Source and symptoms of COVID-19 among hospital workers in Milan.

BACKGROUND: Healthcare workers (HCWs) are commonly infected by SARS-CoV-2 and represent one of the most vulnerable groups. Adequate prevention strategies are necessary to guarantee HCWs' safety, as well as to prevent dissemination of the infection among patients. AIMS: To describe a case series of SARS-CoV-2-positive HCWs in a large public healthcare organization in Milan (Italy) during the most devastating weeks of the epidemic and analyse the sources, symptoms and duration of SARS-CoV-2 infection. METHODS: This study included 172 SARS-CoV-2-positive HCWs who were infected between the 25th of February and the 7th of April 2020. A nasopharyngeal swab (NPS) and RT-PCR were used to indicate. RESULTS: Initially, the most common sources of infection were other positive HCWs (49%). Medical doctors and nursing assistants were most frequently infected, with infection rates of 53/1000 and 50/1000, respectively. COVID-19 departments were less affected than internal medicine, surgery, intensive care, or emergency room. The most commonly reported symptom was mild cough, while loss of smell (anosmia) and loss of taste (ageusia) were reported as moderate and severe by 30-40% of HCWs. The time necessary for 50% of workers to recover from the infection was 23 days, while it took 41 days for 95% of HCWs to become virus-free. CONCLUSIONS: HCWs are commonly infected due to close contacts with other positive HCWs, and non-COVID departments were most affected. Most HCWs were asymptomatic or subclinical but contact tracing and testing of asymptomatic HCWs help identify and isolate infected workers.

Diagnostic specificity of autoantibodies to M-type phospholipase A2 receptor (PLA2R) in differentiating idiopathic membranous nephropathy (IMN) from secondary forms and other glomerular diseases.

Autoantibody against phospholipase A2 receptor (anti-PLA2R) is a sensitive and specific biomarker of idiopathic membranous nephropathy (iMN), being found in approximately 70% of iMN patients and only occasionally in other glomerular diseases. However, whereas its diagnostic specificity vs. normal controls and other glomerulonephritides (GN) has been firmly established, its specificity vs. membranous nephropathy associated with various diseases (sMN) has given inconsistent results. The aim of our study was to evaluate the prevalence of anti-PLA2R antibodies in iMN in comparison with various control groups, including sMN. A total of 252 consecutive iMN patients, 184 pathological and 43 healthy controls were tested for anti-PLA2R antibody using indirect immunofluorescence (PLA2R IIFT, Euroimmun). Anti-PLA2R autoantibodies were detectable in 178/252 iMN patients, 1/80 primary GN, 0/72 secondary GN, 9/32 sMN and 0/43 healthy controls, with a diagnostic sensitivity of 70.6%. The diagnostic specificity of anti-PLA2R antibody vs. normal and pathological controls was 100 and 94.6% respectively. However, when the diagnostic specificity was calculated only vs. secondary forms of MN, it decreased considerably to 71.9%. Interestingly enough, 9 out of 10 anti-PLA2R positive patients in the disease control groups had membranous nephropathy associated with various diseases (7 cancer, 1 Crohn's disease, 1 scleroderma). In conclusion, anti-PLA2R positivity in a patient with MN, should not be considered sufficient to abstain from seeking a secondary cause, especially in patients with risk factors for neoplasia. The causal relationship between tumors and anti-PLA2R-induced MN remains to be established, as well as the possible mechanisms through which malignancies provoke autoimmunity.

Proficiency of Italian clinical laboratories in detecting reduced glycopeptide susceptibility in Enterococcus and Staphylococcus spp. using routine laboratory methodologies.

