X.—The Natural History of Yellow Fever in Africa

1969 ◽  
Vol 70 (3) ◽  
pp. 191-227 ◽  
Author(s):  
A. J. Haddow
Keyword(s):  
Natural History ◽  
Aedes Aegypti ◽  
Yellow Fever ◽  
Narrative Form ◽  
Tropical Africa ◽  
Principal Vector ◽  
Vector Mosquito ◽  
Natural Hosts ◽  
History Of ◽  
Classical Vector

SynopsisThe studies on the epidemiology of yellow fever which have been carried out in Africa in the period 1925–1966 are presented in narrative form.The original isolation of the virus is described, leading on to the survey work which showed that the infection is widespread in tropical Africa and that monkeys are very important hosts—perhaps the definitive mammalian hosts—of the virus. The discoveries of a monkey-to-man cycle in which the classical vector mosquito,Aedes aegypti, is replaced byA. simpsoniand of a monkey-to-monkey cycle, in whichA. africanusis the vector, are described.Recent epidemics are discussed, particularly that in Ethiopia, where there were about 200,000 cases, with 30,000 deaths, in the period 1960–62 and where the principal vector in the man-to-man cycle wasA. simpsoni.Work on groups of animals other than monkeys is reviewed, with particular reference to studies on the lemuroid Primates of the genusGalago, which are believed to be natural hosts of the virus. It is concluded that there are still many unknown facets in the epidemiology.

scholarly journals The Absence of Yellow Fever in Asia: History, Hypotheses, Vector Dispersal, Possibility of YF in Asia, and Other Enigmas

Viruses ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 1349
Author(s):  
Goro Kuno
Keyword(s):  
Yellow Fever ◽  
Current Knowledge ◽  
Vector Competence ◽  
Viral Persistence ◽  
Critical Factor ◽  
Holistic Approach ◽  
Principal Vector ◽  
Transmission Mechanisms ◽  
History Of ◽  
Rich History

Since the recent epidemics of yellow fever in Angola and Brazil as well as the importation of cases to China in 2016, there has been an increased interest in the century-old enigma, absence of yellow fever in Asia. Although this topic has been repeatedly reviewed before, the history of human intervention has never been considered a critical factor. A two-stage literature search online for this review, however, yielded a rich history indispensable for the debate over this medical enigma. As we combat the pandemic of COVID-19 coronavirus worldwide today, we can learn invaluable lessons from the historical events in Asia. In this review, I explore the history first and then critically examine in depth major hypotheses proposed in light of accumulated data, global dispersal of the principal vector, patterns of YF transmission, persistence of urban transmission, and the possibility of YF in Asia. Through this process of re-examination of the current knowledge, the subjects for research that should be conducted are identified. This review also reveals the importance of holistic approach incorporating ecological and human factors for many unresolved subjects, such as the enigma of YF absence in Asia, vector competence, vector dispersal, spillback, viral persistence and transmission mechanisms.

scholarly journals Suppressing mosquito populations with precision guided sterile males

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ming Li ◽  
Ting Yang ◽  
Michelle Bui ◽  
Stephanie Gamez ◽  
Tyler Wise ◽  
...  
Keyword(s):  
Control System ◽  
Aedes Aegypti ◽  
Yellow Fever ◽  
Sterile Insect Technique ◽  
Life Stage ◽  
Molecular Genetic ◽  
Control Methods ◽  
Wild Populations ◽  
Principal Vector ◽  
Platform Technology

AbstractThe mosquito Aedes aegypti is the principal vector for arboviruses including dengue/yellow fever, chikungunya, and Zika virus, infecting hundreds of millions of people annually. Unfortunately, traditional control methodologies are insufficient, so innovative control methods are needed. To complement existing measures, here we develop a molecular genetic control system termed precision-guided sterile insect technique (pgSIT) in Aedes aegypti. PgSIT uses a simple CRISPR-based approach to generate flightless females and sterile males that are deployable at any life stage. Supported by mathematical models, we empirically demonstrate that released pgSIT males can compete, suppress, and even eliminate mosquito populations. This platform technology could be used in the field, and adapted to many vectors, for controlling wild populations to curtail disease in a safe, confinable, and reversible manner.

scholarly journals [NO TITLE AVAILABLE]

2008 ◽  
Vol 50 (1) ◽  
pp. 26-28 ◽  
Author(s):  
Regina Geris ◽  
Ionizete Garcia da Silva ◽  
Heloísa Helena Garcia da Silva ◽  
Andersson Barison ◽  
Edson Rodrigues-Filho ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Confidence Intervals ◽  
Organic Solvents ◽  
Yellow Fever ◽  
Larvicidal Activity ◽  
Distilled Water ◽  
Isolation And Identification ◽  
Principal Vector ◽  
Toxic Compound ◽  
Lc50 And Lc90

The objective of this study was to evaluate the larvicidal activity of diterpenoids obtained from the oil-resin of Copaifera reticulata against Aedes aegypti larvae, the principal vector of dengue and urban yellow fever. Four diterpenes were obtained from oil-resin extraction with organic solvents and subsequent chromatographic and spectroscopic procedures allowed to isolation and identification of these compounds as 3-b-acetoxylabdan-8(17)-13-dien-15-oic acid (1), alepterolic acid (2), 3-b-hidroxylabdan-8(17)-en-15-oic acid (3), and ent-agatic acid (4). Each compound was previously dissolved in dimethylsulphoxide, and distilled water was added to obtain the desired concentrations. Twenty larvae of third instars were placed into plastic beckers, containing the solution test (25 mL), in a five repetitions scheme, and their mortality, indicated by torpor and darkening of the cephalic capsule, was recorded after 48h. Probit analyses were used to determine lethal concentrations (LC50 and LC90) and their respective 95% confidence intervals. This study showed that only diterpenoids 1 and 2 exhibited larvicidal properties with LC50 of 0.8 ppm and 87.3 ppm, respectively, revealing the former as the most toxic compound against third instars of Ae. aegypti. Therefore, this compound seems to be an interesting source for new metabolite to be exploited.

