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

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Most of these infections are water of food-borne, which means that they are
transmitted through contaminated food or water.
Usually they are more common in the summer, especially those of bacterial origin,
basically because high temperatures stimulate microbial replication.
Gastroenteritis seems to affect universally all the individuals in a population, but the
infection tends to be severest among those already weak for other reasons, as age or poor
nutritional status.
Being caused by many different agents it is difficult to talk about immunity related to
gastroenteritis as a whole. In any case, it does not seem to be a very important
phenomenon. More relevant seems to be the acquisition of some resistance against those
organisms prevalent in the population. This contributes to explain the important role of
these diseases in infant mortality.
Nowadays, diarrhoeas are responsible of about 4 per cent of all the deaths. They
produce about 2.2 million deaths per year, especially among children in the Third World
(WHO 2004). It can be assumed that their impact on mortality must have been
significantly bigger before the antibiotic era.
In Finland, some kinds of gastroenteritis, such as salmonellosis, seem to have been
endemic for years, especially in the southeastern areas and in the Ostrobothnian coast. On
the other hand, more acute gastrointestinal infections, such as dysentery, were a very
important cause of death during war times (von Bonsdorff 1975).
4.2 Smallpox
Smallpox is an infectious disease produced by the Variola virus. Eradicated from
mankind in 1977, it was characterized by producing a rash distributed centrifugally in the
body, and had a relatively high mortality rate.
The Variola virus was specifically human and it was transmitted trough the air by
face-to-face contacts among infected and susceptible individuals.
Its incidence was bigger during winter and springtime probably due to the fact that the
viability of the virus was superior at low than at high temperatures (Fenner et al. 1988).
Variola viruses induced long lasting immunity, and that explains why in those
populations where it was endemic, it attacked mainly children. This phenomenon was of
dramatic importance for its eradication. Inoculation first and vaccination later (employing
Vaccinia or cowpox virus) were used for stimulating an immune response from the body
without experiencing the disease. The strategic use of vaccination led to the eradication
of this, in other times, worldwide disease.
In Finland, smallpox was endemic during the study period. The inoculation technique
was introduced in the country in 1754, but it never reached great popularity except
perhaps in Ostrobothnia (Railo 1994). Vaccination arrived in 1802 and started to become
a common practice only after the Finnish War (Mielke et al. 1984). The disease
disappeared from the country in 1941 (von Bonsdorff 1975).