Comparison of the transmission of Theileria parva between different instars of Rhipicephalus appendiculatus

Parasitology ◽  
1996 ◽  
Vol 113 (3) ◽  
pp. 243-253 ◽  
Author(s):  
H. Ochanda ◽  
A. S. Young ◽  
C. Wells ◽  
G. F. Medley ◽  
B. D. Perry
Keyword(s):  
Acute Infection ◽  
Adult Tick ◽  
Rhipicephalus Appendiculatus ◽  
Theileria Parva ◽  
Adult Males ◽  
Type Iii ◽  
Source Of Infection ◽  
High Prevalence ◽  
Irregular Period ◽  
The Mean

SUMMARYThe transmission of Theileria parva by nymphal and adult Rhipicephalus appendiculatus was compared by the assessment of salivary gland infections in tick batches fed on the same group of infected cattle at the same time. When larval and nymphal R. appendiculatus Muguga ticks were fed concurrently on cattle undergoing acute infection with T. parva Muguga, the resultant nymphae developed a slightly lower prevalence of infection than did the adult ticks. The abundance of infection was 5–20 times higher in the adult ticks than in the nymphae. When larval and nymphal R. appendiculatus Muguga and R. appendiculatus McIlwaine were fed to repletion on cattle infected with T. parva Boleni, a parasite causing subacute infection, resultant adult tick batches had a relatively high prevalence of infection, but infection was not detected in resultant nymphal batches. When cattle that were carriers of 2 stocks of T. parva, Marikebuni and Kiambu 5, were used as the source of infection, the infections developing in adult R. appendiculatus Muguga ticks were much higher than those developing in nymphae. The structure of salivary glands differed between nymphal ticks, adult males and adult females, and this is considered to be an important factor affecting the infection levels. The morphology of the type III acini, the target acini for sporogony, was similar, but the mean numbers of type III acini were different, with 87 in nymphae, 1346 in males and 1736 in females. This difference was correlated with the different infection levels produced in the various instars and sexes. While the process of sporogony in the different tick instars and sexes was similar, the rate of sporogony was fastest in feeding nymphae, taking on average 2–3 days, compared to 3–4 days in females and an irregular period in the males. These results are discussed in relation to the epidemiology of T. parva.

scholarly journals Assessment of acquired immune response to Rhipicephalus appendiculatus tick infestation in different goat breeds

2013 ◽  
Vol 80 (1) ◽  
Author(s):  
Jeyanthi B.P. Gopalraj ◽  
Francoise C. Clarke ◽  
Edward F. Donkin
Keyword(s):  
Immune Response ◽  
South African ◽  
Tick Infestation ◽  
Gamma Globulin ◽  
Adult Tick ◽  
Rhipicephalus Appendiculatus ◽  
Female Tick ◽  
Laboratory Conditions ◽  
The Mean ◽  
Indigenous Goats

Changes in serum gamma globulin levels, numbers of replete female ticks and engorged tick mass were used as parameters to monitor the acquired immune response (antibody mediated immune response) elicited by Rhipicephalus appendiculatus adult tick infestations. Three consecutive Rhipicephalus appendiculatus adult tick infestations were applied to South African Indigenous goats (Nguni), Saanen goats and cross-bred goats (Saanen goats crossed with South African Indigenous goats [Nguni]) under laboratory conditions. During the three consecutive Rhipicephalus appendiculatus adult tick infestations the serum gamma globulin levels increased in all three breeds, whilst the mean replete female tick numbers and engorged tick mass decreased. Even though all three goat breeds exhibited an acquired immune response, the South African Indigenous goats (Nguni) response was significantly higher than that of the Saanen and cross-bred goats. However, the acquired immune response elicited by Saanen goats was significantly lower when compared with cross-bred goats.

