sensitivity compared to microscopy. The validity and reliability of assays need to be ensured when used to evaluate the efficacy of candidate drugs in clinical trials. Methods A previously described 18S rRNA gene qPCR assay for quantifying Plasmodium falciparum in blood samples was evaluated. Assay performance characteristics including analytical sensitivity, reportable range, precision, accuracy and specificity were assessed using experimental data and data compiled from phase 1 volunteer infection studies conducted between 2013 and 2019. Guidelines for validation of laboratory-developed molecular assays were followed. Results The reportable range was 1.50 to 6.50 log10 parasites/mL with a limit of detection of 2.045 log10 parasites/mL of whole blood based on a parasite diluted standard series over this range. The assay was highly reproducible with minimal intra-assay (SD = 0.456 quantification cycle (Cq) units [0.137 log10 parasites/mL] over 21 replicates) and inter-assay (SD = 0.604 Cq units [0.182 log10 parasites/mL] over 786 qPCR runs) variability. Through an external quality assurance program, the QIMR assay was shown to generate accurate results (quantitative bias + 0.019 log10 parasites/mL against nominal values). Specificity was 100% after assessing 164 parasite-free human blood samples. Conclusions The 18S rRNA gene qPCR assay is specific and highly reproducible and can provide reliable and accurate parasite quantification. The assay is considered fit for use in evaluating drug efficacy in malaria clinical trials.


Pathogens ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 25
Author(s):  
Abdullah D. Alanazi ◽  
Abdulaziz S. Alouffi ◽  
Mohamed S. Alyousif ◽  
Mohammad Y. Alshahrani ◽  
Hend H. A. M. Abdullah ◽  
...  

Dogs and cats play an important role as reservoirs of vector-borne pathogens, yet reports of canine and feline vector-borne diseases in Saudi Arabia are scarce. Blood samples were collected from 188 free-roaming dogs and cats in Asir (70 dogs and 44 cats) and Riyadh (74 dogs), Saudi Arabia. The presence of Anaplasma spp., Bartonella spp., hemotropic Mycoplasma spp., Babesia spp., and Hepatozoon spp. was detected using a multiplex tandem real-time PCR. PCR-positive samples were further examined with specific conventional and real-time PCR followed by sequencing. Dogs from Riyadh tested negative for all pathogens, while 46 out of 70 dogs (65.7%) and 17 out of 44 cats (38.6%) from Asir were positive for at least one pathogen. Positive dogs were infected with Anaplasma platys (57.1%), Babesia vogeli (30%), Mycoplasma haemocanis (15.7%), and Bartonella henselae (1.4%), and cats were infected with Mycoplasma haemofelis (13.6%), Candidatus Mycoplasma haemominutum (13.6%), B. henselae (9.2%), and A. platys (2.27%), all of which are reported for the first time in Saudi Arabia. Co-infection with A. platys and B. vogeli was detected in 17 dogs (24.28%), while coinfections were not detected in cats. These results suggest that effective control and public awareness strategies for minimizing infection in animals are necessary.


Author(s):  
Chensong Lin ◽  
Longfeng Wu

Many empirical studies have shown evidence of multiple health benefits provided by green and blue spaces. Despite the importance of these spaces, investigations are scarce in details for blue spaces rather than green. Moreover, most research has focused on developed regions. A limited number of studies on blue spaces can be found in China with a focus on the city level. Outcomes have been mixed due to varying research scales, methodologies, and definitions. This study relies on a national-level social survey to explore how the self-rated health (SRH) of senior individuals is associated with local green and blue space availability in urban and rural areas. Results indicate that the coverage ratio of overall green spaces and waterbodies around a resident’s home have marginal effects on SRH status in both urban and rural areas. In urban areas, living close to a park can is marginally beneficial for older people’s health. Regarding different types of blue spaces, the presence of a major river (within 0.3–0.5 km) or coastline (within 1 km and 1–5 km) in the vicinity of home negatively affects SRH among the elderly in urban areas. Close proximity to lakes and other types of waterbodies with a water surface larger than 6.25 ha did not significantly influence SRH. These findings not only evaluate general health impacts of green/blue space development on senior populations across the county but inform decision makers concerning the health-promoting qualities and features of different green/blue spaces to better accommodate an aging population in the era of urbanization.


BMJ Open ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. e044066
Author(s):  
Prashant Mathur ◽  
Vaitheeswaran Kulothungan ◽  
Sravya Leburu ◽  
Anand Krishnan ◽  
Himanshu Kumar Chaturvedi ◽  
...  

ObjectiveTo generate national estimates of key non-communicable disease (NCD) risk factors for adolescents (15–17 years) identified in the National NCD Monitoring Framework and, study the knowledge, attitudes and practices towards NCD risk behaviours among school-going adolescents.Design and settingA community-based, national, cross-sectional survey conducted during 2017–2018. The survey was coordinated by the Indian Council of Medical Research—National Centre for Disease Informatics and Research with 10 reputed implementing research institutes/organisations across India in urban and rural areas.ParticipantsA multistage sampling design was adopted covering ages between 15 and 69 years—adolescents (15–17 years) and adults (18–69 years). The sample included 12 000 households drawn from 600 primary sampling units. All available adolescents (15–17 years) from the selected households were included in the survey.Main outcome measuresKey NCD risk factors for adolescents (15–17 years)—current tobacco and alcohol use, dietary behaviours, insufficient physical activity, overweight and obesity.ResultsOverall, 1402 households and 1531 adolescents completed the survey. Prevalence of current daily use of tobacco was 3.1% (95% CI: 2.0% to 4.7%), 25.2% (95% CI: 22.2% to 28.5%) adolescents showed insufficient levels of physical activity, 6.2% (95% CI: 4.9% to 7.9%) were overweight and 1.8% (95% CI: 1.0% to 2.9%) were obese. Two-thirds reported being imparted health education on NCD risk factors in their schools/colleges.ConclusionThe survey provides baseline data on NCD-related key risk factors among 15–17 years in India. These national-level data fill information gaps for this age group and help assess India’s progress towards NCD targets set for 2025 comprehensively. Though the prevalence of select risk factors is much lower than in many developed countries, this study offers national evidence for revisiting and framing appropriate policies, strategies for prevention and control of NCDs in younger age groups.


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