Risk factors for incidence and case-fatality rates of healthcare-associated infections: a 20-year follow-up of a hospital-based cohort.

Information is lacking on the integrated evaluation of mortality rates in healthcare-associated infections (HAIs). Our aim was to differentiate the risk factors responsible for the incidence from those for the case-fatality rates in association with HAIs. We therefore examined the time trends of both incidence and case-fatality rates over a 20-year period at a tertiary-care teaching medical centre in Taiwan and the mortality rate was expressed as the product of the incidence rate and the case-fatality rate. During the study period the overall mortality rate fell from 0·46 to 0·32 deaths/1000 patient-days and the incidence rate fell from 3·41 to 2·31/1000 patient-days, but the case-fatality rate increased marginally from 13·5% to 14·0%. The independent risk factors associated with incidence of HAIs were age, gender, infection site, admission type, and department of hospitalization. Significant prognostic factors for HAI case-fatality were age, infection site, intensive care, and clinical department. We conclude that the decreasing trend for the HAI mortality rate was accompanied by a significant decline in the incidence rate and this was offset by a slightly increasing trend in the case-fatality rate. This deconstruction approach could provide further insights into the underlying complex causes of mortality for HAIs.

Trends in the susceptibility of methicillin-resistant Staphylococcus aureus to nine antimicrobial agents, including ceftobiprole, nemonoxacin, and tyrothricin: results from the Tigecycline In Vitro Surveillance in Taiwan (TIST) study, 2006-2010.

This study investigated the in vitro susceptibilities of methicillin-resistant Staphylococcus aureus (MRSA) to nine antimicrobial agents in Taiwan. A total of 1,725 isolates were obtained from 20 hospitals throughout Taiwan from 2006 to 2010. The minimum inhibitory concentrations (MICs) of the nine agents were determined by the agar dilution method. The MICs of mupirocin and tyrothricin were determined for 223 MRSA isolates collected from 2009 to 2010. For vancomycin, 99.7 % were susceptible; however, 30.0 % (n = 517) exhibited MICs of 2 µg/ml and 0.3 % (n = 6) demonstrated intermediate susceptibility (MICs of 4 µg/ml). Nearly all isolates (≥ 99.9 %) were susceptible to teicoplanin, linezolid, and daptomycin. The MIC90 values were 2 µg/ml for ceftobiprole and 1 µg/ml for nemonoxacin. The MIC90 values of mupirocin and tyrothricin were 0.12 and 4 µg/ml, respectively. MIC creep was noted for daptomycin during this period, but not for vancomycin, teicoplanin, linezolid, or tigecycline. For isolates with vancomycin MICs of 2 µg/ml, the MIC90 values were 2 µg/ml for teicoplanin, 0.5 µg/ml for daptomycin, and 0.5 µg/ml for tigecycline. Those values were four- to eight-fold higher than those among isolates with vancomycin MICs of 0.5 µg/ml (2, 0.06, and 0.12 µg/ml, respectively). Of the nine MRSA isolates exhibiting non-susceptibility to vancomycin (n = 6), teicoplanin (n = 1), daptomycin (n = 2), or tigecycline (n = 1), all had different pulsotypes, indicating the absence of intra-hospital or inter-hospital spread. The presence of a high proportion of MRSA isolates with elevated MICs (2 µg/ml) and MIC creep of daptomycin might alert clinicians on the therapy for serious MRSA infections in Taiwan.

Diagnosis of pyogenic liver abscess by abdominal ultrasonography in the emergency department.

BACKGROUND: Delayed diagnosis of pyogenic liver abscess remains a challenging problem in the emergency department because of the associated high morbidity and mortality. OBJECTIVE: To evaluate the sensitivity of ultrasono-graphy in the diagnosis of pyogenic liver abscess in patients presenting to the emergency department and the factors that may influence this sensitivity. METHODS: A retrospective study was conducted in patients diagnosed with pyogenic liver abscess in the emergency department (ED) of a tertiary care teaching hospital for a period of 5 years. Between May 2001 and April 2006, 268 patients diagnosed with pyogenic liver abscess were evaluated by ultrasonography and/or CT scanning. The age, sex, clinical presentation, location and number of abscesses and the underlying disease of these two groups were compared. RESULTS: Of the 268 patients admitted via the ED who were discharged or died with a diagnosis of pyogenic liver abscess, there was a predominance of men (M/F 173/95) and the mean age was 57.6 years (range 17-90). 38 had false negative findings on ultrasonography (sensitivity 85.8%) and required abdominal CT scanning for definitive diagnosis. In the other 230 cases, ultrasonography alone was sufficient for diagnosis. Location of the abscess in segments 4 and 5 of the liver raised the sensitivity of ultrasound for diagnosis, while location in segment 8 was most associated with delayed diagnosis by ultrasonography. Right costal angle knocking pain was significant for pyogenic liver abscess even if ultrasound was negative. CONCLUSIONS: The size and location of the liver abscess and the underlying comorbid diseases may affect the diagnostic sensitivity of ultrasound for pyogenic liver abscess in clinical practice. A high index of suspicion should be maintained in patients with diabetes mellitus, previous biliary tract intervention or gastrointestinal malignancy. Follow-up CT scanning is recommended if right flank knocking pain is present, even if ultrasonography is non-revealing. A diagnostic protocol for liver abscess may be feasible in the future.

