scholarly journals Malaria prevalence amongst Brazilian Indians assessed by a new mathematical model

1993 ◽  
Vol 111 (3) ◽  
pp. 525-538 ◽  
Author(s):  
M. N. Burattini ◽  
E. Massad ◽  
F. A. B. Coutinho ◽  
R. G. Baruzzi
Keyword(s):  
Mathematical Model ◽  
Control Strategies ◽  
Age Distribution ◽  
Malaria Prevalence ◽  
Reproductive Rate ◽  
Force Of Infection ◽  
Age Related ◽  
Serological Data

SummaryAn alternative way to estimate the endemic level of malaria amongst Brazilian indians is proposed. This is achieved by estimating the age-related “force of infection’ of malaria (the effective inoculation rate), applying a mathematical model, described elsewhere, to serological data. In addition we present a way to estimate the Basic Reproductive Rate of malaria in the same area. The results have shown a good degree of accuracy in describing the endemic pattern of malaria in the area, and also indicate some relevant aspects of its age distribution related to the design of control strategies.

scholarly journals Malaria transmission rates estimated from serological data

1993 ◽  
Vol 111 (3) ◽  
pp. 503-524 ◽  
Author(s):  
M. N. Burattini ◽  
E. Massad ◽  
F. A. B. Coutinho
Keyword(s):  
Mathematical Model ◽  
Malaria Transmission ◽  
Compartmental Model ◽  
Parasite Prevalence ◽  
Prevalence Data ◽  
Transmission Rates ◽  
Force Of Infection ◽  
Age Dependent ◽  
Serological Data

SummaryA mathematical model was used to estimate malaria transmission rates based on serological data. The model is minimally stochastic and assumes an age-dependent force of infection for malaria. The transmission rates estimated were applied to a simple compartmental model in order to mimic the malaria transmission.The model has shown a good retrieving capacity for serological and parasite prevalence data.

scholarly journals Trend Analysis of Malaria Prevalence in Bati District, Northeastern Ethiopia (From 2015 to 2020): A Retrospective Study

2021 ◽  
Author(s):  
chala daba ◽  
Edosa Kebede ◽  
Amanuel Atamo
Keyword(s):  
Retrospective Study ◽  
Trend Analysis ◽  
Control Strategies ◽  
Scale Up ◽  
Age Distribution ◽  
Age Groups ◽  
Public Health Problem ◽  
Malaria Prevention ◽  
Malaria Prevalence ◽  
Major Public Health Problem

Abstract Background: Malaria is the leading cause of morbidity and mortality in developing country including Ethiopia. Ethiopia is one of on ways to minimize the incidence of malaria by 40% as per its 2020 malaria reduction strategy since 2016. Thus, this study aimed to analyze six-year trend analysis of malaria prevalence in Bati district, Northeastern Ethiopia.Methods: Institutional based retrospective study was conducted to determine six-year trend analysis of malaria prevalence in Bati district. All malaria cases reported from 2015 to 2020 were carefully reviewed by trained laboratory technologist from the laboratory record books of Bati hospital and health center.Results: A total of 84,269 and 22,185 of malaria suspected patients were requested for blood films and Rapid diagnostic test (RDT) respectively. Of this, 12,032 (11.3%) malaria cases were microscopically confirmed. Plasmodium falciparum were the most dominant parasites detected, which accounted 57.6 %. Malaria has been reported from all age groups; however, age distribution showed that the majority of cases were adults’ age 15 years (57.2%). Even though there was fluctuation of malaria prevalence in the study area, the highest peak of malaria cases was reported during summer season which accounted 47.2%.Conclusion: Malaria is still a major public health problem in Bati district and the overall trend of total confirmed malaria cases were decreased in the past six years (2015–2020) with exception slightly increased cases from 2015 to 2016. Therefore, government, all healthcare workers and community should strengthen and scale up malaria prevention and control strategies in the study area

scholarly journals Modeling the spread of porcine reproductive and respiratory syndrome virus (PRRSV) in a swine population: transmission dynamics, immunity information, and optimal control strategies

2019 ◽  
Vol 2019 (1) ◽  
Author(s):  
Phithakdet Phoo-ngurn ◽  
Chanakarn Kiataramkul ◽  
Farida Chamchod
Keyword(s):  
Mathematical Model ◽  
Vaccination Coverage ◽  
Control Strategies ◽  
Vaccination Rate ◽  
Transmission Dynamics ◽  
Respiratory Syndrome Virus ◽  
Respiratory Problems ◽  
Prrs Virus ◽  
Swine Population ◽  
Swine Disease

