A 7-month outbreak of 15 cases of postpartum sepsis with group A haemolytic Streptococci (GAS) was stopped when a carrier was identified. Comparing delivery dates with duty rotas revealed that the carrier had been present during delivery in 13 of the 15 cases. The epidemic GAS type, T3-13-B3264, was found in a carbuncle in her groin and in atopic dermatitis lesions behind her ears and on her eyelids. Thus, it was not the microbiological screening of staff that helped detect the carrier. The outbreak went unnoticed for 6 months, as no 2 cases were diagnosed by the same physician and 5 cases were diagnosed by different general practitioners. The main risk factors for infection were presence of the carrier relative risk (relative risk RR 47.8, 95% confidence interval (CI) 10.9-209.5) and suturing of episiotomy (RR 11.0; 95% CI 2.6-47.9). We recommend that a thorough epidemiological investigation should be carried out in every single case of GAS postpartum infection. Despite initial intravenous treatment with penicillin, 8 patients experienced > 15 recurring postpartum GAS infections, such as endometritis, wound infection, tonsillitis, erysipelas and Brodie's abscess. Eradication of GAS should be confirmed after completion of treatment.
During 1981-1993, 229 episodes of bacteraemia due to beta-haemolytic streptococci of groups A, B, C and G were diagnosed in the County of Northern Jutland, Denmark. The annual rates for bacteraemia were quite constant during the 13-year period for each streptococcal group. Group A streptococcal (GAS) bacteraemia was the most frequent, comprising 1.4% of all bacteraemias. The incidence of GAS bacteraemia was 1.8/100,000/year in children 60 years old. With the notable exception of group B streptococcal (GBS) bacteraemia in neonates, beta-haemolytic streptococci of groups B, C (GCS) and G (GGS) were isolated mostly from elderly patients. Except for GBS bacteraemia in neonates, approximately one-third of the bacteraemias in each group was nosocomially acquired. Predisposing factors included operative procedures in GAS and GCS bacteraemia, and diabetes mellitus in GBS bacteraemia. The skin was the most common primary focus in GAC, GCC and GGS bacteraemias, whereas the urinary tract was the commonest focus in GBS bacteraemia in adults. The mortality rates in GAS, GCS, GGS, and adult GBS bacteraemia were 23%, 16%, 17% and 19%, respectively. Of the 23 fatal cases of GAS bacteraemia, 57% died within 24 h after blood cultures had been obtained.
Bacterial, nonnecrotizing cellulitis is a localized and often recurrent infection of the skin. The aim of this study was to identify the beta-hemolytic streptococci that cause acute nonnecrotizing cellulitis infection in Finland.
A case-control study of 90 patients hospitalized for acute cellulitis and 90 control subjects was conducted during the period of April 2004-March 2005. Bacterial swab samples were obtained from skin lesions or any abrasion or fissured toe web. Blood culture samples were taken for detection of bacteremia. The patients, their household members, and control subjects were assessed for pharyngeal carrier status. beta-Hemolytic streptococci and Staphylococcus aureus were isolated and identified, and group A and G streptococcal isolates were further analyzed by T serotyping and emm and pulsed-field gel electrophoresis typing.
beta-Hemolytic streptococci were isolated from 26 (29%) of 90 patients, 2 isolates of which were blood-culture positive for group G streptococci, and 24 patients had culture-positive skin lesions. Group G Streptococcus (Streptococcus dysgalactiae subsp. equisimilis) was found most often and was isolated from 22% of patient samples of either skin lesions or blood, followed by group A Streptococcus, which was found in 7% of patients. Group G streptococci were also carried in the pharynx of 7% of patients and 13% of household members but was missing from control subjects. Several emm and pulsed-field gel electrophoresis types were present among the isolates. Six patients (7%) had recurrent infections during the study. In 2 patients, the group G streptococcal isolates recovered from skin lesions during 2 consecutive episodes had identical emm and pulsed-field gel electrophoresis types.
Group G streptococci, instead of group A streptococci, predominated in bacterial cellulitis. No clear predominance of a specific emm type was seen. The recurrent nature of cellulitis became evident during this study.
The data obtained in the study of an explosive outbreak of acute respiratory diseases, tonsillitis and scarlet fever in one of schools in Moscow have made it possible to exclude the alimentary mechanism of its development and to demonstrate the role of the droplet mechanism of transmission in the appearance of its outbreak. The epidemiological analysis of the outbreak has permitted the formulation of the hypothesis on the conditions of the formation and spread of the epidemic variant of the infective agent; this hypothesis corresponds to the available data in literature on the qualitative changes of the infective agent in the course of the epidemic process. The study has shown that the prophylaxis of the explosive outbreaks of respiratory streptococcal infections must be ensured by the system of epidemiological surveillance with timely intervention into the epidemiological process at its early stages.
Streptococcus equi subspecies zooepidemicus is a rare infection in humans associated with contact with horses or consumption of unpasteurized milk products. On October 23, 2003, the National Public Health Institute was alerted that within one week three persons had been admitted to Tampere University Central Hospital (TaYS) because of S. equi subsp. zooepidemicus septicaemia. All had consumed fresh goat cheese produced in a small-scale dairy located on a farm. We conducted an investigation to determine the source and the extent of the outbreak.
