cdad - related deaths were identified by using multiple cause - of - death 
                 data from national mortality records for 19992004 . cdad - related deaths were defined as all deaths for which the 
                 underlying cause of death or any of the contributing causes of death included the 
                 international classification of diseases , 10th revision ( icd-10 ) code a04.7 
                 ( enterocolitis due to c. difficile ) . information about the size and 
                 demographic breakdown of the us population for each year during 19992004 
                 was obtained from censal and intercensal year estimates with bridged race data 
                     ( 9,10 ) . age - adjusted mortality rates were calculated by using the age distribution 
                 of the 2000 us population as a standard ( 11 ) . the us population was divided into 5 racial / ethnic categories : white , 
                 hispanic , asian / pacific islander , black , and american indian / alaska native . during 19992004 cdad was reported as the underlying cause for 12,264 ( 59% ) of these deaths . a total of 3,256 deaths were reported related to all other intestinal infectious 
                 diseases combined ( icd-10 codes a00 to a09 , excluding a047 ) over the same period . age - adjusted mortality rates 
                 from cdad were slightly higher for men than for women ( table ) and were higher for whites than for any other 
                 racial / ethnic group . most cdad - related deaths occurred in hospitals ( n = 16,557 , 
                 80% ) ; 1,634 ( 8% ) occurred in long - term care facilities , and 2,027 ( 10% ) occurred at 
                 home . * this statistic is not age - adjusted because it only pertains to 1 age 
                     group . common coexisting conditions for cdad - related deaths included septicemia ( n = 7,654 , 
                 37% ) , renal failure ( n = 4,786 , 23% ) , pneumonia ( n = 3,430 , 17% ) , urinary tract 
                 infection ( n = 1,496 , 7% ) , and anemia ( n = 785 , 4% ) . hiv was reported for 81 
                 cdad - related deaths ( < 1% ) . however , among the 697 deaths reported in persons 
                 2554 years of age , hiv was reported for 72 ( 10% ) . mortality rates related to 
                 cdad increased during the study period ( figure ) , rising from 5.7 deaths per million population in 1999 to 23.7 
                 deaths per million population in 2004 . poisson regression estimates showed mortality 
                 rates increased by 35% per year ( coefficient = 0.30 , standard error = 0.004 , 95% 
                 confidence interval = 0.290.31 ) during the study period . due to the inclusion of cdad - related deaths when cdad was not reported as the 
                 underlying cause of death , reported death rates in this study were higher than those 
                 published in an earlier analysis of cdad - related deaths in the united states ( 7 ) . c. difficile is a cause of a substantial and increasing 
                 proportion of deaths in the united states and may be underrecognized as a cause of 
                 death . little attention has been paid to c. difficile prevention ; 
                 media and public health awareness efforts have focused largely on the prevention of 
                 disease from other intestinal pathogens such as escherichia coli or 
                     salmonella . however , the incidence of deaths from c. 
                     difficile is greater than the extent of deaths from all other 
                 intestinal infectious diseases combined . c. 
                 difficile  related mortality rates were higher for whites than 
                 for other racial / ethnic groups . racial / ethnic differences in insurance status and 
                 access to care ( 12 ) may render elderly whites more likely to receive treatment with 
                 antimicrobial drugs that put them at risk for c. difficile 
                 infection . however , genetic or other factors may also be involved , and further 
                 research is needed to determine the causes of racial / ethnic differences in 
                     c. difficile previous research showed increases in cdad - related mortality rates in the united 
                 states until 2002 ( 7,8 ) . this analysis estimates the rate of increase at 35% per year , and shows 
                 that mortality rates continued to increase at least until 2004 . increases in 
                 incidence and deaths from cdad may be associated with the emergence of a new and 
                 more virulent strain of c. difficile ( 5 ) . the emergence of virulent strains of c. difficile makes 
                 continued assessment of mortality statistics important . infection with c. difficile is associated with recent use of 
                 antimicrobial medications and with residence in hospitals . most cdad cases are 
                 acquired in healthcare settings ( 1 ) , and as many as 90% of cases may be associated with antimicrobial drug use 
                     ( 2,3 ) . high c. difficile death rates call attention to the 
                 importance of proper infection control practices in hospitals and long - term care 
                 facilities and the judicious use of antimicrobial medications . further research is 
                 needed to explore current questions concerning which antimicrobial medications , if 
                 any , will lead to cdad ( 13,14 ) . infections such as septicemia , pneumonia , and urinary tract infections were commonly 
                 reported in conjunction with c. difficile  related 
                 deaths . for some of these patients , the administration of antimicrobial medications 
                 to treat infections from other pathogens may have paved the way for infection with 
                     c. difficile . however , other risk factors are known , so that in 
                 many cases the careful use of antimicrobial agents may not be enough to prevent 
                     c. difficile infection . hiv infection was only reported in a 
                 small fraction of cdad  related deaths . however , 
                 immunosuppression and the use of prophylactic antimicrobial drugs in persons with 
                 aids may increase the risk for cdad ( 15 ) , and the effects of hiv should not be overlooked . in persons 2554 years of age , in whom hiv infection is most common , hiv infection 
                 was reported in approximately one tenth of cdad - related deaths . thus , hiv can considerably increase c. difficile death rates for 
                 demographic groups in which hiv prevalence is high . this 
                 analysis was limited to deaths in which icd-10 code a047 ( enterocolitis due to 
                     c. difficile ) was mentioned and may have failed to capture 
                 cdad - related deaths in which colitis was not present . no data were available 
                 regarding which strains of c. difficile were responsible for 
                 reported cdad  related deaths . c. difficile is an underrecognized cause of severe illness and 
                 death . this analysis underscores the importance of cdad as a public health problem 
                 and the increasing incidence of cdad - related deaths in the united states .
reported mortality rates from clostridium difficile disease in 
                     the united states increased from 5.7 per million population in 1999 to 23.7 per 
                     million in 2004 . 
 increased rates may be due to emergence of a highly virulent 
                     strain of c. difficile . 
 rates were higher for whites than for 
                     other racial / ethnic groups .