scholarly journals Of Mice, Cattle, and Men: A Review of the Eco-Epidemiology of Leptospira borgpetersenii Serovar Ballum

2021 ◽  
Vol 6 (4) ◽  
pp. 189
Author(s):  
Marie Moinet ◽  
David A. Wilkinson ◽  
Danielle Aberdein ◽  
James C. Russell ◽  
Emilie Vallée ◽  
...  
Keyword(s):  
Disease Ecology ◽  
Control Strategies ◽  
Rattus Rattus ◽  
Domestic Species ◽  
Source Of Infection ◽  
Infection Dynamics ◽  
Narrative Methodology ◽  
Leptospira Borgpetersenii ◽  
Abattoir Workers

In New Zealand (NZ), leptospirosis is a mostly occupational zoonosis, with >66% of the recently notified cases being farm or abattoir workers. Livestock species independently maintain Leptospira borgpetersenii serovar Hardjo and L. interrogans serovar Pomona, and both are included in livestock vaccines. The increasing importance in human cases of Ballum, a serovar associated with wildlife, suggests that wildlife may be an overlooked source of infection. Livestock could also act as bridge hosts for humans. Drawing from disease ecology frameworks, we chose five barriers to include in this review based on the hypothesis that cattle act as bridge hosts for Ballum. Using a narrative methodology, we collated published studies pertaining to (a) the distribution and abundance of potential wild maintenance hosts of Ballum, (b) the infection dynamics (prevalence and pathogenesis) in those same hosts, (c) Ballum shedding and survival in the environment, (d) the exposure and competency of cattle as a potential bridge host, and (e) exposure for humans as a target host of Ballum. Mice (Mus musculus), rats (Rattus rattus, R. norvegicus) and hedgehogs (Erinaceus europaeus) were suspected as maintenance hosts of Ballum in NZ in studies conducted in the 1970s–1980s. These introduced species are distributed throughout NZ, and are present on pastures. The role of other wildlife in Ballum (and more broadly Leptospira) transmission remains poorly defined, and has not been thoroughly investigated in NZ. The experimental and natural Ballum infection of cattle suggest a low pathogenicity and the possibility of shedding. The seroprevalence in cattle appears higher in recent serosurveys (3 to 14%) compared with studies from the 1970s (0 to 3%). This review identifies gaps in the knowledge of Ballum, and highlights cattle as a potential spillover host. Further studies are required to ascertain the role that wild and domestic species may play in the eco-epidemiology of Ballum in order to understand its survival in the environment, and to inform control strategies.

Seroprevalence of leptospirosis in Chennai city, India.

2016 ◽  
Vol 5 (03) ◽  
pp. 4897 ◽  
Author(s):  
Padma Kumari J.* ◽  
Sheila Doris T. ◽  
Usha Krishnan K.
Keyword(s):  
Control Strategies ◽  
Signs And Symptoms ◽  
Laboratory Diagnosis ◽  
Community Change ◽  
Standard Test ◽  
Agglutination Test ◽  
Source Of Infection ◽  
Potential Reservoir ◽  
Study Population ◽  
Chennai City

Leptospirosis is a zoonotic disease, it occurs worldwide but is most common in tropical and subtropical countries. The magnitude of the problem varies from community to community. The serovars which cause the disease in a community change with adaptation to a new maintenance host and is epidemiologically important. Aims and Objectives: To determine the seroprevalence of leptospirosis in Chennai city. To identify the prevalent serovar in Chennai causing leptospirosis by using gold standard test Microscopic Agglutination Test (MAT). Methods: 1209 patients from Chennai, with fever of one-week duration and with signs and symptoms of Leptospirosis were the study population and were screened for Leptospirosis by Macroscopic Slide Agglutination Test (MSAT). The positive samples by MSAT were tested for the prevalent serovar and for confirmation by MAT and the results were analyzed statistically. Result: The seroprevalence of Leptospirosis is 17.8%. The prevalent serovar circulating in Chennai is L. grippotyphosa. Conclusion: Laboratory diagnosis is essential to confirm the current illness, and for epidemiological and public health reasons, namely to determine which serovar caused the infection, the likely source of infection and the potential reservoir and its location. This helps in control strategies.

scholarly journals Predicting the Presence of Leptospires in Rodents from Environmental Indicators Opens Up Opportunities for Environmental Monitoring of Human Leptospirosis

