scholarly journals Studies in the epidemiology of infectious myxomatosis of rabbits: I. Recovery of Australian wild rabbits (Oryctolagus Cuniculus) from myxomatosis under field conditions

1953 ◽  
Vol 51 (2) ◽  
pp. 225-244 ◽  
Author(s):  
Frank Fenner ◽  
I. D. Marshall ◽  
Gwendolyn M. Woodroofe
Keyword(s):  
Mortality Rate ◽  
Neutralizing Antibodies ◽  
Complement Fixation ◽  
Small Population ◽  
Myxoma Virus ◽  
Rabbit Population ◽  
Eastern Australia ◽  
Before And After ◽  
Grade Ii ◽  
Case Mortality

1. Australian wild rabbits which had recovered from myxomatosis acquired in the field contained in their serum antibodies which could be detected by complement-fixation or neutralization tests for a long period (more than 18 months) after their recovery. The titre of complement-fixing antibody fell fairly rapidly during the first few months, and remained at a steady level thereafter. No change could be detected in the titre of neutralizing antibodies throughout the observation period.2. Inoculation of such rabbits with myxoma virus was sometimes followed by the development of a local lesion at the inoculation site, and in these rabbits the titre of complement-fixing antibody rose, but there was no alteration in the neutralizing power of the serum. In other animals no lesion developed and there was no change in the antibody titre.3. Serum was collected from a total of 824 wild rabbits from seventeen localities in eastern Australia with varying histories of myxomatosis since December 1950. Examination of 135 of these sera by both neutralization and complement-fixation tests showed that the results obtained by the two methods were in close agreement.4. In many areas in which the disease was absent in the summer of 1950–1 and produced a violent epizootic in 1951–2, the majority (70–90 %) of the sera collected from rabbits 2–5 months after the height of the epizootic contained antibody to myxoma virus, i.e. the majority of the survivors had recovered from the disease.5. Counts of the rabbit population before and after a violent epizootic in the summer of 1951–2, and the proportion of immune animals amongst the survivors in these areas showed that the case-mortality rate was between 99·4 and 99·8%.6. Consideration of the results obtained in the serological surveys showed that the case-mortality rate was probably of this order (about 99·5%) in all areas in which there had been no disease or a negligible outbreak in 1950–1, whether they had a grade I or grade II kill in 1951–2.7. In certain other areas, in which a grade I outbreak in 1950–1 was followed by a grade II or poorer kill in 1951–2, the observed immune rate was considerably higher than would be expected if the case-mortality rate (assuming that the whole rabbit population was susceptible) was 99·5%. The possible causes of this are discussed. Survival of immune survivors from the first epizootic through the second may be a factor of some importance, but it is probably not the only factor involved.8. The areas just mentioned were exceptional. In most places there was either no build-up of population after the 1950–1 epizootic, or a second effective epizootic destroyed the majority of rabbits in the small population which had developed by reproduction of the survivors of the first outbreak.

A winter epizootic of myxomatosis in subalpine south-eastern Australia

1971 ◽  
Vol 19 (3) ◽  
pp. 275 ◽  
Author(s):  
JD Dunsmore ◽  
RT Williams ◽  
WJ Price
Keyword(s):  
Social Contact ◽  
Myxoma Virus ◽  
Infection Transmission ◽  
South Eastern ◽  
Rabbit Population ◽  
Slow Progression ◽  
Eastern Australia ◽  
The Common ◽  
Case Mortality ◽  
Established Population

An epizootic of myxomatosis in rabbits that occurred during the winter months (March-August) of 1969 is described in detail. Virus of virulence grade 111, the common virulence of field strains of myxoma virus presently in Australia, was isolated during the epizootic. The estimated case mortality was 86% over the 5 months during which the epizootic was active. Only 41228 of the original susceptible and established population completely avoided infection. Transmission through the population was relatively slow and apparently depended on social contact between individual rabbits. The seasonal conditions and the slow progression of the disease through the population make it most unlikely that mosquitoes were involved in transmitting the virus. The origin of the virus that initiated the epizootic is discussed, including the possibility that it was not a reintroduction of myxoma virus to the population. This implies that the virus may have remained latent in the rabbit population for several years.

