Virological surveillance of influenza and other respiratory viruses during six consecutive seasons from 2006 to 2012 in Catalonia, Spain

Most attention is given to seasonal influenza and respiratory syncytial virus outbreaks, but the cumulative burden caused by other respiratory viruses (RV) is not widely considered. The aim of the present study is to describe the circulation of RV in the general population during six consecutive seasons from 2006 to 2012 in Catalonia, Spain. Cell culture, immunofluorescence and PCR-based assays were used for the RV laboratory-confirmation and influenza subtyping. Phylogenetic and molecular characterizations of viral haemagglutinin, partial neuraminidase and matrix 2 proteins were performed from a representative sampling of influenza viruses. A total of 6315 nasopharyngeal samples were collected, of which 64% were laboratory-confirmed, mainly as influenza A viruses and rhinoviruses. Results show the significant burden of viral aetiological agents in acute respiratory infection, particularly in the youngest cases. The study of influenza strains reveals their continuous evolution through either progressive mutations or by segment reassortments. Moreover, the predominant influenza B lineage was different from that included in the recommended vaccine in half of the studied seasons, supporting the formulation and use of a quadrivalent influenza vaccine. Regarding neuraminidase inhibitors resistance, with the exception of the 2007/08 H275Y seasonal A(H1N1) strains, no other circulating influenza strains carrying known resistance genetic markers were found. Moreover, all circulating A(H1N1)pdm09 and A(H3N2) strains finally became genetically resistant to adamantanes. A wide knowledge of the seasonality patterns of the RV in the general population is well-appreciated, but it is a challenge due to the unpredictable circulation of RV, highlighting the value of local and global RV surveillance.

Incidence of respiratory viruses among travelers with a febrile syndrome returning from tropical and subtropical areas

Fifty million people are estimated to travel from industrial countries to the tropics annually. In spite of exhaustive studies and widely different diagnosis among returned patients, some cases of febrile illnesses remain without an etiological diagnosis, suggesting that these cases could be due to viral respiratory tract infections. From August 2005 to October 2006, 118 febrile patients without a specific diagnosis in their first visit at the Center for International Health of the Hospital Clínic of Barcelona were included. In all of them, in order to study respiratory viruses, a nasopharyngeal swab was collected. Clinical and radiological features and epidemiological data, as well as other samples for microbiologic studies, were also collected during consultation. Based on the physician's judgment at the time of consultation, patients were classified into four groups: respiratory symptoms (62%), febrile syndrome with nonspecific symptoms (24%), digestive symptoms (10%), and patients presenting both respiratory and digestive symptoms (4%). A pathogen microorganism was detected in 61 patients (52%). Respiratory viruses were detected in 44 out of 118 (37%) travelers included in the study, representing 56% of the patients with respiratory symptoms. The most frequently viruses detected were influenza virus (38%), rhinovirus (23%), adenovirus (9%), and respiratory syncytial virus (9%). Respiratory viruses have been shown to play an important role in imported fever. In light of the fact that international tourism is an increasing phenomenon, new strategies to prevent the spread of respiratory viruses should be considered, specially for influenza when a vaccine is available. J. Med. Virol. 80:711–715, 2008. © 2008 Wiley‐Liss, Inc.

Isolation of an amikacin-resistant Escherichia coli strain after tobramycin treatment of previous recurrent episodes of respiratory tract infections caused by Pseudomonas aeruginosa

Amikacin-resistant Escherichia coli strains are isolated rarely from clinical samples. In the present study, investigation of an amikacin-resistant clinical isolate of E. coli demonstrated the presence of two class 1 integrons carrying the aacA4 gene plus the aacA7 gene, and the dfrA17 gene plus the aadA5 gene, respectively. Resistance to amikacin in this E. coli isolate was related to the presence of both aacA4 and aacA7.

Native valve endocarditis due to Candida glabrata treated without valvular replacement: a potential role for caspofungin in the induction and maintenance treatment

Conventional antifungal therapy for fungal endocarditis has been associated with a poor cure rate. Therefore, combined medical and surgical therapy has been recommended. However, new potent antifungal agents, such as echinocandins, could increase the medical options and, in some cases, avoid the need for surgery. We report a case of Candida endocarditis treated successfully without valve replacement with intravenous liposomal amphotericin B (total dose, 4 g) and intravenous caspofungin (a 100-mg loading dose followed by 50 mg per day for 8 weeks) as induction therapy and intravenous caspofungin (100 mg 3 times per week for 12 weeks) as maintenance therapy.

[Evaluation of the Phoenix system for identifying and determining the susceptibility of clinical isolates. Comparative study with the Microscan system]

The Phoenix system (BD Diagnostic Systems), a rapid ID/AST system, was compared with the MicroScan WalkAway-40 system for accuracy of identification and antimicrobial susceptibility test results. The 327 bacterial isolates, were comprised of 191 Gram-negative bacilli (187 Enterobacteriaceae and 4 Aeromonas spp.) and 136 Gram-positive cocci (27 Staphylococcus aureus, 53 coagulase-negative staphylococci, 45 enterococci and 11 beta haemolytic streptococci). The overall rate of agreement between the two systems for species level identification was 95.8% and 96.3% for Gram-negative bacilli and Gram-positive cocci, respectively. Enterococcus and Streptococcus species both achieved a 100% rate of species level agreement. The genus level agreement was >99% overall. Arbitration of the 8 Gram-negative bacilli disagreements resolved with 7 in agreement with the Phoenix identification. For the 5 Gram-positive cocci disagreements, 3 resolved in agreement with Phoenix. Overall, 3688 antimicrobial/organism combinations were evaluated in both systems. For Gram-negative isolates, the rate of essential agreement for the MICs was 98.5%, while the categorical agreement rate was 95.9%. Arbitration of 13 Gram-negative disagreements resolved with 11 in agreement with the Phoenix system. For Staphylococcus spp. and Enterococcus spp. isolates, the essential agreement rates were 96.4% and 99% respectively. Categorical agreement rates for both genera were 94.7% and 96.1%, respectively. Arbitration of 5 staphylococci disagreements resolved with 2 in agreement with Phoenix system. Our results show that the Phoenix system is a rapid and reliable system for both identification and antimicrobial susceptibility testing of common clinical isolates.

Characterization of the molecular mechanisms of quinolone resistance in Yersinia enterocolitica O:3 clinical isolates

OBJECTIVES

The aim of this study was to determine the roles of mutations in the gyrA and parC genes and the overexpression of efflux pump(s) as mechanisms of resistance to quinolones. Forty-five Yersinia enterocolitica O:3 clinical isolates (41 nalidixic acid-resistant, three nalidixic acid-susceptible and one nalidixic acid-resistant strain obtained in vitro) were analysed.

RESULTS

All the nalidixic acid-resistant strains showed mutations in the gyrA gene and none in the parC gene. The presence of the inhibitor produced decreases in the MIC values of nalidixic acid by two to six serial dilution steps in 37 of the 41 nalidixic acid-resistant strains. Meanwhile, the MIC value of ciprofloxacin was affected in two strains whose values diminished three serial dilution steps. The nalidixic acid-resistant mutant obtained in vitro was also affected by the inhibitor decreasing the MIC value of nalidixic acid three serial dilutions steps whereas the MICs for the nalidixic acid-susceptible strains were not affected.