2021 ◽  
Vol 13 (2) ◽  
pp. 325
Author(s):  
Leon Biscornet ◽  
Christophe Révillion ◽  
Sylvaine Jégo ◽  
Erwan Lagadec ◽  
Yann Gomard ◽  
...  
Keyword(s):  
Infectious Disease ◽  
Environmental Factors ◽  
Control Strategies ◽  
Sampling Site ◽  
Rattus Rattus ◽  
Environmental Parameters ◽  
Environmental Indicators ◽  
Small Island ◽  
Urban Landscapes ◽  
Infection Prevalence

Leptospirosis, an environmental infectious disease of bacterial origin, is the infectious disease with the highest associated mortality in Seychelles. In small island territories, the occurrence of the disease is spatially heterogeneous and a better understanding of the environmental factors that contribute to the presence of the bacteria would help implement targeted control. The present study aimed at identifying the main environmental parameters correlated with animal reservoirs distribution and Leptospira infection in order to delineate habitats with highest prevalence. We used a previously published dataset produced from a large collection of rodents trapped during the dry and wet seasons in most habitats of Mahé, the main island of Seychelles. A land use/land cover analysis was realized in order to describe the various environments using SPOT-5 images by remote sensing (object-based image analysis). At each sampling site, landscape indices were calculated and combined with other geographical parameters together with rainfall records to be used in a multivariate statistical analysis. Several environmental factors were found to be associated with the carriage of leptospires in Rattus rattus and Rattus norvegicus, namely low elevations, fragmented landscapes, the proximity of urbanized areas, an increased distance from forests and, above all, increased precipitation in the three months preceding trapping. The analysis indicated that Leptospira renal carriage could be predicted using the species identification and a description of landscape fragmentation and rainfall, with infection prevalence being positively correlated with these two environmental variables. This model may help decision makers in implementing policies affecting urban landscapes and/or in balancing conservation efforts when designing pest control strategies that should also aim at reducing human contact with Leptospira-laden rats while limiting their impact on the autochthonous fauna.

scholarly journals Determinants of Eimeria and Campylobacter infection dynamics in UK domestic sheep: the role of co-infection

Parasitology ◽  
2021 ◽  
Vol 148 (5) ◽  
pp. 623-629
Author(s):  
Raed Taha Al-Neama ◽  
Kevin J. Bown ◽  
Damer P. Blake ◽  
Richard J. Birtles
Keyword(s):  
Domestic Sheep ◽  
Infection Dynamics ◽  
Campylobacter Infection

Abstract

scholarly journals The Role of Trip Lengths Calibration in Model-Based Perimeter Control Strategies

2021 ◽  
pp. 1-11
Author(s):  
Sergio F. A. Batista ◽  
Deepak Ingole ◽  
Ludovic Leclercq ◽  
Monica Menendez
Keyword(s):  
Control Strategies ◽  
Model Based

scholarly journals Mycobacterium tuberculosis adhesins: potential biomarkers as anti-tuberculosis therapeutic and diagnostic targets

Microbiology ◽  
2014 ◽  
Vol 160 (9) ◽  
pp. 1821-1831 ◽  
Author(s):  
Viveshree S. Govender ◽  
Saiyur Ramsugit ◽  
Manormoney Pillay
Keyword(s):  
Immune Response ◽  
Mycobacterium Tuberculosis ◽  
Control Strategies ◽  
Host Cells ◽  
Tuberculosis Control ◽  
Surface Molecules ◽  
Host Pathogen Interaction ◽  
Bacterial Aggregation ◽  
Insight Into

Adhesion to host cells is a precursor to host colonization and evasion of the host immune response. Conversely, it triggers the induction of the immune response, a process vital to the host’s defence against infection. Adhesins are microbial cell surface molecules or structures that mediate the attachment of the microbe to host cells and thus the host–pathogen interaction. They also play a crucial role in bacterial aggregation and biofilm formation. In this review, we discuss the role of adhesins in the pathogenesis of the aetiological agent of tuberculosis, Mycobacterium tuberculosis. We also provide insight into the structure and characteristics of some of the characterized and putative M. tuberculosis adhesins. Finally, we examine the potential of adhesins as targets for the development of tuberculosis control strategies.