scholarly journals Innate resistance to myxomatosis in wild rabbits in England

1977 ◽  
Vol 79 (3) ◽  
pp. 411-416 ◽  
Author(s):  
J. Ross ◽  
M. F. Sanders
Keyword(s):  
Great Britain ◽  
Mortality Rate ◽  
Oryctolagus Cuniculus ◽  
Mortality Rates ◽  
Myxoma Virus ◽  
Considerable Degree ◽  
Survival Times ◽  
Innate Resistance ◽  
Low Level ◽  
Rabbit Population

SUMMARYWild rabbits (Oryctolagus cuniculus) from one study area in England have been used over a period of 11 years to investigate the possible appearance of innate resistance to myxomatosis. Rabbits of 4–6 weeks old were captured alive, retained in the laboratory until at least 4 months old, and then infected with a type of myxoma virus which kills 90–95% of laboratory rabbits. Observations were made of symptoms, mortality rate and survival times.In the first 4 years of the study (1966–9), mortality rates were not significantly different from those of laboratory rabbits, although survival times of wild rabbits were appreciably longer. In 1970, the mortality rate amongst wild rabbits was 59%, in 1974 it was 17%, and in 1976 it was 20%, thus showing that a considerable degree of inherited resistance to myxomatosis has developed.The types of myxoma virus most commonly isolated from wild rabbits in Great Britain in recent years have been those which cause 70–95% mortality in laboratory rabbits. Therefore, if the degree of innate resistance demonstrated is widespread in Great Britain, there are serious implications regarding the size of the rabbit population, because myxomatosis has been an important factor in holding rabbit numbers at a relatively low level.

A non-winter epizootic of myxomatosis in subalpine south-eastern Australia

1972 ◽  
Vol 20 (4) ◽  
pp. 405 ◽  
Author(s):  
JD Dunsmore ◽  
WJ Price
Keyword(s):  
Morbidity Rate ◽  
South Eastern ◽  
Rabbit Population ◽  
Eastern Australia ◽  
Epidemiological Pattern ◽  
The Difference ◽  
Case Mortality ◽  
South Eastern Australia

A myxomatosis epizootic, that occurred in February-April 1972 in a rabbit population in which a winter epizootic was observed in 1969, is described. Rabbit fleas had been introduced into the rabbit population in the intervening period. In the 1972 outbreak the case mortality was only 33% compared with 86% in 1969. The difference is thought to be related to the colder conditions during the 1969 epizootic. The morbidity rate could not be accurately measured in 1972 but was a minimum of 65%. It is believed that in the 1972 epizootic the virus was transmitted by rabbit fleas. It appears that any change in the epidemiological pattern of myxomatosis towards summer epizootics in areas in which they have previously occurred in winter will drastically reduce the rabbit mortality currently caused by myxomatosis. The introduction of rabbit fleas may increase the likelihood of epizootics in summer and autumn.

scholarly journals A comparison of the virulence for European rabbits (Oryctolagus cuniculus) of strains of myxoma virus recovered in the field in Australia, Europe and America

1957 ◽  
Vol 55 (2) ◽  
pp. 149-191 ◽  
Author(s):  
Frank Fenner ◽  
I. D. Marshall
Keyword(s):  
Mortality Rate ◽  
South America ◽  
Laboratory Strain ◽  
Myxoma Virus ◽  
Research Station ◽  
Standard Laboratory ◽  
Department Of Agriculture ◽  
Case Mortality ◽  
Virus Strains ◽  
Highly Virulent

