Infections caused by aterial catheters used for hemodynamic monitoring

Utilizing a semiquantitative technique for culturing vascular catheters, we prospectively studied the risk and profile of infection caused by arterial catheters used for hemodynamic monitoring in 95 patients with a high risk of nosocomial infection. Of 130 catheters, 23 (18 per cent) produced local infection (larger than or equal to 15 colonies on semi-quantitative culture) and five septicemia (4 per cent). Sixteen of the 23 local infections and all septicemias occurred with catheter placements exceeding four days (p less than 0.001). Other factors associated with an increased risk of infection included insertion by surgical cut-down rather than percutaneously (ninefold increased rate of bacteremia, p = 0.008) and the presence of local inflammation (12-fold increase, p = 0.009). Systemic antimicrobial therapy (given to 80 per cent of the entire group and to four of the five with septicemia) did not protect against catheter-related infection but may account for the predominance of enterococci, Candida and gram-negative bacilli in these infections. Twelve per cent of all nosocomial bacteremias occurring in this critical care unit population originated from an arterial catheter. Indwelling arterial catheters pose a significant risk of bacteremic infection to ctirically ill patients. The percutaneous mode of placement is preferred; when prolonged arterial cannulation is required, the site should be rotated every four days. Local pain or inflammation, or clinical signs of sepsis without an obvious source should prompt removal and culture of the catheter.     

Granulocytopenia in hospitalized patients: I. Prognostic factors and etiology of fever

The clinical course of 126 hospitalized patients during 192 episodes of granulocytopenia and fever was studied. Fever was a regular accompaniment of granulocytopenia, occurring in 94 per cent of granulocytopenic episodes. The mean duration of granulocytopenia (less than 1,000/mm3) was 18 days, with fever (temperature greater than 38 degrees C) being present during 44 per cent of those days. Fever was present during 69 per cent of days with a granulocyte count less than 10/mm3. A presumed infection was present in 86 of 128 febrile granulocytopenic episodes in adults and in 19 of 64 febrile granulocytopenic episodes in children. A fungal infection was found in 11 patients; a viral infection in 23 patients. Bacteremia occurred during 44 granulocytopenic episodes with 16.8 bacteremias/1,000 days of granulocytopenia in adults and 12.7 bacteremias/1,000 days in children. The mortality was 33 per cent per granulocytopenic episode in adults and only 8 per cent per episode in children.     

Clinical correlates of bacteremia in a Veterans Administration extended care facility

Little is known about bacteremia in long-term care facilities. We have conducted a retrospective study during a 12-month period analyzing the clinical correlates of bacteremia in 533 chronically institutionalized, predominantly male patients, with an average age of 69 years. Thirty-four men had forty-two bacteremic illnesses during this period. The incidence rate was 0.30 episodes per 1000 patient care days, and the mortality rate was 21%. The urinary tract was the most frequently identified tissue source (56%), followed by respiratory tract (7%) and skin (7%). Providencia stuartii was the most common gram-negative organism, while Staphylococcus aureus, Streptococcus pneumoniae and enterococcus were the frequent gram-positive microbes. Gram-negative bacteremia accounted for 63% of the episodes (15% mortality rate), and gram-positive bacteremia accounted for 27% (18% mortality rate); 10% of the bacteremias were polymicrobial (25% mortality rate). Most of the isolated organisms were sensitive to available antimicrobial agents. The leading risk factor for bacteremia was an indwelling urinary catheter (odds ratio 39, 95% confidence limits 16 to 97). Patients with urinary catheters at the beginning of the study constituted only 5% of the population, but accounted for 40% of the gram-negative bacteremias during the year of observation.     

Bacteremia in the elderly

Bacteremia has a high mortality rate in all elderly populations, but especially nursing home residents and the hospitalized elderly. Elderly patients with bacteremia may present in a nonspecific fashion with incontinence, with falls, or afebrile. Mortality is greater in patients whose bacteremia originates outside the genitourinary tract or who are bacteremic with gram-positive organisms. Early appropriate treatment has been found to reduce mortality in some studies, especially in patients over 85 years old or with gram-positive bacteremias. Gram-negative bacteremias are more common than those caused by gram-positive organisms in most studies.E. coli is the most common gram-negative isolate, followed in most studies by either Proteus or Klebsiella. Staphylococcus aureus is the most common gram-positive isolate; enterococcus and pneumococcus are also frequently isolated.     