Abstract Porcine reproductive and respiratory syndrome (PRRS) is an important swine disease that affects many swine industries worldwide. The disease can cause reproductive failure and respiratory problems in a swine population. As vaccination is an important tool to control the spread of PRRS virus (PRRSV), we employ a mathematical model to investigate the transmission dynamics of PRRSV and the effects of immunity information, as well as vaccination control strategies. We also explore optimal vaccination coverage and vaccination rate to minimize the number of infected swines and vaccination efforts. Our results suggest that: (i) higher vaccination coverage and vaccination rate together with prior knowledge about immunity may help reduce the prevalence of PRRSV, and (ii) longer maximum vaccination efforts are required when swines stay longer in a population and it takes them longer time to recover from PRRS infections.

scholarly journals The development and validation of an age-structured model for the evaluation of disease control strategies for intestinal helminths

Parasitology ◽  
1994 ◽  
Vol 109 (3) ◽  
pp. 389-396 ◽  
Author(s):  
M. S. Chan ◽  
H. L. Guyatt ◽  
D. A. P. Bundy ◽  
G. F. Medley
Keyword(s):  
Helminth Infection ◽  
Control Strategies ◽  
Intestinal Helminth ◽  
Intestinal Helminths ◽  
Parasite Control ◽  
Age Related ◽  
Control Programmes ◽  
Age Structured ◽  
Development And Validation ◽  
Age Structured Model

SummaryEpidemiological modelling can be a useful tool for the evaluation of parasite control strategies. An age-structured epidemiological model of intestinal helminth dynamics is developed. This model includes the explicit representation of changing worm distributions between hosts as a result of treatment, and estimates the morbidity due to heavy infections. The model is used to evaluate the effectiveness of different programmes of age-targeted community chemotherapy in reducing the amount of morbidity due to helminth infection. The magnitude of age-related heterogeneities is found to be very important in determining the results of age-targeted treatment programmes. The model was verified using field data from control programmes for Ascaris lumbricoides and Trichuris trichiura, and was found to provide accurate predictions of prevalence and mean intensities of infection during and following different control regimes.

Changing Trends in Age and Sex Distributions of Lyme Disease—United States, 1992-2016

2021 ◽  
pp. 003335492110267
Author(s):  
Kiersten J. Kugeler ◽  
Paul S. Mead ◽  
Amy M. Schwartz ◽  
Alison F. Hinckley
Keyword(s):  
United States ◽  
Lyme Disease ◽  
Disease Incidence ◽  
Age Distribution ◽  
Relative Size ◽  
The United States ◽  
Male Predominance ◽  
Age Related ◽  
Over Time ◽  
Age And Sex

Lyme disease is the most common vector-borne disease in the United States and is characterized by a bimodal age distribution and male predominance. We examined trends in reported cases during a 25-year period to describe changes in the populations most affected by Lyme disease in the United States. We examined demographic characteristics of people with confirmed cases of Lyme disease reported to the Centers for Disease Control and Prevention during 1992-2016 through the National Notifiable Diseases Surveillance System. We grouped cases into 5-year periods (1992-1996, 1997-2001, 2002-2006, 2007-2011, 2012-2016). We calculated the average annual incidence by age and sex and used incidence rate ratios (IRRs) to describe changes in Lyme disease incidence by age and sex over time. We converted patient age at time of illness into patient birth year to ascertain disease patterns according to birth cohorts. The incidence of Lyme disease in the United States doubled from 1992-1996 to 2012-2016 (IRR = 1.74; 95% CI, 1.70-1.78) and increased disproportionately among males; IRRs were 39%-89% higher among males than among females for most age groups. During the study period, children aged 5-9 years were most frequently and consistently affected. In contrast, the average age of adults with Lyme disease increased over time; of all adults, people born during 1950-1964 were the most affected by Lyme disease. Our findings suggest that age-related behaviors and susceptibilities may drive infections among children, and the shifting peak among adults likely reflects a probability proportional to the relative size of the baby boom population. These findings can inform targeted and efficient public health education and intervention efforts.

Age structure, growth, and demographic parameters in breeding-age female subantarctic fur seals, Arctocephalus tropicalis

2004 ◽  
Vol 82 (7) ◽  
pp. 1043-1050 ◽  
Author(s):  
Willy Dabin ◽  
Gwénaël Beauplet ◽  
Enrique A Crespo ◽  
Christophe Guinet
Keyword(s):  
Age Distribution ◽  
Reproductive Rate ◽  
Reproductive Period ◽  
Demographic Parameters ◽  
Island Population ◽  
Female Population ◽  
Regulatory Processes ◽  
Fur Seals ◽  
Subantarctic Fur Seals ◽  
Arctocephalus Tropicalis

Age distribution was estimated for 108 breeding-age female subantarctic fur seals, Arctocephalus tropicalis (Gray, 1872), sampled during the 1999–2000 breeding season on Amsterdam Island, southern Indian Ocean. The growth features were described and demographic parameters assessed from transversal life tables constructed for this female population. The breeding females had a longer mean body length than was observed for other breeding populations of the same species. These females also showed a later start to reproduction (6 years old), a lower overall age-specific reproductive rate (R6–16 = 48.0%), and a lower survival in older age classes (>13 years). Females reproduced up to a maximum age of 16 years, with none older than 19 years observed in the colony, suggesting an apparent senescence in the population. This consequently reduced the theoretical reproductive period of the females, which has led to a lower number of reproductive outputs per individual (i.e., 3.65 weaned pups per female throughout its reproductive life). Although such differences between islands may be related to genotypic traits, these results are consistent with low food availability and suggest that density-dependent regulatory processes operate on the Amsterdam Island population.

