Viral and atypical bacterial detection in acute respiratory infection in children under five years

Background

Acute respiratory infection (ARI) is a leading cause of morbidity and mortality in children worldwide. This study aimed to determine the viral and atypical bacterial causes of different severities and clinical manifestations of ARI in preschool children from low-income families in North-East Brazil.

Methods

Clinical/demographic data and nasopharyngeal aspirates (NPA) were prospectively collected from children <5 years presenting with ARI over one year to a paediatric A&E department. Disease severity was grouped according to presence of lower respiratory tract signs, need for hospital admission and need for oxygen. Clinical manifestation of ARI was based on discharge diagnosis from hospital with four conditions predominating: bronchiolitis, pneumonia, episodic viral wheeze/asthma and upper respiratory tract infection. Multiplex PCR was used to detect 17 common respiratory viral and atypical bacterial pathogens in NPA.

Findings

407 children with a median age of eight months were recruited. Pathogens were detected in 85·5% samples with co-infection being particularly common (39·5%). Respiratory Syncytial Virus (RSV; 37%), Adenoviruses (AdV; 25%), Rhinoviruses (hRV; 19%), Bocavirus (hBoV; 19%), human Meta-pneumovirus (hMPV; 10%) and Mycoplasma pneumoniae (Mpp; 10%) were most prevalent. Detection and co-infection rates were similar in all severities and clinical manifestations of ARI apart from RSV, which was associated with more severe disease and specifically more severe cases of bronchiolitis, and Mpp, which was associated with more severe cases of pneumonia. Mpp was detected in 17% of children admitted to hospital with pneumonia.

Interpretation

This study underlines the importance of viral and atypical bacterial pathogens in ARI in pre-school children and highlights the complex epidemiology of these pathogens in this age group. Generally, viruses and atypical bacteria were detected in all severities and clinical manifestations of ARI but RSV and Mpp were associated with more severe cases of bronchiolitis and pneumonia respectively.     

The burden of invasive bacterial infections in Pemba, Zanzibar

Background

We conducted a surveillance study to determine the leading causes of bloodstream infection in febrile patients seeking treatment at three district hospitals in Pemba Island, Zanzibar, Tanzania, an area with low malaria transmission.

Methods

All patients above two months of age presenting to hospital with fever were screened, and blood was collected for microbiologic culture and malaria testing. Bacterial sepsis and malaria crude incidence rates were calculated for a one-year period and were adjusted for study participation and diagnostic sensitivity of blood culture.

Results

Blood culture was performed on 2,209 patients. Among them, 166 (8%) samples yielded bacterial growth; 87 (4%) were considered as likely contaminants; and 79 (4%) as pathogenic bacteria. The most frequent pathogenic bacteria isolated were Salmonella Typhi (n = 46; 58%), followed by Streptococcus pneumoniae (n = 12; 15%). The crude bacteremia rate was 6/100,000 but when adjusted for potentially missed cases the rate may be as high as 163/100,000. Crude and adjusted rates for S. Typhi infections and malaria were 4 and 110/100,000 and 4 and 47/100,000, respectively. Twenty three (51%), 22 (49%) and 22 (49%) of the S.Typhi isolates were found to be resistant toward ampicillin, chloramphenicol and cotrimoxazole, respectively. Multidrug resistance (MDR) against the three antimicrobials was detected in 42% of the isolates.

Conclusions

In the presence of very low malaria incidence we found high rates of S. Typhi and S. pneumoniae infections on Pemba Island, Zanzibar. Preventive measures such as vaccination could reduce the febrile disease burden.     

The age-related risk of co-existing meningitis in children with urinary tract infection

Objective

The primary aim of this study was to determine age-stratified rates of co-existing bacterial meningitis in children with urinary tract infection (UTI). The secondary aims of this study were to determine the causative pathogens of UTI, and the clinical features and outcome of children with co-existing meningitis.

Methods

Analysis of data collected over a nine-year period at a tertiary pediatric hospital in Australia. Study population: children below 16 years of age with culture-confirmed UTI and a paired CSF sample.