On denial

Evaluation of 612 episodes of gram-negative bacteremia over a 10-year period demonstrated its progressively increasing frequency. This increase was associated with an increasing proportion of patients with more severe underlying disease, increasing patient age, increasing frequency of cardiac surgery and manipulative procedures, and increasing frequency of treatment with antibiotics, corticosteroids and antimetabolites in patients with bacteremia. Fatality rates paralleled the severity of the host's underlying disease as noted in previous reports. The urinary tract was the most frequent source of bacteremia, but in 30 per cent of the patients, predominantly those with more severe underlying disease, the original source could not be identified. Of all blood cultures obtained in these patients, 72 per cent were positive. Bacteremia was of low magnitude with 77 per cent of the patients having quantitative blood cultures with less than 10 gram-negative bacilli per milliliter of blood. Escherichia coli was the most frequent etiologic agent followed in frequency by Klebsiella-Enterobacter-Serratia species, Pseudomonas aeruginosa, Proteus and Providencia species, and species of Bacteroides. Sixteen per cent of the bacteremias were polymicrobic. K and O-antigen typing of Escherichia coli and capsular typing of K. pneumonias demonstrated that a large number of serologic types of these strains were responsible for bacteremia. Over-all, bacteremia caused by multiple species of bacteria was associated with higher fatality rates, but no significant differences in fatality rates could be demonstrated for bacteremias caused by individual species of gram-negative bacilli when comparisons were made between patients with underlying diseases of similar severity. The presence or type of K-antigen did not influence the lethality of Esch. coli infections. Although some O-antigen types, 0:4, 0:6 and 0:8, were associated with higher fatality rates than other O-antigen types, “rough” or autoagglutinable Esch. coli were as lethal as smooth strains. These findings indicate that bacterial factors, other than antibiotic resistance, have little influence on the outcome of gram-negative bacteremia and that gram-negative bacilli function primarily as “opportunistic” pathogens.     

Pseudomonas bacteremia: Review of 108 cases

The current circumstances associated with Pseudomonas aeruginosa bacteremia are reviewed in 108 episodes to assess the impact of new antimicrobial drugs on this infection. Since 1961, Pseudomonas bacteremia has apparently become more frequent with proportional increases in middle-aged patients. The respiratory tract has become the major source of infection. Clinical features are not characteristic, but infected patients are almost uniformly severely ill before blood stream invasion occurs. The use of gentamicin, carbenicillin and colistin has not changed the outcome of Pseudomonas bacteremia. Although better than no anti-microbial treatment, these drugs cannot be shown to be superior to any other available antibiotics. A reassessment is needed to evaluate the relationship between the in vitro action and the effectiveness of antibiotics in the treatment of Pseudomonas infection and the use of gentamicin, carbenicillin and colistin in these bacteremias. In view of the poor results with antibiotics, investigation into immunologic prophylaxis and therapy is needed. At the present time, control of the patients' underlying disease contributes most towards assuring survival with Pseudomonas bacteremia.     

Simultaneous antibiotic levels in “breakthrough” gram-negative rod bacteremia

Of 237 cases of gram-negative rod bacteremia observed at the UCLA Medical Center during a 12 month period, 52 (22 per cent) occurred while the patient was receiving antibiotics which inhibited the infecting organism by disc diffusion tests. One half of the plasma samples available from 42 such patients with “breakthrough” bacteremia had subinhibitory circulating antibiotic levels when cultures were positive. Sepsis documented within 72 hours of initiation of therapy was usually due to antibiotic-sensitive Esch. coll and was associated with inadequate antibiotic levels; the patient was usually treated with a penicillin or cephalosporin. The source of bacteremia was most frequently the urinary tract or the biliary tree. In contrast, sepsis occurring more than 72 hours after the administration of antibiotics was frequently caused by multiple antibiotic-resistant Esch. coll in patients treated with gentamicin in adequate dosage and was associated with leukopenia or undrained purulent collections. Therapy ultimately failed in 20 cases (48 per cent): in early “breakthrough” bacteremia, failure was associated with subinhibltory antibiotic levels, and in late “breakthrough” bacteremias with inadequate drainage or impaired host defenses.     

Streptococcal and enterococcal bacteremia in patients with cancer.