Strains of myxoma virus associated with a case-mortality rate in wild rabbits of 90—95% can be distinguished from those associated with a case-mortality rate of more than 99% by the use of a standardized virulence test carried out in groups of five laboratory rabbits, and tests carried out on laboratory rabbits are closely correlated with the results obtained with Australian wild rabbits. The test, which attempts to mimic natural mosquito transmission, consists of the intradermal inoculation in one site of about 5 rabbit-infectious doses of the virus, and the subsequent observation of the rate of progress of clinical symptoms and ultimate fate of the rabbit. The mean survival time provides a figure which allows satisfactory classification of all known myxoma virus strains into one of four grades of virulence, very attenuated strains being recognized by their low case-mortality rates.Using this test, 92 strains of myxoma virus have been compared. These comprised 6 laboratory strains, 62 strains recovered from Australian wild rabbits or from wild caught mosquitoes, between February, 1951 and March, 1955, 19 strains recovered from naturally infected rabbits in Europe between October, 1953 and August, 1955, 3 strains from South America, and 2 from California. Eight types have been described and illustrated, differentiation being based on their virulence and the clinical picture of the disease they cause in laboratory rabbits. The differences are summarized in Text-fig. 2. Four of the virus types produce recognizably different pocks on the chorioallantois of developing chick embryos.In Australia the repeatedly introduced standard laboratory strain of virus has been replaced by a moderately virulent strain, which appears to be better adapted for survival than either the highly virulent standard laboratory strain, or less virulent variants of which only a few had been recovered up to 1955. Strains of the type dominant in 1953–55 have appeared independently in many widely separated parts of Australia. Examination of these attenuated variants by pure clone techniques showed that the variability in symptomatology associated with them is not due to a mixture of virus strains, but to the expression of differences in innate resistance of the host animals which are obscured by the overwhelming virulence of the highly virulent strains.Only one introduction of a different strain of virus was made in Europe. All field strains recovered during the first two years after the introduction were of high virulence, but a few attenuated strains appeared in 1955, and they have since become widespread. One of them appears to be a relatively stable mixture of a highly virulent and a greatly attenuated strain.The collection of the large numbers of strains of virus described in this paper has been made possible only by the generous collaboration of many people. In Australia we would like to acknowledge the great help afforded us by Mr F. N. Ratcliffe, officer-in-charge of the Wildlife Survey Section, Commonwealth Scientific and Industrial Research Organization and his officers, especially Messrs J. H. Calaby, G. Douglas, A. L. Dyce, B. V. Fennessy, E. W. Lines, K. Myers, R. Mykytowycz, W. E. Poole and E. Waterhouse. Messrs B. D. Robinson and T. Pearce of the Lands Department of Victoria have also provided us with specimens, as have Mr G. Edgar, Director of the Veterinary Research Station, Glenfield, New South Wales, Dr D. Surrey Dane of the Institute of Medical and Veterinary Science, Adelaide, Mr D. Gooding, Department of Agriculture, Western Australia, and Messrs T. B. Alexander and A. F. Ryan, Department of Agriculture, Tasmania.We are indebted to Dr H. de B. Aragão of the Instituto Oswaldo Cruz, Rio de Janeiro, and Dr B. Szyfres, of the Laboratorio de Biologia Animal, Uruguay, for specimens from South America; Dr D. G. McKercher of the University of California School of Veterinary Medicine, Davis, California, for the Californian strains; Drs P. Lépine and H. Jacotot, of the Institut Pasteur, Paris, for strains from France; and Mr J. R. Hudson, of the Veterinary Laboratory, Weybridge, and Dr C. H. Andrewes of the National Institute for Medical Research, Mill Hill, for material from England.We are grateful to Dr S. Fazekas de St Groth and Dr G. S. Watson of this University for advice on the statistical treatment of the data.Mr V. Paral took the photographs.

