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event. The changes in rainfall projected by climate
change scenarios will cause water imbalances
that may facilitate the spread of viruses
and bacteria. While monthly cases of diarrhea
can be increased from a more pronounced
seasonality (warmer dry periods), extreme rain
events can cause major outbreaks of diarrhea in
flood-prone areas outside urban centers.
Abdominal Angiostrongilosis is a parasitosis
caused by the nematode Angiostrongylus
costarricensis (Aa), which uses two hosts to
complete its life cycle: the rodent which is its
natural definitive host, and the intermediate
host, mainly slugs of the family Veronicellidae.
A study held in the Northern Region and the
Central Valley showed that there is a correlation
between precipitation and the prevalence
of Angiostrongilosis; the disease shows a clear
seasonality. The dry period (January-May) accounts
for 33% of the cases, while the remaining
67% happen from June to December, during
the rainy season.
Although he information gathered does not
range over a long period of time, so the results
are not conclusive as to the effect of climate
variability on disease fluctuation, a behavior
linked to the phases of ENSO and its impact on
the yearly precipitation throughout Costa Rica
can be observed.
By contrasting areas of greatest exposure with
the future climate scenario (figure i.7), it is evidenced
that areas with higher incidence of certain
diseases coincide with regions whose climate
is projected to become drier and warmer.
That is, some diseases will find enhanced spaces
for development due to climate change. This
type of analysis is valuable for future planning.
Figure i.7 Regions with greatest exposure in Costa Rica, and scenario A2 for yearly
precipitation during 2071-2100
Source: IMN, 2009
II Comunicación Nacional 2009