Results

A total of 748 episodes in 735 cases were included in the final analysis. The commonest pathogens causing UTI were Escherichia coli (67.4%), Enterococcus faecalis (8.4%), Klebsiella oxytoca (3.5%) and Klebsiella pneumoniae (3.5%). Only two (1.2%; 95% CI: 0.15–4.36%) of 163 neonates (between 0 and 28 days of age) with UTI had co-existing meningitis. Both presented with pyrexia, irritability and lethargy, and recovered uneventfully with antibiotic treatment. There were no cases of co-existing meningitis among 499 infants (between 29 days and 12 months of age) with UTI (95% CI: 0.00–0.74%), or any of the 86 children aged 12 months or over (95% CI: 0.00–4.20%).

Conclusions

These findings indicate that clinicians should have a low threshold to perform a lumbar puncture in neonates with UTI, as the risk of co-existing meningitis is not insignificant in this age group. In contrast, beyond the neonatal period, the risk is small and a more selective approach is warranted.     

Wheeze in preschool age is associated with pulmonary bacterial infection and resolves after antibiotic therapy

Background

Neonates with airways colonized by Haemophilus influenzae, Streptococcus pneumoniae or Moraxella catarrhalis are at increased risk for recurrent wheeze which may resemble asthma early in life. It is not clear whether chronic colonization by these pathogens is causative for severe persistent wheeze in some preschool children and whether these children might benefit from antibiotic treatment. We assessed the relevance of bacterial colonization and chronic airway infection in preschool children with severe persistent wheezing and evaluated the outcome of long-time antibiotic treatment on the clinical course in such children.

Methodology/Principal Findings

Preschool children (n = 42) with severe persistent wheeze but no symptoms of acute pulmonary infection were investigated by bronchoscopy and bronchoalveolar lavage (BAL). Differential cell counts and microbiological and virological analyses were performed on BAL samples. Patients diagnosed with bacterial infection were treated with antibiotics for 2–16 weeks (n = 29). A modified ISAAC questionnaire was used for follow-up assessment of children at least 6 months after bronchoscopy. Of the 42 children with severe wheezing, 34 (81%) showed a neutrophilic inflammation and 20 (59%) of this subgroup had elevated bacterial counts (≥10⁴ colony forming units per milliliter) suggesting infection. Haemophilus influenzae, Streptococcus pneumoniae and Moraxella catarrhalis were the most frequently isolated species. After treatment with appropriate antibiotics 92% of patients showed a marked improvement of symptoms upon follow-up examination.

Conclusions/Significance

Chronic bacterial infections are relevant in a subgroup of preschool children with persistent wheezing and such children benefit significantly from antibiotic therapy.     

Streptococcus pneumoniae carriage in the Gaza strip

Background

Pneumococcal infections cause major morbidity and mortality in developing countries. We report the epidemiology of S. pneumoniae carriage in a developing region, the Gaza strip, and evaluate the theoretical coverage of carriage strains by pneumococcal conjugate vaccines (PCVs).

Methodology

In 2009 we conducted a cross-sectional survey of S. pneumoniae carriage in healthy children and their parents, living throughout the Gaza strip. Data were collected and nasopharyngeal swabs were obtained. Antibiotic susceptibilities were determined by Vitek-2 and serotypes by the Quellung reaction.

Principal Findings

S. pneumoniae carriage was detected in 189/379 (50%) of children and 30/376 (8%) of parents. Carriage prevalence was highest in children <6 months of age (63%). Significant predictors for child carriage were number of household members and DCC attendance. The proportion of pediatric and adults isolates with serotypes included in PCV7 were 32% and 20% respectively, and 46% and 33% in PCV13 respectively. The most prominent non-vaccine serotypes (NVT) were 35B, 15B/C and 23B. Penicillin-nonsusceptible strains were carried by70% of carriers, penicillin-resistant strains (PRSP) by 13% and Multi-drug-resistant (MDR) by 30%. Of all PRSP isolates 54% belonged to serotypes included in PCV7 and 71% in the PCV13. Similarly, 59% and 73% of MDR-SP isolates, would theoretically be covered by PCV7 and PCV13, respectively.

Conclusions

This study demonstrates that, PCV13-included strains were carried by 46% and 33% of pediatric and adult subjects respectively. In the absence of definitive data regarding the virulence of the NVT strains, it is difficult to predict the effect of PCVs on IPD in this region.     