Eighty-two episodes of bacteremia due to streptococci (including the genus Enterococcus) in 78 patients hospitalized at Institut Jules Bordet between 1986 and 1988 were reviewed. The incidence ranged from 5.5 to 7.6 per 1,000 admissions (16% of all bacteremias). Enterococcus faecalis, Streptococcus sanguis, and Streptococcus mitis were the most prevalent isolates, followed by Streptococcus angionosus, Streptococcus salivarius, and large colony-forming beta-hemolytic species (A, B, C, and G). Twenty-one episodes were polymicrobial. One-half of the patients had solid tumors, and one-half had hematologic malignancies. Forty-two patients were neutropenic (less than 1,000 polymorphonuclear neutrophils/microL). Only 15 episodes were acquired outside the hospital, and 11 episodes were breakthrough bacteremias. Twenty patients died within 1 month of the onset of streptococcal bacteremia. Five patients, two of whom were neutropenic, had fatal adult respiratory distress syndrome. The source of bacteremia remained undetermined in 35.4% of the episodes; the oral mucous membrane and the gastrointestinal tract were the most frequently recognized associated sites of infection. No unexpected antimicrobial resistance was observed except in two penicillin-resistant strains, one S. mitis and one E. faecium. No relation between peak or trough serum bactericidal titers and outcome could be demonstrated.     

Patient factors contributing to the emergence of gentamicin-resistant Serratia marcescens.

One hundred forty nosocomial Serratia marcescens infections (including 76 cases of bacteremia) were identified by prospective surveillance from 1975 through 1977 and retrospective chart review from 1968 through 1974. Thirty-four cases (24 per cent) involved gentamicin-resistant strains. All gentamicin-resistant strains appeared after 1974. Ninety per cent of the patients had undergone surgery, and 88 per cent had received prior antimicrobial therapy. The emergence of gentamicin-resistant S. marcescens paralleled the increase in usage of gentamicin. Prior use of gentamicin for more than two days in an individual patient was a significant risk factor (P = 0.0002) for being infected with a Serratia that was gentamicin-resistant. Other factors which separated gentamicin-resistant Serratia infections from gentamicin-sensitive Serratia infections were (1) urinary site of infection (P = 0.0005), (2) urinary catheter (P = 0.002), (3) endotracheal tube or tracheotomy (P = 0.03) and (4) increasing duration of hospitalization (P less than 0.05). Thirty-three of 34 (97 per cent) patients with gentamicin-resistant strains had urinary catheters. Specific measures to control infection were effective in decreasing the incidence of infections caused by gentamicin-resistant Serratia.     

Clinical characteristics and outcomes of patients with extended-spectrum ��-lactamase-producing bacteremias in the emergency department

Extended-spectrum β-lactamase (ESBL)-producing bacteria have been spreading from hospitals to communities. Despite this, there are limited emergency department (ED) patient-based studies about these bacteremias. A retrospective matched case-control study with a ratio of 1:3 was conducted at a university hospital. The case group consisted of patients aged >16 years with ESBL-producing bacteremias in the ED. Patients matched for age and sex with non-ESBL-producing bacteremias were sampled as the control group. Finally, 64 episodes of ESBL-producing Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis bacteremias were included in our study. The median age of case patients was 71 years, and 29 (45.3%) were males. The most common type of infection was urinary tract infection (71.9%), followed by intra-abdominal infection (12.5%). Inappropriate empirical antibiotics therapy was prescribed in 87.5% of case patients, which was significantly higher than the control group (13.0%; p < 0.001). Patients with inappropriate empirical antibiotics had a significantly longer hospital stay than those with appropriate empirical antibiotics (p < 0.001). Multivariate analysis showed that hospital-acquired infection, urinary catheterization, and previous antibiotics use were independent risk factors for the acquisition of ESBL-producing bacteremia. The 28-day mortality rate of case patients was 18.8%. Whether they received appropriate empirical antibiotics treatment or not, there was no statistical difference in the mortality of patients with ESBL-producing bacteremias (p = 0.167). To face these emerging multidrug-resistant bacteria and to guide the empirical antibiotics therapy, it is crucial for emergency physicians to recognize the characteristics and risk factors for ESBL-producing organisms.     