CONCLUSIONS

Our results show that the high level of resistance to nalidixic acid is likely due to an overexpression of an efflux pump plus a mutation in the gyrA gene, whereas decreased susceptibility to ciprofloxacin is only associated with the presence of a mutation in the gyrA gene.

Study of resistance to anti-tuberculosis drugs in five districts of Equatorial Guinea: rates, risk factors, genotyping of gene mutations and molecular epidemiology

SETTING

Five districts in Equatorial Guinea, March 1999 to February 2001.

OBJECTIVES

To determine tuberculosis drug resistance among new and previously treated cases, the risk factors associated with resistance, and the mutations associated with isoniazid and rifampicin (katG, inhA and rpoB genes) resistance, and to genotype resistant strains.

RESULTS

A positive culture identified as Mycobacterium tuberculosis complex was obtained in 240/499 patients. Susceptibility testing was performed in 236 strains. The overall resistance rate in new cases was 16.9% compared to 41.6% in previously treated cases. Isoniazid resistance was the most frequent (respectively 12.5% and 16.6%) in the two groups, while multidrug resistance was observed in 1.7% and 25% of new and previously treated cases, respectively. Female sex was statistically associated with resistance in new cases. Of 41 isoniazid-resistant strains, 33 (80.5%) had mutations in the inhA gene; none had mutations in the katG gene and eight had no mutations in either gene. All strains had low-level isoniazid resistance. Of eight strains resistant to rifampicin, six had mutations in the rpoB gene. Genotyping defined seven clusters.

CONCLUSIONS

Moderate resistance was found in new cases. Low-level isoniazid resistance predominated among mutations in the inhA gene, with a high percentage of clustering in resistant strains.

Trends in frequency and in vitro susceptibilities to antifungal agents, including voriconazole and anidulafungin, of Candida bloodstream isolates. Results from a six-year study (1996-2001)

The frequency of isolation and antifungal susceptibility patterns to established and two new antifungal agents were determined for 218 Candida spp isolates causing bloodstream infection from 1996 to 2001. Overall, 41.7% of the candidemias were due to C. albicans, followed by C. parapsilosis (22%), C. tropicalis (16.1%), C. glabrata (11.9%), C. krusei (6%) and miscellaneous Candida spp (2.3%). Isolates of C. albicans C. parapsilosis and C. tropicalis (80% of isolates) were highly susceptible to fluconazole (94 to 100% at </= 8 microg/ml) and voriconazole (97 to 100% at </= 1 microg/ml). By comparison with the newer agents itraconazole was less active (77 to 97% at </=0.12 microg/ml). Only 77% and 15% of C. glabrata isolates were inhibited by fluconazole at </= 8 microg/ml and itraconazole at </=0.12 microg/ml, respectively. Voriconazole showed a remarkable in vitro potency against C. glabrata as well as C. krusei isolates (100% at </= 1 microg/ml). Anidulafungin was very active against Candida spp isolates (MIC90: </= 0.5 microg/ml), except C. parapsilosis (MIC90: 4 microg/ml) and two C. guilliermondii isolates (MIC: >/= 32 microg/ml).

A nosocomial outbreak of influenza during a period without influenza epidemic activity

The objective of this study was to describe a nosocomial outbreak of influenza during a period without influenza epidemic activity in the community. Outbreak investigation was carried out in an infectious diseases ward of a tertiary hospital. Presence of two or more of the following symptoms were used to define influenza: cough, sore throat, myalgia and fever. Epidemiological survey, direct immunofluorescence, viral culture, polymerase chain reaction, haemagglutination-inhibition test in throat swabs and serology for respiratory viruses were performed. Twenty-nine of 57 healthcare workers (HCW) (51%) and eight of 23 hospitalised patients (34%) fulfilled the case definition. Sixteen HCW (55%) and three inpatients (37%) had a definitive diagnosis of influenza A virus infection (subtype H1N1). Among the symptomatic HCW, 93% had not been vaccinated against influenza that season. Affected inpatients were isolated and admissions in the ward were cancelled for 2 weeks. Symptomatic HCW were sent home for 1 week. On the seventeenth day of the outbreak the last case was declared. The incidence of cases in this outbreak of influenza, which occurred during a period without influenza epidemic activity in the community, was notably high. Epidemiological data suggest transmission from healthcare workers to inpatients. Most healthcare workers were not vaccinated against influenza. Vaccination programmes should be reinforced among healthcare workers.

Rapid urinary antigen test for diagnosis of pneumococcal community-acquired pneumonia in adults

Streptococcus pneumoniae is suspected to cause an important proportion of community-acquired pneumonia (CAP) whose aetiology cannot be detected with conventional tests. In this study, the authors evaluated the diagnostic yield of a new immunochromatographic membrane test (ICT) for the detection of the S. pneumoniae antigen in the urine of patients admitted with diagnosed CAP. ICT was performed in unconcentrated and concentrated urine from all the patients. ICT was repeated 1 month after discharge in a group initially testing positive. The authors also studied the ICT in clinically stable human immunodeficiency virus type 1 (HIV1)-infected patients. S. pneumoniae antigen was detected in all of the 68 (100%) patients tested with definitive pneumococcal pneumonia. In five of these cases ICT was only positive when it had been performed on the patients. The S. pneumoniae antigen was also detected in 36 (69.2%) of 52 patients with probable pneumococcal pneumonia and in 50 of 277 (18%) patients without pneumococcal pneumonia. ICT remained positive in 16 (69.5%) of 23 patients, 1 month after hospital discharge. Nasopharyngeal colonisation with S. pneumoniae was detected in 8 (12%) of 68 clinically stable HIV1 infected patients, but none tested ICT positive. The Binax NOW it immunochromatographic membrane test is a rapid, sensitive and specific test for detecting pneumococcal community-acquired pneumonia in adults. The test may remain positive for several weeks after pneumococcal pneumonia.

Correlation between the activity of different fluoroquinolones and the presence of mechanisms of quinolone resistance in epidemiologically related and unrelated strains of methicillin-susceptible and -resistant Staphylococcus aureus

OBJECTIVE

To study the activity of five different fluoroquinolones against 22 epidemiologically related and unrelated strains of Staphylococcus aureus (13 methicillin-resistant (MRSA) strains and nine methicillin-susceptible (MSSA) strains) in which the mechanisms of quinolone resistance are also investigated.

METHODS

The MICs of the different fluoroquinolones were determined by the microdilution method, in the presence and absence of reserpine. The quinolone resistance-determining regions of the gyrA, gyrB, grlA and grlB genes were amplified and sequenced to establish the presence of mutations. The molecular epidemiology of the 22 strains was performed by low-frequency restriction analysis of chromosomal DNA with SmaI.

RESULTS

MSSA strains showed lower homology than MRSA strains, in which only two clones were seen. Trovafloxacin showed the best activity against these clinical isolates of S. aureus, since strains carrying one amino acid change in both GyrA and GrlA subunits remained susceptible to this antimicrobial agent. Furthermore, trovafloxacin did not seem to be a substrate for NorA.

