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

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6.2 Acute gastroenteritis
− During the study period, acute gastroenteritis was an important factor conditioning
general mortality in Finland, and one of the main reasons for the rise of mortality
during crisis periods.
− The disease remained stable and without greater oscillations in its endemic areas,
except when any crises in the population acted as a trigger for the expansion of more
virulent forms of the disease, causing then major increases in the number of deaths.
− Its endemic areas were the Åland Islands, Ostrobothnia, the southeastern regions of
the country and. In the two latter areas, the diseases seemed to be more associated to
river basins than to lakes.
− In the endemic areas, the gastroenteritis caused the death of the youngest in the
population, especially in summertime.
− In wartimes, gastroenteritis moved together with the troops, causing great harm among
the population. The Finnish War provides a good example of this, when one fifth of
the large number of deaths can be attributed to gastroenteritis.
− After one of these gastroenteritis-induced major mortality peaks, it was not rare to
have a sequence of following peaks at regular time intervals with gradually decreasing
magnitude. Probably, the affected areas during the conflicts stayed contaminated for
some time, generating relapses of the disease in successive summers.
− During the periods of crises, the average age of people dying of gastroenteritis was
higher than in normal periods. This rise in the number of affected adults may be
related to an increase in population movements as a consequence of the crises. These
movements contributed to the spread of virulent gastroenteritis strains among the
population.
− During especial periods the proportion of gastroenteritis-related deaths occurring in
summertime was greater than in normal times.
− Variations in age and seasonality during especial times are probably related to the kind
of gastroenteritis affecting the population. During crises times, bacillary dysentery
could have played a central role due to its high transmissibility, short incubation
period and high case-fatality rate. During normal periods and in endemic areas,
probably other kinds of less severe gastroenteritis like salmonellosis or paratyphoid
fever were more important.
− The relationship between crop failures and gastroenteritis does not seem clear during
the study period. An exception was the great famine of 1833, which was associated to
major movements of population. It is possible that crop failures and gastroenteritis
mortality are related at a regional level, but there is no available information on the
crops at a regional scale for the study period.
− Analyzing the disease behavior on a long term scale, one can observe a rising trend
during the first decades of the study period, followed by a decrease. The initial rise is
probably due to the numerous conflicts that took place in Finnish territory during the
18th century, and to the continuous increment of both the population and the degree of
urbanization. The subsequent decrease might be due to an absence of important
conflicts and/or to a very gradual progress in knowledge and mentality about public
hygiene and child care.