An investigation of enterococcal bacteremia

Records of all 34 patients with positive blood cultures for enterococcus at Mount Sinai Medical Center of Greater Miami in 1981 were reviewed. Twenty-four true bacteremias were identified from sources including the pelvis/abdomen (9), urinary tract (6), wounds (2), IV catheter (2), contaminated needle (1), endocarditis (1), and primary bacteremia (3). Sixteen of the 24 true bacteremias were hospital acquired, and these infectious accounted for 7 of 9 (78%) fatal outcomes. Fourteen of 16 patients with hospital-acquired infection received prior antibiotic therapy. Eight (24%) of the original 34 patients had positive blood cultures for enterococcus as a result of cross-contamination from an automated blood culture analyzer. The rate of cross-contamination per positive blood culture for enterococcus in 1981 was 22%. Two remaining patients in the original series could not be placed in a category of true infection of cross-contamination. Although there was a real increase in the number of enterococcal bacteremias in 1981, a much larger apparent increase was explained by several episodes of pseudobacteremia.     

Comparison of methicillin-resistant and methicillin-sensitive Staphylococcus aureus bacteremia

Methicillin-resistant Staphylococcus aureus (MRSA) has become endemic in Detroit, accounting for 50% of bacteremias in heroin abusers. To identify the salient epidemiologic and clinical features of MRSA bacteremia, case-control studies were performed comparing 28 cases of MRSA bacteremia to 28 cases of methicillin-sensitive S. aureus (MSSA) bacteremia in intravenous drug abusers. Infective endocarditis was diagnosed in 46.4% (13 of 28). In endocarditis and nonendocarditis bacteremia alike, the duration of fever, length of hospitalization, need for surgery, and mortality rates were similar. A history of recent antimicrobial therapy, especially cephalosporins, was more common in the MRSA group (p = 0.006). Complications including neurologic, renal, vascular, and musculoskeletal manifestations were more common in the MSSA endocarditis patients than MRSA endocarditis patients, although this difference was not significant. Complications related to antibiotic therapy were similar for both groups. The case-control studies indicate that MRSA and MSSA are similar in their virulence as measured by duration of hospitalization, duration of fever, complications, and mortality.     

Gram-negative bacteremia: IV. Re-evaluation of clinical features and treatment in 612 patients

Clinical features and specific aspects of treatment were evaluated in 612 patients with gram-negative bacteremia observed over a 10 year period. Coagulation abnormalities or thrombocytopenia were observed in 64 per cent of the patients. Evidence of disseminated intravascular coagulation (DIG) was found in approximately 10 per cent of them but was of sufficient severity to be associated with subcutaneous or visceral bleeding in 3 per cent of them. The frequency of coagulation abnormalities, other than DIC, was greater in patients with more severe underlying disease but DIC occurred with similar frequency irrespective of the severity of underlying host disease. Coagulation abnormalities of all types were associated with increased fatality rates. Hypothermia was noted in 13 per cent of the patients at the onset of bacteremia but was transient and was not associated with increased fatality. Failure to mount a febrile response >99.6 °F within the first 24 hours of bacteremia was associated with a significant increase in fatality rates. Prior corticosteroid therapy diminished the febrile response to bacteremia. Age, underlying host disease, granulocytopenia, congestive heart failure, diabetes mellitus, renal insufficiency, nosocomial infections, and antecedent treatment with antibiotics, corticosteroids, and antimetabolites significantly increased fatality rates. Appropriate antibiotic treatment reduced the fatality rate of those with bacteremia by approximately one-half among patients in each category of severity of underlying host disease. In addition, it was shown that early appropriate antibiotic therapy also reduced the frequency with which shock developed by one half. Even after development of shock, appropriate antibiotic therapy significantly reduced fatality rates. The use of combinations of antibiotics could not be demonstrated to significantly improve survival rates. Minimal differences in therapeutic efficacy could be demonstrated between individual antibiotics and various combinations of antimicrobials. Shock occurred in approximately 40 per cent of the patients and its frequency was not influenced by the species of etiologic agent. Contrary to previous reports, corticosteroid therapy in patients with shock did not enhance survival and treatment with an average of 4.0 g/day of hydrocortisone or its equivalents was associated with a significant increase in fatality rates.     