CONCLUSION

Trovafloxacin was the most active quinolone tested against S. aureus strains, followed by levofloxacin and sparfloxacin, whereas ciprofloxacin and norfloxacin were the least active quinolones, in both the presence and absence of reserpine. Epidemiologically related S. aureus strains presented different mechanisms of quinolone resistance, suggesting a divergent evolution of the same clone. Finally, 16 S. aureus strains with a ciprofloxacin plus reserpine MIC > or = 1 mg/L already showed a mutation in the grlA gene. This MIC may be useful as a marker of mutation in this gene, contraindicating the use of this quinolone, since a second mutation may develop during treatment.

Frequency of selection of fluoroquinolone-resistant mutants of Neisseria gonorrhoeae exposed to gemifloxacin and four other quinolones

We studied the frequency of mutation of clinical isolates of Neisseria gonorrhoeae (two nalidixic acid susceptible and two nalidixic acid resistant), and the stability of the mutants obtained, in the presence of three different concentrations of five fluoroquinolones. The frequency of mutation was low for all the quinolones. Only one N. gonorrhoeae mutant, obtained with trovafloxacin at 4 x MIC presented a stable increase in the MIC of this quinolone, not attributable to novel mutation(s), both in the gyrA and parC genes, although not showing any increase in the MIC of the other quinolones tested. In summary, gemifloxacin was the only quinolone tested for which resistant mutants were not obtained.

Detection of unsuspected cases of nosocomial transmission of tuberculosis by use of a molecular typing method

The aim of this study was to use restriction fragment length polymorphism to detect unsuspected cases of nosocomial transmission of tuberculosis (TB) among patients who had been admitted to a university hospital. One hundred fifty-one samples of Mycobacterium tuberculosis isolated from patients with pulmonary TB were studied. The isolates from 37 patients (24.5%) defined 11 clusters. None of the patients infected with these cluster isolates had hospital stays that coincided with one another, and for 5.4% of the patients, the epidemiological link was clearly outside the hospital. Previous incarceration was associated with infection with cluster isolates. In addition, 109 patients without TB (41 of whom were infected with human immunodeficiency virus) who shared a room with patients who had TB were followed for 18-60 months. Among the patients who survived, secondary cases of TB due to nosocomial transmission were not detected.

New rapid antigen test for diagnosis of pneumococcal meningitis

Conventional diagnostic methods for bacterial meningitis are frequently not rapid or sensitive enough to guide initial antimicrobial therapy. Streptococcus pneumoniae is the most frequent and severe cause of community-acquired bacterial meningitis and treatment is complicated by the increasing prevalence of antimicrobial resistance to third-generation cephalosporins. We used a new rapid antigen test in the cerebrospinal fluid and urine of patients with suspected bacterial meningitis, and found it to be highly sensitive and specific for the detection of pneumococci. This test might help guide initial therapy for bacterial meningitis according to the local rates of pneumococcal antimicrobial resistance.

Clinical evaluation of an in-house IS6110 polymerase chain reaction for diagnosis of tuberculosis

The aim of this study was to clinically validate a heminested polymerase chain reaction (PCR) method, based on the IS6110 insertion segment of Mycobacterium tuberculosis complex, for the diagnosis of tuberculosis. Samples of pulmonary, extrapulmonary and blood origin were collected prospectively from 331 patients. All samples were processed to detect acid-fast bacilli by direct stain, culture and PCR. The gold standard comparison was a clinically based final case definition of tuberculosis corresponding to group 3 of the American Thoracic Society's classification system. The sensitivities of stain, culture and PCR were 41%, 65% and 59%, respectively. Overall specificity exceeded 97% for all techniques. The combination of PCR and direct stain achieved a sensitivity similar to that of culture alone. The PCR method detected 74 of 95 (78%) culture-positive results. In a hospital setting, PCR could be a useful, reliable tool for diagnosis of tuberculosis and may be introduced as a complementary routine diagnostic laboratory method.

[Bacteremia and meningitis caused by Yersinia spp]

Yersinia spp infection in human people are increasing attention last thirty years. We have reviewed the bacteremia in our hospital last five years. Three episodes were Yersinia spp bacteremia. Presence of disease or predisponent therapy were present in most of episodes. All patients were more than seventy years old. The septic metastasis were present in all the cases: one with meningitis, other with liver abscess and one with septic arthritis. We have documented a good clinical evolution, though the mortality in different reports is around 50%. The election therapy for all episodes were cephalosporins, and in two cases we added quinolones.

[Dating anti-Toxoplasma IgM in pregnancy using VIDAS-ELFA methods]

BACKGROUND

To study the usefulness of IgG and IgM titration, and avidity of IgG to date IgM anti-Toxoplasma gondii.

METHODS

VIDAS Toxo IgG, VIDAS Toxo IgM and VIDAS Toxo IgG Avidity tests were used. 64 sera containing both IgM and IgG T. gondii antibodies were analyzed, 32 from 12 individuals infected 40 weeks previously (group I), and the remainder from 17 individuals with an infection of more than 40 weeks (group II).

RESULTS

An IgM index < 1.05 was associated with an infection > 12 weeks. An avidity index > 0.164 excluded 100% infections of < or = 12 weeks. Avidity indexes > 0.26 and 0.45 excluded infections of < or = 20 and < or = 40 weeks, respectively.

CONCLUSIONS

The serology methods used in this study can adequately identify residual IgM anti-T. gondii, often avoiding the need of a new blood extraction to analyze IgG kinetics in pregnant women.

Decreased production of AmpC-type beta-lactamases associated with the development of resistance to quinolones in Citrobacter freundii strains

The effect of fluoroquinolones in Citrobacter freundii strains that results in a decreased expression of cephalosporin-hydrolysing beta-lactamases was studied. Resistance to broad-spectrum cephalosporins and penicillins in two C. freundii clinical isolates was associated with moderate production of chromosomal AmpC-type-beta-lactamase in addition to changes in the outer membrane proteins profile with respect to wild-type C. freundii strains. Ten quinolone-resistant mutants were derived from the two clinical isolates using increasing fluoroquinolone concentrations. The level of susceptibility to cephalosporins and meropenem of these 10 mutants was increased and was associated with a 3.6-32% diminution in the hydrolyzing activity of their periplasmic extracts containing beta-lactamases on cephaloridine as compared with those from their parent strains. Susceptibility to cephalosporins and meropenem, as well as the expression of chromosomal AmpC-type-beta-lactamase in C. freundii strains, was influenced by the exposure to quinolones.

Decreased permeability and enhanced proton-dependent active efflux in the development of resistance to quinolones in Morganella morganii

Five quinolone-resistant strains were developed from a clinical Morganella morganii isolate (M1 strain) which was susceptible to nalidixic acid and fluoroquinolones. All five in vitro selected mutants showed diminished norfloxacin accumulation and two of them also decreased the expression of the AgO in the outer membrane lipopolysaccharide with respect to their parent strain and to the M. morganii NCTC-235 type strain. Likewise, the M1 strain did not express a 37-38 kDa protein and accumulated less norfloxacin than the M. morganii NCTC-235 strain. The decreased norfloxacin uptake in the five mutants compared with the M. morganii NCTC-235 strain was due to an enhanced proton-dependent active efflux plus a pre-existent decreased expression of a 37-38 kDa protein in the parent strain.