Optimization of the in vitro feeding of Rhipicephalus appendiculatus nymphae for the transmission of Theileria parva

Parasitology ◽  
1995 ◽  
Vol 111 (4) ◽  
pp. 463-468 ◽  
Author(s):  
S. M. Waladde ◽  
A. S. Young ◽  
S. N. Mwaura ◽  
G. N. Njihia ◽  
F. N. Mwakima
Keyword(s):  
Rhipicephalus Appendiculatus ◽  
Artificial Feeding ◽  
Ixodid Ticks ◽  
Theileria Parva ◽  
Feeding Apparatus ◽  
Artificial Membrane ◽  
Feeding Performance ◽  
The Mean ◽  
In Vitro Feeding

SUMMARYAn apparatus for artificial feeding of Rhipicephalus appendiculatus nymphae was modified to improve feeding performance. Heparinized blood was supplied above a treated artificial membrane while the ticks attached below on its undersurface. The feeding apparatus was incubated at 37 °C in an atmosphere of 3% CO2 concentration and a relative humidity of 75–80%. Under these conditions, 91% of the engorged nymphae attained a mean weight of 6–11 mg, and an average of 93% of those nymphae moulted into adults. When this system was used to feed nymphal ticks on blood infected with Theileria parva piroplasms, the mean prevalence of infection in the resultant female and male ticks was 86% and 54%, respectively. The feeding performance and T. parva infection levels were comparable to those of nymphal ticks fed on the blood donor cattle. The apparatus used in this study has potential for modification to suit the artificial feeding needs of other species of ixodid ticks and for use in investigations to examine other tick/pathogen relationships.

Maintenance of Theileria parva parva infection in an endemic area of Kenya

Parasitology ◽  
1986 ◽  
Vol 93 (1) ◽  
pp. 9-16 ◽  
Author(s):  
A. S. Young ◽  
B. L. Leitch ◽  
R. M. Newson ◽  
M. P. Cunningham
Keyword(s):  
Endemic Area ◽  
Lake Victoria ◽  
Bos Indicus ◽  
Rhipicephalus Appendiculatus ◽  
Carrier State ◽  
Theileria Parva ◽  
Infection Rates ◽  
Antibody Titres ◽  
The Mean ◽  
First Time

SUMMARYThe maintenance of Theileria parva parva infection in an endemic area of Kenya on the shore of Lake Victoria was studied in the field and laboratory. High prevalences of antibodies against T. parva and T. mutans and intra-erythrocytic piroplasms were detected in local zebu (Bos indicus) cattle. The mean infection rate of Theileria parasites in the tick, Rhipicephalus appendiculatus, in field collections was 1·1 %. Most of the infection was attributed to T. parva parva by application of field ticks to susceptible cattle. Five cattle, all about 1·5 years old, were purchased from local owners and transported to the laboratory. All five had oscillating antibody titres against T. parva and T. mutans and had patent theilerial infections during the subsequent 13 months. Uninfected R. appendiculatus nymphs were applied to cattle at 0, 3, 6, 9 and 13 months after transport to Muguga, and 18 out of 23 batches transmitted T. parva parva infection to cattle when 100 resultant R. appendiculatus adults were applied. Infection rates in the tick batches were usually low, with 1 salivary gland acinus infected/tick. Hence, a frequent carrier state of naturally infected cattle has been demonstrated for T. parva parva for the first time, and it is likely that this carrier state is of great importance in maintenance of T. parva parva infection in the field.

scholarly journals Isolation of infectious Theileria parva sporozoites secreted by infected Rhipicephalus appendiculatus ticks into an in vitro tick feeding system

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Rubikah Vimonish ◽  
Kelcey D. Dinkel ◽  
Lindsay M. Fry ◽  
Wendell C. Johnson ◽  
Janaina Capelli-Peixoto ◽  
...  
Keyword(s):  
Acute Infection ◽  
Rhipicephalus Appendiculatus ◽  
Theileria Parva ◽  
Feeding System ◽  
Tick Feeding ◽  
Global Food Security ◽  
Vector Borne Diseases ◽  
Infected Adult ◽  
Bovine Lymphocytes

