Deep, respiratory tract and ear infections caused by Pseudallescheria (Scedosporium) and Microascus (Scopulariopsis) in Finland. A 10-year retrospective multi-center study

Deep, respiratory tract and ear infections due to Microascaceae (Pseudallescheria, Scedosporium, Microascus or Scopulariopsis) were studied nationwide in Finland during 1993-2002. The data were based on 52,000 fungal cultures that represented about 50% of all such specimens in Finland and included all Finnish cases of profound immunosuppression. There were 39 cases that were re-evaluated as clinically significant, i.e., three pneumonias, two deep pedal infections and five wound infections, 11 sinusitis and 18 ear infections. The pedal infections and most pneumonias occurred in immunocompromised patients. Most cases, except the ear infections, were due to Pseudallescheria boydii. Two patients had lethal P. boydii pneumonia and a deep P. boydii infection of the foot contributed to a third lethal case. Two of the patients with lethal outcomes had received an allogeneic haematopoietic stem cell transplantation (AHSCT). Two patients with haematological malignancies were cured of deep site infections by a prolonged course of itraconazole. Wound, sinus and ear infections were cured or improved by local surgery or topical therapy. There were 0.8-1.7 cases of any type of infection per million inhabitants per year (MY) and 3.4 cases/1000 AHSCT. Mortality associated with Microascaceae in any type of patient was 0.06-0.12 MY.

Diagnostic Value of Bronchoalveolar Lavage in Community-acquired Pneumonia in a Routine Setting: A Study on Patients Treated in a Finnish University Hospital

Only a few previous studies have focused on the use or bronchoalveolar lavage (BAL) in patients with community-acquired pneumonia (CAP). Our aim was to evaluate the diagnostic value of BAL in CAP in a routine clinical setting. 71 disease episodes were retrospectively analysed. The patients had undergone BAL for serious or slowly responding pneumonia. All procedures were performed during antimicrobial treatment of the patient. BAL fluid was cultivated for bacteria, fungi, and viruses. In 68 episodes, 1 or several specific polymerase chain reaction tests were performed. Only 1 (1.3%) quantitative bacterial culture was considered diagnostic for CAP, and indicated a change of antimicrobial treatment. The diagnostic yield increased to 9.8% when other methods were used. A respiratory virus was the only aetiology in 3 (6.0%) patients. In slowly responding pneumonia, also hospital-acquired pathogens and malignancies were identified, resulting in a total diagnostic yield of 20.0%. Thus, even when a large array of diagnostic assays was applied, the value of BAL in pretreated patients with CAP was very small, and its therapeutic implications minimal. In a subgroup of slowly responding pneumonia, the procedure was of some usefulness even after commencement of antimicrobial treatment.

Evaluation of detection of extended-spectrum beta-lactamases among Escherichia coli and Klebsiella spp. isolates by VITEK 2 AST-N029 compared to the agar dilution and disk diffusion methods

A total of 123 clinical Escherichia coli and Klebsiella spp. isolates were included in the study in order to evaluate VITEK 2 AST-NO29 (Nordic) card for detection of extended-spectrum beta-lactamases (ESBL) and to compare the results with genotypic ESBL verification. The results were also compared to alternative phenotypic methods, i.e. agar dilution and disk diffusion. The strains that were ESBL-positive according to AST-N029 were further analysed with the ESBL test card, VITEK 2 AST-N041. Using genotype as reference, Vitek 2 AES had the highest accuracy of the tested methods in classifying the strains as ESBL-positive or -negative (91.1%). When VITEK 2 gave ESBL as the only option for E. coli or K. pneumoniae, 44 of 45 (97.8%) strains had an ESBL gene. VITEK 2 achieved an accuracy of 94.9% and disk diffusion 95.9% compared to the agar dilution method as the phenotypic reference method for the E. coli and K. pneumoniae strains. For the K. oxytoca strains VITEK 2 achieved the highest accuracy (84.0%) of the methods used in this work.

Aetiological diagnosis of community acquired pneumonia: utility of rapid microbiological methods with respect to disease severity

The present study investigated the utility of rapid microbiological methods in the aetiological diagnosis of community acquired pneumonia (CAP) according to the severity of CAP. Between 1999 and 2004, 384 adult patients with CAP were studied prospectively. In addition to standard microbiological methods, PCR and antigen detection techniques were used to identify pathogens. A total of 230 microbial agents in 209 patients were identified, with 134 (58.2%) identified by antigen detection or PCR tests. Of these 134 microbial agents, 95 (70.9%) were identified only by these rapid methods. Streptococcus pneumoniae urinary antigen detection was positive in 24.3% (81/333) of the patients with a diagnostic yield of 38.7% in those with severe pneumonia. Respiratory viral antigen detection was positive in 11.1% (35/314) of the patients with the highest diagnostic yield (20.3%) in patients with severe pneumonia. Mycoplasma pneumoniae PCR was positive in 7.5% (13/174) of the patients, all of whom were low-risk patients. Only 1 case of Chlamydia pneumoniae was identified by PCR. In conclusion, besides yielding the aetiological diagnosis rapidly, new methods add to the total diagnostic yield in CAP. The diagnostic yield of rapid methods differs according to the severity of the pneumonia.

In vitro susceptibility of viridans group streptococci isolated from blood in southwest Finland in 1993-2004

We studied in vitro activity against invasive viridans group streptococci (VGS) of penicillin and 4 newer antibiotics, i.e. telithromycin, linezolid, levofloxacin and quinupristin-dalfopristin. Also 7 other antibiotics were tested. Antibiotic susceptibility of 263 VGS blood isolates, collected from southwest Finland during a 12-y period was determined. We wished to discover whether there is an increasing trend of antimicrobial resistance among VGS in Finland. Our results showed that penicillin is still a good choice for treating VGS infections based on the considerably low resistance percentage, 2.3%. Also newer antibiotics showed good in vitro activity: susceptibilities for telithromycin, linezolid and levofloxacin were 100%, 98.9% and 94.6%, respectively. However, quinupristin-dalfopristin was not as effective as described in previous studies, with only 57% susceptibility.

