Difference between revisions of "Team:Pasteur Paris/Context"
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| − | <img src="https://static.igem.org/mediawiki/2016/ | + | <img src="https://static.igem.org/mediawiki/2016/e/ec/T--Pasteur_Paris--Mosquito_Pasteur.png" width="25%" alt="image"/></img> |
<B>Vector-borne pathogens</B> are important global (re)-emerging pathogens (more than 17% of infectious diseases) making them a major concern for public health[4]. They are transmitted by a vector, generally an haematophagous arthropods such as mosquitoes or ticks. Vectors are living organisms that can transmit infectious diseases between humans or from animals to humans. Many of these vectors are bloodsucking insects, which ingest disease-producing microorganisms during a blood meal from an infected host (human or animal) and later inject it into a new host during their subsequent blood meal. <B>Mosquitoes</B> are the most important and the best known disease vectors. [4]. </br></br> | <B>Vector-borne pathogens</B> are important global (re)-emerging pathogens (more than 17% of infectious diseases) making them a major concern for public health[4]. They are transmitted by a vector, generally an haematophagous arthropods such as mosquitoes or ticks. Vectors are living organisms that can transmit infectious diseases between humans or from animals to humans. Many of these vectors are bloodsucking insects, which ingest disease-producing microorganisms during a blood meal from an infected host (human or animal) and later inject it into a new host during their subsequent blood meal. <B>Mosquitoes</B> are the most important and the best known disease vectors. [4]. </br></br> | ||
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| − | </a>Pathogens responsible for vector-borne diseases can be parasite (Plasmodium falciparum, dirofilaria immitis), and viruses (i.e. arboviruses). 100 out of 500 estimated unique arboviruses are pathogen for humans. <B>Arboviruses</B> do not represent a single family of viruses but several viruses from different families: <B><i>Flaviviridae</i></B> (Dengue virus DENV, Zika virus ZIKV[1], Yellow Fever virus YFV, West Nile virus WNV, etc), <B><i>Togaviridae</i></B> (Chikungunya virus CHIKV, Ross River virus RRV, etc), Bunyaviridae (Rift Valley virus RVV, etc), which explain why specific treatments or vaccines need to be adapted for each family | + | </a>Pathogens responsible for vector-borne diseases can be parasite (Plasmodium falciparum, dirofilaria immitis), and viruses (i.e. arboviruses). 100 out of 500 estimated unique arboviruses are pathogen for humans. <B>Arboviruses</B> do not represent a single family of viruses but several viruses from different families: <B><i>Flaviviridae</i></B> (Dengue virus DENV, Zika virus ZIKV[1], Yellow Fever virus YFV, West Nile virus WNV, etc), <B><i>Togaviridae</i></B> (Chikungunya virus CHIKV, Ross River virus RRV, etc), Bunyaviridae (Rift Valley virus RVV, etc), which explain why specific treatments or vaccines need to be adapted for each family [2][3]. By infecting more than 400 million people per year, DENV is the most important arbovirus. In recent decades, the global incidence of dengue has risen sharply and the transmission has increased in urban and suburban areas. More recently, Zika virus has been in the news : outbreaks occurred in French Polynesia (2013) and Brazil (2016), causing serious neurological complications such as Guillain-Barré syndrome and microcephaly. ZIKV epidemic has become since the begining of 2016 a Public <i>Health Emergency of International</i> Concern, according to WHO.</br></br> |
| − | One of the particularities of the arboviruses is that they <B>infect</B> two kinds of host : a <B>mammalian host</B>, which ensures the | + | One of the particularities of the arboviruses is that they <B>infect</B> two kinds of host : a <B>mammalian host</B>, which ensures the maintenance and the amplification of the virus, and an </B>arthropod vector</B> (mosquitoes) that ensures its <B>dissemination</B>. In fact, arboviruses originally circulate in a sylvatic cycle in which the virus is transmitted between non-human primates by zoophilic mosquitoes. During its repeated intrusions into forests (hunting, deforestation…), men are accidentally contaminated by contact with anthropo-zoophilic vectors. Then, anthropophilic vectors ensure the dissemination of arboviruses between humans in urban areas, during the urban cycle and epidemic cycle.
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Then, an <B>adult mosquito</B> emerges and flies away. Male and female adult mosquitoes are physically distinguishable thanks to a very bushy antennae of the male, allowing it to sense females. While males feed on nectar and sources of sugar, only females are haematophagous because they need supplemental proteins to develop eggs. During <B>blood-feeding</B>, adult female mosquitoes bite people and animals and pump blood. We don’t feel the bite of the mosquito because of the anesthetic agents injected with saliva (that contains also anticoagulants and anti-inflammatory molecules). </br></br> | Then, an <B>adult mosquito</B> emerges and flies away. Male and female adult mosquitoes are physically distinguishable thanks to a very bushy antennae of the male, allowing it to sense females. While males feed on nectar and sources of sugar, only females are haematophagous because they need supplemental proteins to develop eggs. During <B>blood-feeding</B>, adult female mosquitoes bite people and animals and pump blood. We don’t feel the bite of the mosquito because of the anesthetic agents injected with saliva (that contains also anticoagulants and anti-inflammatory molecules). </br></br> | ||
| − | <center><img src="https://static.igem.org/mediawiki/2016/ | + | <center><img src="https://static.igem.org/mediawiki/2016/3/33/T--Pasteur_Paris--Cycle_de_vie_des_moustiques_Pasteur.png" alt="" width="90%"/></img></center></br></br></br> |
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Fortunately, not all mosquitoes are able to transmit arboviruses! The <B>competence</B> of a mosquito is the ability of a vector to be infected by and to transmit a pathogen in natural conditions. For example, competent vectors of malaria are <i>Anopheles</i> mosquitoes. Competent vectors for DENV, CHIKV, ZIKV, YFV, RRV are mostly mosquitoes <i>Aedes genus</i>.
| Fortunately, not all mosquitoes are able to transmit arboviruses! The <B>competence</B> of a mosquito is the ability of a vector to be infected by and to transmit a pathogen in natural conditions. For example, competent vectors of malaria are <i>Anopheles</i> mosquitoes. Competent vectors for DENV, CHIKV, ZIKV, YFV, RRV are mostly mosquitoes <i>Aedes genus</i>.
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| − | <center><img src="https://static.igem.org/mediawiki/2016/ | + | <center><img src="https://static.igem.org/mediawiki/2016/e/e3/T--Pasteur_Paris--Aedes.png" width="90%" alt="image"/></img></center></br> |
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Vector-borne pathogens are important global (re)-emerging pathogens (more than 17% of infectious diseases) making them a major concern for public health[4]. They are transmitted by a vector, generally an haematophagous arthropods such as mosquitoes or ticks. Vectors are living organisms that can transmit infectious diseases between humans or from animals to humans. Many of these vectors are bloodsucking insects, which ingest disease-producing microorganisms during a blood meal from an infected host (human or animal) and later inject it into a new host during their subsequent blood meal. Mosquitoes are the most important and the best known disease vectors. [4].
