European Surveillance of Antibiotic Resistance (ESAR)

A Study of the European Society of Biomodulation and Chemotherapy

Alert Organisms

The total number of Alert organisms increased from 4565 in 1999 to 6536 in 2000 with all centres contributing increased numbers, the greatest numbers continuing to come from Bratislava National Cancer Institute (NCI) and Aberdeen (table 1). Overall there was a slight preponderance of male patients with Alert organism, but this varied between centres (table 2). Approximately of patients had a prior operation although in Leipzig this applied to the majority of patients (table 3). Three quarters of patients were in-patients (table 4), with internal medicine and surgery accounting for approximately 20% each of disciplines (table 5). Approximately 40% of patients had an ICU stay, but this ranged from over 50% in Bratislava NCI to 17% in Aberdeen (table 6).

17.6% of specimens were surveillance, ranging from 11.6% in Warsaw to 29.1% in Leipzig (table 7). 49.4% were definitely or probably causing an infection and 32.4% possibly causative. The Alert organisms are ranked in table 8. Pseudomonas was most common (20%) ranging from 4% in Aberdeen to 29% in Bratislava NCI. Staphylococci were next (18.6%) overall, but 52.6% in Aberdeen, followed by E. coli (17%), Enterococci (9.7%) – ranging from 0.03% in Aberdeen to 39.6% in Leipzig.

Blood cultures accounted for 4.9% of Alerts, urines 33.9%, respiratory specimens 30.8%, wounds 14% (table 9). Overall, there was not much variation in specimen source between centres. In of patients an infection was documented, ranging from 55% in Bratislava Saint Elizabeth (SE) to 79% in Aberdenn, Bratislava NCI and Warsaw (table 10).

The most common infection was UTI (28.8%) followed by LRTI (with or without pulmonary infiltrates) in 13.1%, wound infections in 9.6%, SSTI (mainly not related to catheters) and URTI both in 8% (table 11). Bacteraemia was detected in 2.9%, ranging from 2.2% in Bratislava SE to 5.5% in Warsaw.

Antibiotic therapy

Data on prior antibiotic treatment was known in 57.5% (30% in Aberdeen to 82.1% in Warsaw. Overall, 25% of patients were known to have received one antibiotic, 11% two and almost 7% three or more. 15.8% were not thought to have received antibiotics, table 12).

Co-amoxiclav (5.2%), ceftazidime (3.7%), cefotaxime (3.9%), ciprofloxacin (8.1%), pip-tazo (3.3%), metronidazole (3.4%), co-trimoxazole (2.5%), vancomycin (2.8%) were the most commonly used antibiotics (table 13). Vancomycin use ranged from 0.5% in Aberdeen to 9.9% in Leipzig. Pip-tazo ranged from 0.6% in Aberdeen to 12.6% in Bratislava SE, imipenem from 0% in Bratislava to 14.6% in Leipzig, ciprofloxacin from 4.5% in Aberdeen to 30.5% in Bratislava SE, ceftazidime from 0.4% in Aberdeen to 10.7% in Warsaw and co-amoxiclav from 8.2% in Aberdeen to 0% in Leipzig.

Underlying Diseases

66% of patients were known to suffer from at least one underlying disease (table 14), the most common being neoplasm (13.5%), circulatory disease (10.3%), respiratory tract disease (9%), genito-urinary disease (11.4%) (table 15).

Risk Factors

Risk factors were unknown in 47.8%, not present in 12.8% and, of the remainder, 18.4% had one recognised risk factor and 9.2% two (table 16). Risk factors included CVCs (9.9%) peripheral catheters (11%) and intubation (11%) (table 17).

Denominator Data

Table 18 shows the large differences in denominator data (=isolates tested) between the different centres. For instance there was a relatively large number of Enterococci isolated in Leipzig, a complete absence of coagulase negative staphylococci (CNS) in Warsaw, a large proportion of Haemophili in Bratislava NCI and a large number of anaerobes in Aberdeen.

The great majority of Alert UTIs were due to E. coli (34.2%) or Pseudomonas (26.4%), over twice as many E. coli being definitely attributed as pathogens compared with Pseudomonas (table 19).

Denominator data included 136 583 organisms in 1999 (table 20) and 135 041 in 2000 (table 21) with similar proportions of each species on each of the two years.

The Alert percentages are seen in tables 20 (1999), 21 (2000) and 18 (total). The only ones to decrease over the two years were Campylobacter, coagulase negative Staphylococci (CNS)and Pseudomonas aeruginosa. The total percentage increased from 3.3 to 4.8% from 1999 to 2000.

Macrolide resistance remained low in beta haemolytic Streptococci (BHS) rising from 1.3 to 3.2% (tables 22, 23 and 24) and in pneumococci from 1.5 to 6.4%. High level penicillin resistance in pneumococci remained very rare but low level resistance increased from 3.1 to 9.4% due to a large increase in Bratislava NCI. Rates in Warsaw actually decreased from 13.5 to 0%. Bratislava SE seemed to have a particular problem with macrolide resistant BHS in 2000 although the number of isolates was small.

