Being mosquitoes the vectors for malaria and other diseases
it is important to understand the way to fight them.
In an article by Harbach
and Besansky they explain that only females of some species bite and suck
blood from human and other animals as they need this blood for the development
of their own eggs; among those blood suckers there is a group of about 100
species that acts as vectors for serious illnesses affecting humans and animals.
Among those illnesses we find (AMCA):
Malaria: About
3.2 billion people are at risk of malaria.
Chikungunya: Africa, Asia, Indian subcontinent.
Dengue: Asia,
Latin America
Yellow Fever:
Africa, Central and South America
The vector for malaria is the Anopheles mosquito. Eckoff in 2011 presented a model for this specie including
biological and dynamics aspects of the mosquitoes and also human measures to
combat them.
The analysis showed that two actions appeared to be
effective: indoor fumigation and nets treated with insecticide.
Note 1: The author of the article is Philip Eckhoff of
IDM. I suggest to those interested in
modelling and diseases to visit this web that show a lot of interesting work
and research.
This modelling seems very interesting and useful, among
other things, as a tool to evaluate different strategies against vectors and
also to assess the effects of changes in weather conditions (temperature and
humidity for example) on malaria spread.
In 2013, appeared a study done in Tanzania by Huho et al. in
it the authors found that the majority of the bites occurred indoor, calling
for future research to check the effectiveness of different human measures,
like the ones already mentioned, to avoid being bitten by mosquitoes. One
interesting conclusion was that mosquitoes do not prefer to “eat” indoor but at
the time of the day when they prefer to suck most of humans are indoors.
The mentioned conclusion is in line with the findings of Chitnis et
al. that in 2012 made another modelling and
concluded that fumigation and the use of nets together are the most effective
combination reducing malaria.
They also concluded that once the actions are suspended the
original malaria status and indicators can be reached back in 3 years. This
sounds perfectly logic as the main measures have the purpose of avoiding the
biting not destroying the mosquitoes
Note 2: Nakul Chitnis works in Swiss THP. Another web worth to visit.
Another idea than has been present is the complete
eliminations of the mosquitoes.
In 2013 Killeen
et al. wrote an article about the topic explaining the advantages of
eliminating mosquitoes over controlling them. They also exposed that the challenges
in this procedure were get coverage on proper time and monitoring i.e.
-
- do it fast enough to avoid creation of
biological resistance in the animals and
-
- control to avoid any potential re-invasion.
But it seems something is missing in their analysis. This
action could create, like climate change, a kind of ecological unbalance. As
mentioned by Harbach
and Besansky mosquitoes are food for
some other animals and do pollination too, so before evaluating this last alternative
it should be clear the potential consequences.
Note 3: Reading an article on BBC about the
annihilation of mosquitos a couple of their comments make me think about our
right as human to exterminate a specie and the possible consequences of this
action. Also it makes me question if all the science is good in a moral sense
and if it is valid to incorporate a moral component in science. These topics are very complex and are not the
objective of this blog, but I just wanted to rise the subject.
Getting back to mosquitoes.
I found that there are a number of institutions and
researches all over the world working on the fight against mosquitoes related to
malaria and other illnesses. So far, it seems that despite any weather change
(than can affect the vectors patterns and behaviours) we as humans have got the
tools to combat these insects and avoid or reduce their impact on health, so
the question is why there are so many problems in some areas of the world. It
could be possible that the answer is the availability of funds. As explained in
my last post Europe
was declared malaria free, I can imagine after reading the summary of the
steps to get there, that this achievement was the result of many years of
public policies and actions that for sure would have required a non-negligible
amount of direct or indirect funds.
