The “Incubation Period” of Subacute Bacterial Endocarditis

In an attempt to gain information about the “incubation period” of subacute bacterial endocarditis, the literature was searched for case reports stating a specific interval between an event likely to cause bacteremia and the onset of symptoms. In 76 cases of streptococcal endocarditis for which this information was given, the median “incubation period” was one week. Symptoms began within two weeks in 64 of these cases (84%). Although there may be a bias toward reporting short incubation periods, it is concluded that the incubation period of subacute bacterial endocarditis is often shorter than is generally realized, and that procedures carried out more than two weeks before onset of symptoms are less likely to be causally related. In postcardiotomy cases, where timing of the bacteremia causing endocarditis is less easy to define, 27% of 122 cases of staphylococcal endocarditis developed within two weeks of surgery. This information is relevant to the planning and evaluation of prophylactic chemotherapy against bacterial endocarditis.