Nasopharyngeal bacterial colonization and gene polymorphisms of mannose-binding lectin and toll-like receptors 2 and 4 in infants

Background

Human nasopharynx is often colonized by potentially pathogenic bacteria. Gene polymorphisms in mannose-binding lectin (MBL), toll-like receptor (TLR) 2 and TLR4 have been reported. The present study aimed to investigate possible association between nasopharyngeal bacterial colonization and gene polymorphisms of MBL, TLR2 and TLR4 in healthy infants.

Methodology/Principal Findings

From August 2008 to June 2010, 489 nasopharyngeal swabs and 412 blood samples were taken from 3-month-old healthy Finnish infants. Semi-quantitative culture was performed and pyrosequencing was used for detection of polymorphisms in MBL structural gene at codons 52, 54, and 57, TLR2 Arg753Gln and TLR4 Asp299Gly. Fifty-nine percent of subjects were culture positive for at least one of the four species: 11% for Streptococcus pneumoniae, 23% for Moraxella catarrhalis, 1% for Haemophilus influenzae and 25% for Staphylococcus aureus. Thirty-two percent of subjects had variant types in MBL, 5% had polymorphism of TLR2, and 18% had polymorphism of TLR4. Colonization rates of S. pneumoniae and S. aureus were significantly higher in infants with variant types of MBL than those with wild type (p = .011 and p = .024). Colonization rates of S. aureus and M. catarrhalis were significantly higher in infants with polymorphisms of TLR2 and of TLR4 than those without (p = .027 and p = .002).

Conclusions

Our study suggests that there is an association between nasopharyngeal bacterial colonization and genetic variation of MBL, TLR2 and TLR4 in young infants. This finding supports a role for these genetic variations in susceptibility of children to respiratory infections.     

The blind nasotracheal aspiration method is not a useful tool for pathogen detection of pneumonia in children

Background

Acute lower respiratory infection (ALRI) is a major cause of hospitalization for children in China, while the etiological diagnosis of ALRI remains a challenge. This study was performed to evaluate the utility of the blind Nasotracheal aspiration (NTA) in the pathogen detection in ALRI through an evaluation of the test''s specificity.

Methodology/Principal Findings

A hospital-based study of children ≤3 years was carried out from March 2006 through March 2007 in Suzhou University Affiliated Children''s Hospital, including 379 cases with ALRI from the respiratory wards, and 394 controls receiving elective surgery. Nasopharyngeal swabs (NPS) and NTA specimens were taken on admission. S. pneumoniae was isolated from 10.3% of NTA samples from ALRI children, H. influenzae from 15.3%, and M. catarrhalis from 4.7%. The false positive rate—the strains from NTA in control group children—was 8.4% (95% CI: 5.8%–11.4%) for S. pneumoniae, 27.2% (95% CI: 22.7–31.5%) for H. influenzae, and 22.1% (95% CI: 18.0%–26.2%) for M. catarrhalis. The agreement between NPS and NTA in the control group was over 70%.

Conclusion/Significance

The blind NTA test is not a useful test for etiologic diagnosis of ALRI.     

Rapid qualitative urinary tract infection pathogen identification by SeptiFast real-time PCR

Background

Urinary tract infections (UTI) are frequent in outpatients. Fast pathogen identification is mandatory for shortening the time of discomfort and preventing serious complications. Urine culture needs up to 48 hours until pathogen identification. Consequently, the initial antibiotic regimen is empirical.

Aim

To evaluate the feasibility of qualitative urine pathogen identification by a commercially available real-time PCR blood pathogen test (SeptiFast^®) and to compare the results with dipslide and microbiological culture.

Design of study

Pilot study with prospectively collected urine samples.

Setting

University hospital.

Methods

82 prospectively collected urine samples from 81 patients with suspected UTI were included. Dipslide urine culture was followed by microbiological pathogen identification in dipslide positive samples. In parallel, qualitative DNA based pathogen identification (SeptiFast^®) was performed in all samples.

Results

61 samples were SeptiFast^® positive, whereas 67 samples were dipslide culture positive. The inter-methodological concordance of positive and negative findings in the gram+, gram- and fungi sector was 371/410 (90%), 477/492 (97%) and 238/246 (97%), respectively. Sensitivity and specificity of the SeptiFast^® test for the detection of an infection was 0.82 and 0.60, respectively. SeptiFast^® pathogen identifications were available at least 43 hours prior to culture results.

