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Tetanus among Slaves and Free People in Porto Alegre

UPDATE:  This research behind this post was revised, expanded and published here.

Figure 1.


Figure 2.

Figure 3.

Because tetanus mostly strikes newborn babies whose umbilical stumps become infected through unhygenic post-natal care, this disease is a unque indicator of medical treatment and life conditions.

These three graphs demonstrate that tetanus, a frequent killer in the 1850s, become a rare disease by the 1890s in the large southern Brazilian city of Porto Alegre.  For a description of tetanus and this current project, see my earlier post.  As seen in Figure 1, infant mortality also declined (at least in relation to deaths of other age groups).  This gives us strong evidence that as tetanus disappeared, newborns had a greater chance of living.  Interestingly, tetanus among slaves showed an opposite trend, as we can see in Figure 2.  Between 1850 and 1870, tetanus increased as a cause of about 3 percent of total slave deaths to 5.5 percent.  This may have been a consequence of the end of the international slave trade in 1850 because after this point, the male to female sex ratio fell and, possibly, more slaves had chidren.  But as an aging population, I would expect to see a falling percentage of tetanus deaths since this group was much older on average and less prone to infantile afflictions.  Data from Santos shows tetanus rates falling even among slaves during this same period so it may be simply that conditions and treatment of slaves in Porto Alegre worsened despite their rising price.  I excluded data after 1871 since all babies born to slaves were legally free in Brazil when the Imperial government passed the "Free Womb Law" in 1872. Figure 3 demonstrates that even though relative rates of tetanus may have been on the rise among slaves, by the 1890s -- after slavery was abolished -- the gap between the (wealthier) white population and the (poorer) "people of color " (i.e., pretos, pardos, morenos, etc.) vanished.  This is another surprising finding since most historians assume that whites continued to recieve superior medical treatment compared to non-whites.

Data is taken from 46,254 free people and 6,739 slaves who were buried in the cemetery of the Santa Casa de Misericordia in Porto Alegre between 1850 and 1898.

For a short discussion of possible bias in the obit data of tetanus deaths, view this.

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Reader Comments (1)

This research was published as an article here:

May 30, 2013 | Unregistered CommenterIan Read

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