Evaluation of Vitek 2 for identification of yeasts in the clinical laboratory

The Vitek 2 system was compared with conventional assimilation, fermentation and morphological methods for its ability to identify yeast isolates from among 151 clinical specimens and 16 known type culture or quality control strains. An unequivocal identification was obtained for 155 (92.8%) isolates, with low discrimination for nine (5.4%) and false identification for three (1.8%) isolates. All isolates of Candida albicans, Candida glabrata and Candida krusei were identified correctly. It was concluded that the Vitek 2 system offers an excellent alternative for the identification of yeasts in a clinical laboratory.

The dynamics of bacteria in the middle ear during the course of acute otitis media with tympanostomy tube otorrhea

BACKGROUND

Dynamics of bacteria during acute otitis media (AOM) has not been thoroughly studied because it requires repeated tympanocentesis. AOM with tympanostomy tube otorrhea provides a unique opportunity to study the appearance and disappearance of pathogens during the course of the disease without stressing the child.

METHODS

Middle ear fluid (MEF) samples were taken before treatment (amoxicillin clavulanate or placebo) and then daily during follow-up from 75 children having AOM with otorrhea through a tympanostomy tube. Bacteria were identified by culture, and typical AOM pathogens also by polymerase chain reaction.

RESULTS

Bacteria were initially shown in 67 (89%) children. New bacteria appeared in MEF more often in placebo than in amoxicillin clavulanate recipients [9 of 38 (24%) versus 2 of 37 (5%); P = 0.032]. During the follow-up, new occurrences of Moraxella catarrhalis were detected in MEF more frequently than those of Streptococcus pneumoniae or Haemophilus influenzae. Of the 28 patients with bilateral otorrhea, 11 (39%) had disparate bacteria at study entry and/or during the follow-up.

CONCLUSIONS

Changes in bacterial findings during the course of AOM are common in patients not receiving treatment, and even possible despite adequate treatment. In bilateral otorrhea, disparate bacterial findings are common.

Occurrence of Scopulariopsis and Scedosporium in nails and keratinous skin. A 5-year retrospective multi-center study

A 5-year retrospective multicenter study was performed for microascaceous moulds (Microascaceae, Ascomycetes) in Finnish clinical specimens. The files from 1993-1997 of six clinical mycology laboratories in Finland were searched for reports of these fungi, mainly Scopulariopsis and Scedosporium anamorphs in keratinous specimens. From the 521 primary findings, 165 cases were selected for further study based on direct microscopy, colony numbers and accompanying fungi. The clinical records of 148 cases (141 Scopulariopsis, 7 Scedosporium) were studied. Of the nail infections from which Scopulariopsis was recovered, 39 cases were further separated which showed clinical or laboratory-based evidence of dermatophytosis. In the remaining 90 'non-dermatophyte' nail cases, Scopulariopsis spp. were the only documented fungal agents (c. 6 cases/million/year). The patients were mainly elderly, 66% of whom had problems involving their big toe nails. For 74% of them, the nail problem was mentioned as their reason for visiting the physician. However, only 18% had documented benefit from treatment. The Scopulariopsis nail infections seem to be treatment-resistant and the pathogenesis and etiological role of Scopulariopsis remain poorly understood.

Bacteria and viruses in maxillary sinuses of patients with primary hypogammaglobulinemia

OBJECTIVE

To study bacteria and viruses in maxillary sinuses of patients with primary hypogammaglobulinemia receiving immunoglobulin therapy.

DESIGN

Prospective cross-sectional study during 6 months.

SETTING

Tertiary care university hospital.

PATIENTS

Seventeen patients with primary hypogammaglobulinemia (10 males and 7 females; mean age, 39 years [age range, 11-71 years]). Sixteen patients had common variable immunodeficiency, and 1 patient had X-linked agammaglobulinemia.

MAIN OUTCOME MEASURES

Magnetic resonance imaging and x-ray imaging of paranasal sinuses when patients did not have signs of acute infection and reevaluation 6 months later. Maxillary sinus aspiration and lavage were performed at a follow-up visit. Sinus fluid analysis for bacteria and viruses was performed by culture and by polymerase chain reaction. A questionnaire on symptoms related to sinusitis was administered during the follow-up period.

RESULTS

Among 17 patients, 9 (53%) had radiologically defined sinusitis without subjective symptoms at study enrollment. At reevaluation 6 months later, radiological findings remained unchanged in two thirds of the patients. Among 15 patients, bacteria were found in sinus lavage samples from 13 patients, and viruses were found in samples from 7 patients. Eight patients had 2 pathogens or more on bacterial culture. Rhinovirus was identified from sinus lavage samples in 5 patients (33%), enterovirus in 3 patients (20%), and respiratory syncytial virus in 1 patient (7%). Pathogenic bacteria were found in maxillary sinuses of all patients who tested positive for rhinovirus and enterovirus. No fungi were found. During the follow-up period, 6 patients reported mucopurulent drainage.

CONCLUSIONS

Bacteria and viruses were commonly found in maxillary sinuses of patients with primary hypogammaglobulinemia. Yearly evaluation by an ear, nose, and throat surgeon is recommended.

Identification of alpha-hemolytic streptococci by pyrosequencing the 16S rRNA gene and by use of VITEK 2

Alpha-hemolytic streptococci are very difficult to identify by phenotypic methods. In this study, a pyrosequencing method for the identification of streptococcal species based on two variable regions of the 16S rRNA gene is described. Almost all studied streptococcal species (n = 51) represented by their type strains could be differentiated except for some closely related species of the Streptococcus bovis or S. salivarius group. The pyrosequencing results of alpha-hemolytic streptococci isolated from blood (n = 99) or from the normal pharyngeal microbiota (n = 25) were compared to the results obtained by the VITEK 2 with GP card (bioMérieux, Marcy l'Etoile, France). As expected, the results of the two methods did not completely agree, but 93 (75.0%) of the isolates assigned to the same streptococcal group by both methods and 57 (46.0%) reached consistent results at the species level. However, 10 strains remained unidentified by VITEK 2, and 4 isolates could not be assigned to any streptococcal group by pyrosequencing. Identification of members of the S. mitis and S. sanguinis groups proved difficult for both methods. Furthermore, the pyrosequencing analysis revealed great sequence variation, since only 43 (32.3%) of the 133 isolates analyzed by pyrosequencing had sequences identical to a type strain. The variation was greatest in the pharyngeal isolates, slightly lower in the blood culture isolates, and nonexistent in invasive pneumococcal isolates (n = 17) that all had the S. pneumoniae type strain sequence. The resolution of the results obtained by the two methods is impeded by the lack of a proper gold standard.