CLINICAL CHARACTERISTICS AND RESULTS OF CATARACT SURGERY IN THE SMALL PUPIL EYE BY PHACOEMUSIFICATION

2018 ◽  
pp. 79-82
Author(s):  
Van Minh Pham ◽  
Van Nam Phan ◽  
Thi Thu Nguyen
Keyword(s):  
Visual Acuity ◽  
Cataract Surgery ◽  
Clinical Characteristics ◽  
Low Vision ◽  
Sample Selection ◽  
Posterior Chamber ◽  
Good Visual Acuity ◽  
Before And After ◽  
Grade Ii ◽  
Small Pupil

Objectives: To investigate the clinical characteristics of cataract patients with small pupils and to evaluate the result of cataract surgery on the eye have small pupils by phacotechnique. Subjects and methods: Descriptive study, prospective, uncontrolled interventions. Sample selection. The sample size of 70 patients with 70 eyes of cataracts with small pupils was treated by phaco technique and intraocular lens implant within posterior chamber. Follow up to 3 months. Results: 70 eyes, the percentage of men and women was not different from 54.2% (38 male) compared to 45.8% (32 female). The mean age was 80 ± 8.74, from 58 to 99 years. The disease was mainly found in the age group over 70 years old with over 80% (51.5%). Visual acuity before surgery was very poor under 3m CF (count finger) for 68.6% (48/70). Visual acuity over 1/10 was only a small amount with 2.8% (2 eyes). Pseudoexfoliation was the most common reason complications of mydriasis with 32/70 eyes (45.7%) and 22/70 eyes (31.4%) for age. The preoperative pupilarysizewas mostly small with 63/70 eyes (90.0%), non-dilated pupils (7/70 eyes) (10.0%). Average pupil size was 3.34 mm (2 - 4mm). Iris condition: iris atrophy 20/10 eyes (28.6%), iris synechiae 11/10 (15.7%), irregular iris muscle with 51, 4% and good iris muscle accounted for 48.6%. Grade of cataract: Grade III: 31/70 eyes (44.3%), Grade IV: 32/70 eyes (45.7%), Grade II: 5/70 eyes (7.1%) and V:2/70 eyes (2.9%). Pupil expander technique: OVD injection with 42/70 eyes (60%), using iris hook with 23/70 eyes (32.9%). Pupillary size before and after intervention has changed from 3.7mm to 4.48mm. Conclusions: Iris expander techniques have been shown to have good dilated pupils: 60.0% OVD injection, iris hook was 32.9%, other methods 7.1% One-week visibility of good visual acuity was higher than that of postoperative one day (12.2%) and increased at 1 month and 3 months (20.0%). Very good visual acuity was not available and low vision group was 1.4% after 3 months. Key words: cataract surgery; phacoemusification, small pupil

scholarly journals Distribution and titres of rotavirus antibodies in different age groups

1977 ◽  
Vol 79 (3) ◽  
pp. 365-372 ◽  
Author(s):  
M. M. Elias
Keyword(s):  
Indirect Immunofluorescence ◽  
Acute Gastroenteritis ◽  
Neutralizing Antibodies ◽  
Complement Fixation ◽  
Age Groups ◽  
Newborn Infants ◽  
Older Age ◽  
Human Rotavirus ◽  
Hospital Patients

SUMMARYThree hundred and fifty-seven sera selected at random from hospital patients of all ages were examined for rotavirus antibodies using indirect immunofluorescence (FA) and complement fixation tests (CFT). Three hundred and fourteen of these were also tested for neutralizing antibodies to human rotavirus. Sera from patients admitted with a diagnosis of acute gastroenteritis were excluded from this survey.FA antibodies were found in newborn infants but fell to undetectable titres at 3 months. The highest titres were found in children between the ages of one and three years. In older age groups, the modal titre fell gradually with increasing age until, in sera from those above 70 years of age, FA antibodies were almost undetectable. The same pattern was observed with neutralizing antibodies. A high modal titre of CF antibodies was only found in sera from those aged one to three years.

