at the end of january 2003 , connecticut clinical laboratories were notified by mail that gpr isolates identified from csf or blood within 72 hours of culture inoculation must be reported to cdph epidemiology program . cdph asked laboratories to call the department immediately if the isolate was identified within 32 hours of inoculation and collected either from an outpatient or an inpatient within 3 days of admission . other gpr reports were to be mailed to cdph . although cdph was most interested in timely telephone reporting of isolates identified within 24 hours of inoculation , we chose 32 hours to identify isolates missed in laboratories lacking sufficient staff to continuously examine blood cultures during night shifts ( generally 8-hour periods ) . blood cultures were processed according to each clinical laboratory 's usual culture practices since reported culture isolates were obtained from routine diagnostic testing . in clinical settings , blood cultures are generally performed by filling commercially manufactured bottles , primed to promote either anaerobic or aerobic bacterial growth , with the patient 's blood at the time of phlebotomy . immediate clinical follow - up was conducted whenever > 1 of the patient 's blood culture bottles yielded the isolate within 32 hours of inoculation and for all csf isolates . this follow - up involved clinically characterizing the patient 's illness through telephone discussion with the patient 's physician or inpatient nurse to determine whether the illness was suspicious for anthrax ( e.g. , respiratory symptoms or widened mediastinum seen on chest radiograph ) . laboratory follow - up was conducted for all isolates , with daily laboratory contact until genus identification . for bacillus spp . , laboratories were asked to report isolates ' hemolysis and motility characteristics , and , if necessary , isolates were forwarded to connecticut 's state laboratory to rule out b. anthracis by -phage lysis . laboratory audits were conducted to ensure complete reporting of qualifying isolates ; 33 of connecticut 's 34 clinical laboratories participated . we provided laboratories a list of gpr genera , and they provided a list of blood and csf cultures that had yielded these genera within 72 hours of inoculation during 2003 . we compared patient names , culture dates , and results with the 2003 gpr reports to identify unreported isolates . health department labor resources were estimated by staff questionnaire administered october 2003 . because laboratories required several weeks to implement the reporting requirement after notification , the analysis period was limited to march in addition , only the first isolate from a given patient 's illness was counted in this analysis . from march to december 2003 , a total of 623 gpr isolates were identified . , 14 listeria spp . , 10 propionibacterium spp . , and 9 other genera ( table 1 ) . annualized incidence of gpr blood isolates was 21.3/100,000 persons . twenty - three of the 195 bacillus isolates were forwarded to connecticut 's state laboratory to rule out b. anthracis by -phage lysis ( all were negative ) . * no . of isolates for which information on time from inoculation to growth and number of bottles to which samples had been added and number of bottles yielding isolate were available , respectively . other category includes bifidobacterium ( 2 ) , brevibacterium ( 2 ) , actinomyces ( 1 ) , aureobacterium ( 1 ) , erysipelothrix ( 1 ) , eubacterium ( 1 ) , and oerskovia spp . ( 1 ) . among the 498 blood isolates with available incubation period , 171 ( 34% ) of these , 131 ( 76% ) were reported to cdph : 97 by telephone ( 61% reported on date detected and 42% reported outside office hours ) , 31 by mail , and 2 by unknown reporting method . overall , 82% of these rapid - growing isolates were either bacillus ( 52% ) or clostridium spp . unreported isolates ( n = 304 ) identified by laboratory audit only grew more slowly ( 80% incubation period > 24 hours versus 54% of reported isolates , p<0.001 ) and/or presumed contaminants ( 65% corynebacterium spp . ) . nearly all ( 98% ) unreported isolates were from clinical laboratories that had reported other isolates but failed to report all isolates . corynebacterium isolates ( all nondiphtheria species , i.e. , " diphtheroids " ) were less likely to be reported than other genera ( 30% vs. 70% ; p<0.001 ) . clostridium isolates grew significantly more quickly in blood culture than other genera ( median incubation 15.3 hours ; table 2 ) and more frequently in inoculated anaerobic culture bottles ( 68% ) than in aerobic culture bottles ( 13% ) . annualized incidence of clostridial bacteremia was 2.3/100,000 persons , excluding 6 postmortem cultures likely due to agonal bacteremia . the 67 patients were elderly ( median age 76 years ) and frequently critically ill ( 22 deaths ) . underlying immune - compromise ( 49% ) and malignancy ( 60% ) were common ; 24% had neither condition . * mean difference is -coefficient of univariate linear regression comparing each genus to clostridium spp . , the reference group ; p value is the p value associated with that -coefficient . other category includes propionibacterium ( 7 ) , bifidobacterium ( 2 ) , brevibacterium ( 2 ) , actinomyces ( 1 ) , aureobacterium ( 1 ) , erysipelothrix ( 1 ) , and oerskovia spp . ( 1 ) . from march to september 2003 , an average of 56 staff hours was required per month to receive , respond to , and process reports . for september 2003 specifically , the most recent month assessed , aggregate personnel time was 45 hours ( 20% outside office hours ) . a major public health preparedness challenge is increasing the sensitivity and timeliness of recognition of individual , potentially sentinel cases of category a bioterrorism agent disease . each category a agent has unique clinical and diagnostic features : no one system can meet the challenge for all agents . for anthrax , we attempted to shorten the time from occurrence of the earliest specific diagnostic finding , gpr identified by gram stain of blood or csf culture , to notification of the public health system . in doing so , we established an around - the - clock gpr laboratory reporting system with < 1 full - time staff position . the system has enhanced rapid communication between cdph and laboratories and provided baseline information on gpr sepsis epidemiology . additional anthrax cases have not occurred to test this system , and most bacillus isolates are attributable to culture contamination . however , through auditing , we determined that 62% of bacillus isolates identified within 24 hours of inoculation were reported by telephone . improvement is needed , but , through auditing , the system tracks the timeliness and completeness of reporting and speciation of all bacillus organisms , including , potentially , the next b. anthracis isolate . overcoming laboratory personnel 's reticence to report results that are likely spurious culture contaminants has been a challenge of implementing the system . ( i.e. , " diphtheroids " ) with their unique gram stain appearance and rare association with pathology . despite this , our analysis indicates that the system has met its second objective of ensuring around - the - clock laboratory reporting of potential bioterrorism events , given that many gpr reports were made by telephone outside office hours . however , during a repeat anthrax attack , the distinct epidemiology of clostridial sepsis could help differentiate clostridial sepsis from inhalational anthrax among persons who are critically ill with a gpr sepsis . predominately grow in anaerobic culture bottles , and clostridial sepsis usually affects elderly persons with abdominal conditions , malignancy , or immune suppression ( 11,12 ) . notably , recent clostridial sepsis outbreaks involving contaminated tissue transplants and illicit drugs have an epidemiology different from this baseline , in which illness predominately affects persons < 50 years of age ( 1315 ) . an ongoing challenge to this surveillance approach is that no precise clinical algorithm exists for how to readily identify whether a bacterium isolated from blood culture is from culture contamination . are now required to report by telephone any blood or csf specimen with growth of gprs within 32 hours of inoculation . growth after 32 hours is no longer reportable , to reduce reporting of culture contaminants without significantly sacrificing sensitivity to detect anthrax or clostridial infections . immediate clinical follow - up is conducted on isolates most likely to be sentinel events : aerobic bottle isolates ( possible anthrax event ) and anaerobic isolates in patients < 50 years of age ( unusual clostridium event ) . the earliest possible knowledge of an anthrax attack could minimize illness and death by allowing more lead time for intervention . connecticut has successfully implemented a laboratory - based system that allows for early detection of even a single case of inhalational anthrax .