scholarly journals Age structure of owned dogs under compulsory culling in a visceral leishmaniasis endemic area

2016 ◽  
Vol 32 (8) ◽  
Author(s):  
Danielly Vieira Bortoletto ◽  
Yuri Tani Utsunomiya ◽  
Silvia Helena Venturoli Perri ◽  
Fernando Ferreira ◽  
Cáris Maroni Nunes
Keyword(s):  
Visceral Leishmaniasis ◽  
Age Structure ◽  
Endemic Area ◽  
Study Data ◽  
Control Measures ◽  
Logarithmic Scale ◽  
Control Programs ◽  
Age Pyramid ◽  
Growth Projection ◽  
The Impact

Abstract: The age structure of the dog population is essential for planning and evaluating control programs for zoonotic diseases. We analyzed data of an owned-dog census in order to characterize, for the first time, the structure of a dog population under compulsory culling in a visceral leishmaniasis endemic area (Panorama, São Paulo State, Brazil) that recorded a dog-culling rate of 28% in the year of the study. Data on 1,329 households and 1,671 owned dogs revealed an owned dog:human ratio of 1:7. The mean age of dogs was estimated at 1.73 years; the age pyramid indicated high birth and mortality rates at the first year of age with an estimated cumulative mortality of 78% at the third year of age and expected life span of 2.75 years. In spite of the high mortality, a growth projection simulation suggested that the population has potential to grow in a logarithmic scale over the years. The estimated parameters can be further applied in models to maximize the impact and minimize financial inputs of visceral leishmaniasis control measures.

scholarly journals USE OF THE POLYMERASE CHAIN REACTION FOR THE DIAGNOSIS OF ASYMPTOMATIC Leishmania INFECTION IN A VISCERAL LEISHMANIASIS-ENDEMIC AREA

2013 ◽  
Vol 55 (2) ◽  
pp. 101-104 ◽  
Author(s):  
Luciana Almeida Silva ◽  
Héctor Dardo Romero ◽  
Aline Fagundes ◽  
Nédia Nehme ◽  
Otávio Fernandes ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Visceral Leishmaniasis ◽  
Endemic Area ◽  
Asymptomatic Infection ◽  
Control Measures ◽  
Skin Tests ◽  
Leishmania Infection ◽  
Chain Reaction ◽  
Serological Tests ◽  
Polymerase Chain

The diagnosis of asymptomatic infection with Leishmania (Leishmania) chagasi has become more important over recent years. Expansion of visceral leishmaniasis might be associated with other routes of transmission such as transfusion, congenital or even vector transmission, and subjects with asymptomatic infection are potential reservoirs. Moreover, the identification of infection may contribute to the management of patients with immunosuppressive conditions (HIV, transplants, use of immunomodulators) and to the assessment of the effectiveness of control measures. In this study, 149 subjects living in a visceral leishmaniasis endemic area were evaluated clinically and submitted to genus-specific polymerase chain reaction (PCR), serological testing, and the Montenegro skin test. Forty-nine (32.9%) of the subjects had a positive PCR result and none of them developed the disease within a follow-up period of three years. No association was observed between the results of PCR, serological and skin tests. A positive PCR result in subjects from the endemic area did not indicate a risk of progression to visceral leishmaniasis and was not associated with a positive result in the serological tests.

scholarly journals Canine Leishmaniasis in Brazil: Serological Follow-Up of a Dog Population in an Endemic Area of American Visceral Leishmaniasis

2009 ◽  
Vol 2009 ◽  
pp. 1-6 ◽  
Author(s):  
Alba Valéria Machado da Silva ◽  
Adelzon Assis de Paula ◽  
Daniela de Pita Pereira ◽  
Reginaldo Peçanha Brazil ◽  
João Carlos Araujo Carreira
Keyword(s):  
Visceral Leishmaniasis ◽  
Western Blot ◽  
Sensitivity And Specificity ◽  
Endemic Area ◽  
High Sensitivity ◽  
Control Measures ◽  
Canine Leishmaniasis ◽  
Indirect Immunofluorescent Assay ◽  
Indirect Immunofluorescent