Role of Overwintering Forms of Erysiphe necator in Epidemiology of Grapevine Powdery Mildew in Palestinian Vineyards

2014 ◽  
Vol 2 (1) ◽  
pp. 20-25
Author(s):  
Ruba Abuamsha ◽  
Hajaj Hajjeh ◽  
Mazen Salman
Keyword(s):  
Powdery Mildew ◽  
Temporal Evolution ◽  
Control Strategies ◽  
Temporal Distribution ◽  
Field Surveys ◽  
Sequence Characterized Amplified Region ◽  
Grapevine Powdery Mildew ◽  
Fungal Populations ◽  
Bud Breaking

The overwintering modes of E. necator were studied on Palestinian vineyards, through observations on the differentiation and maturation of cleistothecia and on the occurrence of flag-shoots (deriving from overwintering mycelium) in vineyards. Field surveys were carried out in 17 vineyards for the presence of Flag shoots and cleistothecia, both forms were not observed. Genetic structure and composition of E. necator populations were investigated by application of already available SCAR (Sequence Characterized Amplified Region) primers specific for the "flag-shoot" and "ascospore" biotypes. These primers were used to evaluate the dynamics of the spatial and temporal distribution of the two biotypes, into fungal populations present in 8 vineyards, with different cultivars and spray histories, in various Palestinian districts (Hebron, Bethlehem, Jerusalem, Ramallah, Jericho, Nablus, Jenin, Tulkarm). 397 samples were analyzed by the uses of the primer pairs UnE-UnF in PCR reactions. All samples were found to be of the ascospore biotypes. This finding shows that the “flag shoot” biotype, appears soon after bud breaking and disappears later, while the “ascospore” biotype is more frequently associated to later infections and bunches damages. Such information would be helpful to understand the reasons underlying possible temporal evolution of the pathogen's populations in vineyards, and can have important implications for powdery mildew rationale control strategies.

scholarly journals Zoonotic cutaneous leishmaniasis due to Leishmania (Viannia) braziliensis associated with domestic animals in Venezuela and Brazil

1989 ◽  
Vol 84 (1) ◽  
pp. 19-28 ◽  
Author(s):  
Cruz Manuel Aguilar ◽  
Elizabeth F. Rangel ◽  
Leonardo Garcia ◽  
Elio Fernandez ◽  
Hooman Momen ◽  
...  
Keyword(s):  
Cutaneous Leishmaniasis ◽  
Rio De Janeiro ◽  
Domestic Animals ◽  
Source Of Infection ◽  
Zoonotic Cutaneous Leishmaniasis ◽  
Significant Difference ◽  
Janeiro State ◽  
Enzootic Cycle

After outbreaks of cutaneous leishmaniasis in Solano State, Venezuela, 5% of the population had parasitized ulcers while after similar outbreaks in Mesquita, Rio de Janeiro State, Brazil, 9% had the disease. In these foci children, including some under six years of age, wre affected. There was no significant difference in the occurence of the disease according to sex or type of employment. In Solano, 3% of dogs and 28% of donkeys had parasitized lesions, while in Mesquita these indices were 19.8% and 30.8% respectively. The parasite from man, dogs and equines was identified as Leishmania (Viannia) braziliensis, by zymodeme and serodeme characterization. In these foci there is evidence suggesting that leishmaniasis is a zoonosis, possibly with equine and dogs as reservoirs, although both a wild enzootic cycle and the role of man as a source of infection can not be ruled out. Transmission is assumed to occur peridomestically by sandfly vectors such as Lutzomyia panamensis in Venezuela and Lutzomyia intermedia in Brazil. Information about the origin of these foci suggests that infected equines may be an important factor in the dissemination of the parasite in a peridomestic situation where these sandflies are abundant.

scholarly journals TRANSMISSION DYNAMICS OF DENGUE IN COSTA RICA: THE ROLE OF HOSPITALIZATIONS

2019 ◽  
Vol 27 (1) ◽  
pp. 241-266
Author(s):  
FABIO SANCHEZ ◽  
JORGE ARROYO-ESQUIVEL ◽  
PAOLA VÁSQUEZ
Keyword(s):  
Costa Rica ◽  
Compartmental Model ◽  
Control Strategies ◽  
Transmission Dynamics ◽  
Basic Reproductive Number ◽  
Reproductive Number ◽  
Specific Parameter ◽  
Public Health Officials ◽  
Disease Free

For decades, dengue virus has caused major problems for public health officials in tropical and subtropical countries around the world. We construct a compartmental model that includes the role of hospitalized individuals in the transmission dynamics of dengue in Costa Rica. The basic reproductive number, R0, is computed, as well as a sensitivity analysis on R0 parameters. The global stability of the disease-free equilibrium is established. Numerical simulations under specific parameter scenarios are performed to determine optimal prevention/control strategies.

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