Microbiology of acute otitis media in children with tympanostomy tubes: prevalences of bacteria and viruses

Background. Bacteria are found in 50%–90% of cases of acute otitis media (AOM) with or without otorrhea, and viruses are found in 20%–49% of cases. However, for at least 15% of patients with AOM, the microbiological etiology is never determined. Our aim was to specify the full etiology of acute middle ear infection by using modern microbiological methods concomitantly for bacterial and viral detection.

Methods. The subjects were 79 young children having AOM with new onset (<48 h) of otorrhea through a tympanostomy tube. Middle ear fluid samples were suctioned from the middle ear through the tympanostomy tube. Bacteria were sought by culture and polymerase chain reaction; viruses were analyzed by culture, antigen detection, and polymerase chain reaction.

Results. At least 1 respiratory tract pathogen was noted in 76 children (96%). Bacteria were found in 73 cases (92%), and viruses were found in 55 (70%). In 52 patients (66%), both bacteria and viruses were found. Bacteria typical of AOM were detected in 86% of patients. Picornaviruses accounted for 60% of all viral findings.

Conclusions. In the great majority of children, AOM is a coinfection with bacteria and viruses. The patent tympanostomy tube does not change the spectrum of causative agents in AOM. A microbiological etiology can be established in practically all cases.

Comparison of workflow and accuracy of identification and antimicrobial susceptibility testing of clinical isolates of Enterobacteriaceae, Pseudomonas aeruginosa and enterococci by Vitek 2 and routine methods

Three hundred and fifty-three consecutive urine cultures growing Enterobacteriaceae, Pseudomonas aeruginosa or enterococci were subjected to parallel identification (ID) and antimicrobial susceptibility testing (AST) by Vitek 2 and routine methods, including simple screening tests or API 20 E for ID and standardized disc diffusion for AST. Accuracy of results, technician hands-on time required by both methods and time to results were compared. Vitek 2 correctly identified 322 (94.7%) of the 340 gram-negative isolates and 17 (81%) of the 21 Enterococcus faecalis strains. AST by Vitek 2 and disc diffusion gave category agreement for 4,058 (95.5%) of 4,248 organism-antimicrobial agent combinations. With MIC determination by E-test as reference, AST by Vitek 2 and disc diffusion produced 15 and 3 very major errors, respectively. Six (40%) of the fifteen very major errors by Vitek 2 were associated with trimethoprim-sulfamethoxazole. With an average of 22 specimens processed per day, use of Vitek 2 saved 80 min per day of technician hands-on time as compared to routine methods. Regarding the cost of hands-on worktime and consumables, use of Vitek 2 for identification of Escherichia coli-screened Enterobacteriaceae saved 0.70 p per sample in comparison to API 20 E. More than 80% of Enterobacteriaceae introduced to Vitek 2 in the morning could be reported by 16:00.

Bronchoalveolar lavage in immunocompromised patients with haematological malignancy--value of new microbiological methods

PURPOSE

To assess the usefulness of new culture-independent microbiological methods to analyse bronchoalveolar lavage (BAL) fluid from haematological patients with clinical pneumonia.

PATIENTS AND METHODS

Results of 135 BALs from 122 disease episodes in 99 patients treated between 1996 and 2002 were retrospectively analysed. Forty-three patients had undergone haematopoietic stem cell transplantation and 56 patients had been treated with conventional chemotherapy for haematological malignancy. In addition to conventional microbiological methods, polymerase chain reaction (PCR) tests for Pneumocystis carinii, cytomegalovirus (CMV), Legionella sp., mycobacterium, Mycoplasma pneumoniae, and Chlamydia pneumoniae and the Aspergillus antigen test were performed.

RESULTS

Three (2.2%) quantitative and four (3.0%) special bacterial cultures gave an aetiological diagnosis. A respiratory virus was isolated in 10 episodes (8.2%). The diagnostic yield increased to 35.6% (48 of 135) by other methods. The P. carinii PCR test was positive in 21 of 24 patients with P. carinii pneumonia, being the only microbiological indication of P. carinii in four cases. The CMV PCR test was positive in 18 patients, but in 14 patients the clinical significance of the finding remained unproven. The Aspergillus antigen test was positive in seven of nine patients with aspergillosis, being the only microbiological indication of Aspergillus in three cases. The result of BAL indicated commencement of specific antimicrobial treatment in 27 episodes (22.1%).

CONCLUSION

The contribution of new culture-independent methods to the total diagnostic yield was of note. Among these methods, the P. carinii PCR and Aspergillus antigen tests proved the most valuable, while the CMV PCR test was not clinically useful.

Aetiological diagnosis of brain abscesses and spinal infections: application of broad range bacterial polymerase chain reaction analysis

OBJECTIVE

To evaluate the usefulness of the broad range bacterial rDNA polymerase chain reaction (PCR) method combined with DNA sequencing in the aetiological diagnosis of intracranial or spinal infections in neurosurgical patients.

METHODS

In addition to conventional methods, the broad range bacterial PCR approach was applied to examine pus or tissue specimens from cerebral or spinal lesions in patients treated in a neurosurgical unit for a clinical or neuroradiological suspicion of bacterial brain abscess or spondylitis.

RESULTS

Among the 44 patients with intracranial or spinal lesions, the final diagnosis suggested bacterial disease in 25 patients, among whom the aetiological agent was identified in 17. A causative bacterial species was identified only by the rDNA PCR method in six cases, by both the PCR methodology and bacterial culture in six cases, and by bacterial culture alone in five. All samples in which a bacterial aetiology was identified only by the PCR approach were taken during antimicrobial treatment, and in three patients the method yielded the diagnosis even after >/= 12 days of parenteral treatment. One case also identified by the PCR approach alone involved a brain abscess caused by Mycoplasma hominis, which is not readily cultured by routine methods.

CONCLUSIONS

In patients with brain abscesses and spinal infections, the broad range bacterial rDNA PCR approach may be the only method to provide an aetiological diagnosis when the patient is receiving antimicrobial treatment, or when the causative agent is fastidious.