Single-tube balanced heminested PCR for detecting Mycobacterium tuberculosis in smear-negative samples

In order to achieve more sensitive and specific results for the rapid diagnosis of tuberculosis, we have developed a new method, named balanced heminested PCR, which avoids the inconvenience of asymmetric amplification and has the advantages of single-tube heminested PCR. This was achieved by replacing the outer primer that participates in both rounds of amplification in the standard heminested technique by another primer containing the sequence of the inner primer attached at its 5' end. When both techniques were tested for the IS6110 target of Mycobacterium tuberculosis complex in 80 smear-negative culture-positive sputum samples and 60 control samples, the results showed 100% specificity for both techniques and sensitivities of 60 and 75% for heminested PCR and balanced heminested PCR, respectively (P = 0.02). In conclusion, the balanced heminested technique shows a higher sensitivity than that of the standard heminested, and it could be applied to any PCR by attaching the inner primer at the 5' end of the opposite outer primer. Thus, the balanced heminested technique provides a target for the inner primer in both strands, avoiding asymmetric amplification and thereby resulting in a more efficient amplification, and, in practice, a higher sensitivity without loss of specificity and with a minimum risk of cross-contamination.

Pathogenic significance of methicillin resistance for patients with Staphylococcus aureus bacteremia

To assess whether methicillin resistance is a microbial characteristic associated with deleterious clinical outcome, we performed a cohort study on 908 consecutive episodes of Staphylococcus aureus bacteremia and a case-control study involving 163 pairs of patients matched for preexisting comorbidities, prognosis of the underlying disease, length of hospitalization, and age. Of 908 bacteremic episodes, 225 (24.8%) were due to methicillin-resistant S. aureus (MRSA). Multivariate analysis did not reveal that methicillin resistance was an independent predictor for mortality when shock, source of bacteremia, presence of an ultimately or rapidly fatal underlying disease, acquisition of the infection in an intensive care unit (ICU), inappropriate empirical therapy, female sex, and age were taken into account. Nonetheless, methicillin resistance was an independent predictor for shock. The case-control study could not confirm that shock was linked to MRSA when prior antimicrobial therapy, inappropriate treatment, ICU residence, and female sex were considered. Our data suggest that cohort studies tend to magnify the relationship of MRSA with clinical markers of microbial pathogenicity and that this effect is a shortcoming of these kind of studies that is caused by inadequate control for underlying diseases.

Resolution of high-molecular-weight components in lipopolysaccharides of Escherichia coli, Morganella morganii, Citrobacter freundii and Citrobacter diversus strains with sodium dodecyl sulfate polyacrylamide gels

The use of 0.5% sodium dodecyl sulfate in polyacrylamide separation gels allowed the resolution in several bands of high-molecular-mass components in smooth lipopolysaccharide of bacterial outer membrane from Escherichia coli, Morganella morganii, Citrobacter freundii and Citrobacter diversus. With or without 0.1% SDS, however, such a result was not possible.

Mechanisms involved in the development of resistance to fluoroquinolones in Escherichia coli isolates

Eighteen quinolone-resistant isolates of Escherichia coli were selected by exposing ten clinical isolates to increasing concentrations of norfloxacin and lomefloxacin. The mutant isolates showed a multiple-antibiotic-resistance phenotype. All of them contained single mutations in gyrA consisting of the substitution of Ser-83-->Leu (n = 14), Val (n = 1) or Ala (n = 1) and the substitution of Asp-87-->Asn (n = 2). Only one concomitant mutation in parC (Ser-80-->Arg) was detected. Four parent isolates exhibited a single mutation in gyrA which required < or = 12 mg/L of norfloxacin to be inhibited. Fluoroquinolone resistance, in the 18 quinolone-resistant mutants, was a result of mutations affecting DNA gyrase plus decreased fluoroquinolone uptake. This latter mechanism of resistance was a combined effect of an absence of OmpF and an increase in active efflux in eight isolates, or an increased active efflux alone in the remaining ten selected mutants.

Pseudomonas aeruginosa bacteremia in patients infected with human immunodeficiency virus type 1

A prospective analysis of 43 episodes of Pseudomonas aeruginosa bacteremia in HIV-1-infected subjects was performed and the results compared with the incidence and outcome of Pseudomonas aeruginosa bacteremia in other high-risk patients, such as transplant recipients, leukemia patients, or patients hospitalized in the intensive care unit. The incidence of bacteremia/fungemia as a whole and of gram-negative and Pseudomonas aeruginosa bacteremia in particular was greater in HIV-1-infected subjects than in the unselected general population admitted. In contrast, the incidence of Pseudomonas aeruginosa bacteremia in HIV-1-infected patients did not differ from that in patients with other high-risk conditions. In patients with HIV-1 infection, independent risk factors for presenting Pseudomonas aeruginosa bacteremia were nosocomial origin (OR, 2.7; 95% CI, 1.3-5.7), neutropenia (OR, 2.7; 95% CI, 1.07-6.8), previous treatment with cephalosporins (OR, 3.6; 95% CI, 1.1-11.6), and a CD4+ cell count lower than 50 cells/mm3 (OR, 3.1; 95% CI, 1.7-8.6). Primary bacteremia and pneumonia were the most common forms of presentation. Fourteen (33%) patients died as a consequence of the bacteremia. The presence of severe sepsis (OR, 17.5; 95% CI, 3.2-68) and the institution of inappropriate definitive antibiotic therapy (OR, 2.7; 95% CI, 1.1-13) were independently associated with a poor outcome. One year after the development of bacteremia, only eight (19%) patients remained alive.

Molecular evidence of mother-to-infant transmission of hepatitis G virus among women without known risk factors for parenteral infections

Hepatitis G virus (HGV) RNA was detected in 18 of 133 pregnant women from Tanzania without known risk factors for HGV infection and in 7 of 18 children born to HGV RNA-positive mothers. Molecular evidence of mother-to-infant transmission was obtained only for three of seven children. HGV RNA was also detected in 4 of 42 children born to non-HGV-infected women. Thus, mechanisms other than materno-filial may play an important role in HGV transmission during early childhood.

[Typification of strains of Helicobacter pylori by the detection of the cagA gene and subtypes of the vacA gene]

BACKGROUND

Helicobacter pylori infection is probably the most common chronic bacterial infection in the world. The consequences of infection are pathologies like peptic ulcer, chronic gastritis, gastric cancer and gastric MALT lymphoma. The aim of this study was to detect the vacuolating cytotoxin gene (vacA) type, the cytotoxin-associated gen (cagA) of H. pylori isolates and study their association with the vacuolising activity.

MATERIAL AND METHODS

Gastric biopsy specimens were obtained from dyspeptic patients. Isolates were further genotypically typed by PCR.

RESULTS

All strains studied were vacA+ and 55% were cagA+. All cytotoxic strains were cagA+, subtype vacA s1/m1 and corresponded to patients with peptic ulceration. The cagA- strains (11) corresponded to subtype s2/m2. We didn't demonstrate vacuolising activity on subtypes s1/m2 and s2/m2.