We performed a serological, clinical, and parasitological follow-up of a dog population in an endemic area of American Visceral Leishmaniasis estimated by indirect immunofluorescent assay (IFA) and western blot (WB). After twelve months, the results obtained from IFA demonstrated that 50% were seropositive and two serological profiles were observed: the first one ranging from 1/40 to 1/80 and the second≥1/160. By WB, it was observed that the same percentage and sera from positive dogs presented the recognition of the peptides of 29 and 32 kDa up to 8 months before IFA serum conversion. Among the positive dogs, all the sera from symptomatic ones with tissue parasitism recognized the peptide of 68.5 kDa. Our results suggest the need of modifications in the control measures regarding the elimination of the dogs. They also corroborate the high sensitivity and specificity of western blot in the diagnosis of canine leishmaniasis, suggesting the possibility of its association with IFA.

scholarly journals A novel age-structured mosquito model for assessing the mechanisms behind vector control success

2020 ◽  
Author(s):  
Emma L Davis ◽  
T Déirdre Hollingsworth ◽  
Matt J Keeling
Keyword(s):  
Vector Control ◽  
Age Structure ◽  
Current Knowledge ◽  
Steady State Solution ◽  
Health Impact ◽  
Control Measures ◽  
Control Methods ◽  
Vector Population ◽  
Age Structured ◽  
The Impact

Abstract Background: Vector control is a vital tool utilised by malaria control and elimination programmes worldwide, and as such it is important that we can accurately quantify the expected public health impact of a range of vector control methods. There are very few previous models that consider vector control induced changes in the age-structure of the vector population and the resulting impact this will have on transmission.Methods: The steady-state solution of a novel age-structured deterministic compartmental model describing the mosquito gonotrophic cycle is analytically derived, with the age of each mosquito measured in the number of gonotrophic cycles (or successful blood meals) completed. From this model we derive analytical expressions for key transmission measures, such as the effective reproductive ratio under control, Rc, and investigate the impact of combinations of commonly used vector control methods on the age-structure of the vector population.Results: Our model output is an explicit solution that can be used to directly quantify key transmission statistics and investigate the age-structured impact of vector control. Application of this model confirms current knowledge thatadult-acting interventions, such as IRS or LLINs, can be highly effective at reducing transmission, due to the dual effects of repelling and killing mosquitoes. However, we demonstrate how larval measures can be implemented in addition to adult-acting measures to reduce Rc and mitigate the impact of waning insecticidal efficacy. We also find that mid-ranges of LLIN coverage see the largest effect of reduced net integrity on transmission.Conclusions: Whilst well-maintain adult-acting vector control measures are substantially more effective than larval-based interventions, incorporating larval control in existing LLIN or IRS programmes could substantially reduce transmission. This would most benefit areas with low coverage or poor maintenance of interventions.

scholarly journals Serological and infection statuses of dogs from a visceral leishmaniasis-endemic area

2014 ◽  
Vol 48 (4) ◽  
pp. 563-571 ◽  
Author(s):  
Daniela Farias Laranjeira ◽  
Vânia Lúcia Ribeiro da Matta ◽  
Thaíse Yumie Tomokane ◽  
Mary Marcondes ◽  
Carlos Eduardo Pereira Corbet ◽  
...  
Keyword(s):  
Visceral Leishmaniasis ◽  
Endemic Area ◽  
Clinical Status ◽  
Humoral Response ◽  
Parasite Load ◽  
Clinical Findings ◽  
Enzyme Linked Immunosorbent Assay ◽  
Control Programs ◽  
Serological Status ◽  
Serological Result

OBJECTIVE This study investigated the serological status of dogs living in a visceral leishmaniasis-endemic area and its correlation with the parasitological condition of the animals.METHODS Canine humoral response was evaluated using the sera of 134 dogs by enzyme-linked immunosorbent assay and immunohistochemistry to detect parasites in the skin, lymph node, and spleen of the animals. The specific antibodies investigated were IgG, IgG1, IgG2, and IgE.RESULTS According to the parasitological, laboratory, and clinical findings, the dogs were placed into one of four groups: asymptomatic with (AP+, n = 21) or without (AP-, n = 36) Leishmania tissue parasitism and symptomatic with (SP+, n = 52) or without (SP-, n = 25) parasitism. Higher IgG and IgE levels were positively correlated with the infection condition and parasite load, but not with the clinical status. In all groups, total IgG was the predominant antibody, which occurred at the expense of IgG2 instead of IgG1. Most of the infected dogs tested positive for IgG (SP+, 98.1%; AP+, 95.2%), whereas this was not observed with IgE (SP+, 80.8%; AP+, 71.2%). The most relevant finding was the high positivity of the uninfected dogs for Leishmania-specific IgG (SP-, 60.0%; AP-, 44.4%), IgE (SP-, 44.0%; AP-, 27.8%), IgG1 (SP-, 28.0%; AP-, 22.2%), and IgG2 antibodies (SP-, 56.0%; AP-, 41.7%).CONCLUSIONS The serological status of dogs, as determined by any class or subclass of antibodies, did not accurately distinguish dogs infected with L. (L.) infantum chagasifrom uninfected animals. The inaccuracy of the serological result may impair not only the diagnosis, but also epidemiological investigations and strategies for visceral leishmaniasis control. This complex serological scenario occurring in a visceral leishmaniasis-endemic area highlights the challenges associated with canine diagnosis and points out the difficulties experienced by veterinary clinicians and coordinators of control programs.