Conclusion

The SeptiFast^® platform identified bacterial DNA in urine specimens considerably faster compared to conventional culture. For UTI diagnosis sensitivity and specificity is limited by its present qualitative setup which does not allow pathogen quantification. Future quantitative assays may hold promise for PCR based UTI pathogen identification as a supplementation of conventional culture methods.     

Clonal differences between Non-Typhoidal Salmonella (NTS) recovered from children and animals living in close contact in the Gambia

Background

Non-Typhoidal Salmonella (NTS) is an important cause of invasive bacterial disease and associated with mortality in Africa. However, little is known about the environmental reservoirs and predominant modes of transmission. Our study aimed to study the role of domestic animals in the transmission of NTS to humans in rural area of The Gambia.

Methodology

Human NTS isolates were obtained through an active population-based case-control surveillance study designated to determine the aetiology and epidemiology of enteric infections covering 27,567 Gambian children less than five years of age in the surveillance area. Fourteen children infected with NTS were traced back to their family compounds and anal swabs collected from 210 domestic animals present in their households. Identified NTSs were serotyped and genotyped by multi-locus sequencing typing.

Principal Findings

NTS was identified from 21/210 animal sources in the households of the 14 infected children. Chickens carried NTS more frequently than sheep and goats; 66.6%, 28.6% and 4.8% respectively. The most common NTS serovars were S. Colindale in humans (21.42%) and S. Poona in animals (14.28%). MLST on the 35 NTS revealed four new alleles and 24 sequence types (ST) of which 18 (75%) STs were novel. There was no overlap in serovars or genotypes of NTS recovered from humans or animal sources in the same household.

Conclusion

Our results do not support the hypothesis that humans and animals in close contact in the same household carry genotypically similar Salmonella serovars. These findings form an important baseline for future studies of transmission of NTS in humans and animals in Africa.     

Genotypic diversity and drug susceptibility patterns among M. tuberculosis complex isolates from South-Western Ghana

Objective

The aim of this study was to use spoligotyping and large sequence polymorphism (LSP) to study the population structure of M. tuberculosis complex (MTBC) isolates.

Methods

MTBC isolates were identified using standard biochemical procedures, IS6110 PCR, and large sequence polymorphisms. Isolates were further typed using spoligotyping, and the phenotypic drug susceptibility patterns were determined by the proportion method.

Result

One hundred and sixty-two isolates were characterised by LSP typing. Of these, 130 (80.25%) were identified as Mycobacterium tuberculosis sensu stricto (MTBss), with the Cameroon sub-lineage being dominant (N = 59/130, 45.38%). Thirty-two (19.75%) isolates were classified as Mycobacterium africanum type 1, and of these 26 (81.25%) were identified as West-Africa I, and 6 (18.75%) as West-Africa II. Spoligotyping sub-lineages identified among the MTBss included Haarlem (N = 15, 11.53%), Ghana (N = 22, 16.92%), Beijing (4, 3.08%), EAI (4, 3.08%), Uganda I (4, 3.08%), LAM (2, 1.54%), X (N = 1, 0.77%) and S (2, 1.54%). Nine isolates had SIT numbers with no identified sub-lineages while 17 had no SIT numbers. MTBss isolates were more likely to be resistant to streptomycin (p<0.008) and to any drug resistance (p<0.03) when compared to M. africanum.

Conclusion

This study demonstrated that overall 36.4% of TB in South-Western Ghana is caused by the Cameroon sub-lineage of MTBC and 20% by M. africanum type 1, including both the West-Africa 1 and West-Africa 2 lineages. The diversity of MTBC in Ghana should be considered when evaluating new TB vaccines.     

First isolation and direct evidence for the existence of large small-mammal reservoirs of Leptospira sp. in Madagascar

Background

Leptospirosis has long been a major public health concern in the southwestern Indian Ocean. However, in Madagascar, only a few, old studies have provided indirect serological evidence of the disease in humans or animals.