CONCLUSIONS

A high genetic diversity exists among strains in our environment. The subset of bacteria, vacA s1/m1/cagA+, is associated with vacuolising activity in culture cells (tox+).

Relationship of the genomic complexity of hepatitis C virus with liver disease severity and response to interferon in patients with chronic HCV genotype 1b infection [correction of interferon]

In patients with chronic hepatitis C, the influence of the genetic heterogeneity of the hepatitis C virus (HCV) on the progression of liver disease and on the responsiveness to interferon therapy is a matter of controversy. In this study we evaluated the genetic complexity of HCV by single-strand conformation polymorphism (SSCP) analysis of amplicons from the hypervariable region 1 (HVR1) in 168 patients with chronic genotype 1b HCV infection, of whom 122 received a single course of interferon therapy (3 MU, three times weekly for 6 months). No correlation was observed between the degree of genetic complexity of HCV (indicated by the number of bands in the SSCP assay) and patient age, serum alanine aminotransferase activity, or serum HCV-RNA concentration, measured by competitive polymerase chain reaction. HCV genomic complexity was not related to gender nor to the presumed source of infection. The number of SSCP bands detected in serum samples from patients with chronic hepatitis, either mild (8.1 +/- 3.9), moderate (8.0 +/- 3.3), or severe (9.2 +/- 3.3), and in patients with liver cirrhosis, either compensated (8.0 +/- 2.9), decompensated (6.3 +/- 2.9), or with superimposed hepatocellular carcinoma (9.5 +/- 2.9), was similar. The number of SSCP bands detected in patients with sustained response (7.5 +/- 3. 9), transient response (8.3 +/- 2.9), or no response (8.2 +/- 3.6) to interferon administration was similar as well. These observations suggest that the genetic complexity of hypervariable region (HVR1) of HCV, as estimated by SSCP analysis, is not related to the severity of liver injury nor to the type of response to interferon therapy. Thus, information offered by SSCP analysis of HVR1 of HCV in chronic HCV genotype 1b infection does not appear to be useful in the clinical management of these patients. (HEPATOLOGY 1999;29:897-903.)

[In vitro activity of fluoroquinolones and oral beta lactam antibiotics against clinical isolates of Escherichia coli]

We studied the in vitro activity of amoxicillin-clavulanic acid, cefprozil, cefuroxime, cefpodoxime, ceftibuten, cefixime, ciprofloxacin and sparfloxacin against 400 strains of Escherichia coli. The strains were obtained from urine cultures from patients with community acquired urinary tract infection who were treated in our hospital in 1997 and 1998. Among the six betalactams, ceftibuten and cefixime were the most active in vitro with MIC90 of 0.5 mg/l. Both antimicrobials were 2- and 16-fold more active than cefpodoxime (MIC90 1 mg/l) and cefprozil (MIC90 8 mg/l), respectively. However, overall, the four cephalosporins inhibited between 95% and 99% of isolates. Cefuroxime and amoxicillin-clavulanic acid showed less activity with a MIC90 of 16 mg/l. The percentage of fluoroquinolone-resistant strains was 24% with a similar activity to ciprofloxacin (MIC90 32 mg/l) and sparfloxacin (MIC90 64 mg/l).

Use of microscopic morphology in smears prepared from radiometric cultures for presumptive identification of Mycobacterium tuberculosis complex, Mycobacterium avium complex, Mycobacterium kansasii, and Mycobacterium xenopi

The aim of this study was to assess the feasibility of a method for presumptive identification of mycobacteria, based on the morphology in smears prepared from radiometric Bactec-positive cultures (Becton Dickinson, USA) and to select the appropriate DNA probe (AccuProbe; Gen Probe, USA). The smear morphology of acid-fast bacilli was evaluated in 468 positive cultures from clinical samples: 313 Mycobacterium tuberculosis complex, 67 Mycobacterium avium complex, 32 Mycobacterium kansasii, 49 Mycobacterium xenopi, and seven Mycobacterium gordonae. The sensitivity and specificity for various morphological patterns were as follows: cord formation for Mycobacterium tuberculosis complex 90% and 100%, respectively; striped bacilli for Mycobacterium kansasii, 66% and 99%; sea urchin for Mycobacterium xenopi, 96% and 99%; short bacilli for Mycobacterium avium complex, 61% and 99%; fine-striped bacilli associated with Mycobacterium avium complex from blood samples, 33% and 98%. This criterion was applied in the selection of a suitable DNA probe for the identification of 178 cultures. The correct probe was selected in 98%, 97%, and 72% of cultures, respectively, for Mycobacterium tuberculosis complex, Mycobacterium avium complex, and Mycobacterium kansasii. The observation of acid-fast bacilli morphology in radiometric cultures is a rapid and cost-efficient method for presumptive identification of common clinical isolates of mycobacteria.

Hepatitis G virus infection in chronic liver disease

BACKGROUND

The hepatitis G virus (HGV), a recently identified member of the Flaviviridae family, can cause chronic infection in man but the role of this agent in chronic liver disease is poorly understood.

AIMS

To evaluate the prevalence and meaning of HGV infection in a large series of patients with chronic liver disease.

SUBJECTS

Two hundred volunteer blood donors, 179 patients with chronic hepatitis C, 111 with chronic hepatitis B, 104 with alcoholic liver disease, 136 with hepatocellular carcinoma, and 24 with cryptogenic chronic liver disease were studied.

METHODS

HGV RNA was investigated in serum samples by reverse transcription and polymerase chain reaction amplification of the 5' non-coding region of HCV and hybridisation to a specific probe. The main features of HGV RNA seropositive and seronegative patients were compared.

RESULTS

The prevalence of HGV infection was 3% in blood donors, 7% in chronic hepatitis C, 8% in chronic hepatitis B, 2% in alcoholic liver disease, 4% in hepatocellular carcinoma, and 8% in cryptogenic chronic liver disease. HGV infected patients tended to be younger than non-infected patients but no differences concerning sex, possible source of infection, clinical manifestations, biochemical and virological parameters, or severity of liver lesions were found.

CONCLUSIONS

The prevalence of HGV infection in chronic liver disease seems to be relatively low in our area. Infection with HGV does not seem to play a significant pathogenic role in patients with chronic liver disease related to chronic HBV or HCV infection or to increased alcohol consumption, or in those with cryptogenic chronic liver disease.

Hepatitis C virus (HCV) genotypes in Spanish patients with HCV infection: relationship between HCV genotype 1b, cirrhosis and hepatocellular carcinoma

BACKGROUND/AIMS

The influence of the infecting virus genotype on the progression of the underlying liver disease in patients with chronic hepatitis C virus (HCV) infection remains controversial. The aim of this study was to investigate the prevalence of HCV genotypes in Spanish patients with chronic HCV infection and to elucidate the relationship between the infecting genotype and the severity of the disease.

METHODS

A cross-sectional, retrospective analysis of frequency distribution of HCV genotypes was carried out in 414 Spanish patients with chronic HCV infection, including 243 patients with asymptomatic or minimally symptomatic chronic hepatitis, 112 patients with cirrhosis and hepatocellular carcinoma and 59 patients with decompensated cirrhosis. HCV genotype was determined by restriction fragment length polymorphisms of the 5' non-coding region.