scholarly journals Sandflies in an endemic area for Visceral Leishmaniasis in Northeastern Brazil

2019 ◽  
Vol 28 (4) ◽  
pp. 569-573 ◽  
Author(s):  
Jonatas Abinadabe Oliveira Silva ◽  
Fernando José da Silva ◽  
Lucia Oliveira de Macedo ◽  
Cléber Vinícius Brito dos Santos ◽  
Leucio Câmara Alves ◽  
...  
Keyword(s):  
Visceral Leishmaniasis ◽  
Cutaneous Leishmaniasis ◽  
Leishmania Infantum ◽  
Endemic Area ◽  
Control Measures ◽  
Northeastern Brazil ◽  
Lutzomyia Longipalpis ◽  
Risk Of Infection ◽  
Light Traps ◽  
Animal Populations

Abstract Phlebotomines of the genus Lutzomyia are important vector for species of Leishmania, the etiological agent of leishmaniasis. The aim of this study was to assess the diversity of sandflies in an endemic area for Visceral Leishmaniasis (VL). Sampling was performed in four localities on the coast of the municipality of Goiana, state of Pernambuco, Northeastern Brazil. Specimens were collected monthly on three consecutive nights, from November 2017 to October 2018. CDC light traps were installed at a height of 1.5 m above the ground, in two ecotypes (i.e. tree and animal facility), both in peridomestic areas. A total of 5,205 sandflies were collected, among which the species Lutzomyia longipalpis (99.85%; 5,197/5,205) was the most common, followed by Lutzomyia evandroi (0.13%; 07/5,205) and Lutzomyia whitmani (0.02%; 01/5,205). Specimens of L. longipalpis were collected throughout the study period and most of them were found near to the animal facilities. The findings from this research indicate that vectors for Leishmania infantum are present in the study area throughout the year, along with occurrences of vectors relating to Cutaneous Leishmaniasis (CL). Preventive vector control measures need to be implemented in Goiana to reduce the risk of infection for the human and animal populations.

scholarly journals Limitations in the implementation of control measures for bovine paratuberculosis in infected Swiss dairy and beef herds

PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0245836
Author(s):  
Myriam Klopfstein ◽  
Alexandra Leyer ◽  
Beat Berchtold ◽  
Paul Robert Torgerson ◽  
Mireille Meylan
Keyword(s):  
Financial Incentives ◽  
Johne's Disease ◽  
Johne’S Disease ◽  
Control Measures ◽  
Control Programs ◽  
Beef Herds ◽  
Cattle Herds ◽  
Management Changes ◽  
The Impact ◽  
Specific Control

Various measures have been advocated for the control of Johne’s disease (caused by Mycobacterium avium subsp. paratuberculosis, MAP) in different countries. Farmers’ compliance has been reported to be variable depending on disease prevalence and incentives to participate in control programs. After the prevalence of MAP shedding and risk factors for within-herd spread of MAP were assessed in 17 Swiss cattle herds (10 dairy and 7 beef), general and herd-specific recommendations were given to the farmers to reduce MAP transmission within the herd. Participation in the study and implementation of control measures were voluntary, no financial incentives were provided for the realization of control measures. After a 3-year period of monitored observation including biannual farm visits and discussion of the situation, the implementation of the recommended control measures and their effect on prevalence of MAP shedding were evaluated. Implementation of recommended general and farm-specific control measures was only partially realized. Neither the number of animals tested positive (before or during the study) nor the farmers’ knowledge about paratuberculosis were significantly associated with their compliance for the implementation of management changes. The apparent within-herd prevalence remained constant despite limited implementation of control measures, and no particular group of control measures was found to be associated with changes in prevalence. Farmers’ compliance for the implementation of control measures to reduce the impact of Johne’s disease in infected farms was very limited under Swiss farming conditions in the frame of voluntary participation in a research project. These results indicate that the losses associated with paratuberculosis in Swiss dairy and beef operations are not estimated to be high enough by the farmers to justify important efforts for control measures, and that incentives may be necessary to achieve efficient implementation of such measures.