OBJECTIVE: To assess the ability of 59 clinical microbiology laboratories distributed throughout Italy to correctly identify and detect reduced susceptibility to glycopeptides in staphylococci and VanA-, VanB- or VanC-mediated glycopeptide resistance in enterococci. METHODS: Eight test strains comprising three staphylococci (S. aureus ATCC 29212 and two vancomycin-intermediate S. haemolyticus [11105301, 10030683Y]) and five enterococci (E. faecalis ATCC 29212, E. faecalis ATCC 51299 VanB, E. faecium AIB40 VanA, E. faecalis V583 VanB and E. gallinarum AIB39 VanC1) were distributed to 59 Italian clinical microbiology laboratories. Each isolate was blind-coded, and laboratories were instructed to identify the strains and test isolates for susceptibility to teicoplanin and vancomycin using their standard methods. Results were assessed against consensus test results obtained by a reference laboratory. In addition, to complement data interpretation, laboratories were asked to provide retrospective routine test results from their respective hospitals. RESULTS: All 59 laboratories participating in the study completed the susceptibility testing and provided data for analysis. A total of 53 laboratories provided retrospective routine data. Overall, laboratories were able to identify isolates to the genus level successfully. E. gallinarum and S. haemolyticus posed problems for species identification, with only 40.6 and 71.2%, respectively, of results reported correctly; most incorrect results were reported as 'other species'. For enterococcal test strains, VanA phenotypes were detected correctly by 96.6% of laboratories; VanB by 30.5% (E. faecalis ATCC 51299) and 88.1% (E. faecalis V583); and VanC1 by 67.8%. For staphylococcal test strains, 28.8% (S. haemolyticus 11105301) and 23.7% (S. haemolyticus 10030683Y) of the laboratories were able to detect reduced susceptibility to vancomycin. Errors in detecting vancomycin resistance in VanB and VanC1 enterococci were made with all methods, most noticeably by disk diffusion users. For staphylococci, most errors in reporting vancomycin-intermediate resistance occurred with disk diffusion and Vitek (software version 5.04) users. Overall, considerably fewer errors occurred with the detection of teicoplanin resistance, especially for staphylococci. For 1999, routine results show that 41/1749 (2.4%) of E. faecium, 220/11 180 (2.0%) of E. faecalis, 29/24 927 (0.12%) of S. aureus and 54/22 102 (0.24%) of coagulase-negative staphylococci were reported as resistant to vancomycin. CONCLUSION: Italian laboratories are able to identify staphylococci and enterococci adequately, although all methodologies used have problems in identifying E. gallinarum and coagulase-negative staphylococci to the species level. While VanA phenotypes were efficiently detected, problems were experienced in detecting VanB and VanC phenotypes. The majority of laboratories were unable to detect reduced vancomycin susceptibility in staphylococci adequately, especially with disk diffusion and older Vitek systems. Teicoplanin appeared useful as a marker for detecting vancomycin resistance, particularly with disk diffusion. Should enterococcal VanB or staphylococcal glycopeptide-intermediate phenotypes become prevalent in Italy, it is likely that they would be under-detected. New systems under development, such as Vitek2, should improve this situation.

Infections in the surgical setting: epidemiology and effect of treatment with cefotaxime in a multicenter trial including 3,032 patients.

Hospital-acquired infections still represent a serious threat to the surgical patient. A nationwide survey of 259 Italian surgical wards involving 11,343 patients was conducted in October 1988. Hospital-acquired infections were recorded in 565 (5%) patients: the microorganisms most commonly involved were gram-negative rods (60% of all isolates), 41% of the infected patients presented one or more intrinsic predisposing factor, and 65% had undergone some invasive procedure. The studied group represented 23% of all surgical patients in the country on the days of the survey. Following the epidemiologic survey, an open multicenter study was conducted in the same wards to evaluate the efficacy and tolerability of cefotaxime (1 g, 2 or 3 times per day) in the treatment of nosocomial surgical infections. Among 3,032 evaluable patients, 1,295 intra-abdominal, 610 wound and soft tissue, 554 urinary, and 367 respiratory infections were observed. Treatment was judged to be clinically effective in 94% of patients, and side effects, mostly involving the gastrointestinal tract, were observed in 1.4% of patients; but interruption of the treatment was required only in 19 patients (0.6%). This study confirms that cefotaxime, after over a decade of use, retains high efficacy in the treatment for nosocomial infections and induces a low rate of side effects.

Prospective study of Clostridium difficile intestinal colonization and disease following single-dose antibiotic prophylaxis in surgery.