Improving Student Creativity Activeness And Implementation Approach In Cbsa On Civics Lesson Grade Ii Sd Negeri 39 Lengayang Gompong.Kec Markets Academic Year 2016/2017

2018 ◽  
Vol 1 (2) ◽  
pp. 89-96
Author(s):  
Darleli Darleli
Keyword(s):  
Civic Education ◽  
Evaluation Study ◽  
Class Action ◽  
Peer Tutors ◽  
Implementation Approach ◽  
Before And After ◽  
Study Population ◽  
Grade Ii ◽  
The Subject ◽  
Academic Year

    The purpose of this study is to prove that the use of the environment around the school can improve students' understanding of the subject Civic Education in Elementary School student 39 Class II Gompong Market. This study uses a class action approach. The study population was taken of all students in grade II , the data collection techniques used artificial teacher learning achievement test. Actions performed a total of two cycles. Data analysis techniques used analysis of the percentage of change in the results of the evaluation study before and after tutoring services with peer tutors. Thus there is an increase in students' mastery of the first cycle and the second cycle. Based on the above, it can be made a conclusion as follows: " Improving Student Creativity activeness And Implementation Approach In CBSA On Civics Lesson Grade II SD Negeri 39 Lengayang Gompong.Kec Markets Academic Year 2016/2017 " .    

scholarly journals Analysis of mortality from diarrheic diseases in under-five children in Brazilian cities with more than 150,000 inhabitants

2009 ◽  
Vol 25 (5) ◽  
pp. 1093-1102 ◽  
Author(s):  
Juraci Vieira Sergio ◽  
Antônio Carlos Ponce de Leon
Keyword(s):  
Mortality Rate ◽  
Time Trends ◽  
Sharp Decrease ◽  
Mortality Rates ◽  
The North ◽  
Indicator Variables ◽  
Before And After ◽  
Geographic Regions ◽  
Annual Mortality ◽  
Children Under 5

This study analyzes mortality from infectious diarrheic diseases in children under 5 years of age in Brazilian municipalities with more than 150,000 inhabitants, excluding State capitals. The annual mortality rates by municipality from 1990 to 2000 were analyzed using a multilevel model, with years as first level units nested in municipalities as second level units. The dependent variable was the yearly mortality rate by municipality, on the log scale. Polynomial time trends and indicator variables to account for differences in geographic regions were used in the modeling. Time trends were centered on 1995, so they could be modeled differently before and after 1995. From 1990 to 1995 there was a sharp decrease in mortality rates by diarrheic diseases in most Brazilian municipalities, while from 1995 to 2000 the decrease was more heterogeneous. In 1995 the North and Northeast of Brazil had higher mortality rates than the Southeast, and the differences were statistically significant. Most importantly, the study concludes that there was an important difference in the pattern of mortality rate decreases over time, comparing the country's five geographic regions.

scholarly journals Expiration Training Maneuver for Chronic Obstructive Pulmonary Disease with Congestive Heart Failure Grade II: A Case Report

2019 ◽  
Vol 7 (01) ◽  
pp. 28
Author(s):  
Nury Nusdwinuringtyas ◽  
Siti Chandra Widjanantie
Keyword(s):  
Chronic Obstructive Pulmonary Disease ◽  
Muscle Strength ◽  
Pulmonary Disease ◽  
Respiratory Muscle ◽  
Walking Distance ◽  
Chronic Obstructive ◽  
Respiratory Muscle Strength ◽  
Obstructive Pulmonary Disease ◽  
Before And After ◽  
Grade Ii