Antibiotic treatment of acute otorrhea through tympanostomy tube: randomized double-blind placebo-controlled study with daily follow-up

OBJECTIVE

The role of routine antimicrobial treatment of acute middle-ear infections is under debate, because the efficacy of antimicrobials in the resolution of middle-ear fluid has not been unambiguously proven. Acute tube otorrhea is regarded as evidence of acute otitis media, and for methodologic reasons it was chosen to provide objectivity for diagnostics and outcome assessment. The objective of this study was to assess whether amoxicillin-clavulanate accelerates the resolution of acute tube otorrhea.

DESIGN AND SETTING

Randomized, double-blind, placebo-controlled study in outpatient setting.

PATIENTS

Volunteer sample of basically healthy 6- to 72-month-old children with a tympanostomy tube. Eligibility required having acute tube otorrhea of <48 hours' of duration and no prior treatment within the last 2 weeks. The mean age of the participants was 25 months; they had a history of 3 episodes of acute otitis media (median), and 99% had manifestations of a concomitant respiratory infection. Of 79 randomized patients, 7 were withdrawn because of adverse events; 66 patients completed the study.

INTERVENTIONS

Amoxicillin-clavulanate (N = 34; 45 mg/kg/d) or matching placebo (N = 32) for 7 days and daily suction of middle-ear fluid through tympanostomy tube.

MAIN OUTCOME MEASURES

Duration of acute tube otorrhea and duration of bacterial growth in middle-ear fluid.

RESULTS

The median duration of tube otorrhea was significantly shorter in amoxicillin-clavulanate than in the placebo group (3 vs 8 days). At the end of the 7-day medication period, tube otorrhea was resolved in 28 of 34 children receiving amoxicillin-clavulanate compared with 13 of 32 children on placebo (treatment-control difference 41%; 95% confidence interval, 20%-63%; number needed to treat, 2.4). The median duration of bacterial growth in middle-ear fluid was shorter in amoxicillin-clavulanate than in the placebo group (1 vs 8 days).

CONCLUSIONS

Oral antibiotic treatment significantly accelerates the resolution of acute tube otorrhea by reducing bacterial growth in middle-ear fluid.

Elimination of epidemic methicillin-resistant Staphylococcus aureus from a university hospital and district institutions, Finland

From August 1991 to October 1992, two successive outbreaks of methicillin-resistant Staphylococcus aureus (MRSA) occurred at a hospital in Finland. During and after these outbreaks, MRSA was diagnosed in 202 persons in our medical district; >100 cases involved epidemic MRSA. When control policies failed to stop the epidemic, more aggressive measures were taken, including continuous staff education, contact isolation for MRSA-positive patients, systematic screening for persons exposed to MRSA, cohort nursing of MRSA-positive and MRSA-exposed patients in epidemic situations, and perception of the 30 medical institutions in that district as one epidemiologic entity brought under surveillance and control of the infection control team of Turku University Hospital. Two major epidemic strains, as well as eight additional strains, were eliminated; we were also able to prevent nosocomial spread of other MRSA strains. Our data show that controlling MRSA is possible if strict measures are taken before the organism becomes endemic. Similar control policies may be successful for dealing with new strains of multiresistant bacteria, such as vancomycin-resistant strains of S. aureus.

The reliability of diagnosis of infection during revision arthroplasties

BACKGROUND

Follow up studies have shown that 0.5 to 4% of the total joint arthroplasties will be complicated by infection. Distinction between aseptic loosening and infection is important for prediction of the final outcome after revision arhtroplasty but also for the choice of operative treatment. However, diagnosis of low grade chronic infection is extremely demanding.

MATERIALS AND METHODS

68 hip and knee revision arthroplasties were reviewed retrospectively in order to evaluate the reliability of pre- and perioperative analysis of infection during total joint revision arthroplasties. The sensitivity and specificity for clinical signs, blood white-cell count, C-reactive protein level, radiographic analysis, bone and leukocyte scans, joint aspirations, and gram staining were determined. Tissue sample were harvested and cultured in all cases. Positive cultures were regarded as a true infection.

RESULTS

We were not able to characterize the infection by clinical signs. Also no single test was able to show the presence of infection in all cases. The best results were obtained from pre- and perioperative joint aspirations. Joint aspiration showed 1.0 specificity and 0.75 sensitivity.

CONCLUSION

It is clear from this study that no single test is able to show the presence of infection in every case. Classical clinical signs, laboratory tests, special imaging studies and joint aspirations have all yielded a notable rate of false negative results. Therefore, we recommend that, if arthroplasty patients have pain in prosthetic joint without clear radiological evidence of loosening, bone scans and preoperative joint aspirations should be undertaken. Also, if radiological evidence of loosening is accompanied with one or more of following criteria; C-reactive protein level elevated, radiologic evidence of infection, loosening within the first five years after implantation. In case of infection a delayed two-stage reconstruction should be managed.

A between-species comparison of antimicrobial resistance in enterobacteria in fecal flora

Enterobacteria in fecal flora are often reported to be highly resistant. Escherichia coli is the main species; resistance data on other species are rare. To assess the effect of the host's environment, antimicrobial resistance was determined in fecal species of the family Enterobacteriaceae from three populations: healthy people (HP)(n = 125) with no exposure to antimicrobials for 3 months preceding sampling, university hospital patients (UP) (n = 159) from wards where the antibiotic use was 112 defined daily doses (DDD)/bed/month, and geriatric long-term patients (LTP) (n = 74) who used 1.8 DDD/bed/month. The mean length of hospital stay was 5 days for the UP and 22 months for the LTP. The isolates were identified to at least genus level, and MICs of 16 antimicrobials were determined. From the university hospital, resistance data on clinical Enterobacteriaceae isolates were also collected. Resistance data for on average two different isolates per sample (range, 1 to 5) were analyzed: 471 E. coli isolates and 261 other Enterobacteriaceae spp. Resistance was mainly found among E. coli; even in HP, 18% of E. coli isolates were resistant to two or more antimicrobial groups, with MIC patterns indicative of transferable resistance. Other fecal enterobacteria were generally susceptible, with little typically transferable multiresistance. Clinical Klebsiella and Enterobacter isolates were significantly more resistant than fecal isolates. The resistance patterns at both hospitals mirrored the patterns of antibiotic use, but LTP E. coli isolates were significantly more resistant than those from UP. Conditions permitting an efficient spread may have been more important in sustaining high resistance levels in the LTP. E. coli was the main carrier of antimicrobial resistance in fecal flora; resistance in other species was rare in the absence of antimicrobial selection.

