The Susceptibility of Autogenous and Anautogenous Races of Culex pipiens to Infection with Avian Malaria (Plasmodium relictum)

Parasitology ◽  
1934 ◽  
Vol 26 (4) ◽  
pp. 512-522 ◽  
Author(s):  
P. Tate ◽  
M. Vincent
Keyword(s):  
Infection Rate ◽  
Culex Pipiens ◽  
Avian Malaria ◽  
Infection Rates ◽  
Chronic Infections ◽  
Seasonal Influence ◽  
Plasmodium Relictum ◽  
The Difference ◽  
Different Strains

1. Anautogenous English and autogenous Greek, Hungarian, Maltese and cross-bred strains of C. pipiens were infected with an Algerian and a German strain of P. relictum.2. The different strains of C. pipiens behaved similarly as regards susceptibility and transmission towards the same strain of P. relictum.3. The two strains of malaria differ in the infection rate produced in mosquitoes. The Algerian strain produces an infection rate of about 89 per cent., while that of the German strain is only about 43 per cent.4. The difference in the infection rates of the two strains is not due merely to differences in the number of gametocytes formed.5. In general C. pipiens fed on birds infected with the Algerian strain of malaria became more heavily infected than those fed on birds infected with the German strain.6. C. pipiens were infected in some cases by feeding on birds with chronic infections of the Algerian strain of P. relictum, but not when fed on birds with chronic infections of the German strain.7. No seasonal influence was found as regards the infection of C. pipiens by P. relictum.8. The Algerian strain of malaria was successfully transmitted by English, Greek, Hungarian, Maltese and Greek-Hungarian strains of C. pipiens, and the German strain of malaria by English, Greek, Maltese and Greek-English strains of C. pipiens.

scholarly journals Avian malaria: a new lease of life for an old experimental model to study the evolutionary ecology of Plasmodium

2015 ◽  
Vol 370 (1675) ◽  
pp. 20140300 ◽  
Author(s):  
Romain Pigeault ◽  
Julien Vézilier ◽  
Stéphane Cornet ◽  
Flore Zélé ◽  
Antoine Nicot ◽  
...  
Keyword(s):  
Culex Pipiens ◽  
Avian Malaria ◽  
Evolutionary Ecology ◽  
Laboratory Research ◽  
Plasmodium Relictum ◽  
Natural Vector ◽  
The World ◽  
Experimental Laboratory ◽  
Analyse Data ◽  
Statistical Relationships

Avian malaria has historically played an important role as a model in the study of human malaria, being a stimulus for the development of medical parasitology. Avian malaria has recently come back to the research scene as a unique animal model to understand the ecology and evolution of the disease, both in the field and in the laboratory. Avian malaria is highly prevalent in birds and mosquitoes around the world and is amenable to laboratory experimentation at each stage of the parasite's life cycle. Here, we take stock of 5 years of experimental laboratory research carried out using Plasmodium relictum SGS1, the most prevalent avian malaria lineage in Europe, and its natural vector, the mosquito Culex pipiens . For this purpose, we compile and analyse data obtained in our laboratory in 14 different experiments. We provide statistical relationships between different infection-related parameters, including parasitaemia, gametocytaemia, host morbidity (anaemia) and transmission rates to mosquitoes. This analysis provides a wide-ranging picture of the within-host and between-host parameters that may bear on malaria transmission and epidemiology.

scholarly journals Complete Life Cycle of Trypanosoma thomasbancrofti, an Avian Trypanosome Transmitted by Culicine Mosquitoes

2021 ◽  
Vol 9 (10) ◽  
pp. 2101
Author(s):  
Magdaléna Fialová ◽  
Anežka Santolíková ◽  
Anna Brotánková ◽  
Jana Brzoňová ◽  
Milena Svobodová
Keyword(s):  
Life Cycle ◽  
Infection Rate ◽  
Culex Pipiens ◽  
Life Cycles ◽  
Protozoan Parasites ◽  
Infection Rates ◽  
Experimental Transmission ◽  
Complete Life Cycle ◽  
High Infection ◽  
Avian Populations