Nosocomial bacteremia: An epidemiologic overview

Each year nosocomial bacteremia develops in approximately 194,000 patients in U.S. hospitals ($\text{5}\text{1,000}$); 75,000 die. These infections portend $.28 to $.86 billion added costs of health care. Most nosocomial bacteremias occur endemically and are secondary bacteremias, caused by postoperative wound or intra-abdominal infections, urinary tract infections or pneumonia; primary bacteremias most frequently originate from intravascular devices, but the source is unrecognized. Between 1965 and 1978, 97 epidemics of nosocomial bacteremia, including 11 of “pseudobacteremia”, were reported. In contrast to endemic bacteremias, 78 percent of the epidemics involved primary bacteremias: 33 outbreaks stemmed from infusion therapy in some form, including seven epidemics traced to a contaminated commercial product. Two thirds of endemic nosocomial bacteremias and 79 percent of epidemics are caused by aerobic gram-negative bacilli. Pseudomonas cepacia, Pseudomonas maltophilia, Flavobacterium and Enterobacter agglomerans rarely cause endemic bacteremia and when encountered often signal an epidemic. Whereas predisposing host conditions greatly increase the risk of bacteremia endemically, nosocomial epidemics occur mainly in immunocompetent patients and are related to what therapeutic measures have been taken: segregation in a special care unit (58 percent of outbreaks) or exposure to infusion therapy or other invasive procedures involving the bloodstream (65 percent). At present only about one fourth of endemic nosocomial bacteremias are in theory preventable by more consistent application of existent knowledge of asepsis. The potential for prevention seems greatest for epidemic bacteremias, most of which are related to exposure to invasive devices, to a common source of contamination, or both.     

Hypoglycemia as a manifestation of sepsis

Hypoglycemia has rarely been described as a clinical sign of severe bacterial sepsis. We recently encountered nine patients in whom hypoglycemia (mean serum glucose of 22 mg/dl) was associated with overwhelming sepsis. Clinical disease in these patients included pneumonia and cellulitis; in three patients, no focus of infection was apparent. Altered mental status, metabolic acidosis, leukopenia, abnormal clotting studies and bacteremia were common features in these cases. In four patients, no cause for hypoglycemia other than sepsis was present. In five patients, another possible metabolic cause for hypoglycemia was present (alcoholism in four and chronic renal insufficiency in one) although none had been observed to be hypoglycemic on previous hospitalizations. Streptococcus pneumoniae (three cases) and Hemophilus influenzae, type b, (two cases) were the most common pathogens, and the over-all mortality was 67 per cent.The mechanism(s) for hypoglycemia with sepsis is not well defined. Depleted glycogen stores, impaired gluconeogenesis and increased peripheral glucose utilization may all be contributing factors. Incubation of bacteria in fresh blood at room temperature does not increase the normal rate of breakdown of glucose suggesting that the hypoglycemia occurs in vivo. Hypoglycemia is an important sign of overwhelming sepsis that may be more common than has previously been recognized.     

Improved prognosis for granulocytopenic patients with gram-negative bacteremia

The grave prognosis associated with gram-negative bacteremia occurring in granulocytopenic patients with cancer suggests that granulocyte transfusions are frequently indicated. We have evaluated 67 episodes of gram-negative bacteremia, studied in four consecutive antibiotic trials, in order to correlate prognostic determinants of recovery. These patients had a median absolute granulocyte count of 100/μl at the time of bacteremia. Empiric antibiotic regimens were begun at the first evidence of suspected infection. Granulocyte transfusions were employed only as clinically indicated by inadequate patient response to antibiotic therapy. Among the 29 patients who had an increase in their granulocyte count of ?100/μl over the subsequent 14 days, 27 (93 per cent) recovered whereas among 38 patients who had no appreciable increase in their granulocyte count, 21 (55 per cent) improved (p = 0.006). In this latter group of patients with no granulocyte recovery, the susceptibility of the pathogen(s) to the initial empiric antibiotic regimen was of major importance. None of four patients responded when the pathogen was resistant to both antibiotics initially utilized, six of 14 (44 per cent) patients responded when there was susceptibility to one antibiotic, and 15 of 20 (75 per cent) patients responded when there was susceptibility to both antibiotics (p < 0.025). We conclude that patients with gramnegative bacteremia and persistent granulocytopenia will often respond to antimicrobial therapy alone provided the initial choice of empiric antibiotics is appropriate and that their use is instituted promptly. Granulocyte transfusions need not be added unless clinical evaluation indicates inadequate response.     

A prospective controlled investigation of prophylactic trimethoprim/sulfamethoxazole in hospitalized granulocytopenic patients.

