Complex sentence: In Portugal, for example, there were still 466 cases, in 1898, and there were sufficient numbers in Portugal in 1938 to warrant the construction of Rovisco Pais, to treat people affected by the disease.
Split into simpler sentences: In Portugal, for example, there were 466 cases in 1898. By 1938 there were sufficient numbers to warrant the construction of Rovisco Pais, to treat people affected by the disease.