Use of pulsed-field gel electrophoresis to investigate an outbreak of Serratia marcescens infection in a neonatal intensive care unit.

Serratia marcescens is a well-recognized hospital-acquired pathogen, which has been associated with a number of specific outbreaks, particularly in critically ill neonates. We used pulsed-field gel electrophoresis (PEGE) typing to analyse an outbreak in a neonatal intensive care unit (NICU). We included samples from nine patients, three handwashes and ten environmental isolates from an outbreak (February to August 1999) in addition to four patient isolates from different wards of our hospital during the same time period. The clinical presentations of the outbreak included bacteraemia (four cases), pneumonia (three cases), umbilical wound infection (one case) and conjunctivitis (one case). Nine outbreak isolates exhibited an identical PFGE fingerprint, while the epidemiologically unrelated strains demonstrated distinct patterns. Epidemiological investigation failed to reveal a common source of the outbreak, although the epidemic S. marcescens strain was isolated from hand-washes and doors of incubators. We concluded that cross-transmission via transient contamination of hands was the major route for this outbreak. Strict handwashing practices, the cohorting and isolation of colonized and infected patients, and the regular dis-infection of incubators are crucial steps for preventing the transmission of S. marcescens in an NICU. This PFGE method is highly discriminatory for the thorough epidemiological investigation of an outbreak of S. marcescens.

Severe acute respiratory syndrome in Taiwan: analysis of epidemiological characteristics in 29 cases.

OBJECTIVES: To describe the clinical characteristics and outcomes of patients with severe acute respiratory syndrome (SARS). METHODS: Between March 28 and June 30 '2003, 29 patients with probable SARS seen at Shin Kong Wu Ho-Su Memorial Hospital, Taipei, were analysed. RESULTS: Presenting symptoms included fever (100%), cough (69.0%), chills or rigor (62.1%), and shortness of breath (41.4%). Mean days to defervescence were 6.8+/-2.9 days, but fever recurred in 15 patients (51.7%) at 10.9+/-3.4 days. Common laboratory features included lymphopenia (72.4%), thrombocytopenia (34.5%) and elevated C-reactive protein (CRP), lactate dehydrogenase (LDH), and aspartate aminotransferase (AST) (93.1, 62.1, 44.8%, respectively). All patients except one had initial abnormal chest radiographs and 20 (69.0%) had radiological worsening at 7.5+/-2.6 days. Nine patients (31.0%) subsequently required mechanical ventilation with four deaths (13.8%). Most patients with clinical deterioration responded to pulse corticosteroid therapy (14 out of 17) but six complicated with nosocomial infections. The risk factors associated with severe disease were presence of diarrhoea, high peak LDH and CRP, high AST and creatine kinase on admission and high peak values. CONCLUSIONS: Prudent corticosteroid use, vigilant microbiological surveillance and appropriate antibiotics coverage are the key to successful treatment.

Characteristics of patients with Burkholderia cepacia bacteremia.

Burkholderia cepacia has become an important pathogen of infections in immunocompromised and nosocomial patients. The characteristics of 42 episodes of B. cepacia bacteremia in 40 patients admitted to the Taipei Veterans General Hospital between January 1997 and December 1999 were retrospectively analyzed. Factors that adversely influenced the mortality rate included respiratory failure, an unknown infection source, a period in an intensive care unit, and shock. Most of the patients had serious underlying diseases, such as diabetes mellitus, malignancy, congestive heart failure, and chronic obstructive pulmonary disease. The mean time for a positive blood culture was 45 days after admission. The overall mortality rate was 28.6% (12/42), and 44.4% (12/27) of all deaths were directly related to B. cepacia bacteremia. Polymicrobial bacteremia was found in 5 patients. Ceftazidime was the most effective antimicrobial agent in vitro, whereas chloramphenicol, imipenem, and trimethoprim/sulfamethoxazole were less effective alternatives. Appropriate antibiotic therapy was given to 30 patients, most of whom responded to the therapy except for 5 who died despite receiving appropriate treatment. Although B. cepacia infection develops in a relatively small proportion of hospitalized individuals, it has a major impact on morbidity and mortality. In view of the fact that B. cepacia develops resistance to a wide range of antimicrobial agents, ceftazidime and/or trimethoprim/sulfamethoxazole should be the drug of choice for empiric therapy.