Oral trimethoprim/sulfamethoxazole (TMP/SMZ) therapy was investigated in the prophylaxis of infections in granulocytopenia. Hospitalized granulocytopenic patients were allocated at random to receive TMP/SMZ (group 1) or to a control group (group 2). The percentage of febrile granulocytopenic days was significantly reduced in group 1, 19 per cent compared to 39 per cent in group 2 (P less than 0.01). In group 1, there were no bacteremias in 59 episodes of granulocytopenia (909 days). In group 2, there were nine bacteremias in 52 episodes of granulocytopenia (796 days)(P = 0.001). Disseminated candidiasis developed in two patients in each group. Candida occurred in similar numbers in surveillance cultures in both groups; Staphylococcus aureus and Pseudomonas aeruginosa were slightly decreased, and Enterobacteriaceae resistant to TMP slightly increased in group 1. This study suggest that oral prophylactic TMP/SMZ therapy is an effective, well tolerated, easily administered alternative to "gut sterilization" with nonabsorbable antibiotics.     

Pneumococcal bacteremia at a medical/surgical hospital for adults between 1975 and 1980

All 72 episodes of pneumococcal bacteremia from 1975 through 1980 at Montefiore Hospital, Pittsburgh, a medical/surgical hospital for adults, were reviewed. There were 10 to 14 episodes per year, accounting for 4 to 5 percent of all bacteremias; it was estimated that one episode occurred for every thousand patients discharged. Patients' ages ranged from 16 to 94 years (mean 61 years); 65 percent were male. There was an underlying disease in 87 percent of all patients, and 78 percent of the infections were community-acquired. Treatment with antimicrobial drugs was given to all but six patients. Overall mortality was 43 percent, but it was higher for asplenic patients (five of six died). In 44 percent of patients, one to four complications occurred. Outcome correlated with presence of coexisting disease (p < 0.03), development of one or more complications (p < 0.04), presence of asplenia (p = 0.04), and the type of antimicrobial treatment used (p < 0.001; patients treated with penicillin alone fared better). Typing of isolates in the last two study years revealed that 67 percent of isolates were pneumococcal types present in 14-valent pneumococcal vaccine available at the time of the study. It is concluded that pneumococcal bacteremia occurs primarily in patients with underlying disease, and that pneumococcal vaccine should be offered to such patients.     

Infections due to encapsulated bacteria, Salmonella, Shigella, and Campylobacter

Bacterial infections occur often in HIV-infected patients. Defects in both cell-mediated and humoral immunity are associated with an increased frequency of infections due to encapsulated and enteric bacteria. Pneumonia caused by Streptococcus pneumoniae, Haemophilus influenzae, and other pathogens may occur early in the course of AIDS and have typical clinical presentations. Bacteremia is extremely common, and patients frequently fail to develop protective elevations in specific antibodies following infection. Recurrences are noted in up to one third of patients, and suppressive antimicrobial therapy may be required. The frequency of salmonellosis is increased as much as 20-fold in AIDS patients and is associated with bacteremia in more than 40 per cent of cases. Salmonella, Shigella, and Campylobacter infections in HIV-infected individuals may precede an AIDS diagnosis, may fail to respond to appropriate therapy, or may recur after completion of treatment. Prevention of bacterial infections with antibiotics or immunotherapy, or both, is recommended for children with AIDS or ARC.     

Bactériémie à Yersinia et surcharge en fer

Yersinia bacteremia and iron overload.A retrospective multicentric study was conducted to determine the real prevalence of underlying iron overloads during Yersinia bacteremias. Ninety-seven cases of bacteremias (84 Yersinia enterocolitica, 13 Yersinia pseudotuberculosis) were registered between 1990 and 1996 in eastern France. Avalaible data were collected in 70 cases (72.2%). Laboratory investigations of iron status were done in 53% (37/70). Three patients had a past record of known hemochromatosis, meanwhile in nine other cases an iron overload was discovered during the Yersinia bacteremia. Two cases of hemochromatosis were confirmed by liver histology. In all of these 12 cases, Yersinia enterocolitica was the causal agent. The effective prevalence of underlying iron overload in Yersinia bacteremias is 40% vshen researched, greater than data commonly published (1.8-14%), showing both epidemiological and clinical under estimation of iron's importance in Yersinia infection pathogenesis. A Yersinia bacteremia must be considered as an indicator of possible iron overload. Yersinia infection must be suspected in febrile hemochromatosic patients. A multicentric study must be conducted to evaluate incidence and characteristics of bacteremias in hemochromatosic patients.