Avian trypanosomes are cosmopolitan and common protozoan parasites of birds; nevertheless, knowledge of their life cycles and vectors remains incomplete. Mosquitoes have been confirmed as vectors of Trypanosoma culicavium and suggested as vectors of T. thomasbancrofti; however, transmission has been experimentally confirmed only for the former species. This study aims to confirm the experimental transmission of T. thomasbancrofti to birds and its localization in vectors. Culex pipiens were fed on blood using four strains of T. thomasbancrofti, isolated from vectors and avian hosts; all strains established infections, and three of them were able to develop high infection rates in mosquitoes. The infection rate of the culicine isolates was 5–28% for CUL15 and 48–81% for CUL98, 67–92% for isolate OF19 from hippoboscid fly, while the avian isolate PAS343 ranged between 48% and 92%, and heavy infections were detected in 90% of positive females. Contrary to T. culicavium, trypanosomes were localized in the hindgut, where they formed rosettes with the occurrence of free epimastigotes in the hindgut and midgut during late infections. Parasites occurred in urine droplets produced during mosquito prediuresis. Transmission to birds was achieved by the ingestion of mosquito guts containing trypanosomes and via the conjunctiva. Bird infection was proven by blood cultivation and xenodiagnosis; mature infections were present in the dissected guts of 24–26% of mosquitoes fed on infected birds. The prevalence of T. thomasbancrofti in vectors in nature and in avian populations is discussed in this paper. This study confirms the vectorial capacity of culicine mosquitoes for T. thomasbancrofti, a trypanosome related to T. avium, and suggests that prediuresis might be an effective mode of trypanosome transmission.

Complete sporogony of Plasmodium relictum (lineage pGRW4) in mosquitoes Culex pipiens pipiens, with implications on avian malaria epidemiology

2015 ◽  
Vol 114 (8) ◽  
pp. 3075-3085 ◽  
Author(s):  
Gediminas Valkiūnas ◽  
Rita Žiegytė ◽  
Vaidas Palinauskas ◽  
Rasa Bernotienė ◽  
Dovilė Bukauskaitė ◽  
...  
Keyword(s):  
Culex Pipiens ◽  
Avian Malaria ◽  
Plasmodium Relictum ◽  
Malaria Epidemiology ◽  
Culex Pipiens Pipiens

scholarly journals Study on Prevalence of Ovine Fasciolosis in and Around Debre Berhan Sheep Breeding and Forage Multiplication Center

2016 ◽  
Vol 1 (3) ◽  
pp. 1-9
Author(s):  
Jarso D
Keyword(s):  
Statistical Analysis ◽  
Infection Rate ◽  
Prevalence Rate ◽  
Ecological Condition ◽  
Infection Rates ◽  
Exotic Breed ◽  
Debre Berhan ◽  
Significant Difference ◽  
The Difference ◽  
The Impact

A study was conducted to determine the prevalence of ovine fasciolosis in Debre Berhan region based on clinical, abattoir and field survey from November 2007 to March 2008. Of total 475 ovine faucal samples examined 229 (48.21%) positive for fasciolosis. Sex wise Prevalence off sciolosis 73.05% in male a nd 26.95% in female animals. Statistical analysis of prevalence rate on sex basis showed no significant difference (P>0.05) infection rate between the two sexes. Age wise prevalenc e recorded was 67.79% in adult and 32.21% in young. Analysis of infection rates on age basis had no significant differences (P>0.05). Asite wise of fasciolosis were 28%, 13.68%, 19.37%, 32.63%, and 6.32% in Atekelt, Delacha, Genet, Kerafino and Seladigay r espectively. Statistical analysis of prevalence rate on site basis showed significant difference (P<0.05) in infection rate between sites. Breed wise of fasciolosis was 75.53% local, 18.11% cross and 6.53% exotic breed is recorded. Statistical prevalence r ate on breed basis showed significant difference (P<0.05). The monthly prevalence of fasciolosis recorded was, 12.42%, 39.16%, 37.05, 5.05 & 6.32% in November, December, January, February and March respectively. The difference in monthly prevalence was sig nificant (P<0.05). The result of the study has been discussed in detail in comparison with the finding of other workers and in relation to site and ecological condition of the area that affects the prevalence rate of fasciolosis. Finally, appropriate contr ol strategies implemented in the study area is recommended to reduce the impact of fasciolosis on livestock production in the area.