Introduction: Chronic Obstructive Pulmonary Disease (COPD) was characteristic by the inflammatory process in the airway which causes air trapping and hyperinflation, then followed by decreasing the respiratory muscle strength. Breathing training using the positive expiratory pressure (PEP) increasing respiratory muscle strength.Methods: A case presentation of a male, age was 60 years old diagnosed as COPD by The Global Initiative for Chronic Obstructive Lung Disease (GOLD) grade 4 group D, and Chronic Heart Failure (CHF) grade II, with complication of excessive phlegm, underweight, and weakness of respiratory muscle, have PEP for 8 weeks.Results: Spirometry evaluation before and after eight week of PEP have found; FEV1 22.12 and 22.42%, FVC 34.24 and 56%, FEV1/FVC 76.8 and 64%. Respiratory muscle strength before and after PEP showed the Muscle Inspiratory Pressure (MIP) 46 and 71 cmH2O, Muscle Expiratory Pressure (MEP) 48 and 104 cmH2O.The values of Six Minute Walk Test (6MWT) evaluation by BORG modified scale before and after PEP were 11 and 13 ( efforts), 2 and 3 (dyspnea), 0 and 1 (Leg Fatigue). The six-minute walking distance (6MWD) before and after PED were 170 and 190 m, equation reference with Nury’s formula showed percentage prediction before and after PEP respectively 29.2 and 32%, VO2Max; 4.96 and 6L, METs; 1.41 and 1.7. The St GeorgeRespiratory Questionnaire (SGRQ) before and after PEP were 20.6 and 49.5% (symptom), 86.6 and 45.1% (activity), 45.5 and 18.4% (impact) and 53.6 and 42% for total.Conclusion: Positive airway pressure exercise had beneficial effect on reducing air-trapping process in COPD and increasing the respiratory muscle strength for both expiratory and inspiratory muscle strength.Keywords: Chronic obstructive pulmonary disease, positive expiratory pressure device, respiratory muscle strength, six minutes walking distance

scholarly journals Vaccination of COVID-19 Convalescent Plasma Donors Increases Binding and Neutralizing Antibodies Against SARS-CoV-2 Variants

2021 ◽  
Author(s):  
Clara Di Germanio ◽  
Graham Simmons ◽  
Chloe Thorbrogger ◽  
Rachel Martinelli ◽  
Mars Stone ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Passive Immunotherapy ◽  
Post Vaccination ◽  
Vaccination Rates ◽  
Beneficial Effects ◽  
Paired Samples ◽  
Igg Binding ◽  
The Us ◽  
Before And After ◽  
The Individual

Background: COVID-19 convalescent plasma (CCP) was widely used as passive immunotherapy during the first waves of SARS-CoV-2 infection in the US. However, based on observational studies and randomized controlled trials, beneficial effects of CCP were limited, and its use was virtually discontinued early in 2021, in concurrence with increased vaccination rates and availability of monoclonal antibody (mAb) therapeutics. However, as new variants of the SARS-CoV-2 spread, interest in CCP derived from vaccine-boosted CCP donors is resurging. The effect of vaccination of previously infected CCP donors on antibodies against rapidly spreading variants of concern (VOC) is still under investigation. Study Design/Methods: In this study, paired samples from 11 CCP donors collected before and after vaccination were tested to measure binding antibodies levels and neutralization activity against the ancestral and SARS-CoV-2 variants (Wuhan-Hu-1, B.1.1.7, B.1.351, P.1, D614G, B.1.617.2, B.1.427) on the Ortho Vitros Spike Total Ig and IgG assays, the MSD V-PLEX SARS-CoV-2 Panel 6 arrays for IgG binding and ACE2 inhibition, and variant-specific Spike Reporter Viral Particle Neutralization (RVPN) assays. Results/Findings: Binding and neutralizing antibodies were significantly boosted by vaccination, with several logs higher neutralization for all the variants tested post-vaccination compared to the pre-vaccination samples, with no difference found among the individual variants. Discussion: Vaccination of previously infected individuals boosts antibodies including neutralizing activity against all SARS-CoV-2 VOC, including the current spreading delta (B.1.617.2) variant. Animal model and human studies to assess clinical efficacy of vaccine boosted CCP are warranted, especially since 15-20% of current donations in the US are from previously infected vaccine-boosted donors.

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