A total of 108 volunteers undergoing an elective surgical procedure were randomly given a single 2-g intravenous prophylactic dose of either a cephalosporin or mezlocillin. Stool samples were cultured for Clostridium difficile the day before the operation and later on postoperative days 4, 7, and 14. C. difficile was detected in 23.0% of patients who received a cephalosporin (cefoxitin, 8.3%; cefazolin, 14.3%; cefotetan, 20.0%; ceftriaxone, 25.0%; cefoperazone, 43.7%), in 3.3% of patients given mezlocillin, and in none of 15 control volunteers given no antimicrobial agent. No patient experienced diarrhea.

Immunoblot analysis of serum immunoglobulin G response to surface proteins of Clostridium difficile in patients with antibiotic-associated diarrhea.

We examined by immunoblot analysis the serum immunoglobulin G antibody response to EDTA-extracted surface proteins of Clostridium difficile in 16 patients with antibiotic-associated diarrhea. For each patient, paired serum samples were tested against proteins of the infecting strain and of a collection strain (C253) known to belong to the electrophoretic group 2 pattern. Eight patients, all harboring group 2 C. difficile strains, exhibited responses to the proteins of the infecting strain; six patients showed increases in the level of antibodies between acute-phase and convalescent-phase sera. A great variability in the antigens recognized was found; however, seven patients possessed antibodies directed against an antigen of about 35 kilodaltons, corresponding to the major protein of group 2 strains. The sera of these seven patients cross-reacted also with the 35-kilodalton and other proteins of strain C253. Our data show that C. difficile proteins other than toxins can elicit an immune response in patients with C. difficile-associated disease; in this group of patients, the major surface protein of the group 2 strains was the antigen most often recognized.

Treatment of Clostridium difficile-associated disease with teicoplanin.

Forty-seven patients affected by Clostridium difficile-associated disease were treated orally with either vancomycin (patients hospitalized from February 1984 to February 1987) or teicoplanin (from March 1987 to December 1988). All patients given teicoplanin remained asymptomatic after discontinuation of treatment, and all but one were also cleared of C. difficile. In the vancomycin group, clinical symptoms recurred in 3 of 23 evaluable patients, and follow-up cultures were positive in another asymptomatic case.

Third generation cephalosporins as a risk factor for Clostridium difficile-associated disease: a four-year survey in a general hospital.

The main clinical features of patients who developed pseudomembranous colitis (PMC) or Clostridium difficile-associated diarrhoea (CDAD) during their stay at the S. Anna General Hospital, Como, over the period February 1984 to May 1988, are reported. Forty patients developed either CDAD (ten cases) or PMC (30 cases). Twenty-seven (65.7%) had undergone surgery and 32 (80.0%) had received prolonged antibiotic treatment. Three patients (7.5%) were given three doses only of ceftriaxone. Five patients (12.5%) had not received any antibiotic treatment; but three were nursed in a bed next to a patient with PMC-CDAD. The number of cases diagnosed were correlated retrospectively with the cumulative consumption of different groups of antibiotics on wards in which PMC or CDAD occurred. A significant difference (P less than 0.01) between third generation cephalosporins (16 cases) and ureidopenicillins (one case), was found. Twenty-five patients were treated with oral vancomycin. Two died of the underlying disease and 23 were cured. The disease recurred clinically in three, and follow-up cultures were positive in another asymptomatic case. Fifteen patients (all PMC cases) were treated with oral teicoplanin. All were clinically cured and remained asymptomatic and all but one were also cleared of C. difficile. No adverse reactions were observed in patients given either drug. Third generation cephalosporins, even when administered as short-term perioperative prophylaxis, but not ureidopenicillins, are significantly associated with C. difficile-related diseases. Teicoplanin proved to be very effective and safe in the treatment of PMC, and should be further evaluated there.

Roxithromycin disposition in tonsils after single and repeated administrations.

