Observations on the diagnosis of typhoid fever in an endemic area

The problem of providing laboratory confirmation of the diagnosis of typhoid in an endemic area was considered. A consecutive series of pyrexial patients was studied clinically, by blood and stool culture, the Widal reaction, the Sclavo rapid slide test and the diazo reaction. High Widal titres at even very early stages of typhoid suggested an anamnestic response. However, few non-typhoid cases had detectable Widal titres, and it seems, therefore, that though post-typhoid levels of antibody may be very low or even undetectable, further contact gives rise to a secondary response. Diagnostic criteria based upon a single Widal reading should be established for endemic areas, since rising titres may not be demonstrable. Though the rapid slide tests and the diazo reaction may be of some use in screening procedures in non-endemic areas, the results in endemic areas are likely to be confusing.S. Afr. Med. J., 48, 1368 (1974)

The various hemodynamic profiles of the patent ductus arteriosus in adults

The patent ductus arteriosus (PDA) has diverse clinical and hemodynamic manifestations depending on its size and the degree of the ensuing left-to-right shunt. A small PDA that causes minor shunting has no major hemodynamic consequences. Conversely, a large PDA with a significant left-to-right shunt may lead to various hemodynamic abnormalities. These include left-sided volume overload that may result in heart failure and/or pulmonary hypertension, the latter being a flow-dependent and mostly reversible phenomenon. The most feared complication is the development of severe and irreversible pulmonary hypertension (Eisenmenger physiology). In this manuscript, we provide examples of the various hemodynamic profiles of PDA as assessed by echocardiography in the adult population