Etiology of community-acquired pneumonia in 254 hospitalized children

BACKGROUND

Childhood community-acquired pneumonia is a common illness, but there have been relatively few comprehensive studies of the viral and bacterial etiology in developed countries. The aim of the present investigation was to determine the etiology of community-acquired pneumonia in hospitalized children by several laboratory methods.

METHODS

In a 3-year prospective study a nasopharyngeal aspirate for viral studies and acute and convalescent serum samples for viral and bacterial serology were taken from 254 children with symptoms of acute infection and infiltrates compatible with pneumonia in the chest radiograph. The role of 17 microbes was investigated.

RESULTS

A potential causative agent was detected in 215 (85%) of the 254 patients. Sixty-two percent of the patients had viral infection, 53% had bacterial infection and 30% had evidence of concomitant viral-bacterial infection. Streptococcus pneumoniae (37%), respiratory syncytial virus (29%) and rhinovirus (24%) were the most common agents associated with community-acquired pneumonia. Only one patient had a positive blood culture (S. pneumoniae) of 125 cultured. A dual viral infection was detected in 35 patients, and a dual bacterial infection was detected in 19 patients.

CONCLUSIONS

The possible causative agent of childhood community-acquired pneumonia can be detected in most cases. Further studies are warranted to determine what etiologic investigations would aid in the management of pneumonia. With effective immunization for S. pneumoniae and respiratory syncytial virus infections, more than one-half of the pneumonia cases in this study could have been prevented.

Direct amplification of rRNA genes in diagnosis of bacterial infections

A broad-range bacterial PCR targeting rRNA genes (rDNAs) was used to directly analyze 536 clinical samples obtained from 459 hospitalized patients during a 4-year study period. The molecular diagnosis based on DNA sequencing of the PCR product was compared to that obtained by bacterial culture. The bacteriological diagnosis was concordant for 447 (83%) specimens. Broad-range rDNA PCR was the only method that yielded an etiologic diagnosis for 11 (2.4%) of 459 patients. Compared to culture and clinical assessment, the sensitivity of the PCR method combined with sequencing was 74.2%, and the specificity was between 98.7 and 99.6%. At present, the described molecular approach proved superior to bacterial culture in two clinical situations: infections caused by bacteria with unusual growth requirements and specimens taken during antimicrobial treatment of the patient.

Bone bank service in Finland. Experience of bacteriologic, serologic and clinical results of the Turku Bone Bank 1972-1995

560 bones were harvested by The Turku Bone Bank between 1972-1995. It was started with massive allografts for bone tumor surgery, but today most are femoral heads for hip revision surgery. The increase in harvested bones nearly trebled from 1984-1989 to 1990-1995. Only 1 positive hepatitis C test was found. There were no hepatitis B or HIV positive donors. The incidence of discarding after screening was 24%, with positive bacterial growth (8%, usually Staphylococcus epidermidis) as the commonest reason. 2 massive grafts with negative cultures when harvesting were positive after thawing and resulted in deep infection. 369 allografts were transplanted. The infection rate of massive allografts for bone tumor surgery was 5/63 in 1973-1995, and 2/52 in 1985-1995. The infection rate for hip revision surgery was 3.4%. The clinical functional results correspond to those reported in larger international series.

Diagnosis of Mycoplasma pneumoniae pneumonia in children

We evaluated a commercial immunoglobulin M (IgM)-capture immunoassay for the detection of Mycoplasma pneumoniae infections in 278 pediatric patients with community-acquired, radiographically defined pneumonia. Acute- and convalescent-phase serum samples were collected from all patients and were tested for M. pneumoniae-specific IgM and IgG antibodies by Platelia enzyme immunoassays (Sanofi Diagnostica Pasteur, Marnes la Coquette, France). Nasopharyngeal aspirates (NPAs) were collected at the time of admission to the hospital. A total of 227 NPAs were subjected to the detection of M. pneumoniae DNA by PCR, and 191 NPAs were cultured by using the Pneumofast kit (International Mycoplasma, Signeswere, France). Southern hybridization of PCR products and the IgM test with solid-phase antigen (Serion Immunodiagnostica, Würzburg, Germany) were used for additional confirmation of a positive result, which required agreement of at least two different methods. A total of 24 (9%) confirmed diagnoses of mycoplasma infection were made, 5 (21%) of which were in children <5 years of age. Of the positive children, 24 of 24 (sensitivity, 100%) were positive by the IgM-capture test with convalescent-phase serum, 19 of 24 (79%) were positive by the IgM-capture test with acute-phase serum, 19 of 24 (79%) were positive by IgG serology, 10 of 20 (50%) were positive by PCR, and 8 of 17 (47%) were positive by culture. An additional 5 (of 254) children were positive by the Platelia IgM test alone (specificity, 98%). When the PCR with Southern hybridization result was combined with the IgM-capture test result with the acute-phase sera, the sensitivity of rapid laboratory diagnosis increased to 95%. In conclusion, the IgM serology test was the single most valuable tool for the diagnosis of M. pneumoniae pneumonia in children of any age.

Diagnosis of meningococcal meningitis by broad-range bacterial PCR with cerebrospinal fluid

We used broad-range bacterial PCR combined with DNA sequencing to examine prospectively cerebrospinal fluid (CSF) samples from patients with suspected meningitis. Fifty-six CSF samples from 46 patients were studied during the year 1995. Genes coding for bacterial 16S and/or 23S rRNA genes could be amplified from the CSF samples from five patients with a clinical picture consistent with acute bacterial meningitis. For these patients, the sequenced PCR product shared 98.3 to 100% homology with the Neisseria meningitidis sequence. For one patient, the diagnosis was initially made by PCR alone. Of the remaining 51 CSF samples, for 50 (98.0%) samples the negative PCR findings were in accordance with the negative findings by bacterial culture and Gram staining, as well as with the eventual clinical diagnosis for the patient. However, the PCR test failed to detect the bacterial rRNA gene in one CSF sample, the culture of which yielded Listeria monocytogenes. These results invite new research efforts to be focused on the application of PCR with broad-range bacterial primers to improve the etiologic diagnosis of bacterial meningitis. In a clinical setting, Gram staining and bacterial culture still remain the cornerstones of diagnosis.