Abstract Background Vector-borne diseases pose an increasing threat to global food security. Vaccines, diagnostic tests, and therapeutics are urgently needed for tick-borne diseases that affect livestock. However, the inability to obtain significant quantities of pathogen stages derived from ticks has hindered research. In vitro methods to isolate pathogens from infected tick vectors are paramount to advance transcriptomic, proteomic, and biochemical characterizations of tick-borne pathogens. Methods Nymphs of Rhipicephalus appendiculatus were infected with Theileria parva by feeding on a calf during an acute infection. Isolation of sporozoites was accomplished by feeding infected adult ticks on an in vitro tick feeding system. Sporozoite viability was tested using in vitro bovine lymphocytes. Results We isolated infectious T. parva sporozoites secreted into an in vitro tick feeding system. Infected adult R. appendiculatus ticks attached to and successfully fed on silicone membranes in the in vitro tick feeding system. Bovine blood in the receptacle was replaced with cell-free medium and the ticks were allowed to feed for 3 h to collect secreted T. parva sporozoites. Secreted sporozoites infected in vitro bovine lymphocytes, demonstrating that isolated sporozoites remained viable and infectious. Conclusions This work is the first to report the isolation of mature infectious T. parva sporozoites using an in vitro tick feeding system, which represents a significant step towards the development of a more efficient control strategy for T. parva. Isolation of infectious tick-stage parasites will facilitate the examination of the vector-pathogen interface, thereby accelerating the development of next-generation vaccines and treatment interventions for tick-borne pathogens. Graphical Abstract

Monitoring Theileria parva infection in adult Rhipicephalus appendiculatus ticks

Parasitology ◽  
1981 ◽  
Vol 82 (1) ◽  
pp. 137-147 ◽  
Author(s):  
A. D. Irvin ◽  
C. D. H. Boarer ◽  
D. A. E. Dobbelaere ◽  
S. M. Mahan ◽  
R. Masake ◽  
...  
Keyword(s):  
Salivary Glands ◽  
Rapid Method ◽  
Rhipicephalus Appendiculatus ◽  
Methyl Green ◽  
Theileria Parva ◽  
Bovine Blood ◽  
Infection Rates ◽  
Subsequent Infection ◽  
The Mean ◽  
Theileria Parva Infection

SUMMARYA rapid method is described for preparing and staining salivary glands of Rhipicephalus appendiculatus ticks infected with Theileria parva. The technique, involving the use of a modified methyl green pyronin stain, minimizes the risk of losing material and allows examination of stained glands within minutes of preparation. The technique was applied in a series of studies in which ticks were either infected with T. parva under different conditions, or maturation of parasites in adult ticks was stimulated by different means. When nymphal ticks were fed on the ears of cattle the subsequent infection rate of the adult ticks showed no correlation with the parasitaemia of the cattle at the time of nymphal engorgement. There was no difference in infection rates between adult ticks in which parasite maturation had been stimulated either by incubation at 37 °C or by feeding on rabbits. However, parasite maturation took about 1 day longer in incubated ticks than in rabbit-fed ticks. Female ticks were consistently more highly infected than males, both in terms of the percentage of ticks infected and the mean number of infected acini/tick. Ticks were infected with T. parva by injection of nymphs with parasitaemic bovine blood, but the resultant adult infection was lower than that in ticks which had been infected naturally by feeding on cattle.

Features of Thrombi and Diagnostic Accuracy of Impedance Plethysmography in Symptomatic and Asymptomatic Deep Vein Thrombosis

1993 ◽  
Vol 70 (02) ◽  
pp. 266-269 ◽  
Author(s):  
Giancarlo Agnelli ◽  
Benilde Cosmi ◽  
Stefano Radicchia ◽  
Franca Veschi ◽  
Enrico Boschetti ◽  
...  
Keyword(s):  
Deep Vein Thrombosis ◽  
Diagnostic Accuracy ◽  
High Sensitivity ◽  
Impedance Plethysmography ◽  
Surveillance Programme ◽  
Vein Thrombosis ◽  
Asymptomatic Patients ◽  
High Prevalence ◽  
The Mean ◽  
Deep Vein

