I'm always fascinated by instances in which a parasite effects its host's behavior--I've started threads on it before, if I remember correctly--and this latest instance is no exception.
One thing I'm curious about though--when the article says “This tremendously important interaction for the person and the mosquito – both can die as a result – is being engineered by the parasite," what about the interaction is potentially fatal for the mosquito? Are they just talking about the risk of being slapped as the mosquitos try to feed, or does carrying the malaria virus actually pose some danger to the mosquito? I can't imagine why the latter would be the case, but the former doesn't make a whole lot of sense either, since I doubt that someone with transmissible malaria is going to be any more likely to swat at mosquitos than anyone else. In fact, I'd guess that someone who was feeling particularly awful would be less likely to bother with slapping the mosquitos away.
Posts: 16059 | Registered: Aug 2000
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quote:plasmodium, cause of malaria, manipulate[s] its mosquito host. When the mosquitoes first take up plasmodium in a drink of human blood, they become more cautious about finding another victim. Their reluctance makes them less likely to be killed. ...at this stage in the life cycle, the parasite needs time to develop in the mosquito before it can be transmitted. "Before the parasite is transmitted to a human, its only goal is to survive, and to help the mosquito to survive,"
The mosquito's behavior changes when the parasite is ready to move on to a human...mosquitoes carrying infective plasmodium become twice as likely as other mosquitoes to bite more than one person in a night. On top of that, they spend more time on each host drinking blood.
Since each feeding carries the same risk of being swatted, and increasing the time spent feeding on a given victim even more greatly increases the likelyhood of getting squashed...
Posts: 8501 | Registered: Jul 2001
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posted
If the mosquitos find the non-malarial population so unattractive, why don't they just leave alone? Posts: 10397 | Registered: Jun 2005
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