Treatment of pyogenic splenic abscess: nonsurgical procedures.

This paper reviews 10 cases of splenic abscess seen from January 1984 to December 1993. Predisposing conditions included preceding pyogenic infections, contiguous infection, trauma, and diabetes. Fever, chills and pain over the left upper quadrant of the abdomen were the most common symptoms. Routine laboratory tests uncovered common abnormalities which included marked leukocytosis and abnormal chest film with left pleural effusion. All 10 patients had a solitary abscess. Enterobacteriaceae and anaerobes were the most common offending organisms and one patient had polymicrobial infections. Nine of the 10 patients were successfully treated with percutaneous sonographically-guided drainage without significant complications. Only one patient underwent splenectomy because of rupture of the splenic abscess into the peritoneal cavity. All 10 patients survived. This review indicates that percutaneous drainage may replace splenectomy as the initial approach in cases of a solitary splenic abscess.

Fulminating gas-forming psoas muscle abscess due to Klebsiella pneumoniae following a deep neck infection.

Psoas muscle abscess due to Klebsiella pneumoniae infection is rare. We report a 55-year-old diabetic man who presented with progressive back pain of 1 month's duration. The patient had undergone surgical drainage for a deep neck infection with K. pneumoniae 43 days previously. On the present admission, physical examination revealed tenderness over the anterior upper aspect of both thighs, and computed tomography showed pneumoretroperitoneum dissecting the bilateral iliopsoas muscles. Parenteral administration of antibiotics was started immediately. Due to the patient's poor health status, we opted for repeated computed tomographic and sonographic-guided percutaneous drainage rather than surgical drainage. Blood and pus cultures revealed only K. pneumoniae. The patient recovered without significant sequelae. This report stresses the risk of metastatic infections caused by K. pneumoniae, especially in diabetic patients. Our experience suggests that repeated percutaneous drainage is feasible in cases of severe iliopsoas abscess, especially when risks associated with surgery are high.

Infections in febrile granulocytopenic patients: clinical features and pathogens.

From 1990 to 1994, we prospectively evaluated patients with cancer or aplastic anemia who had granulocyte counts of less than 500/mm3 and fever, in order to study infections in febrile granulocytopenic patients in Taiwan. A total of 100 episodes in 95 patients were evaluated. Aerobic Gram-negative bacilli were responsible for 72.5% of the 80 organisms identified in the infections. Escherichia coli was the most common isolate, accounting for 46.5% of Gram-negative bacilli. Pseudomonas aeruginosa and Klebsiella spp caused 24.1% and 18.9% of these infections, respectively. Aerobic Gram-positive cocci were responsible for 12.5% of the 80 organisms identified in the infections. Fungal infections were responsible for 8.8% of isolates. Septicemia, predominantly due to Gram-negative bacilli, accounted for 39 episodes. Infection sites included the respiratory tract, urinary tract, skin and soft tissue, oral cavity, intestines, anus and ear canal. Identification of the pathogens and their clinical features is important in the immediate treatment of such infections.

Gram-negative bacillary meningitis in adults: a recent six-year experience.

Thirty-eight cases of Gram-negative bacillary meningitis in adults have been identified over the past six years at the Veterans General Hospital, Taipei. Twenty cases were associated with head trauma and/or neurosurgery, while 18 cases occurred spontaneously. The overall mortality was 58%. Within the spontaneous meningitis group, 13 cases (72%) were due to Klebsiella pneumoniae, 11 cases (61%) were associated with bacteremia and eight cases (44%) with diabetes mellitus. In spite of the administration of third-generation cephalosporins, most cases of spontaneous meningitis (15 patients, 83%) died soon after diagnosis. In contrast, the clinical course for the postneurosurgical patients was more benign. Only seven patients (35%) died during the course of therapy. Common causative agents in postneurosurgical patients included Pseudomonas aeruginosa, Acinetobacter baumannii, and Escherichia coli. External cerebrospinal fluid drainage devices were thought to be the most important predisposing factor in Gram-negative bacillary meningitis in the postneurosurgical patients. Factors that adversely influenced the mortality of Gram-negative bacillary meningitis included the presence of bacteremia, shock, deep coma and a high initial cerebrospinal fluid leukocyte count.