Clinical significance and outcome of anaerobic bacteremia

We retrospectively studied the incidence of anaerobic bacteremia during 6 years (1991-1996) at Turku University Central Hospital (Turku, Finland). The clinical significance of a positive anaerobic blood culture, the effect of a positive culture on the choice of antimicrobial therapy, and the outcome for patients were evaluated. Cultures of blood from 81 patients yielded anaerobic bacteria (4% of all bacteremias). Anaerobic bacteremia was clinically significant in 57 patients (0.18 cases per 1,000 admissions). Only half (28) of these patients received appropriate and effective antimicrobial treatment before the results of blood cultures were reported; for 18 patients (32%), initially ineffective treatment was changed on the basis of the bacteriologic results, and for 11 patients (19%), the treatment was not changed. The mortality in these patient groups was 18%, 17%, and 55%, respectively. Empirical therapy may provide coverage for anaerobes in only half of the patients with anaerobic bacteremia, and failure to pay attention to the results of anaerobic blood cultures may have serious consequences for patients.

Coinfection is common in measles-associated pneumonia

BACKGROUND

Measles continues to be a significant health problem in developing countries.

OBJECTIVES

To describe the clinical features of measles-associated pneumonia (MAP) and to identify other pathogens involved.

METHODS

Measles diagnosis was ascertained either by the typical symptom complex or by a sensitive enzyme immunoassay for antibody among children < 5 years of age admitted to the hospital with pneumonia. Other pathogens were identified by blood culture, virus isolation or antigen detection from nasopharyngeal aspirate and antibody determination from serum.

RESULTS

Of 182 MAP cases 162 (89%) had clinically typical measles. Twenty patients had a diagnostic antibody finding with an atypical clinical presentation. Thirteen percent were younger than 9 months of age. The case fatality rate was 17%, with a significantly increased odds ratio (OR) for those with cyanosis [OR 4.6, 95% confidence interval (CI) 1.7 to 13], respiratory rate > or = 60/min (OR 3, 95% CI 1.3 to 7) or fulfilling criteria for very severe pneumonia (OR 5.3, 95% CI 2.3 to 12). Mixed infection was found in 53% of patients. Blood culture was positive in 10 patients, Streptococcus pneumoniae (N = 5) being the most common finding. Adenovirus (19%) and parainfluenza (25%) viruses were the most frequent other viruses. A dense infiltrate was seen significantly more often among measles patients with bacterial coinfection (87.5%) than those with other viruses (36%, P = 0.007) or no evidence of other infection (33%, P = 0.004).

CONCLUSION

In MAP, coinfection with other microbes is common. Cyanosis and a respiratory rate of > or = 60/min predict a greater risk of dying.

Longitudinal analysis of human salivary immunoglobulins, nonimmune antimicrobial agents, and microflora after tonsillectomy

In order to study the role of tonsils in the host defense in the oral region one pre- and two postoperative (1 and 6 months) whole saliva samples were collected from 25 young adults referred for tonsillectomy. Saliva samples were analyzed for selected host defense factors, representing both immune (total IgA, IgG, IgM, anti-Streptococcus mutans, anti-EBV, anti-CMV, and anti-adenovirus IgA and IgG) and nonimmunoglobulin (lysozyme, lactoferrin, salivary peroxidases, thiocyanate, hypothiocyanite, and agglutinins) mediators. Following tonsillectomy, a significant (P < 0.04) reduction was observed in specific IgG antibodies, suggesting that tonsils participate in local IgG response to oral antigens. Total IgM levels also decreased (P< 0.006), which may to some extent reflect reduced antigenic stimuli compared to preoperative status with frequent tonsillitis. Saliva-derived nonimmunoglobulin host defense factors, except lactoferrin, which declined significantly, remained normal throughout the study period. Our study indicates that tonsils play a role in local oral IgG-mediated immune response but tonsillectomy does not seem to lead to any significant long-term impairment of salivary defense capacity.

Bacteraemic pneumococcal disease in a teaching hospital in Finland

A total of 94 adult patients with bacteraemic pneumococcal disease were retrospectively analyzed for the factors associated with a fatal outcome. Included there were 61 males and 33 females with a mean age of 54.1 =/- 17.7 years. Of all patients, 28 (29.8%) were previously healthy, 66 (70.2%) had at least one chronic underlying disease and 29 (30.9%) were classified as alcohol abusers. The total case-fatality rate was 34%, which is higher than in the other recent Scandinavian studies. The disease was fulminant in 13 patients who died within 24 hours of admission. The mortality was significantly higher among those patients who had underlying diseases than among those who were previously healthy (p = 0.03). In addition, unfavourable prognosis was associated with septic shock on arrival (p = 0.03) respiratory insufficiency requiring mechanical ventilation (p < 0.05) and nosocomial infection (p = 0.03). The patients who succumbed were significantly older that those who survived (p < 0.01). Moreover, the absence of leucocytosis, thrombocytopenia and elevated serum creatinine levels predicted an unfavourable outcome. Contradictory to some previous reports, increased mortality was associated neither with the male sex, alcohol abuse nor the focus of infection. The continuously high mortality and rapid lethality of bacteraemic pneumococcal disease underscore the importance of following the present recommendations on the use of pneumococcal vaccine in high-risk patients.

Virus-specific, antibody-secreting cells during upper respiratory infections

The humoral immune response of 18 army recruits with febrile upper respiratory infection (URI) was studied by enumerating virus-specific, antibody-secreting cells in the peripheral blood. Diagnosis was based on viral antigen detection in nasopharyngeal specimens, virus isolation from throat swabs, or on antibody measurement from paired serum samples. At the time of the sample collection, three viruses, including adenovirus, influenza A, and influenza B, were found mainly to cause URIs among the recruits, and ELISPOT assay for enumeration of the specific antibody-secreting cells was selected for these viruses. Of the 36 patients with febrile URI studied, viral diagnosis was made in 18 cases, which included 11 patients with adenovirus infection, three with influenza A, and four with influenza B. The first blood sample was collected at the first signs of URI and the second and third samples at 2-week intervals. The adenovirus-positive patients developed a strong IgG class antibody-secreting cell response against the homologous virus, which peaked at the first sample and decreased steeply by the second and third samples. In the influenza A and B patients, the response was similar kinetically to that seen in adenovirus-positive patients. In those cases where also IgA and IgM class antibody-secreting cells were determined, the IgG response dominated. The ELISPOT method has potential also as a diagnostic tool for respiratory infections.