SummaryImpedance plethysmography (IPG) has high sensitivity and specificity in patients with symptomatic deep vein thrombosis (DVT) while it fails to detect asymptomatic DVT. The aim of this study was to determine whether the features of thrombi such as location, size and occlusiveness could explain the different accuracy of IPG in symptomatic and asymptomatic DVT patients. One-hundred and seventeen consecutive outpatients with a clinical suspicion of DVT and 246 consecutive patients undergoing hip surgery were admitted to the study. In symptomatic patients IPG was performed on the day of referral, followed by venography, while in asymptomatic patients IPG was performed as a surveillance programme, followed by bilateral venography.A venography proved DVT was observed in 37% of the symptomatic patients and 34% of the asymptomatic limbs. A significantly higher proportion of proximal DVTs was found in symptomatic patients than in asymptomatic patients (78% vs 46%; p = 0.001). The mean Marder score, taken as an index of thrombus size, was significantly higher in symptomatic patients than in asymptomatic patients (19.0 vs 9.6; p = 0.0001). A significantly higher proportion of occlusive DVTs was observed in symptomatic than in asymptomatic patients (69% vs 36%; p = 0.001).We conclude that the unsatisfactory diagnostic accuracy of IPG in asymptomatic DVT is due to the high prevalence of distal, small and non occlusive thrombi. Such thrombi are unlikely to cause a critical obstruction of the venous outflow and therefore to produce a positive IPG.

HAPTEN-RADIOIMMUNOASSAY OF PLASMA OESTRADIOL

1973 ◽  
Vol 72 (2) ◽  
pp. 330-344 ◽  
Author(s):  
Peter Doerr
Keyword(s):  
Adult Male ◽  
Normal Values ◽  
Normal Adult ◽  
Adult Males ◽  
Reagent Blank ◽  
Keyhole Limpet Haemocyanin ◽  
Ether Extraction ◽  
The Mean ◽  
Assay Precision ◽  
Plasma Oestradiol

ABSTRACT A hapten-radioimmunoassay for plasma oestradiol is described and information about the reliability of the method is given in detail. Oestradiol-3-hemisuccinate coupled to keyhole limpet haemocyanin is used for immunization of rabbits. The antiserum utilized for the assay is characterized by its titer, affinity and specificity. Following ether extraction and NaOH-light petroleum partition oestradiol is separated from crossreacting oestrogens by TLC. Oxidation of oestradiol on the plate is prevented by mercaptoethanol. To separate free and antibody bound ligand 250 μg dextran-coated charcoal per tube is used in the presence of bovine serum gammaglobulin (1 mg/ml). The between-assay precision based on 15 different determinations of control samples from normal adult male plasma was 9.4% (C. V.). The mean reagent blank value of 31 determinations was equivalent to 0.3 pg oestradiol and the detection limit in terms of the 99% confidence limit for a single blank value, was equivalent to 4.3 pg oestradiol. A procedure for detecting plasma blanks is described. Plasma oestradiol is separated from approximately all concomitant substances originally present in the sample by enzymatic conversion into oestrone and a second TLC. No plasma blanks could be detected with respect to normal adult male plasma. Normal values for adult males based on 51 subjects were characterized by a median of 17.2 pg/ml and the 95 percentiles of 9.5–27.6.

Prevalence of Self-Medication and Its Factors among University Students in Bandar Abbas City

2018 ◽  
Vol 7 ◽  
Author(s):  
Atefeh Mohammadi
Keyword(s):  
Herbal Medicines ◽  
Target Population ◽  
Easy Access ◽  
Medical Sciences ◽  
Self Medication ◽  
Delay In Diagnosis ◽  
Consumption Culture ◽  
High Prevalence ◽  
The Mean ◽  
Bandar Abbas