Xanthomonas maltophilia bacteremia: an analysis of 32 cases.

Thirty-two cases of Xanthomonas maltophilia bacteremia have been identified over the last two years at the Veterans General Hospital, Taipei. Among them, 27 cases (84%) were due to hospital-acquired infections, and 14 cases (44%) were polymicrobial bacteremia. One case was confirmed as prosthetic valve endocarditis and one case was complicated by recurrent attacks of ecthyma gangrenosum. Most cases had severe debilitating conditions. Twelve cases (38%) had a malignancy, 19 cases (59%) were resident in the Intensive Care Unit and 16 cases (50%) had undergone major surgery. The main predisposing factors included central venous catheterization, endotracheal intubation or tracheostomy, prior antibiotic therapy and prolonged hospitalization. Moxalactam, chloramphenicol and trimethoprim-sulfamethoxazole were the most effective agents in vitro against X. maltophilia. Twenty-two cases (69%) died during hospitalization; 13 cases (41%) were directly attributed to septicemia. Factors that adversely influenced mortality included inappropriate antimicrobial therapy and prior antibiotic treatment. Of particular interest is the fact that none of the patients who did not receive appropriate antimicrobial therapy survived. Early diagnosis and appropriate antibiotic therapy are critical for improving the prognosis of X. maltophilia infection.

Enterococcal meningitis: analysis of twelve cases.

From 1986 to 1993, 12 cases of enterococcal meningitis were identified at the Veterans General Hospital, Taipei. Most of the cases were caused by Enterococcus faecalis and three cases were mixed bacterial meningitis. There were six adult and six pediatric patients. Among the adult patients, four had undergone neurosurgical procedures before onset of meningitis and the other two had severe chronic underlying diseases. In contrast, all six pediatric patients had underlying central nervous system (CNS) pathology such as meningomyelocele or hydrocephalus. Placement of CNS devices was the most important predisposing factor of enterococcal meningitis in this study series. Direct microbial invasion via CNS devices or neural tube defects was considered the most likely portal of entry in most patients. Only one patient had primary meningitis, and one other had an enterococcal infection outside the CNS. The overall mortality rate was 25%. None of the pediatric patients died. Underlying conditions were considered the most important factor influencing the prognosis of these patients.

Antimicrobial susceptibility and beta-lactamase production of Moraxella catarrhalis isolates in Taiwan.

Between 1 August 1993 and 31 July 1994, 135 clinical isolates of Moraxella catarrhalis were collected from 12 large medical laboratories in Taiwan. The majority of specimens came from sputum (124 isolates). Other specimens included four isolates from throats, three isolates from wounds or pus, two isolates from eyes, one isolate from blood and one from cerebrospinal fluid. Epidemiologically, M. catarrhalis isolates were found frequently in winter and spring with a peak in February, and only sporadically from April to September. The overall rate of beta-lactamase producing isolates was 98.5% (132/135). All isolates were considered to be ampicillin-resistant, none were found to be resistant to other beta-lactam agents. Among other antimicrobial agents, all isolates were susceptible to chloramphenicol, erythromycin, roxithromycin, ofloxacin and ciprofloxacin, but uniformly resistant to trimethoprim (minimum inhibitory concentration (MIC) > or = 4 micrograms/mL, zone diameter < or = 19 mm). There were 12 isolates (8.8%) resistant to sulfamethoxazole (MIC > or = 32 micrograms/mL, zone diameter < or = 19 mm) and 19 isolates (14.4%) resistant to tetracycline (MIC > or = 16 micrograms/mL, zone diameter < or = 19 mm). The high level of resistance to ampicillin due to beta-lactamase production indicates that this is no longer a reliable agent for the treatment of M. catarrhalis infections. Among the beta-lactam agents tested, amoxicillin + clavulanate and the cephalosporins were active. These agents appear to be reliable first-line therapies when infection with M. catarrhalis is suspected. Misidentification of the species and difficulties in determining susceptibility to ampicillin are still widespread in Taiwanese laboratories. The application of the butyrate hydrolysis test and an appropriate test for beta-lactamase production is necessary for the resolution of these problems.

beta-Lactam resistance and beta-lactamase isoforms of Moraxella catarrhalis isolates in Taiwan.