RESULTS

Infection with HCV genotype 1b was found in 72% of patients with chronic hepatitis and in more than 90% of patients with cirrhosis, with or without hepatocellular carcinoma. Older age, infection with genotype 1b and absence of overt parenteral exposure as a possible source of infection were associated with cirrhosis and hepatocellular carcinoma by univariate analysis and this association was confirmed by regression analysis.

CONCLUSIONS

HCV genotype 1b is associated with advanced liver disease in our geographical area. However, this may be related to a cohort-effect caused by over-representation of genotype 1b in older patients with more advanced disease, because, in our country, this HCV genotype appeared earlier in time and is therefore associated with more prolonged periods of infection.

Hepatitis G virus infection in fulminant hepatic failure

BACKGROUND

RNA sequences of the recently identified hepatitis GB virus C (HGBV-C), also named hepatitis G virus (HGV), have been detected in patients with idiopathic fulminant hepatic failure (FHF) but the role of this agent in the disease remains controversial.

AIMS

To investigate the presence and implications of HGV infection in a large series of Spanish patients with FHF.

PATIENTS

Sixty eight patients with FHF, including 19 with idiopathic disease, were studied. In 28 cases, studies were performed before and after liver transplantation. For comparison 200 volunteer blood donors and 22 patients transplanted for chronic liver disease were also studied.

METHODS

HGV RNA was measured in serum by reverse transcriptase polymerase chain reaction of the 5' non-coding region.

RESULTS

Evidence of HGV infection was found in 3% (6/200) of blood donors and in 19% (13/68) of patients with FHF. HGV infection was more frequent in patients with hepatitis B (24%, 6/25) or hepatitis D (42%, 5/12), than in patients with idiopathic disease (11%, 2/19). Half of the patients with HGV infection used illicit intravenous drugs. Specific clinical features associated with HGV infection were not identified. A very high rate of infection with HGV was observed in patients who underwent liver transplantation, either for FHF (60%, 15/24) or chronic liver disease (45%, 9/20).

CONCLUSIONS

In our geographical area, HGV infection is relatively frequent in FHF, but it does not seem to play a major role in idiopathic cases.

Significance of the isolation of Candida species from respiratory samples in critically ill, non-neutropenic patients. An immediate postmortem histologic study

The diagnosis of pulmonary candidiasis is still controversial. We undertook a prospective study on 25 non-neutropenic, mechanically ventilated (> 72 h) patients who died in our ICU with the aim of assessing the incidence and significance of the isolation of Candida species from quantitative cultures of immediate postmortem lung biopsies and different respiratory sampling techniques. Immediate postmortem respiratory samples (endotracheal aspirate, protected specimen brush [PSB], bronchoalveolar lavage [BAL], blind biopsies [average 14/patient], and bilateral bronchoscopically guided biopsies [two per patient]) were taken from all patients. Lung tissue specimens were histologically examined. Respiratory samples were classified as having Candida or otherwise. Ten (40%) patients had at least one pulmonary biopsy yielding Candida spp. Among these 10 patients with Candida isolates, only two had definite pulmonary candidiasis. A total of 470 microorganisms were isolated from 280 of 375 (77%) lung biopsy samples in all 25 patients. Candida species represented 9% (n = 40) of the isolates, corresponding to 10 patients (40%). In the 10 patients in whom Candida species was isolated from pulmonary biopsies, this was always associated with the isolation of the same microorganism from one of the sampling methods. Quantitative cultures of Candida species from different sampling methods correlated well among each other but could not discriminate the presence from absence of Candida pneumonia. A logistic regression model adjusted for the presence of antibiotics, days of antibiotic treatment, mechanical ventilation period, age, ARDS, parenteral nutrition, and gender did not show any independent risk factor for developing positive pulmonary samples for Candida species. The incidence of Candida isolation from pulmonary biopsies in critically ill mechanically ventilated, non-neutropenic patients who die is high (40%). However, the incidence of definite Candida pneumonia was 8%. We also found that Candida colonization is uniform throughout the different lung regions, and that the presence of Candida in respiratory samples, independently of quantitative cultures, is not a good marker of Candida pneumonia in critically ill, non-neutropenic, non-AIDS patients.

Antibodies to mycobacterial 65-kD heat shock protein cross-react with the main mitochondrial antigens in patients with primary biliary cirrhosis

Primary biliary cirrhosis (PBC) is a chronic cholestatic liver disease associated with autoimmune disorders. The aetiology is unknown, although it has been suggested that the disease may be related to infectious agents. Previous studies revealed that sera from patients with PBC react against Mycobacterium gordonae. This specific reactivity, characterized by a recognition of two membrane polypeptides of 70-65 and 55 kD, cross-react with the two major mitochondrial autoantigens of PBC. As the most immunogenic components of mycobacteria are the heat shock proteins (hsp), which have been associated with autoimmunity, this study has been undertaken to characterize whether the reacting polypeptides in PBC are hsp from M. gordonae. Cultures of M. gordonae were incubated at 37 degrees C and 46 degrees C before sonication, protein extraction and separation by SDS-PAGE. Exposure of M. gordonae to heat shock treatment resulted in membrane protein overexpression, similar to the 70-65-kD polypeptide recognized by the sera from patients with PBC. Immunoprecipitation assays with a monoclonal antibody directed against the Hsp65 kD of mycobacteria and with sera from patients with PBC revealed similar reacting profiles characterized by the precipitation of the overexpressed 65-kD polypeptide from M. gordonae. Competitive immunoblotting showed that binding of the monoclonal antibody to the Hsp65 kD protein was prevented by preincubation with sera from patients with PBC, but not with sera from healthy subjects. Furthermore, monoclonal antibody to the Hsp65 kD protein recognized the main mitochondrial autoantigens of PBC (PDH-E2 and BCKDH-E2). These data indicate the existence of cross-reacting epitopes contained on M. gordonae Hsp65 kD and the main mitochondrial antigens in patients with PBC.

Risk factors for oxacillin/methicillin resistance in coagulase-negative staphylococci

The clinical variables associated with isolation of oxacillin- and methicillin-resistant, coagulase-negative staphylococci (CNS) from blood cultures of hospitalized patients were studied. One hundred CNS strains (49 oxacillin-susceptible; 51 oxacillin-resistant) isolated consecutively from one of two or more sets of blood cultures were collected. Only two variables were independently associated with recovery of oxacillin/methicillin-resistant strains by a multivariate analysis: length of hospital stay > 10 days (OR 5.2, 95% CI = 1.7-15.7), and administration of antimicrobial agents in the previous 14 days (OR 4.5, 95% CI = 1.7-11.7). Analysis of the antibiotics administered indicated that only beta-lactams were associated with a statistically significant risk of resistance to oxacillin/methicillin (OR of beta-lactams vs no antibiotics = 6.94, 95% CI = 1.9-25.3; OR of non-beta-lactams vs no antibiotics = 2.64, 95% CI = 0.8-8.3). Length of hospital stay (especially > 10 days) and prior administration of antimicrobial agents (mainly beta-lactams) independently predicted the presence of oxacillin/methicillin-resistant CNS in blood cultures.