scholarly journals Recent Epidemiology Study Data of Myopia

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Zhao-Yu Xiang ◽  
Hai-Dong Zou
Keyword(s):  
Epidemiological Studies ◽  
Study Data ◽  
Observation Time ◽  
Control Measures ◽  
Sufficient Evidence ◽  
Smoking During Pregnancy ◽  
Education Levels ◽  
Prevention And Control Measures ◽  
Distance Work ◽  
The Impact

Myopia, a pandemic refractive error, is affecting more and more people. The progression of myopia could cause numerously serious complications, even leading to blindness. This review summarizes the epidemiological studies on myopia after 2018 and analyzes the risk factors associated with myopia. The prevalence of myopia varies in different regions, age, and observation time. East Asia has been gripped by an unprecedented rise in myopia, and other parts of the world have also seen an increase. The prevalence of myopia in children continues to rise and aggravates with age. The prevalence of high myopia has also increased along with myopia. Racial dependence and family aggregation can be seen frequently in myopia patients. Increased outdoor activities are proven to be protective factors for myopia, as near-distance work and higher education levels affect in the opposite. The impact of gender or urbanization on myopia is controversial. The relationship between nutrition, digital screens, Kawasaki disease, pregnant women smoking during pregnancy, and myopia is still not clear for lack of sufficient evidence. Understanding the various factors that affect myopia helps to clarify the mechanism of myopia formation and also to formulate reasonable prevention and control measures of myopia to protect people’s health, especially for adolescents.

scholarly journals A novel age-structured mosquito model for assessing the mechanisms behind vector control success

2020 ◽  
Author(s):  
Emma L Davis ◽  
T Déirdre Hollingsworth ◽  
Matt J Keeling
Keyword(s):  
Vector Control ◽  
Age Structure ◽  
Current Knowledge ◽  
Steady State Solution ◽  
Control Measures ◽  
Control Methods ◽  
High Coverage ◽  
Transmission Potential ◽  
Age Structured ◽  
The Impact

Abstract Background: Vector control is a vital tool utilised by malaria control and elimination programmes worldwide, and as such it is important that we can accurately quantify the expected public health impact of a range of vector control methods. There are very few previous models that consider vector control induced changes in the age-structure of the vector population and the resulting impact this will have on transmission.Methods: The steady-state solution of a novel age-structured deterministic compartmental model describing the mosquito gonotrophic cycle is analytically derived, with the age of each mosquito measured in the number of gonotrophic cycles (or successful blood meals) completed. From this model we derive analytical expressions for key transmission measures, such as the effective reproductive ratio under control, Rc, and investigate the impact of commonly used vector control methods on the age-structure of the vector population.Results: We derive and analyse a novel model with an explicit solution that can be used to directly quantify key transmission statistics and investigate the age-structured impact of vector control. Application of this model confirms current knowledge that adult-acting interventions, such as IRS or LLINs, are highly effective at reducing transmission, particularly in comparison to larvicide usage at the same coverage. We also find that scaling up coverage results in a wider gap in transmission reduction between adult-active and larval-based interventions. For LLINs and IRS the effective reproductive ratio under control, Rc, decreases exponentially with coverage, whereas for larvicides the relationship is linear. We also find that mid-ranges of LLIN coverage see the largest effect of reduced net integrity on transmission.Conclusions: Well-maintained, adult-acting vector control measures are substantially more effective than larval-based action at reducing the transmission potential of the mosquito population, particularly at medium to high coverage levels.