Methodology/Principal Findings

We conducted a large animal study focusing on small-mammal populations. Five field trapping surveys were carried out at five sites, from April 2008 to August 2009. Captures consisted of Rattus norvegicus (35.8%), R. rattus (35.1%), Mus musculus (20.5%) and Suncus murinus (8.6%). We used microbiological culture, serodiagnosis tests (MAT) and real-time PCR to assess Leptospira infection. Leptospira carriage was detected by PCR in 91 (33.9%) of the 268 small mammals, by MAT in 17 of the 151 (11.3%) animals for which serum samples were available and by culture in 9 of the 268 animals (3.3%). Rates of infection based on positive PCR results were significantly higher in Moramanga (54%), Toliara (48%) and Mahajanga (47.4%) than in Antsiranana (8.5%) and Toamasina (14%) (p = 0.001). The prevalence of Leptospira carriage was significantly higher in R. norvegicus (48.9%), S. murinus (43.5%) and R. rattus (30.8%) than in M. musculus (9.1%) (p<0.001). The MAT detected antibodies against the serogroups Canicola and Icterohaemorrhagiae. Isolates were characterized by serology, secY sequence-based phylogeny, partial sequencing of rrs, multi-locus VNTR analysis and pulsed field gel electrophoresis. The 10 isolates obtained from nine rats were all identified as species L. interrogans serogroup Canicola serovar Kuwait and all had identical partial rrs and secY sequences.

Conclusions/Significance

We present here the first direct evidence of widespread leptospiral carriage in small mammals in Madagascar. Our results strongly suggest a high level of environmental contamination, consistent with probable transmission of the infection to humans. This first isolation of pathogenic Leptospira strains in this country may significantly improve the detection of specific antibodies in human cases.     

Molecular identification of bacteria in tracheal aspirate fluid from mechanically ventilated preterm infants

Background

Despite strong evidence linking infections to the pathogenesis of bronchopulmonary dysplasia (BPD), limitations of bacterial culture methods have precluded systematic studies of airway organisms relative to disease outcomes. Application of molecular bacterial identification strategies may provide new insight into the role of bacterial acquisition in the airways of preterm infants at risk for BPD.

Methods

Serial (within 72 hours, 7, 14, and 21 days of life) tracheal aspirate samples were collected from 10 preterm infants with gestational age ≤34 weeks at birth, and birth weight of 500–1250 g who required mechanical ventilation for at least 21 days. Samples were analyzed by quantitative real time PCR assays for total bacterial load and by pyrosequencing for bacterial identification.

Results

Subjects were diagnosed with mild (1), moderate (3), or severe (5) BPD. One patient died prior to determination of disease severity. 107,487 sequences were analyzed, with mean of 3,359 (range 1,724–4,915) per sample. 2 of 10 samples collected <72 hours of life contained adequate bacterial DNA for successful sequence analysis, one of which was from a subject exposed to chorioamnionitis. All other samples exhibited bacterial loads >70copies/reaction. 72 organisms were observed in total. Seven organisms represented the dominant organism (>50% of total sequences) in 31/32 samples with positive sequences. A dominant organism represented>90% of total sequences in 13 samples. Staphylococcus, Ureaplasmaparvum, and Ureaplasmaurealyticum were the most frequently identified dominant organisms, but Pseudomonas, Enterococcus, and Escherichia were also identified.

Conclusions

Early bacterial colonization with diverse species occursafter the first 3 days of life in the airways of intubated preterm infants, and can be characterized by bacterial load and marked species diversity. Molecular identification of bacteria in the lower airways of preterm infants has the potential to yield further insight into the pathogenesis of BPD.     

Comparison of real-time quantitative PCR and culture for the diagnosis of emerging Rickettsioses

Background

Isolation of Rickettsia species from skin biopsies may be replaced by PCR. We evaluated culture sensitivity compared to PCR based on sampling delay and previous antibiotic treatment.

Methodology/Principal Findings

Skin biopsies and ticks from patients with suspected Rickettsia infection were screened for Rickettsia spp. using qPCR, and positive results were amplified and sequenced for the gltA and ompA genes. Immunofluorescence for spotted fever group rickettsial antigens was done for 79 patients. All skin biopsies and only ticks that tested positive using qPCR were cultured in human embryonic lung (HEL) fibroblasts using the centrifugation-shell vial technique. Patients and ticks were classified as definitely having rickettsioses if there was direct evidence of infection with a Rickettsia sp. using culture or molecular assays or in patients if serology was positive. Data on previous antibiotic treatments were obtained for patients with rickettsiosis. Rickettsia spp. infection was diagnosed in 47 out of 145 patients (32%), 41 by PCR and 12 by culture, whereas 3 isolates were obtained from PCR negative biopsies. For 3 of the patients serology was positive although PCR and culture were negative. Rickettsia africae was the most common detected species (n = 25, [17.2%]) and isolated bacterium (n = 5, [3.4%]). The probability of isolating Rickettsia spp. was 12 times higher in untreated patients and 5.4 times higher in patients from our hometown. Rickettsia spp. was amplified in 24 out of 95 ticks (25%) and we isolated 7 R. slovaca and 1 R. raoultii from Dermacentor marginatus.

