Importancia de la viruela, gastroenteritis aguda y paludismo ... - Oulu

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where the percentage rises up to 8%. The importance of these causes of death in both
areas was described in the bibliography (von Bonsdorff 1975). This picture is the one that
better describes the distribution of the disease during normal or peace times. During
periods of crises, like wars or famines, its distribution closely follows that of the biggest
movements of people (not shown in this figure, but represented in figures 28 and 29 in
the thesis. Maps related to the spread of gastroenteritis together with movement of the
troops in the Finnish War can also be seen in the CD attached).
In the third map of the Figure 4 can be seen the distribution of Malaria. It was endemic
in the southwestern regions of the country: The Åland Islands (reg. 20), Uusimaa (reg. 1),
Varsinais-Suomi (reg. 2) and Itä-Uusimaa (reg. 3). In the map, this cannot be fully
appreciated due to the compromises in the scale for representing the other diseases, better
figures can be found in the thesis, for example Figure 112. Malaria was not completely
absent from the rest of the country. During the hundred years analyzed there were some
deaths of malaria in every region of Finland.
5.4 Seasonality
Figure 5 shows the seasonality pattern of the deaths due to the three causes under study.
The main feature of these patterns is that they do not differ much from what is described
in the bibliography. Gastroenteritis is more common in the summertime, with a peak in
August. Smallpox is mainly a winter-spring disease, with a peak in May.
Maybe the most interesting seasonality pattern is that of malaria. Having its more
important peak in May, as smallpox, it tends to increase again, even if moderately, at the
end of autumn. If the first seasonal peak is typical for those areas infected with the
parasite Plasmodium vivax hibernans, the second one does not correspond to it. The
phenomenon can have several biological implications. It might reflect the presence of
other plasmodia than P. vivax hibernans in 18th and 19th centuries Finland. Among the
most probable candidates there are other strains of P. vivax, the most feasible possibility,
but also P. malariae parasites could be behind those autumnal deaths (Núñez et al. 2003).