Molecular and biological characteristics of echovirus 22, a representative of a new picornavirus group

Recent sequence analysis revealed that the human pathogen echovirus 22 (EV22) is genetically distant from all the other picornaviruses studied to date (T. Hyypiä, C. Horsnell, M. Maaronen, M. Khan, N. Kalkkinen, P. Auvinen, L. Kinnunen, and G. Stanway, Proc. Natl. Acad. Sci. USA 89:8847-8851, 1992). We have further characterized the biological properties of the virus and show here that the virion has properties similar to those of other picornaviruses. However, the protein composition is unique, in that most copies of one of the three major capsid proteins, VP0, do not undergo the further processing to VP2 and VP4 observed during the maturation of the virus in previously studied picornaviruses. Alignment of the capsid protein sequences with those of other picornaviruses revealed, furthermore, that the VP3 polypeptide contains an apparent insertion of approximately 25 amino acids at its amino terminus. An arginine-glycine-aspartic acid (RGD) motif is found in VP1, and by using synthetic peptides, it was shown that this sequence plays a role in cell surface receptor recognition. Finally, EV23 was shown to share remarkable identity with EV22 in certain parts of the genome and also belongs to this previously unrecognized picornavirus group.

Performance of two new enzyme immunoassays for the detection of IgM and IgG antibodies to rubella

Two new enzyme immunoassays for detection of rubella-specific IgM and IgG antibodies, Rubaset EIA-M and Rubaset EIA-G, were evaluated. Serum samples from 350 patients with or without rubella symptoms were tested. Rubaset EIA-M had a sensitivity of 98.0%, a specificity of 95.2% and an overall agreement of 96.8% compared with Rubazyme-M. Sera from patients with autoimmune diseases showed no false-positive reactivity. The corresponding values for Rubaset EIA-G were 98.5%, 94.8% and 96.9% respectively, compared with Rubazyme. Sera yielding discordant results were mainly acute-phase specimens from patients with confirmed rubella infection.

Does parvovirus B19 have a role in rheumatoid arthritis?

OBJECTIVES

To determine whether parvovirus B19 (B19) infection is associated with rheumatoid arthritis (RA).

METHODS

The polymerase chain reaction was applied to serum, cells isolated from synovial fluid, and synovial fluid. Enzyme immunoassay technique was used to detect antibodies against B19.

RESULTS

Of 142 patients with early RA (onset of disease under one year) and 67 control patients, serological evidence of recent parvoviral infection was found in 4/135 and 2/62, respectively. However, no evidence for the presence of parvoviral DNA was observed in 18 synovial fluids, 21 samples of synovial fluid granulocytes or 40 sera, all obtained from 65 patients diagnosed with early RA.

CONCLUSION

Although there is published evidence of chronic rheumatoid-like arthropathy following acute parvovirus infection, our findings do not support the involvement of B19 in the aetiopathogenesis of RA.

Clinical scoring system in the evaluation of adult pharyngitis

OBJECTIVE

To compare results of a clinical scoring system for diagnosis of group A streptococcal pharyngitis with microbiologic results, when several different pharyngeal pathogens were tested simultaneously.

DESIGN

Evaluation of clinical manifestations of 106 adult patients with pharyngitis of different microbial origin.

SETTING

General private practice; Health Center Pulssi, Turku, Finland.

PATIENTS

Adult patients whose chief complaints were sore throats.

MAIN OUTCOME MEASURE

A symptom score that was assigned to each patient according to the total number of certain signs and symptoms that are postulated to increase the probability of group A streptococcal pharyngitis and blood measurements for infection.

RESULTS

The highest symptom scores, 3 and 4, were found in 21 patients. These patients had pharyngitis due to group A streptococcus (four patients), group C streptococcus (four patients), group G streptococcus (two patients), group F streptococcus, Mycoplasma pneumoniae, Chlamydia pneumoniae, influenza A virus, influenza B virus, herpes simplex type 1 virus (two patients), and coxsackie B4 virus. No pathogen could be identified from three of the 21 patients. The C-reactive protein values and the leukocyte counts were raised significantly more often in streptococcal infections than in infections of other origin; the P values were .00016 and .028, respectively.

CONCLUSION

Use of a clinical scoring system alone for diagnosis of pharyngitis may lead to improper use of anti-microbial agents. There is a need for accurate microbiologic diagnostic procedures in general practice to determine proper treatment of pharyngitis as well as to test the effect of antibacterial and, in the future, antiviral treatment in respiratory tract infections.

Preceding respiratory infection predisposing for primary and secondary invasive Haemophilus influenzae type b disease

Cases (117) with invasive Haemophilus influenzae type b (Hib) disease and their family members reported symptoms of respiratory infection during the 4-week period before the onset of Hib disease significantly more often than age-, sex- and residence-matched controls (225) and their family members during the same time period. Viral (adenovirus; influenza A and B; parainfluenza types 1, 2 and 3; and respiratory syncytial virus) and Mycoplasma pneumoniae serology was performed in 84 paired sera from cases and 112 paired sera from controls, who were healthy children matched to the cases by age, year and season. Viral or M. pneumoniae infection was diagnosed equally often among cases and controls (18% for both groups). However, patients who were associated cases of Hib disease (i.e. either the primary or secondary case of a case pair) had a diagnostic viral serology more often (50%) than did sporadic cases (13%) (odds ratio, 7.0; 95% confidence interval, 1.6 to 33; P = 0.006). These results suggest that some infectious agent(s) caused symptoms among the patients and circulated among the patients' closest contacts immediately before their development of Hib disease and possibly predisposed for invasive Hib disease. For the development of associated Hib disease among close contacts of an index case, adenovirus, influenza A, respiratory syncytial virus or para-influenza type 1, 2 and 3 infections may be important.