Moraxella catarrhalis is an important pathogen in both upper and lower respiratory tract infections. More than 90% of isolates worldwide produce beta-lactamase. The beta-lactamases produced by M. catarrhalis can be differentiated by isoelectric focusing (IEF) into BRO-1 and BRO-2 patterns. In this study, we investigated the prevalence of various beta-lactamase isoforms in clinical isolates of M. catarrhalis in Taiwan, as well as the relationships of these isoforms with antibiotic resistance. A total of 271 clinical isolates of M. catarrhalis were collected from 12 large medical laboratories in Taiwan from 1 August 1993 to 31 July 1995. The overall prevalence of beta-lactamase production was 98.2% (266 of 271 isolates). Analytical IEF revealed BRO-1 was the most common beta-lactamase pattern among the isolates (238 isolates, 88%); BRO-2 was the only other pattern found, with 32 (12%) isolates. The geometric mean minimum inhibitory concentration of ampicillin for BRO-1 producers was 63-fold higher than that for beta-lactamase-negative isolates, and 6.5-fold higher than that for BRO-2 producers. beta-Lactam antibiotics, such as amoxicillin + clavulanate and the cephalosporins, tested were very active against this species, regardless of whether the isolate produced beta-lactamase or not. In conclusion, beta-lactamase is common among clinical isolates of M. catarrhalis in Taiwan, with BRO-1 being the most common isoform. However, because most isolates tested were still sensitive to amoxicillin + clavulanate and cephalosporins, these agents appear to be reliable alternatives to first-line therapy when M. catarrhalis is contributing to a clinical infection.

Nosocomial gram-negative bacteremia in critically ill patients: epidemiologic characteristics and prognostic factors in 147 episodes.

Although gram-positive organisms are the most common causes of nosocomial bloodstream infections, gram-negative bacteremia carries higher risks of severe sepsis, septic shock, and death among critically ill patients in intensive care units (ICUs). We performed a prospective epidemiologic analysis of nosocomial gram-negative bacteremia episodes among ICU patients and sought to identify risk factors for mortality among these patients. All episodes of nosocomial gram-negative bacteremia documented in five ICU wards of our hospital during a 2-year period were included. There were 147 episodes (124 patients) of gram-negative bacteremia documented during the study period. The overall mortality rate was 36.1%, and 77.4% of all deaths were directly related to the bloodstream infection. Gram-negative bacteremia was associated with prolonged ICU stay (45.7 d vs 6.1 d for all ICU patients). The most common isolate was Acinetobacter baumannii, followed by Burkholderia cepacia and Enterobacter cloacae. The most frequent source of infection was the lower respiratory tract (32.0%). Of the agents tested, ciprofloxacin, imipenem, and ceftazidime were the most active against the clinical isolates. Multivariate logistic regression analysis identified the presence of septic shock (odds ratio, OR = 17.66, p < 0.001) and rapidly fatal and ultimately fatal underlying conditions (OR = 3.47, p = 0.032) as being independent risk factors for mortality. Early appropriate antibiotic treatment did not result in significant improvement in survival. These findings suggest that prevention of lower respiratory tract colonization and nosocomial pneumonia are crucial for reducing the incidence of nosocomial gram-negative bacteremia in the ICU. Serious underlying illnesses and septic shock were the most important risk factors for death in these patients.

Risk factors and impact of nosocomial Acinetobacter baumannii bloodstream infections in the adult intensive care unit: a case-control study.

During a nine-year study period, 96 episodes of nosocomial bloodstream infection (BSI) due to Acinetobacter baumannii were identified in the adult intensive care units (ICUs) of Shin Kong Wu Ho-Su Memorial Hospital. Seventy-seven (80.2%) of these were available for matching in terms of age, sex, primary diagnosis of ICU admission, ICU ward, and disease severity. Univariate analysis showed that central venous catheter use, ventilator use, prior A. baumannii colonisation, and respiratory and cardiovascular organ failure were significantly associated with acquiring A. baumannii BSI in the ICU. By multivariate analysis, only prior A. baumannii colonisation [odds ratio (OR): 3.81; P<0.001] and cardiovascular failure (OR: 2.24; P=0.04) were identified as independent risk factors. The lower respiratory tract (32/77; 41.6%) was the most frequent source of infection, followed by intravascular catheters (13/77; 16.9%). Cumulative survival curves for patients with A. baumannii BSI and control patients showed no significant difference (30 day crude mortality: 29.9% and 27.3%, respectively; P=0.916). However, the mean length of ICU and hospital stay and mean hospital cost of patients with A. baumannii BSI significantly increased, with an estimated 8.7 days excess length of ICU stay, 19.1 days excess hospital stay, and US $8480 extra hospital costs. Imipenem and meropenem remained the most active antimicrobial agents, both with 95.5% susceptibility (MIC50=0.25 and 0.5, respectively). Improving hand hygiene of healthcare workers and aseptic care of vascular catheters and endotracheal tubes are important measures to prevent A. baumannii colonisation and decrease the incidence of BSI.