[Antibiotic treatment of acute gastroenteritis]

The empiric antibiotic therapy for acute gastroenteritis (AGE) is indicated only in patients with underlying diseases or risk for bacteremia. The clinical characteristics, clinical efficiency of antibiotic therapy with pivmecillinam (52 patients) or ciprofloxacin (75 patients) and its effects on the fecal carrier state of Salmonella spp. were studied in 127 adult patients with AGE and antibiotic therapy indication. The initial stool culture was positive in 90 patients (71%). The microorganism recovered most frequently was Salmonella spp., with a bacteremia rate in these patients of 5%. The susceptibility of Salmonella spp. to ciprofloxacin and mecillinam was 100% and 90%, respectively. Therapy with ciprofloxacin or pivmecillinam showed a similar efficiency. Fecal excretion lasted no longer than five weeks and no chronic carriers were observed.

Hepatitis G virus infection in chronic hepatitis C: frequency, features and response to interferon therapy

BACKGROUND/AIMS

The pathogenic relevance of the hepatitis G virus (HGV) and its sensitivity to interferon are currently under investigation. This study aimed to investigate the prevalence of HGV infection in patients with chronic hepatitis C and to elucidate if HGV co-infection modifies the clinical course and the response to interferon therapy in this disease.

METHODS

HGV-RNA was investigated by reverse transcription-polymerase chain reaction in serum from 143 consecutive patients who received interferon alpha-2b (3 MU t.i.w.) for 24 weeks. Baseline features and response to therapy in HGV-infected and non-infected patients were compared. To assess the antiviral effect of interferon, serial quantitative measurement of HCV-RNA and HGV-RNA in serum was performed in patients co-infected with HCV and HGV.

RESULTS

Eight patients (5.6%) presented HGV-RNA sequences in serum. No significant differences were found between HGV-infected and non-infected patients in relation to age, sex, source of infection, liver function tests, liver histology and HCV genotype, nor in the biochemical response to interferon, which was sustained in 12% and 15%, transient in 37% and 30% and absent in 50% and 55% of HGV-infected and non-infected patients, respectively. HGV-RNA became negative in all treated patients, but sustained viral inhibition was observed only in those with low viral load.

CONCLUSIONS

The prevalence of HGV infection in HCV-infected patients is relatively low in our geographical area. HGV co-infection does not appear to modify the clinical presentation nor the response to interferon in chronic hepatitis C. HGV is sensitive to interferon, particularly if pre-treatment viral load is low.

Low dose alpha interferon therapy can be effective in chronic active hepatitis C. Results of a multicentre, randomised trial

BACKGROUND

There is some controversy concerning the efficacy of low dose alpha interferon therapy in chronic hepatitis C.

AIMS

To evaluate the effectiveness of treatment with low doses of alpha interferon in chronic hepatitis C.

PATIENTS

One hundred and forty one patients with anti-HCV positive chronic active hepatitis C from six hospitals were enrolled in the study.

METHODS

Patients were randomised to treatment with 5 MU (group A) or 1.5 MU (group B) injections. The dose was reduced in responders from group A or increased in non-responders from group B to maintain treatment with the minimal effective dose. Patients were treated for 48 weeks and followed up for 24 additional weeks with no treatment. Normalisation of alanine aminotransferase (ALT) was used to evaluate response.

RESULTS

A sustained response was seen in eight patients from group A (12%) and in 15 (21%) from group B. This difference was not statistically significant. Increasing the dose of interferon led to sustained response in only five of 58 patients (9%) from group B who did not respond to 1.5 MU injections. In contrast, 15 of 21 patients (71%) in whom ALT remained normal with 1.5 MU injections developed a sustained response. By multivariate analysis sustained response seemed associated with young age and was more frequent in patients with genotype 3 HCV infection. Sustained response was preceded by a rapid normalisation of ALT and was inversely related to the amount of alpha interferon necessary to maintain ALT at low values during treatment.

CONCLUSIONS

Some patients with chronic hepatitis C are very sensitive to alpha interferon and can be successfully treated with low doses. Treatment with higher doses may be effective in a minority of patients who do not respond to low doses.

A pilot case-control study of zidovudine compared with zidovudine plus didanosine in patients with advanced HIV-1 disease and no previous experience with antiretrovirals

Although zidovudine (ZDV) is effective in HIV-1-infected patients, the duration of its efficacy may be short when treatment is started in advanced HIV disease. This pilot prospective case-control study was designed to evaluate the combination of ZDV plus didanosine [ddI] compared with ZDV monotherapy as an initial therapeutic strategy. 'Control' patients (ZDV monotherapy) were matched with 'case' patients (ZDV plus ddI combination therapy) according to the presence or absence of AIDS-defining criteria at entry and CD4 cell count. The case patient group consisted of 35 consecutive HIV-1-infected individuals with < or = 300 CD4 cells/mm3, no previous experience of antiretroviral therapy and who accepted treatment with a combination of ZDV plus ddI. The control patient group consisted of 35 consecutive patients with similar characteristics, but who preferred to start treatment with ZDV alone. Control patients received 250 mg ZDV bid and case patients received ZDV at the same dose plus ddI (200 mg bid). Primary study endpoints were virological (serum HIV-1 RNA) and immunological (CD4 cell count) responses. Viral phenotype (syncytium-inducing (SI) or non-syncytium-inducing (NSI)), development of mutations at codons 215, 41 and 74 and clinical progression (new AIDS-defining event or death) were also assessed. Virological and CD4 cell count responses were significantly greater and more sustained in the group treated with ZDV plus ddI than in the control group, with peak responses of -1.2 +/- 0.7 log10 versus -0.3 +/- 0.4 log10 at 1 month (P = 0.0003) and 61 +/- 52 cells/mm3 versus 19 +/- 25 cells/mm3 at 2 months (P = 0.001), respectively. In both groups the percentage of patients developing a mutation at codon 215 was around 80 per cent at 12 months. A mutation at codon 74 was detected in 30 per cent of case patients at 12 months. Five case patients (14 per cent) versus 12 control patients (34 per cent) showed signs of clinical progression (P = 0.09). In a multivariate model, clinical progression was significantly associated with a baseline

[Relationship between Epstein-Barr virus and lymphoproliferative syndromes in patients without immunodeficiency]

PURPOSE

The relationship between Epstein-Barr virus (EBV) and infectious mononucleosis, pharyngeal carcinoma and Burkitt's lymphoma is well known. Further relationship seems to exist between EBV and the lymphoproliferative syndromes appearing in immunodeficient subjects. The present work is aimed to study the possible relationship between the virus and the lymphoproliferative syndromes presented by people without any apparent immunodeficiency.

PATIENTS AND METHODS

The presence of antibodies against different antigens of the virus was analysed. Antibodies against the viral capsid antigen were studied along with those against the early antigen and the viral core antigen in 55 patients with lymphoproliferative syndromes, of whom 38 had non-Hodgkin's lymphoma and 17 had acute lymphoblastic leukaemia, and none of them had immunodeficiency.