Conclusions/Significance

We found a positive correlation between the bacteria copies and the isolation success in skin biopsies and ticks. Culture remains critical for strain analysis but is less sensitive than serology and PCR for the diagnosis of a Rickettsia infection.     

Identification of serotype in culture negative pneumococcal meningitis using sequential multiplex PCR: implication for surveillance and vaccine design

Background

PCR-based serotyping of Streptococcus pneumoniae has been proposed as a simpler approach than conventional methods, but has not been applied to strains in Asia where serotypes are diverse and different from other part of the world. Furthermore, PCR has not been used to determine serotype distribution in culture-negative meningitis cases.

Methodology

Thirty six serotype-specific primers, 7 newly designed and 29 previously published, were arranged in 7 multiplex PCR sets, each in new hierarchies designed for overall serotype distribution in Bangladesh, and specifically for meningitis and non-meningitis isolates. Culture-negative CSF specimens were then tested directly for serotype-specific sequences using the meningitis-specific set of primers. PCR-based serotyping of 367 strains of 56 known serotypes showed 100% concordance with quellung reaction test. The first 7 multiplex reactions revealed the serotype of 40% of all, and 31% and 48% non-meningitis and meningitis isolates, respectively. By redesigning the multiplex scheme specifically for non-meningitis or meningitis, the quellung reaction of 43% and 48% of respective isolates could be identified. Direct examination of 127 culture-negative CSF specimens, using the meningitis-specific set of primers, yielded serotype for 51 additional cases.

Conclusions

This PCR approach, could improve ascertainment of pneumococcal serotype distributions, especially for meningitis in settings with high prior use of antibiotics.     

Diagnostic accuracy of real-time PCR assays targeting 16S rRNA and lipL32 genes for human leptospirosis in Thailand: a case-control study

Background

Rapid PCR-based tests for the diagnosis of leptospirosis can provide information that contributes towards early patient management, but these have not been adopted in Thailand. Here, we compare the diagnostic sensitivity and specificity of two real-time PCR assays targeting rrs or lipL32 for the diagnosis of leptospirosis in northeast Thailand.

Methods/Principal Findings

A case-control study of 266 patients (133 cases of leptospirosis and 133 controls) was constructed to evaluate the diagnostic sensitivity and specificity (DSe & DSp) of both PCR assays. The median duration of illness prior to admission of cases was 4 days (IQR 2–5 days; range 1–12 days). DSe and DSp were determined using positive culture and/or microscopic agglutination test (MAT) as the gold standard. The DSe was higher for the rrs assay than the lipL32 assay (56%, (95% CI 47–64%) versus 43%, (95% CI 34–52%), p<0.001). No cases were positive for the lipL32 assay alone. There was borderline evidence to suggest that the DSp of the rrs assay was lower than the lipL32 assay (90% (95% CI 83–94%) versus 93%, (95%CI 88–97%), p = 0.06). Nine controls gave positive reactions for both assays and 5 controls gave a positive reaction for the rrs assay alone. The DSe of the rrs and lipL32 assays were high in the subgroup of 39 patients who were culture positive for Leptospira spp. (95% and 87%, respectively, p = 0.25).

Conclusions/Significance

Early detection of Leptospira using PCR is possible for more than half of patients presenting with leptospirosis and could contribute to individual patient care.     

Temporal trends in the impact factor of European versus USA biomedical journals

Background

The impact factors of biomedical journals tend to rise over time. We sought to assess the trend in the impact factor, during the past decade, of journals published on behalf of United States (US) and European scientific societies, in four select biomedical subject categories (Biology, Cell Biology, Critical Care Medicine, and Infectious Diseases).

Methods

We identified all journals included in the above-mentioned subject categories of Thomson Reuters Journal Citation Reports® for the years 1999, 2002, 2005, and 2008. We selected those that were published on behalf of US or European scientific societies, as documented in journal websites.

