El bicentenario de John Snow, 1813-2013 / The John Snow Bicentennial, 1813-2013

John Snow nació en York el 15 de marzo de 1813 y murió en Londres el 16 de junio de 1858. En 1844, obtuvo su grado de Doctor en Medicina por la Universidad de Londres y estableció su consulta de médico general y obstetra en la zona londinense de Soho. El cólera era endémico en la India y había estado presente en Inglaterra desde 1830 con ocasionales brotes, ninguno tan grave como el que se produjo en Londres en el verano de 1854 y en el que murieron más de 600 personas en el barrio de Soho.

John Snow was born in York on 15 March 1813 and died in London on 16 June 1858. In 1844, he obtained his degree of Doctor of Medicine from the University of London and established his practice as a general practitioner and obstetrician in London's Soho area. Cholera was endemic in India and had been present in England since 1830 with occasional outbreaks, none as severe as the one in London in the summer of 1854 in which more than 600 people died in the Soho district.

Diagnostic electrocardiography in epidemiological studies of Chagas' disease: Multicenter evaluation of a standardized method

An electrocardiographic recording method with an associated reading guide, designed for epidemiological studies on Chagas' disease, was tested to assess its diagnostic reproducibility. Six cardiologists from five countries each read 100 electrocardiographic (ECG) tracings, icluding 30 from chronic chagasic patients, then reread them after an interval of 6 months. The readings were blind, with the tracings numbered randomly for the first reading and renumbered randomly for the second reading. The physicians, all experienced in interpreting ECGs from chagasic patients, followed printed instructions for reading the tracings. Reproducibility of the readins was evaluated using the Kappa (k) index for concordance. The results showed a high degree of interobserver concordance with respect to the diagnosis of normal vs. abnormal tracings (k= 0.66; SE 0.02). While the interpretations of some categories of ECG abnormalities were highly reproducible, others, especially those having a low prevalence, showed lower levels of concordance. Intraobserver concordance was uniformly higher than interobserver concordance. The findings of this study justify the use by specialists of the recording of readings method proposed for epidemiological studios on Chagas' disease, but warrant caution in the interpretation of some categories of electrocardiographic alterations