RESULTS

Significantly higher geometric means of the titres against capsid antigen and of the prevalence of antibodies against early antigen were seen in the patients with non-Hodgkin's lymphoma with respect to the control group. On the contrary, patients with acute lymphoblastic leukaemia showed lower immunologic response than the control group, although the difference was not significant for any of the antibodies under study.

CONCLUSIONS

The higher immunologic response against EBV and its reactivation in non-Hodgkin's lymphoma would suggest that such agent could play a role favouring the onset of the disease, if not as a direct aetiological factor.

Comparison of rufloxacin and norfloxacin effects on faecal flora

The suppression of faecal Escherichia coli by quinolones was studied in a randomized cross-over phase I trial with single oral doses of 400 mg rufloxacin or norfloxacin. Both drugs caused > 70% decontamination in a similar number of subjects in the 72 h post-dose period (83% vs 100% respectively), but suppression of E. coli at 168 h was significantly (P < 0.05) higher after rufloxacin (83.3 vs 40%).

The incidence of human parvovirus B19 infection during pregnancy and its impact on perinatal outcome

A prospective study of parvovirus B19 infection during pregnancy was conducted at a large teaching hospital in Barcelona, Spain. Women (1610) who were < 28 weeks pregnant at enrollment were screened for parvovirus infection. The prevalence of IgG positivity was 35.03% (564/1610). The incidence of acute infection during pregnancy was 3.7% (60/1610). There were five abortions among the B19-infected women but only one was caused by parvovirus, as assessed by histologic examination and polymerase chain reaction assay. The incidence of fetal loss caused by parvovirus was, therefore, 1.66% (1/60). The remaining 55 pregnancies were uneventful, and at 1 year of age, none of the infants had serious abnormalities. The incidence of vertical transmission of infection was estimated at 25%. This study provides evidence that although acute parvovirus infection may occur relatively commonly during pregnancy, an adverse fetal outcome is a rare complication.

Lack of relationship between human immunodeficiency virus infection and systemic lupus erythematosus

The objective of this work was to determine whether HIV-1 and HIV-2 could be involved in the pathogenesis of systemic lupus erythematosus (SLE). Seventy-five consecutive Caucasian patients with SLE presenting at one institution over a 2-year period were studied. Serum samples were surveyed for anti-HIV-1 antibodies by a commercial ELISA coated with HIV-1-p24. For confirmation, conventional immunoblots were performed with the following antigens: HIV-1-gp41, p31, p24 and p17 (recombinant) and HIV-2-gp36 (synthetic peptide). Additionally, Western blots with HIV-1-gp160, gp120, gp41, p65, p51, p24 and p18 bands were applied. Seventeen (23%) patients exhibited reactivity with HIV-1-p24 in the ELISA, but in the immunoblots and Western blots these sera samples were negative. Patients with SLE may exhibit a reactivity with HIV-1-p24 in the ELISA for HIV infection screening but not in the confirmatory blots. This false-positive reactivity is probably due to molecular mimicry between autoantigens and retroviruses or a contaminant or artefacts in the antigen preparation procedure.

[Seroepidemiology of hepatitis C virus infection in pregnant women in Catalonia]

BACKGROUND

The aim of this study was to investigate the prevalence of hepatitis C virus (HCV) infection in a population of pregnant women in Catalonia and the sociodemographic variables and risk factors associated to this prevalence.

METHODS

A representative sample of the pregnant women in Catalonia (n = 4,551) randomly selected by clusters (hospitals with maternity clinics) was studied. Detection of antiHCV antibodies was performed by the third generation ELISA test. Reactive cases were confirmed with RIBA 3 and MATRIX.

RESULTS

The prevalence of antiHCV was found to be 1% and was not significantly associated with any of the sociodemographic variables studied (age, social and cultural level, origin and residence). A history of blood transfusion, intravenous drug consumption and hepatitis in the sexual partner were the only risk factors associated with the prevalence of infection found on univariate analysis although these were only present in 47% of the antiHCV positive cases detected. The association between the positivity of antiHCV and the history of hepatitis in the partner was lost on stratification of the cases according to the possible existence of history of drug addiction.

CONCLUSIONS

A high proportion of young asymptomatic people (1%) were found to have hepatitis C virus infection with the possible mode of infection not being detected in approximately half of these subjects. In the other half of these cases the infection was found to have been acquired by an intravenous mechanism: blood transfusion or drug use.

Cross-reactivity of anti-Mycobacterium gordonae antibodies with the major mitochondrial autoantigens in primary biliary cirrhosis

Primary biliary cirrhosis is a chronic cholestatic liver disease associated with autoimmune disorders. Antimitochondrial autoantibodies and granulomatous portal lesions are characteristic in primary biliary cirrhosis. Since granuloma may be induced by Mycobacteria, and there is evidence implicating Mycobacteria as infectious agents capable of initiating autoimmunity, a study was performed to determine the presence of antibodies against 10 atypical Mycobacteria in 19 patients with primary biliary cirrhosis, and in 35 controls (25 patients with other chronic liver diseases and 10 healthy subjects). All primary biliary cirrhosis sera and none of the controls reacted with the extract from Mycobacterium gordonae, showing identical recognition profiles with two polypeptides of 70-65 and 55 kDa. No other reaction was found in primary biliary cirrhosis patients and in controls with the extracts from the other nine atypical Mycobacteria tested. Eluted immunoglobulins which reacted with the 70-65 and 55 kDa polypeptides from M. gordonae, bound to the mitochondrial antigens PDH-E2 and BCKDH-E2. Furthermore, when the extract from M. gordonae was tested with eluted immunoglobulins from recognized PDH-E2 and BCKDH-E2 by primary biliary cirrhosis patients, we observed both 70-65 and 55 kDa polypeptides. These data indicate that antibodies to M. gordonae, found in all primary biliary cirrhosis patients, cross-react with the major mitochondrial targets of the disease. We suggest that M. gordonae may play a potential pathogenic role in primary biliary cirrhosis.

[Infection by the human immunodeficiency virus type 1 in the population of prisoners of Catalonia]

BACKGROUND

The prison population represents a high risk group for the human immunodeficiency virus type 1 infection. The present study was carried out to know the prevalence of infection in this collective in three penitentiary centers in Catalonia.

METHODS

All the subjects who were in or who were admitted to the three penitentiaries for men from October 1987 to April 1988 were included in the study (n = 1,579). Demographic risk factor and penitentiary variables were obtained. The determination of anti-HIV-1 antibodies was performed by enzymoimmunoanalysis (Dupont HIV ELISA).

RESULTS

The global prevalence of HIV-1 infection was of 40.6%. Significant statistical differences were found among intravenous drug users (IVDU) and non IVDU (chi 2 = 376.8, p < 0.0001, OR = 9.6, CI 95% = 7.5 - 12.3) and between habitual and sporadic users (chi 2 = 23.9, p < 0.0001, OR = 3.0, CI 95% = 1.9 x 4.7).

CONCLUSIONS

The penitentiary population in Catalonia is a collective with a high prevalence of infection by the human immunodeficiency virus type 1, with intravenous drug use being the fundamental factor associated to this prevalence.