Background: Self-medication can lead to the latency of the real severity of disease, delay in diagnosis, a complication of treatment, threatening side effects, and unexpected intoxication. The present research aimed to explore the prevalence of self-medication and its factors among students affiliated to Bandar Abbas universities in 2016. Materials and Methods: This Descriptive Analytic study was performed on 600 students affiliated to the universities in Bandar Abbas; Islamic Azad University, Payam-e-Noor University, and University of Medical Sciences. The sample was selected through a stratified sampling method, and the data were collected by a questionnaire comprised of two parts, demographic information (6 items), and risk factors of self-medication and self-medicated drugs (26 items). SPSS version 19 was used to analyze the data through the required tests. Result: The mean age of the students was 24.11±5.85 years. One hundred and ninety-one subjects (31.8%) were male, and 409 (68.2%) were female. The results revealed the prevalence of self-medication in the target population was 80.2%., the main reasons for self-medication were reported underestimating the disease 461(77.0%), previous experience of the disease 457(76.4%), repeated prescription 441(73.6%), and easy access to drug 423(70.6%). The most prevalent drugs self-medicated by students were acetaminophen, herbal medicines, antibiotics, other drugs, sedatives, and anti-acids, respectively. Conclusion: Considering the high prevalence of self-medication (80.2%) revealed in this research, there is a need for more attentive care for consistent education and drug consumption culture promotion. Specific approaches can help the provision of easy access to medical services in universities.

High prevalence of heterotopic ossification after cervical disc arthroplasty: outcome and intraoperative findings following explantation of 22 cervical disc prostheses

2012 ◽  
Vol 17 (2) ◽  
pp. 141-146 ◽  
Author(s):  
Christopher Brenke ◽  
Johann Scharf ◽  
Kirsten Schmieder ◽  
Martin Barth
Keyword(s):  
Neck Disability Index ◽  
Adjacent Segment Degeneration ◽  
Cervical Disc ◽  
Cervical Disc Arthroplasty ◽  
Adjacent Segment ◽  
Analog Scale ◽  
Osteophyte Formation ◽  
High Prevalence ◽  
The Mean ◽  
Neck Disability

Object Cervical disc arthroplasty (CDA) has been increasingly used for the treatment of cervical disc herniations. However, the impact of CDA on adjacent-segment degeneration and the degree of heterotopic ossification (HO) of the treated segment remain a subject of controversy. Due to a product failure of the Galileo-type disc prosthesis, 22 of these devices were explanted. The radiological and clinical course in each case was investigated in detail with an emphasis on the incidence of HO and facet joint degeneration 18 months following the operation. Intraoperative findings regarding ossification and implant fixation were documented. Thus, the authors were able to describe the true rate of adjacent-segment degeneration and HO following CDA and the clinical relevance thereof. Methods In all 22 patients, functional radiographic imaging was performed prior to surgery, 3 and 12 months after surgery, and prior to disc prosthesis explantation. At all time points, the range of motion (ROM) in the operated and adjacent segments was determined. A motion index was calculated using the preoperative and all postoperative ROMs (preoperative ROM/postoperative ROM). Computed tomography was used preoperatively to measure the height of the index segment, extent of HO, and the degree of the progression of facet arthrosis, and was used postoperatively prior to prosthesis explantation. Patients completed clinical questionnaires that included a visual analog scale and the Neck Disability Index. Results The motion index of the index segment declined gradually from 1.4 at 3 months postoperative to 1.2 prior to explantation, while the motion index of the adjacent upper segment increased from 0.9 to 1.3. The mean ROM of the index segment was 10.4° ± 6.7°, and fusion was observed in 2 (9%) of the 22 patients. Prosthesis migration was present in 3 patients (13.6%). Severe HO (Grades 3 and 4) was present in 17.4%. Computed tomography showed a significant increase of segmental height of the index segment (1.6 ± 1.1 mm, p = 0.035), and a significant increase of left-sided lateral osteophytes (1.7 ± 2.1 mm, p = 0.009). The incidence of severe osteophyte formation (> 2 mm) occurred in 40%. Intraoperative findings reflected the results from CT, with primary lateral proliferation of osteophytes found in approximately 25% of patients. The mean visual analog scale scores were 3.8 ± 2.7 (neck) and 2.4 ± 2.5 (arms), and the mean Neck Disability Index score was 30 ± 22. No correlation was found between radiological and clinical parameters. Conclusions In this study, a higher incidence of HO after CDA could be demonstrated using CT, compared with studies using fluoroscopy only. However, patient selection and/or the operative technique might have contributed to the high prevalence of osteophyte formation. Thus, the exact indication for CDA has to be reconsidered. Because implant migration was detected, using fixation in the present CDA model appears suboptimal.

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