Community- and Healthcare-Associated Clostridium difficile Infections, Finland, 2008-2013

We evaluated incidence, case-fatality rate, and trends of community-associated (CA) and healthcare-associated (HA) Clostridium difficile infections (CDIs) in Finland during 2008-2013. CDIs were identified in the National Infectious Disease Register, deaths in the National Population Information System, hospitalizations to classify infections as CA or HA in the National Hospital Discharge Register, and genotypes in a reference laboratory. A total of 32,991 CDIs were identified: 10,643 (32.3%) were CA (32.9 cases/100,000 population) and 22,348 (67.7%) HA (69.1/100,000). Overall annual incidence decreased from 118.7/100,000 in 2008 to 92.1/100,000 in 2013, which was caused by reduction in HA-CDI rates (average annual decrease 8.1%; p<0.001). The 30-day case-fatality rate was lower for CA-CDIs than for HA-CDIs (3.2% vs. 13.3%; p<0.001). PCR ribotypes 027 and 001 were more common in HA-CDIs than in CA-CDIs. Although the HA-CDI incidence rate decreased, which was probably caused by increased awareness and improved infection control, the CA-CDI rate increased.

Impact of ten-valent pneumococcal conjugate vaccination on invasive pneumococcal disease in Finnish children--a population-based study.

BACKGROUND: The ten-valent pneumococcal conjugate vaccine (PCV10) was introduced into the Finnish National Vaccination Program (NVP) in September 2010 with a 2+1 schedule (3, 5, 12 months) without catch-up vaccinations. We evaluated the direct and indirect effects of PCV10 on invasive pneumococcal disease (IPD) among children ≤5 years of age during the first three years after NVP introduction. METHODS: We conducted a population-based, observational follow-up study. The cohort of vaccine-eligible children (all children born June 1, 2010 or later) was followed from 3 months of age until the end of 2013. For the indirect effect, another cohort of older children ineligible for PCV10 vaccination was followed from 2011 through 2013. Both cohorts were compared with season- and age-matched reference cohorts before NVP introduction. National, population-based laboratory surveillance data were used to compare culture-confirmed serotype-specific IPD rates in the vaccine target and reference cohorts by using Poisson regression models. RESULTS: The overall IPD rate among vaccine-eligible children was reduced by 80% (95%CI 72 to 85); the reduction in vaccine-type IPD was 92% (95%CI 86 to 95). However, a non-significant increase in non-vaccine type IPD was observed. During 2012-2013, we also observed a 48% (95%CI 18 to 69) reduction in IPD among unvaccinated children 2 to 5 years of age, which was mostly attributable to the ten vaccine serotypes. CONCLUSIONS: This is the first population-based study investigating the impact of PCV10 introduction without prior PCV7 use. A substantial decrease in IPD rates among vaccine-eligible children was observed. A smaller and temporally delayed reduction among older, unvaccinated children suggests that PCV10 also provides indirect protection against vaccine-type IPD. Changes in serotype distribution warrant continuous monitoring of potential increases in non-vaccine serotypes.

Standard method for detecting upper respiratory carriage of Streptococcus pneumoniae: updated recommendations from the World Health Organization Pneumococcal Carriage Working Group.

In 2003 the World Health Organization (WHO) convened a working group and published a set of standard methods for studies measuring nasopharyngeal carriage of Streptococcus pneumoniae (the pneumococcus). The working group recently reconvened under the auspices of the WHO and updated the consensus standard methods. These methods describe the collection, transport and storage of nasopharyngeal samples, as well as provide recommendations for the identification and serotyping of pneumococci using culture and non-culture based approaches. We outline the consensus position of the working group, the evidence supporting this position, areas worthy of future research, and the epidemiological role of carriage studies. Adherence to these methods will reduce variability in the conduct of pneumococcal carriage studies undertaken in the context of pneumococcal vaccine trials, implementation studies, and epidemiology studies more generally so variability in methodology does not confound the interpretation of study findings.

Detection of virulence genes of Clostridium difficile by multiplex PCR.