39 Managing Burn Wounds with Silvadene

2021 ◽  
Vol 42 (Supplement_1) ◽  
pp. S29-S30
Author(s):  
Tomer Lagziel ◽  
Louis J Born ◽  
Luis H Quiroga ◽  
Eliana Duraes ◽  
Pragna N Shetty ◽  
...  
Keyword(s):  
Length Of Stay ◽  
Wound Infection ◽  
Standard Of Care ◽  
Infection Rates ◽  
Average Amount ◽  
Once Daily ◽  
Preliminary Results ◽  
The Difference ◽  
Dressing Change ◽  
Hospital Acquired

Abstract Introduction Topical delivery of antibacterial agents is typically incorporated and is an essential component of burn wound therapy. The goal is to prevent infection and promote the healing process. Poorly treated wounds can result in scarring or severely in sepsis and multi-organ dysfunction. Topical SSD cream has been the gold-standard for initial local care in partial thickness or full thickness burns. Due to immediate burst release of the drug into the exposed areas, application is relatively frequent (usually twice daily). However, it remains unknown whether twice-daily SSD dressings are superior to once-daily. Methods We maintained a twice-daily dressing change standard of care until 01/01/2019. Patients admitted after that date had their dressing changed once-daily. Our goal is to review outcomes for 75 patients before the change-of-practice and 75 patients after. The main outcomes recorded are wound infection rates, hospital-acquire complications (non-wound related), pain scores, daily narcotic requirements, average amount of SSD used, and length-of-stay. Results Preliminary results of the 75 pre-change-of-practice and 75 post-change-of-practice patients showed slightly better outcomes in the post-change group. Wound-infection rates were the same for both groups (pre=5.33%, post=5.33%), average daily pain-levels for the pre-change group were slightly higher but the difference was negligible and not statistically significant (pre=5.76, post=5.69). The pre-change group had a higher average daily narcotic dosage (pre=6.81mg, post=6.38mg), hospital-acquired complication rates were higher pre-change (pre=10.67%, post=6.67%), and length-of-stay was longer in the pre-change group (pre=10.81, post=9.25). The average amount of SSD jars used per patient was higher as well (pre=6.30, post=2.85). Statistical analysis of the distribution of burn type, age, and burn depth showed no discrepancy and a generalized decreased length-of-stay with once-daily SSD dressing change. Conclusions Preliminary results show that once-daily dressing changes of SSD in burn wounds have no negative impact on wound outcomes. However, it is associated with a decreased length-of-stay, decreased pain levels, and less hospital-acquired complications. A decreased length-of-stay means reduced medical expenses for the patient and the hospital. In addition, less hospital-acquired complications result in better patient recovery. Since the difference in wound outcomes is negligible and statistically insignificant, changing the standard-of-care to once-daily could prove beneficial.

scholarly journals Toxoplasma gondii in Sheep and Goats from Central Iran

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Mojtaba Bahreh ◽  
Bahador Hajimohammadi ◽  
Gilda Eslami
Keyword(s):  
Toxoplasma Gondii ◽  
Dna Extraction ◽  
Infection Rate ◽  
Nested Pcr ◽  
Prevention Programs ◽  
Central Iran ◽  
Infection Rates ◽  
Sheep And Goats ◽  
One Year ◽  
Undercooked Meat