Levels of roxithromycin in serum and tissue were investigated in 29 subjects undergoing tonsillectomy. A total of 13 subjects received a single oral dose of 300 mg, and 16 received four oral doses 12 h apart as follows: a 300-mg loading dose followed by three 150-mg doses. Measurable levels of roxithromycin were present in tonsil samples of 11 of 13 subjects in the first group. The mean levels in tonsils and serum were 0.8 microgram/g and 6.7 micrograms/ml, resulting in a mean tissue/serum ratio of 0.16. In the multiple-dose group, roxithromycin was found in 14 of 16 subjects at mean levels in tonsils and serum of 1.6 micrograms/g and 8.7 micrograms/ml, and the tissue/serum ratio was 0.23.

High homology of membrane proteins electrophoretic pattern in Bacteroides fragilis as confirmed by various solubilizing methods.

Membrane proteins from 25 strains of B. fragilis isolated in different laboratories in Northern Italy were examined by SDS-PAGE and isoelectrofocusing. The electrophoretic patterns of inner and outer membrane after Sarkosyl and SDS solubilization of all the isolates were consistently similar to that of the reference strain. The protein profiles of the different species belonging to the B. fragilis group are clearly distinguishable with negligible similarities. Our data clearly show that this approach is extremely helpful and reliable in providing additional verification of the identity of strains recognized by conventional tests. In this connection PAGIF analysis of triton solubilized isolated envelopes reduces technical time and difficulties, thus improving analytical accuracy.

Thiamphenicol in the prophylaxis and treatment of mixed infections of the female genital tract.

Surgical procedures involving bacteriologically contaminated sites (e.g., vaginal or abdominal hysterectomy) are frequently followed by local or systemic infections. The efficacy of thiamphenicol against such infections was investigated in two studies: an open clinical study of the treatment of severe, mixed aerobic-anaerobic infections of the female genital tract and a randomized, prospective, controlled trial of short-term perioperative prophylaxis. Thirty-five patients were enrolled in the first study and 750 patients in the second (490 undergoing abdominal hysterectomy and 260 undergoing vaginal hysterectomy). Thiamphenicol appeared to be effective in both trials. When used for prophylaxis, it significantly reduced three postoperative parameters: infectious morbidity, use of antibiotics, and period of hospitalization. When used for treatment, it cured 30 (86%) of 35 postoperative gynecologic infections, including 13 infections that had not responded to previous, empirical antibiotic therapy.

Randomized clinical trial of short-term antibiotic prophylaxis in 750 patients undergoing vaginal and abdominal hysterectomy.

We have carried out a controlled, prospective, randomized study with the aim of evaluating the efficacy of a short-term antibiotic prophylaxis on patients undergoing simple total hysterectomy. 750 patients entered the trial, starting in September 1977, 260 underwent vaginal hysterectomy, 490 abdominal hysterectomy. The patients were subdivided randomly into four groups, which were homogeneous in number, age, weight, associated disease, indication for surgery and hormonal status: control group, without treatment; prophylaxis with Cefazolin; prophylaxis with Thiamphenicol; prophylaxis with Cefazolin plus Thiamphenicol. Each antibiotic was administered parenterally, at the dose of 1 g, 1 hour before surgery, and 5 and 12 hours later. Postoperative infectious morbidity was evaluated according to febrile morbidity, the need for antibiotic therapy during the postoperative period and the length of postoperative hospitalization. The incidence and severity of febrile morbidity was significantly reduced in the three groups of patients who received prophylaxis. The use of antibiotics in the postoperative period resulted significantly reduced and the period of hospitalization was shorter for the groups with prophylaxis than for the control group.

The colonization of Streptococcus faecium in human intestinal tract after oral administration.

The colonizing ability of Streptococcus faecium strain SF 68 at different levels of the gastrointestinal tract was assessed in ten patients. They were orally treated with a preparation containing the bacteria in lyophilized form for three days. During an abdominal surgical operation a sample of bacterial content of jejunum, ileum and colon was taken and cultured. The Streptococcus faecium was detected in all treated patients in a quite high concentration compared to the counts of both aerobic and anaerobic germs. These data confirms the rapid growth of SF 68 after oral administration in the gastrointestinal human tract.