Clostridium difficile strains belonging to the PCR ribotype 027, pulse-field gel electrophoresis (PFGE) type NAP1, toxinotype III and restriction endonuclease analysis group BI harbouring mutations in the tcdC gene and possessing binary toxin components A and B have been described to cause epidemics with increased morbidity and mortality. In the present study we developed a conventional multiplex PCR designed to detect selected virulence associated markers of the hypervirulent C. difficile PCR ribotype 027. The multiplex PCR assay detected the major toxins A and B, binary toxin components A and B as well as a possible deletion in the tcdC gene: a characteristic pattern of amplification products for the PCR ribotype 027 strains was detected. This rather simple method was specific for the screening of this hypervirulent C. difficile strain. The correlation between the multiplex PCR and PCR ribotyping methods was excellent. The sensitivity and specificity were 100% in our epidemiological situation. In conclusion, this multiplex PCR was found useful in the preliminary screening for the hypervirulent C. difficile PCR ribotype 027.

Methicillin-sensitive Staphylococcus aureus bacteraemia and endocarditis among injection drug users and nonaddicts: host factors, microbiological and serological characteristics.

BACKGROUND: Endocarditis has been associated with lower mortality and fewer complications among injection drug users (IDUs) than nonaddicts in Staphylococcus aureus bacteraemia (SAB). The better prognosis of IDUs has not been clarified but it has generally been explained by younger age and other host factors. In this study, bacterial strains, their virulence factors, and host immune responses were compared among IDUs and nonaddicts with SAB, including those with and without endocarditis. METHODS: A total of 430 consecutive adult patients with methicillin-sensitive SAB were followed prospectively for 3 months. All 44 IDUs were included, and 44 nonaddicts as controls for them. According to the modified Duke criteria, 20 patients in both groups had endocarditis. For each addict without endocarditis, an age and sex matched nonaddict was selected as a control. S. aureus isolates were assigned a genotype by PFGE, Panton-Valentine leukocidin (PVL), staphylokinase (SAK), protease, and haemolysin production. Acute and convalescent sera were tested for antibodies to alpha-haemolysin (ASTA) and teichoic acid (TAA). RESULTS: There were no differences between IDUs and nonaddicts with SAB in the proportion of patients with a deep infection (98% vs 86%, P=0.06) or a thromboembolic complication (30% vs 14%, P=0.12). Endocarditis among IDUs was not associated with any specific strains, and only the FIN-4 strain was observed more often in IDUs than in nonaddicts (21% vs 5%, P=0.03). The majority of isolates (98%) were PVL negative, and there were no differences in the numbers of SAK, protease and haemolysin production among strains between IDUs and nonaddicts. However, haemolytic properties were found more frequently in strains from IDUs without endocarditis than those with endocarditis (88% vs 47%, P=0.007). IDUs displayed more often elevated TAA titers than nonaddicts, especially in endocarditis at acute phase (33% vs 5%, P=0.04) and at convalescent phase (50% vs 10%, P=0.01). The ASTA titer was more frequently initially positive among IDUs without endocarditis than with endocarditis (44% vs 6%, P=0.01). CONCLUSIONS: Characterization of the bacterial strains and their virulence factors, and host immune responses did not reveal significant differences between IDUs and nonaddicts with similar clinical picture of SAB. Serological tests were not helpful in identifying patients with endocarditis.

The pls gene found in methicillin-resistant Staphylococcus aureus strains is common in clinical isolates of Staphylococcus sciuri.

pls, a gene found in type I staphylococcal cassette chromosome mec (SCCmec) regions of methicillin-resistant Staphylococcus aureus strains, was present in 12 of the 15 human clinical Staphylococcus sciuri isolates studied. Pls was expressed in the S. sciuri isolates, although at a lower level than in S. aureus. Other parts of SCCmec could also be found in the S. sciuri genome.

Myiasis during adventure sports race.

Travelers who have visited tropical areas may exhibit aggressive forms of obligatory myiases, in which the larvae (maggots) invasively feed on living tissue. The risk of a traveler's acquiring a screwworm infestation has been considered negligible, but with the increasing popularity of adventure sports and wildlife travel, this risk may need to be reassessed.

Alloiococcus otitidis in acute otitis media.

OBJECTIVE: The bacterium Alloiococcus otitidis has been found to be associated with otitis media with effusion (OME). When the culture method is used, its detection rate is low, whereas applying the polymerase chain reaction (PCR) yields significantly higher frequencies. This study was carried out to investigate the incidence of A. otitidis in children with acute otitis media (AOM). METHODS: Multiplex PCR was used to detect A. otitidis together with Haemophilus influenzae, Moraxella catarrhalis, and Streptococcus pneumoniae in the middle ear effusions (MEEs) of 118 children with AOM. The clinical outcome of AOM and the bacterial findings of MEEs were compared. RESULTS: A. otitidis was detected in 25% (30 of 118) of the tested MEE samples. Children over 2 years of age had significantly more often A. otitidis-positive MEEs (37%; 22 of 59) than younger children (14%; 8 of 59) (chi-square test, P<0.01). There were no significant differences in the duration, clinical failures (after antibiotic treatment), or number of recurrences of AOM between the A. otitidis-positive and A. otitidis-negative children. CONCLUSIONS: A. otitidis is found from the MEEs of AOM. The present data suggest that it has no clinical significance in AOM, and it does not increase the risk of developing OME after AOM.

