The admnistration of sulphas in place of antiplague serum reduced the case fatality rate.
João de Barros Barreto, Almir de Castro 1946, 'Aspectos epidemiológicos da peste no Brasil', Memórias do Instituto Oswaldo Cruz.http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0074-02761946000300006. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)