Results

We included 167 journals (35 in the subject category of Biology, 79 in Cell Biology, 27 in Critical Care Medicine, and 26 in Infectious Diseases). Between 1999 and 2008, the percentage increase in the impact factor of the European journals was higher than for the US journals (73.7±110.0% compared with 39.7±70.0%, p = 0.049). Regarding specific subject categories, the percentage change in the factor of the European journals tended to be higher than the respective US journals for Cell Biology (61.7% versus 16.3%), Critical Care Medicine (212.4% versus 65.4%), Infectious Diseases (88.3% versus 48.7%), whereas the opposite was observed for journals in Biology (41.0% versus 62.5%).

Conclusion

Journals published on behalf of European scientific societies, in select biomedical fields, may tend to close the “gap” in impact factor compared with those of US societies.

What''s Already Known About This Topic?

The impact factors of biomedical journals tend to rise through years. The leading positions in productivity in biomedical research are held by developed countries, including those from North America and Western Europe.

What Does This Article Add?

The journals from European biomedical scientific societies tended, over the past decade, to increase their impact factor more than the respective US journals.     

Percutaneous cryoablation of pulmonary metastases from colorectal cancer

Objective

To evaluate the safety and efficacy of cryoablation for metastatic lung tumors from colorectal cancer.

Methods

The procedures were performed on 24 patients (36–82 years of age, with a median age of 62; 17 male patients, 7 female patients) for 55 metastatic tumors in the lung, during 30 sessions. The procedural safety, local progression free interval, and overall survival were assessed by follow-up computed tomographic scanning performed every 3–4 months.

Results

The major complications were pneumothorax, 19 sessions (63%), pleural effusion, 21 sessions (70%), transient and self-limiting hemoptysis, 13 sessions (43%) and tract seeding, 1 session (3%). The 1- and 3-year local progression free intervals were 90.8% and 59%, respectively. The 3-years local progression free intervals of tumors ≤15 mm in diameter was 79.8% and that of tumors >15 mm was 28.6% (p = 0.001; log-rank test). The 1- and 3-year overall survival rates were 91% and 59.6%, respectively.

Conclusion

The results indicated that percutaneous cryoablation is a feasible treatment option. The local progression free interval was satisfactory at least for tumors that were ≤15 mm in diameter.     

Seeking clarity within cloudy effluents: differentiating fungal from bacterial peritonitis in peritoneal dialysis patients

Background

Fungal peritonitis is a serious complication of peritoneal dialysis (PD) therapy with the majority of patients ceasing PD permanently. The aims of this study were to identify risk factors and clinical associations that may discriminate between fungal from bacterial peritonitis.

Methods

We retrospectively identified episodes of fungal peritonitis from 2001–2010 in PD patients at Liverpool and Westmead Hospitals (Australia). Fungal peritonitis cases were matched in a 1∶2 ratio with patients with bacterial peritonitis from each institution''s dialysis registry, occurring closest in time to the fungal episode. Patient demographic, clinical and outcome data were obtained from the medical records.

Results

Thirty-nine episodes of fungal peritonitis (rate of 0.02 episodes per patient-year of dialysis) were matched with 78 episodes of bacterial peritonitis. Candida species were the commonest pathogens (35/39; 90% episodes) with Candida albicans (37%), Candida parapsilosis (32%) and Candida glabrata (13%) the most frequently isolated species. Compared to bacterial peritonitis, fungal peritonitis patients had received PD for significantly longer (1133 vs. 775 catheter-days; p = 0.016), were more likely to have had previous episodes of bacterial peritonitis (51% vs. 10%; p = 0.01), and to have received prior antibacterial therapy (51% vs. 10%; p = 0.01). Patients with fungal peritonitis were less likely to have fever and abdominal pain on presentation, but had higher rates of PD catheter removal (79% vs. 22%; p<0.005), and permanent transfer to haemodialysis (87% vs. 24%; p<0.005). Hospital length of stay was significantly longer in patients with fungal peritonitis (26.1 days vs. 12.6 days; p = 0.017), but the all-cause 30-day mortality rate was similar in both groups. Fluconazole was a suitable empiric antifungal agent; with no Candida resistance detected.

Conclusion

Prompt recognition of clinical risk factors, initiation of antifungal therapy and removal of PD catheters are key considerations in optimising outcomes.