Human lice: some basic facts and misconceptions.

crease in the overall case-fatality rate should provide firm evidence of the impact of ORT in hospitals. It is likely, however, that deaths occurring outside the hospital are underreported, a factor which may clearly complicate interpretation of changes in overall hospital case-fatality rates. Regarding inpatient case-fatality rates, in 13 instances (including separate collections of data for adults and for children at the Bamrasnadura Infectious Diseases Hospital in Thailand) it was possible to calculate this rate for both preand post-ORT periods. In only four of these instances were there statistically significant decreases, and in one instance there was a significant increase in the inpatient case-fatality rate. Changes (including non-significant changes) ranged from an 86% decrease to a more than five-fold increase; the median finding was a reduction of 50%. Decreases in inpatient case-fatality rates may result from generally improved case management (including improved intravenous therapy) associated with a better awareness of the problem of dehydration. Use of ORT for maintenance therapy will also reduce the length of intravenous therapy and the component risk of fatal complications such as septicemia. Increases in inpatient case-fatality rates might be explained by effective outpatient management with ORT resulting in only the most severe cases being admitted.