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bacteria in marine environments has been studied in order to
understand the molecular mechanisms at work [ROZ 05].
Other bacteria of non-fecal origin are also responsible for
infections from food or serious illnesses, in particular bacteria of the
Vibrio genus. These bacteria are indigenous to marine environments
(they can cause death in aquacultural production, like that of oysters).
More seriously, the presence of the species Vibrio cholerae , the
cholera agent, can decimate human populations in countries where
hygiene is poorly controlled. Other species of Vibrio cause diarrhea
and skin infections and can be found varyingly concentrated in
shellfish [PRU 05].
3.2.1.3. Parasites
Protists (unicellular organisms), which cause parasitic diseases, can
be transmitted by arthropod vectors, or by the contamination of
drinking water or food.
Malaria is caused by the parasite Plasmodium , and remains the
foremost vectorial infectious disease in the world, principally in
developing countries. The parasite is transmitted by vectors,
mosquitoes of the Anopheles genus that need water points to ensure
their development. Certain anopheles tolerate and develop in brackish
waters (of variable salinity), which explains a widespread distribution
of vectors for malaria even in coastal zones. The Camargue, the
coastal lagoons of littoral Languedoc or the lagoon of Venice were, in
past centuries, environments where malaria was rife. Malaria was,
therefore, present up to the time of the Second World War in the
Breton marshes and the Camargue [CAL 47]. In Asia, the coastal
lagoons are also favorable environments for the development of
mosquitoes that are vectors of malarial agents [RAM 12].
The protozoa Giardia is the main cause of diarrhea parasites in the
world and can reach a prevalence of close to 50% in come tropical
countries. Its transmission is oral-fecal, through cysts (a form of
environmental resistance) present in water or food or by dissemination
in vegetative form in used water. The protozoa of the genus
Cryptosporidium are agents of diarrheas, sometimes accompanied by
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