Introduction to pertussis transmission and epidemiological dynamics

Pertussis ◽  
2018 ◽  
pp. 6-25
Author(s):  
Pejman Rohani ◽  
Samuel V. Scarpino
Keyword(s):  
Control Strategies ◽  
Age Distribution ◽  
Population Level ◽  
Vaccine Uptake ◽  
Effective Control ◽  
Transmission Potential ◽  
Epidemic Period ◽  
The Impact ◽  
Pertussis Epidemiology

Resolving the long-term, population-level consequences of changes in pertussis epidemiology, arising from bacterial evolution, shifts in vaccine-induced immunity, or changes in surveillance, are key challenges for devising effective control strategies. This chapter reviews some of the key features of pertussis epidemiology, together with the underlying epidemiological principles that set the context for their interpretation. These include the relationship between the age distribution of cases and pertussis transmission potential, the impact of vaccine uptake on incidence, periodicity and age incidence, as well as spatially explicit recurrent pertussis epidemics and associated extinction frequency. This review highlights some of the predictable and consistent aspects of pertussis epidemiology (e.g. the systematic increase in the inter-epidemic period with the introduction of whole-cell vaccines) and a number of important heterogeneities, including variations in contemporary patterns of incidence and geographic spread.

scholarly journals Estimation of Ice Cream Mixture Viscosity during Batch Crystallization in a Scraped Surface Heat Exchanger

Processes ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 167 ◽  
Author(s):  
Alejandro De la Cruz Martínez ◽  
Rosa E. Delgado Portales ◽  
Jaime D. Pérez Martínez ◽  
José E. González Ramírez ◽  
Alan D. Villalobos Lara ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Control Strategies ◽  
Coupled Model ◽  
Ice Cream ◽  
Surface Heat ◽  
Model Based ◽  
Scraped Surface Heat Exchanger ◽  
Surface Heat Exchanger ◽  
Ice Fraction

Ice cream viscosity is one of the properties that most changes during crystallization in scraped surface heat exchangers (SSHE), and its online measurement is not easy. Its estimation is necessary through variables that are easy to measure. The temperature and power of the stirring motor of the SSHE turn out to be this type of variable and are closely related to the viscosity. Therefore, a mathematical model based on these variables proved to be feasible. The development of this mathematical relationship involved the rheological study of the ice cream base, as well as the application of a method for its in situ melting in the rheometer as a function of the temperature, and the application of a mathematical model correlating the SSHE stirring power and the ice cream viscosity. The result was a coupled model based on both the temperature and stirring power of the SSHE, which allowed for online viscosity estimation with errors below 10% for crystallized systems with a 30% ice fraction at the exit of the SSHE. The model obtained is a first step in the search for control strategies for crystallization in SSHE.

Malaria infection status of European Robins seems to associate with timing of autumn migration but not with actual condition

Parasitology ◽  
2019 ◽  
Vol 146 (6) ◽  
pp. 814-820
Author(s):  
Nóra Ágh ◽  
Imre Sándor Piross ◽  
Gábor Majoros ◽  
Tibor Csörgő ◽  
Eszter Szöllősi
Keyword(s):  
Avian Malaria ◽  
Arrival Time ◽  
Parasite Prevalence ◽  
Malaria Prevalence ◽  
Blood Parasites ◽  
Autumn Migration ◽  
Actual Condition ◽  
Infection Status ◽  
Stopover Site ◽  
Age Related

AbstractAvian malaria parasites can negatively affect many aspects of the life of the passerines. Though these parasites may strongly affect the health and thus migration patterns of the birds also during autumn, previous studies on avian malaria focused mainly on the spring migration and the breeding periods of the birds. We investigated whether the prevalence of blood parasites varies in relation to biometrical traits, body condition and arrival time in the European Robin (Erithacus rubecula) during autumn migration. We found no sex or age related differences in avian malaria prevalence and no relationship between infection status and body size or actual condition of the birds was found either. However, the timing of autumn migration differed marginally between infected and non-infected juveniles, so that parasitized individuals arrived later at the Hungarian stopover site. This is either because avian malaria infections adversely affect the migration timing or migration speed of the birds, or because later arriving individuals come from more distant populations with possibly higher blood parasite prevalence. The possible delay that parasites cause in the arrival time of the birds during autumn migration could affect the whole migratory strategy and the breeding success of the birds in the next season.

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