Serological evaluation for tuberculosis by antigen 60 IgG ELISA test.

BACKGROUND: Tuberculosis remains a significant global health problem, especially among developing countries. It unfortunately results in high morbidity and mortality rates. This disease is also prevalent to a large extent in Taiwan. The traditional tuberculous tests, including the acid-fast smear and culture, have a limited activity in regard to extrapulmonary or smear-negative tuberculosis. A new testing is necessary to improve diagnosis of this disease. METHODS: An enzyme-linked immunosorbent assay (ELISA) test for detection of serum IgG antibodies, based on Antigen 60, was applied to 146 subjects including 68 non-tuberculous cases and 78 tuberculous cases. A titer of less than 200 serounits was considered negative, and one of 200 or more serounits was thought positive. RESULTS: In the healthy group, which included 5 newborns, 5 children and 20 healthy adults, 6.1% (2/30) showed positive results. Of the 15 hospital attendants, 60% (9/15) also displayed positive results. Nine of 17 cases (52.9%) with non-tuberculous pulmonary diseases had positive results. Among 6 cases with other diseases, the results were all negative. The false positive rate in non-tuberculous group was 29.4% (20/68). In 10 cases with inactive pulmonary tuberculosis, 30% (3/10) showed positive results. In 50 with active pulmonary tuberculosis, 88% (44/50) generated positive results. Effectual results were obtained in 66.7% (8/12) of the cases with extrapulmonary tuberculosis. Including 6 cases with mixed pulmonary and extrapulmonary tuberculosis, 83.3% (5/6) proved positive results. The positive rate in active tuberculous group was 83.8% (57/68). CONCLUSIONS: The ELISA test, for detection of IgG antibody with Antigen 60, is helpful in improving the diagnosis of tuberculosis, especially in extrapulmonary tuberculosis.

Infective endocarditis complicated with progressive heart failure due to beta-lactamase-producing Cardiobacterium hominis.

We describe a 66-year-old woman with infective endocarditis due to Cardiobacterium hominis whose condition, complicated by severe aortic regurgitation and congestive heart failure, necessitated aortic valve replacement despite treatment with ceftriaxone followed by ciprofloxacin. The blood isolate of C. hominis produced beta-lactamase and exhibited high-level resistance to penicillin (MIC, >==256 microgram/ml) and reduced susceptibility to vancomycin (MIC, 8 microgram/ml).

Invasive group G streptococcal infections: a review of 37 cases.

BACKGROUND: Beta-hemolytic streptococci group A, B, and D which cause many diseases have been well studied. Infection caused by group G Streptococcus has increased in clinical significance, and thus is attracting more physicians attention. This retrospective analysis reports clinical experience with such infections at the Veterans General Hospital-Taipei. METHODS: Medical records of invasive group G streptococcal isolates from March 1991 to April 1994 were reviewed. Thirty-seven cases were included. RESULTS: There were 33 males and 4 females with a mean age of 67.4. Major underlying diseases included diabetes (24.3%), cardiovascular diseases (21.6%), malignancy (21.6%), bone or joint diseases (18.9%) and cirrhosis of the liver (13.5%). Only 8.1% cases had no underlying disease. The most common portal of entry was the skin (64.9%). There was a wide spectrum of clinical manifestations, including cellulitis (32.4%), arthritis or osteomyelitis (16.2%), endocarditis (8.1%), meningitis (8.1%), peritonitis (8.1%), empyema (5.4%) and primary bacteremia (27%). All of these isolates were susceptible to penicillin, oxacillin, cefazolin, clindamycin and vancomycin. Ten patients died, and five of these expired from group G streptococcal infections. CONCLUSIONS: Group G Streptococcus is a low virulent microorganism. Clinical improvement after therapy is fast. Poor response to antibiotics should prompt investigation of the underlying diseases or undrained foci of infection.