Shedding of infectious virus and virus antigen during acute infection with respiratory syncytial virus

Shedding of respiratory syncytial virus (RSV) in nasopharyngeal aspirates (NPA) of hospitalized children with acute respiratory infection was studied using direct antigen detection by time-resolved fluoroimmunoassay, rapid identification of infectious virus in centrifugally inoculated cell cultures by immunoperoxidase staining and conventional virus culture. Sequential NPAs, in which also local RSV-specific IgA response was measured, were collected from children with proven RSV infection. The shedding pattern was similar for both infectious virus and viral antigen. The overall agreement of the three methods was good (81%) in diagnostic specimens collected on admission, but markedly reduced (46%) in follow-up specimens. Secretory IgA was abundant in specimens giving discrepant or negative results only. The proportion of patients who shed RSV was high (> or = 87%) in the first week after onset of symptoms, and decreased sharply in the second week. An opposite temporal pattern was found in the proportion of patients with detectable RSV-IgA in their secretions. Sequentially isolated strains were antigenically stable as determined by their reactivity with a large panel of monoclonal antibodies. The findings suggest that RSV shedding should be monitored by using more than one method for virus detection.

Immunoglobulin G antibody avidity in patients with respiratory syncytial virus infection

The titer and avidity of respiratory syncytial virus-specific antibodies were measured in 196 serum specimens from 93 children with an acute, laboratory-confirmed respiratory syncytial virus infection. An enzyme immunoassay method based on the ability of urea to dissociate the bound antibodies with low avidity from the antigen was used. Three patterns of immune responses were observed. Children less than 6 months of age usually had low titers of antibodies with high avidity in their acute-phase serum samples. These antibodies were concluded to be of maternal origin, since their reaction pattern was similar to that of healthy adults. During the next few weeks, a slight increase in titers with a concurrent decrease in antibody avidity was observed. All children 6 to 24 months of age had low-avidity antibodies in their acute-phase serum samples, which matured to high avidity during the follow-up. On the contrary, about half of the children greater than 24 months of age had high-avidity antibodies already in the acute-phase serum samples. We conclude that the former children were experiencing primary infections with respiratory syncytial virus and the latter were experiencing reinfections. All adults with remote immunity had antibodies with high avidity.

Salivary antimicrobial proteins and mutans streptococci in tonsillectomized children

Whole saliva from 53 children who had been tonsillectomized when they were younger than 4 years old was analyzed for selected antimicrobial proteins and oral mutans streptococci 3-4 years after the operation. The results were compared with those from age- and gender-matched control children with no history of tonsillectomy. The salivary analyses comprised both immune (total IgA, IgG and IgM) and selected nonimmune (lactoferrin, myeloperoxidase, salivary peroxidase) antimicrobial proteins. Specific IgA and IgG antibodies against viral antigens (adeno-, cytomegalo-, respiratory syncytial- and Epstein-Barr-viruses) and against Streptococcus mutans cells were quantitated in both groups. The tonsillectomized children had statistically significantly higher concentrations of all immunoglobulin isotypes (P 0.001) as well as of lactoferrin (P less than 0.005), and myeloperoxidase (P less than 0.001) in saliva. However, no differences were found in the numbers of cariogenic mutans streptococci or in the total oral aerobic flora. In line with the streptococcal counts, no differences existed in anti-S. mutans IgA or IgG titers between the groups. Most antibodies against viruses, especially of IgG isotype, were significantly (P less than 0.001) higher in saliva of tonsillectomized children than in that of the controls. The results suggest that, within a long run, the humoral immune status of human saliva is not weakened by tonsillectomy. Also, mainly serum-derived antimicrobial proteins (myeloperoxidase, lactoferrin, IgG) exist in high concentrations in whole saliva after tonsillectomy.

Prokaryotic expression of a VP1 polypeptide antigen for diagnosis by a human parvovirus B19 antibody enzyme immunoassay

To produce parvovirus B19 antigen for diagnostic purposes, partially overlapping segments covering the genes encoding the viral structural proteins VP1 and VP2 were cloned into expression vectors. The constructs were induced in Escherichia coli, resulting in the expression of beta-galactosidase fusion proteins. In immunoblotting experiments with sera from patients with erythema infectiosum, immunoglobulin G (IgG) and IgM antibodies bound to a single polypeptide of 235 amino acids at the N terminus of VP1. The DNA fragment encoding this polypeptide was amplified by the polymerase chain reaction and cloned into an expression vector. The viral capsid antigen expressed in E. coli was purified by preparative agarose gel electrophoresis and used in IgG and IgM solid-phase enzyme immunoassays. Comparison with reference gamma- and mu-capture radioimmunoassays using whole virus antigen showed that these antibody tests are suitable for the serodiagnosis of human infections caused by parvovirus B19.

Serologic diagnosis of pertussis: evaluation of pertussis toxin and other antigens in enzyme-linked immunosorbent assay

IgM, IgA, and IgG antibodies to Bordetella pertussis were measured in paired sera from 34 patients who were culture-positive for pertussis by enzyme-linked immunosorbent assay (ELISA) with disrupted B. pertussis bacteria, purified pertussis toxin, or outer membrane proteins (OMP) as antigens. Paired sera from 50 patients with other respiratory infections were used as controls. The sensitivities of the assays from paired sera were 61%, 90%, and 90% and specificities were 98%, 92%, and 72%, respectively. Of the patients culture-positive for pertussis, 68% had positive levels of antibody to pertussis toxin antigen in their first serum samples, obtained at the same time as samples for culture. Infants had antibody responses to pertussis toxin antigen, in contrast to weak antibody responses measured by B. pertussis antigen. The results from this study indicate that ELISA, especially measuring pertussis toxin IgA, is a valuable additional tool for diagnosing pertussis and can be used as a complementary test with cultures.

Viral lower respiratory tract infections in Filipino children

Viral causes of acute lower respiratory tract infection were studied prospectively between 15 June and 31 October 1984 in 312 Filipino children less than 5 years old living in periurban slums and middle-class housing. The cause was based on viral antigen detection, virus isolation, and antibody assays. There were 131 children (41.2%) who were admitted to the hospital, and 150 (47%) had an infiltrate on chest radiograph. A total of 198 viral infections were confirmed in 162 patients (51.9%), 42.3% with single viral infection and 9.6% with mixed (two or more) infection. The infections were measles (21.4%), influenza A (15.9%), parainfluenza types 1, 2, and 3 (8.8%), respiratory syncytial virus (7.1%), influenza B (5.8%), enteroviruses (5.1%), adenoviruses (3.9%), herpes simplex virus (1.6%), and cytomegalovirus (1.3%). Viral infections other than measles were seen in 39.7% of the cases. The presence of viral infection correlated with better nutritional status. Influenza A or B diagnosis was associated with mild forms of acute respiratory tract infection, measles and a preceding rash with severe disease.