Coexistent Osteoarthritis and Parkinson’s Disease: Data from the Parkinson’s Foundation Outcomes Project

2020 ◽  
Vol 10 (4) ◽  
pp. 1601-1610
Author(s):  
Jaimie A. Roper ◽  
Abigail C. Schmitt ◽  
Hanzhi Gao ◽  
Ying He ◽  
Samuel Wu ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Study Data ◽  
Functional Mobility ◽  
Quality Improvement Initiative ◽  
Timed Up And Go ◽  
Mobility Performance ◽  
Risk Of Mortality ◽  
The Impact

Background: The impact of concurrent osteoarthritis on mobility and mortality in individuals with Parkinson’s disease is unknown. Objective: We sought to understand to what extent osteoarthritis severity influenced mobility across time and how osteoarthritis severity could affect mortality in individuals with Parkinson’s disease. Methods: In a retrospective observational longitudinal study, data from the Parkinson’s Foundation Quality Improvement Initiative was analyzed. We included 2,274 persons with Parkinson’s disease. The main outcomes were the effects of osteoarthritis severity on functional mobility and mortality. The Timed Up and Go test measured functional mobility performance. Mortality was measured as the osteoarthritis group effect on survival time in years. Results: More individuals with symptomatic osteoarthritis reported at least monthly falls compared to the other groups (14.5% vs. 7.2% without reported osteoarthritis and 8.4% asymptomatic/minimal osteoarthritis, p = 0.0004). The symptomatic group contained significantly more individuals with low functional mobility (TUG≥12 seconds) at baseline (51.5% vs. 29.0% and 36.1%, p < 0.0001). The odds of having low functional mobility for individuals with symptomatic osteoarthritis was 1.63 times compared to those without reported osteoarthritis (p < 0.0004); and was 1.57 times compared to those with asymptomatic/minimal osteoarthritis (p = 0.0026) after controlling pre-specified covariates. Similar results hold at the time of follow-up while changes in functional mobility were not significant across groups, suggesting that osteoarthritis likely does not accelerate the changes in functional mobility across time. Coexisting symptomatic osteoarthritis and Parkinson’s disease seem to additively increase the risk of mortality (p = 0.007). Conclusion: Our results highlight the impact and potential additive effects of symptomatic osteoarthritis in persons with Parkinson’s disease.

The methodological approach for the determination of the pressure of artificial raindrops as a question of the theory of splash soil erosion

2020 ◽  
pp. 24-28
Author(s):  
Mihail Zver'kov
Keyword(s):  
Block Diagram ◽  
Methodological Approach ◽  
Control Measures ◽  
Soil Conditions ◽  
Effective Pressure ◽  
Long Distance ◽  
Splash Erosion ◽  
Rain Drops ◽  
Artificial Rain ◽  
The Impact

To the article the results of the theoretical and experimental researches are given on questions of estimates of the dynamic rate effect of raindrop impact on soil. The aim of this work was to analyze the current methods to determine the rate of artificial rain pressure on the soil for the assessment of splash erosion. There are the developed author’s method for calculation the pressure of artificial rain on the soil and the assessment of splash erosion. The study aims to the justification of evaluation methods and the obtaining of quantitative characteristics, prevention and elimination of accelerated (anthropogenic) erosion, the creation and the realization of the required erosion control measures. The paper considers the question of determining the pressure of artificial rain on the soil. At the moment of raindrops impact, there is the tension in the soil, which is called vertical effective pressure. It is noted that the impact of rain drops in the soil there are stresses called vertical effective pressure. The equation for calculation of vertical effective pressure is proposed in this study using the known spectrum of raindrops. Effective pressure was 1.4 Pa for the artificial rain by sprinkler machine «Fregat» and 5.9 Pa for long distance sprinkler DD-30. The article deals with a block diagram of the sequence for determining the effective pressure of rain drops on the soil. This diagram was created by the author’s method of calculation of the effective pressure of rain drops on the soil. The need for an integrated approach to the description of the artificial rain impact on the soil is noted. Various parameters characterizing drop erosion are considered. There are data about the mass of splashed soil in the irrigation of various irrigation machinery and installations. For example, the rate (mass) of splashed soil was 0.28…0.78 t/ha under irrigation sprinkler apparatus RACO 4260–55/701C in the conditions of the Ryazan region. The method allows examining the environmental impact of sprinkler techniques for analyzes of the pressure, caused by raindrops, on the soil. It can also be useful in determining the irrigation rate before the runoff for different types of sprinkler equipment and soil conditions.

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