Microbiology of chronic hyperplastic sinusitis.

BACKGROUND: Patients with chronic hyperplastic sinusitis (CHS) form a heterogeneous group with similar symptoms and similar treatment despite of possible different mechanisms behind the disease. In the present study we focused on the microbiological findings in CHS and compared these results to the patient history in order to find out a possible explanation for the aetiology and chronicity of CHS. METHODS: In 30 patients the sinus mucus was collected under endoscopic sinus surgery. Samples from 20 healthy volunteers were collected by nasal lavage. Eosinophil staining, bacterial culturing and fungal staining and culturing were done. Histological samples were obtained from all patients. RESULTS: Bacterial cultures were positive in 93% of the patients compared to 70% in controls. Staphylococcus aureus and coagulase-negative Staphylococci were the two most common findings in both groups. A total of seven patients had positive fungal finding. The only fungal genus found was Aspergillus. In the control group no samples were positive for fungi. CONCLUSIONS: Microbiological findings do not seem to explain the chronic course of CHS, but fungi may play some part in the pathophysiology of the disease. These results may be more a reflection of a change in the environment in the paranasal sinuses and a change in normal flora than the actual cause of CHS.

The clinical role of Alloiococcus otitidis in otitis media with effusion.

OBJECTIVE: To investigate the presence of Alloiococcus otitidis (A. otitidis) in MEEs from patients with otitis media with effusion (OME) using PCR and to correlate the findings with the clinical picture of children with OME for assessing the clinical role of A. otitidis in OME. METHODS: Bacterial culture and PCR were used to detect A. otitidis, Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis in MEE samples from 123 patients with OME. The culture and PCR results and the clinical picture of the patients were compared. RESULTS: Bacteria were cultured in 55 (45%) of the 123 MEEs, and major pathogens (S. pneumoniae, H. influenzae and M. catarrhalis) were found in 40 (33%); A. otitidis was not found in culture. PCR of the MEEs yielded positive results for one or more of the four tested pathogens in 108 (88%) of the samples and 25 (20%) were positive for A. otitidis. The effusions that persisted 3 months or longer had a higher prevalence of A. otitidis than those with shorter durations (P=0.03). A. otitidis was found to be more often positive in PCR in mucoid MEEs than in mucoserous MEEs (30 vs. 9%; P=0.015). CONCLUSIONS: While A. otitidis is extremely difficult to detect with bacterial culture, PCR provides a sensitive and specific means for detecting it. A. otitidis is associated with a more prolonged course and mucoid MEEs in OME. Thus, its existence seems to be related to a more chronic stage of OME, but its pathogenic potential should be the subject of further investigation.

Role of pneumococcal surface protein C in nasopharyngeal carriage and pneumonia and its ability to elicit protection against carriage of Streptococcus pneumoniae.

Previous studies suggested that PspC is important in adherence and colonization within the nasopharynx. In this study, we conducted mutational studies to further identify the role PspC plays in the pathogenesis of pneumococci. pspC and/or pspA was insertionally inactivated in a serotype 2 Streptococcus pneumoniae strain and in a serotype 19 S. pneumoniae strain. In the mouse colonization model, pneumococcal strains with mutations in pspC were significantly attenuated in their abilities to colonize. In a mouse pneumonia model, strains with mutations in pspC were unable to infect or multiply within the lung. Using reverse transcriptase PCR we were able to demonstrate that pspC is actively transcribed in vivo, when the bacteria are growing in the nasal cavity and in the lungs. In the bacteremia model, a strain mutated for pspC alone behaved like the wild type, but the absence of both pspC and pspA caused accelerated clearance of the bacteria. Intranasal immunization with PspC with cholera toxin subunit B as an adjuvant protected against intranasal challenge. Evidence was also obtained that revertants that spontaneously acquired PspC expression could multiply and colonize the nasal tissue. This latter finding strongly indicates that pneumococci are actively metabolizing and growing while in the nasopharynx.