Abstract Objective Toxoplasmosis, caused by Toxoplasma gondii, infects humans by consuming infected raw or undercooked meat and foods harboring mature oocysts. In this study, we assessed the prevalence of T. gondii in sheep and goats coming from central Iran. After completing the questionnaire, about one gram of liver or diaphragm tissue was taken as a sample from 90 sheep and 90 goats slaughtered in Yazd Province and stored at – 20 ºC. DNA extraction was done, and then T. gondii was detected using nested PCR. Results This study indicated that the prevalence of T. gondii in all slaughtered animals was 11.6% (21 of 180), including 14.4% (13/90) in sheep and 8.8% (8/90) in goats. The infection rates in liver and diaphragm samples were 12.2% (11/90) and 11.1% (10/90), respectively (p = 0.8163). The infection rate in animals older than one was 16.3% (15/92), and it was 6.8% (6/88) in animals under one year of age. Therefore, no significant differences were found (p = 0.475). Infection rates were 19.5% (18/92) in males and 3.4% (3/88) in females (p = 0.0007). In conclusion, the infection rates of toxoplasmosis in livestock in this area are almost high, and therefore, it is necessary to design appropriate prevention programs to control the disease.

scholarly journals The Effect of Vaccination Rates on the Infection of COVID-19 under the Vaccination Rate below the Herd Immunity Threshold

2021 ◽  
Vol 18 (14) ◽  
pp. 7491
Author(s):  
Yi-Tui Chen
Keyword(s):  
Infection Rate ◽  
Herd Immunity ◽  
The United States ◽  
Vaccination Rate ◽  
Infection Rates ◽  
Vaccination Rates ◽  
The United Kingdom ◽  
The World ◽  
Almost All ◽  
The Impact

Although vaccination is carried out worldwide, the vaccination rate varies greatly. As of 24 May 2021, in some countries, the proportion of the population fully vaccinated against COVID-19 has exceeded 50%, but in many countries, this proportion is still very low, less than 1%. This article aims to explore the impact of vaccination on the spread of the COVID-19 pandemic. As the herd immunity of almost all countries in the world has not been reached, several countries were selected as sample cases by employing the following criteria: more than 60 vaccine doses per 100 people and a population of more than one million people. In the end, a total of eight countries/regions were selected, including Israel, the UAE, Chile, the United Kingdom, the United States, Hungary, and Qatar. The results find that vaccination has a major impact on reducing infection rates in all countries. However, the infection rate after vaccination showed two trends. One is an inverted U-shaped trend, and the other is an L-shaped trend. For those countries with an inverted U-shaped trend, the infection rate begins to decline when the vaccination rate reaches 1.46–50.91 doses per 100 people.

Biological control of Fusarium wilt of cucumber with nonpathogenic isolates of Fusarium oxysporum

1987 ◽  
Vol 33 (5) ◽  
pp. 349-353 ◽  
Author(s):  
T. C. Paulitz ◽  
C. S. Park ◽  
R. Baker
Keyword(s):  
Biological Control ◽  
Fusarium Oxysporum ◽  
Infection Rate ◽  
Fusarium Wilt ◽  
Disease Incidence ◽  
Infection Rates ◽  
Control Activity ◽  
Significant Difference ◽  
Cucumber Roots ◽  
Linear Regressions

Nonpathogenic isolates of Fusarium oxysporum were obtained from surface-disinfested, symptomless cucumber roots grown in two raw (nonautoclaved) soils. These isolates were screened for pathogenicity and biological control activity against Fusarium wilt of cucumber in raw soil infested with Fusarium oxysporum f. sp. cucumerinum (F.o.c.). The influence of three isolates effective in inducing suppressiveness and three ineffective isolates on disease incidence over time was tested. The effective isolates reduced the infection rate (R), based on linear regressions of data transformed to loge (1/1 – y). Effective isolate C5 was added to raw soil infested with various inoculum densities of F.o.c. In treatments without C5, the increase in inoculum densities of F.o.c. decreased the incubation period of wilt disease, but there was no significant difference in infection rate among the inoculum density treatments. Isolate C5 reduced the infection rate at all inoculum densities of F.o.c. Various inoculum densities of C5 were added to raw soils infested with 1000 cfu/g of F.o.c. In the first trial, infection rates were reduced only in the treatment with 10 000 cfu/g of C5; in the second trial, infection rates were reduced in treatments with 10 000 and 30 000 cfu/g of C5.

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