Using data from an ongoing Swedish intervention project, the observed durations of nasopharyngeal carriage of penicillin-nonsusceptible Streptococcus pneumoniae (PNSP) (MIC of penicillin G of >0.5 g/ml) stratified by both pneumococcal serogroup and age of the carrier were compared. The means and 95% confidence intervals (CIs) were estimated by fitting a gamma distribution to the observed duration of carriage for each age and serogroup stratum. The mean observed duration of carriage for all cases was 37 days (95% CI, 35 to 38 days). Children below the age of 5 years carried PNSP for significantly longer periods (43 days; 95% CI, 41 to 45 days) compared with older individuals (25 days; 95% CI, 24 to 27 days). There were also differences within the group of cases below the age of 5 years, as the duration of carriage became significantly shorter for each increasing age step: <1, 1 to 2, and 3 to 4 years. In addition, patients <5 years of age carried serogroups 9 and 14 for significantly shorter periods than groups 6 and 23. Serogroup 9 was also carried for significantly shorter periods than group 19. For patients aged 5 years or older, no significant difference in carriage duration for different ages or serogroups could be noted. As young children have the longest duration of PNSP carriage, interventions aiming to reduce the prevalence in this group are of great importance. The results highlight the importance of taking both serogroup and age of the carriers into account when studying the dynamics of pneumococcal transmission in young children.Nasopharyngeal carriage is an important feature in the epidemiology of Streptococcus pneumoniae (the pneumococcus). Colonization precedes the development of disease in the individual (9, 11), and the nasopharynx acts as the main reservoir from which the bacteria are spread between individuals in the community (3, 4). As high penicillin resistance levels are reported in pneumococci today (13), modeling trends and evaluating the effect of interventions are of great interest. Since prevalence is a composite of both the incidence and the duration of carriage, an understanding of this relationship requires a separation of the two components.Large variations in the duration of nasopharyngeal pneumococcal carriage have been observed. Age has been reported to be an important determinant, with the longest duration of carriage seen in the youngest individuals (7,19,25). Previous studies have also shown that serogroups 6, 19, and 23 are carried for longer periods than other serogroups (11, 25). However, as these serogroups are more common among the youngest children, age-related bias cannot be excluded (7). To our knowledge, durations of carriage adjusted for both the age of the carrier and the pneumococcal serogroup in order to avoid this bias have not been described previously.In the Skåne Region of Sweden, all identified cases of pneumococci with an MIC to penicillin G (PcG) of Ն0.5 g/ml (designated penicillin-nonsusceptible Streptococcus pneumoniae [PNSP]) are monitored with repeated...

In order to evaluate the value of bacterial cultures taken from the throat, 266 patients with MRSA were retrospectively assessed. At the time when MRSA was first detected in the patient, the most frequent sites positive for MRSA were a skin lesion (110 patients, 41%), the anterior nares (109 patients, 41%), and the throat (102 patients, 38%). In 26%, 17%, and 17% of the patients, a skin lesion, the anterior nares, and the throat, respectively, were the only site where MRSA was seen. In 123 patients cultured for MRSA because of a close contact with an already known MRSA patient, 65 patients (53%) were positive for MRSA in their throat and in 40 patients (33%), throat was the only sample site with MRSA at the time when the patient was found to be MRSA positive. 146 of the 266 patients (55%) were colonized with MRSA in the throat any time throughout the period they were MRSA positive. We conclude that throat is an important reservoir for MRSA and that samples taken from the throat should be included in screening patients for MRSA.

In a 6-y period, 114 household contacts connected to newly diagnosed MRSA patients screened for MRSA in the southern part of Sweden. In 22 of 51 (43%) families, 1 to 4 household contact(s) connected to a MRSA patient were positive for MRSA. In the 22 families, 42 of 60 (70%) household contacts were positive for MRSA and transmission of MRSA occurred between adult couples, parents and children, grandparent and children and between siblings. Within a family, MRSA-positive family members had in all but 1 instance identical MRSA strain genotypes (spa types) making intrafamilial spread of MRSA highly probable. MRSA transmission among household contacts may contribute to the prevalence of MRSA in the community and failure to identify MRSA in household contacts may maintain MRSA colonization in an already known MRSA patient. MRSA screening of family members living in the same household as a known MRSA patient should therefore be considered.

Improvement in the high mortality from Staphylococcus aureus septicemia must address the individualized treatment (surgery and/or prolonged antibiotic treatment) of metastatic complications. The aim of this study was to evaluate the results of a comprehensive diagnostic monitoring for metastatic complications in S. aureus septicemia. 68 consecutive patients with S. aureus septicemia were prospectively followed. The performance rate and results of chest X-ray, echocardiography, bone scintigraphy and leukocyte scintigraphy are described. Metastatic complications were found in 53% of the 68 patients, endocarditis in 26%. Positive findings resulted in surgical intervention in 23 patients. The total mortality defined as all deaths within 12 weeks was 24%; 81% of the deceased were > or = 60 years of age. Non-endocarditis patients with peripheral septic metastases had good prognosis. An active monitoring for metastatic complications in S. aureus septicemia is a necessary prerequisite for optimizing treatment and to improve survival rate.

Since 1986, 68% of the Listeria monocytogenes isolates from human cases of invasive listeriosis in Sweden are available for retrospective studies. The aim of the present study was to characterize 601 human invasive isolates of L. monocytogenes in Sweden from 1986 to 2007 by using serotyping and pulsed-field gel electrophoresis. Since 1996, serovar 4b was permanently reduced to the second or third most common serovar in human cases in Sweden. During the latter period, 2000-2007, only 13% belonged to serovar 4b and 71% to 1/2a. The dendrogram, based on pulsovars, reveals two clusters with different serovars. Cluster 1 exhibits serovars 4b and 1/2b, whereas cluster 2 consists of serovar 1/2a. Serovar 1/2a seems to be more heterogeneous than serovar 4b.