scholarly journals Eliminating Mosquitoes with Precision Guided Sterile Males

2021 ◽  
Author(s):  
Ming Li ◽  
Ting Yang ◽  
Michelle Bui ◽  
Stephanie Gamez ◽  
Tyler Wise ◽  
...  
Keyword(s):  
Control System ◽  
Aedes Aegypti ◽  
Yellow Fever ◽  
Sterile Insect Technique ◽  
Life Stage ◽  
Molecular Genetic ◽  
Control Methods ◽  
Wild Populations ◽  
Principal Vector ◽  
Platform Technology

AbstractThe mosquito Aedes aegypti is the principal vector for arboviruses including dengue/yellow fever, chikungunya, and zika, infecting hundreds of millions of people annually. Unfortunately, traditional control methodologies are insufficient, so innovative control methods are needed. To complement existing measures, here we develop a molecular genetic control system termed precision guided sterile insect technique (pgSIT) in Aedes aegypti. PgSIT uses a simple CRISPR-based approach to generate sterile males that are deployable at any life stage. Supported by mathematical models, we empirically demonstrate that released pgSIT males can compete, suppress, and eliminate mosquitoes in multigenerational population cages. This platform technology could be used in the field, and adapted to many vectors, for controlling wild populations to curtail disease in a safe, confinable, and reversible manner.

scholarly journals Yellow fever and dengue: a threat to Europe?

2010 ◽  
Vol 15 (10) ◽  
Author(s):  
P Reiter
Keyword(s):  
Natural History ◽  
Yellow Fever ◽  
Aedes Albopictus ◽  
Vector Borne Diseases ◽  
History Of ◽  
Vector Borne ◽  
Broad Overview

The introduction and rapidly expanding range of Aedes albopictus in Europe is an iconic example of the growing risk of the globalisation of vectors and vector-borne diseases. The history of yellow fever and dengue in temperate regions confirms that transmission of both diseases could recur, particularly if Ae. aegypti, a more effective vector, were to be re-introduced. The article is a broad overview of the natural history and epidemiology of both diseases in the context of these risks.

scholarly journals Eliminating Mosquitoes with Precision Guided Sterile Males

2021 ◽  
Author(s):  
Ming Li ◽  
Ting Yang ◽  
Michelle Bui ◽  
Stephanie Gamez ◽  
Tyler Wise ◽  
...  
Keyword(s):  
Control System ◽  
Aedes Aegypti ◽  
Yellow Fever ◽  
Sterile Insect Technique ◽  
Life Stage ◽  
Molecular Genetic ◽  
Control Methods ◽  
Wild Populations ◽  
Principal Vector ◽  
Platform Technology

Abstract The mosquito Aedes aegypti is the principal vector for arboviruses including dengue/yellow fever, chikungunya, and zika, infecting hundreds of millions of people annually. Unfortunately, traditional control methodologies are insufficient, so innovative control methods are needed. To complement existing measures, here we develop a molecular genetic control system termed precision guided sterile insect technique (pgSIT) in Aedes aegypti. PgSIT uses a simple CRISPR-based approach to generate sterile males that are deployable at any life stage. Supported by mathematical models, we empirically demonstrate that released pgSIT males can compete, suppress, and eliminate mosquitoes in multigenerational population cages. This platform technology could be used in the field, and adapted to many vectors, for controlling wild populations to curtail disease in a safe, confinable, and reversible manner.

General Observations on Mosquitos in relation to Yellow Fever in the Anglo-Egyptian Sudan

1947 ◽  
Vol 37 (4) ◽  
pp. 543-566 ◽  
Author(s):  
D. J. Lewis
Keyword(s):  
Aedes Aegypti ◽  
Yellow Fever ◽  
Mosquito Control ◽  
Practical Interest ◽  
Control Measures ◽  
General Survey ◽  
History Of

1. Owing to the history of yellow fever in the Sudan and the lines of communication which traverse the country, a general survey of the mosquitos, particularly the Culicines, is of practical interest. The known potential vectors of yellow fever are listed.2. Observations on the man-biting or man-ignoring habits of some species are recorded and also notes on the bionomics of Taeniorhynchus africanus, T. uniformis, Aëdes aegypti and other species.3. For purposes of description the country is divided into sub-divisions of the recognized faunal areas and notes are given on the Culicines of each.4. Brief observations are made on mosquito control measures against yellow fever.

How is the moral stance related to the intentional stance and group thinking?

2020 ◽  
Vol 43 ◽  
Author(s):  
Hannes Rakoczy
Keyword(s):  
Natural History ◽  
Social Cognitive ◽  
Intentional Stance ◽  
Cognitive Capacities ◽  
Shared Intentionality ◽  
History Of ◽  
Group Thinking ◽  
Moral Stance

Abstract The natural history of our moral stance told here in this commentary reveals the close nexus of morality and basic social-cognitive capacities. Big mysteries about morality thus transform into smaller and more manageable ones. Here, I raise questions regarding the conceptual, ontogenetic, and evolutionary relations of the moral stance to the intentional and group stances and to shared intentionality.

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