Warsaw and Leipzig seemed to have a particular problem with Enterococci Alerts, but these rates fell in 2000, although overall, Enterococci Alerts almost doubled in frequency to 5.9% of all Enterococci (tables 20 and 21). There was very little problem with glycopeptide resistance although there were eight isolates in Leipzig in 2000. Most of the problem is with high-level aminoglycoside resistance although Leipzig (and Bratislava in 2000) have significant numbers of b -lactamase positive isolates. Aberdeen had basically no enterococcal Alerts although it does not screen routinely for high-level aminoglycoside resistance.

b -lactamase positivity in H. influenzae increased from 1.6 to 5% between 1999 and 2000, but no centre seemed to have a particular problem and no strains were detected in Leipzig. There was no quinolone or third generation cephalosporin resistance anywhere (tables 22, 23 and 24).

The highest rate of Alert Enterobacteriaceae were in Warsaw (tables 20 and 21). Overall, rates increased from 3.4 to 4.6% . The 4-fluoroquinolone Alert was the most common (3% in 2000), followed by gentamicin resistance (2.3%) (tables 22, 23 and 24). There was very little gentamicin resistance and hardly any ESBL detection in Aberdeen.

Warsaw and Bratislava NCI provided most of the Acinetobacter Alerts which increased from 14 to 18.9% from 1999 to 2000 (tables 20 and 21). The great majority of the Alerts were due to gentamicin resistance (tables 22, 23 and 24). The great majority of the MRSA (S. aureus Alerts) were from Aberdeen with an increase from 2.8% in 1999 to 4.8% over all centres.. Only one vancomycin resistant S. aureus was reported (from Leipzig in 1999).

Ciprofloxacin resistance in Campylobacter dropped from 11.5% in 1999 to 3.7% in 2000, exclusively due to a drop in resistance rates in Aberdeen. Ciprofloxacin resistance was not described in Shigella and was very rare in Salmonella (tables 22, 23 and 24).

Only one Alert meningococci was detected (Aberdenn in 2000) however, gonococcal Alerts increased from 5.1 to 9.2%, but were only detected in Aberdeen, Bratislava NCI and Leipzig (tables 20 and 21). b -lactamase mediated resistance and ciprofloxacin resistance were equally common (tables 22, 23 and 24).

Anaerobe Alerts remained very rare although Bratislava NCI had a significant percentage positive metronidazole resistant strains, although numbers were small.

There was very little glycopeptide resistance in CNS.

Pseudomonas Alerts decreased a little from 12.8% in 1999 to 11.8% in 2000 but Aberdeen had consistently low numbers (tables 20 and 21). Most Alerts were due to gentamicin resistance (tables 22, 23 and 24).

Aberdeen was notable for a much lower number of isolates of pneumococci and haemophili (and pseudomonas), but a much greater number of anaerobes. Overall Aberdeen and Bratislava NCI contributed >90% of all denominator data, although the other centres contributed a much greater proportion of Alerts.

It can be seen from table 25 that the isolates of beta heamolytic streptococci, Campylobacter, Haemophilus, Pneumococci and Neisseria came mainly from outpatients, but the great majority of all (and other) isolates came from in-patients.

Table 26 shows Alert organisms from hospitalised patients by stay in ICU. There was a higher proportion of Pseudomonas and Acinetobacter in the ICU Alerts.

The links by center to table 26 show the relatively low yield of Alerts from ICU in Aberdeen and Bratislava SE.

Table 28 and links show the Alerts by discipline and centre. The high yield of MRSA from Aberdeen, Enterococci from and Pseudomonas from Bratislava NCI are notable.

Table 29 shows the large number of MRSA and Acinetobacter detected on surveillance and not causing infection. The highest proportion definitely causing infection is with Alert E. coli (table 30). Few of the Pseudomonas and Enterococci Alerts are thought definitely to be causing infection.

Table 30 shows that, amongst the Enterobacteriaceae. E. coli are more often thought to be definitely associated with infection and the other species are more often picked up on surveillance.

Outcome and treatment data were only documented in a minority of patients (table 31). Overall mortality was 12.8% and was highest in septic shock (31.8%), bacteraemia (26.2%) respiratory tract infections (20.1%) and fever of unknown origin (16.7%) (table 32).

In urinary tract infections, E. coli comprised 34.2% of Alerts and Pseudomonas 26.4% of Alerts (table 33) although a higher proportion of Pseudomonas (13.4%) were thought only possibly causative. A higher proportion of UTIs from Internal Medicine were in ICU (table 34).

Very little of the documented antibiotic use was for prophylaxis although the most commonly used agent for prophylaxis and treatment was a quinolone (table 35).

Staphylococci (32.8%), Pseudomonas (17%) and Haemophilus (10.8%) were the most common Alerts in the respiratory tract (table 36). Third generation cephalosporins, b -lactamase inhibitor combinations and quinolones were the most commonly used agents (table 37).

Staphylococci, Pseudomonas, Enterococci and Acinetobacter were the most common causes of wound infection and skin and soft tissue infections, although for the latter Alerts, there were more in the "possible" than the "definite" category (tables 38, 39). Surgery was the discipline most often involved with wound infections (table 40). Treatment was most often with a quinolone, third generation cephalosporins or b -lactamase inhibitor combinations (tables 41, 42).

ESBiC Datacenter Munich, 2001