Cases were identified from the National Infectious Disease Register. Cases were persons with S. equi subsp. zooepidemicus isolated from a normally sterile site who had illness onset 15.9-31.10.2003. All cases were telephone interviewed by using a standard questionnaire and clinical information was extracted from patient charts. Environmental and food specimens included throat swabs from two persons working in the dairy, milk from goats and raw milk tank, cheeses made of unpasteurized milk, vaginal samples of goats, and borehole well water. The isolates were characterized by ribotyping and pulsed-field gel electrophoresis (PFGE).
Seven persons met the case definition; six had septicaemia and one had purulent arthritis. Five were women; the median age was 70 years (range 54-93). None of the cases were immunocompromized and none died. Six cases were identified in TaYS, and one in another university hospital in southern Finland. All had eaten goat cheese produced on the implicated farm. S. equi subsp. zooepidemicus was isolated from throat swabs, fresh goat cheese, milk tank, and vaginal samples of one goat. All human and environmental strains were indistinguishable by ribotyping and PFGE.
The outbreak was caused by goat cheese produced from unpasteurized milk. Outbreaks caused by S. equi subsp. zooepidemicus may not be detected if streptococcal strains are only typed to the group level. S. equi subsp. zooepidemicus may be a re-emerging disease if unpasteurized milk is increasingly used for food production. Facilities using unpasteurized milk should be carefully monitored to prevent this type of outbreaks.
The antibiotic susceptibility of 297 invasive isolates of group B streptococci (GBS) to a panel of 12 antibiotics was analysed using the E-test. The isolates (from 123 neonates and 174 adults) were collected from south-west Sweden during the 2 periods 1988-1997 and 1998-2001. The breakpoints of the Clinical and Laboratory Standards Institute were used. All isolates were sensitive to cefotaxime, meropenem, linezolid, vancomycin, moxifloxacin and quinupristin-dalfopristin. Two strains displayed a slightly decreased susceptibility to penicillin G (MIC 0.25 microg/ml) also when tested by the broth dilution method. Two per cent were resistant to erythromycin and 1% to clindamycin. Strains with intermediate sensitivity to erythromycin and clindamycin increased over the 2 study periods. 68% were resistant to doxycycline, and the resistance rate for doxycycline increased over the 2 study periods. No strain was resistant to trimethoprim-sulfamethoxazole. Serotype V dominated among strains with intermediate susceptibility to erythromycin and clindamycin. There were no other relationships between serotypes and decreased sensitivity to any agent. There were no significant differences in susceptibility to any agent tested between strains isolated from neonates and adults. In conclusion, penicillins remain the drug of choice in the region but with the increasing rates of intermediate susceptibility to both erythromycin and clindamycin, antibiotic sensitivity analysis should be performed on the GBS isolates from penicillin-allergic patients.
Serotypes of serious, sometimes fatal, streptococcal infections in Sweden during 1988-1989 were analyzed. The T1M1 type totally dominated, representing almost 70% of all group A streptococci from serious and uncomplicated infections at the peak of the outbreak. Immunoblots of isolates from various patient groups showed that all isolates produced high amounts of erythrogenic toxin (ET) B and high amounts of ET-C, whereas ET-A was released only in small amounts and from few isolates. ELISAs showed high antibody levels to these toxins and to the M1 antigen in patients with uncomplicated infections. Low antibody levels against M1 were seen in patients with bacteremia and in fatal cases; the latter also had low antibody levels against ET-B. It seems likely that a combination of production of large amounts of toxin and low antibody titers to it and to the M antigen of the infecting isolate are determining factors for the outcome of the infection. No signs of primary immune deficiency were noted.
Some Aerococcus-like organisms (ALOs) have recently been described in Denmark. The bacteria were originally isolated from the urine of elderly patients with urinary tract infections. Since 1987, we have identified 17 cases of bacteremia/septicemia in which ALOs have been isolated in pure culture of blood; we report the data from these cases. Six of the patients presented with endocarditis, eight presented with urosepticemia, and three presented with septicemia. In all but one of the reports, the urinary tract was suspected as the focus of infection, and ALOs were isolated from the urine of nine patients. All but one patient had predisposing illnesses; these were predominantly of urinary or cardiac origin. Five patients died of their infection, two survived the infection but eventually died during hospitalization, and 10 recovered. All of the patients received adequate antimicrobial therapy.
During an outbreak of streptococcal tonsillitis in an apartment house area the interfering capacity of alpha-hemolytic streptococci isolated from the inhabitants' throat flora on the beta-hemolytic streptococcal strains recovered during the outbreak was investigated. Strains of alpha-streptococci with an inhibiting capacity on beta-streptococci were isolated mainly from individuals seemingly resistant to streptococcal tonsillitis while patients with repeated tonsillitis often had beta-streptococcal strains inhibiting the growth of the patients own alpha-streptococcal flora. Inhibiting alpha-streptococcal strains were isolated in high frequency in healthy patients that had recently recovered from tonsillitis.
Bacterial analyses were carried out of 2069 udder secretions, isolated from 1481 heifers with mastitis in eight veterinary districts in Sweden. Streptococci, e.g. Streptococcus dysgalactiae and Str. uberis, dominated the bacterial flora, being isolated from 34.4 and 19.5% respectively of heifers with clinical mastitis occurring from puberty up to 14 d post partum. Bacterial species generally regarded as important pathogens in the summer mastitis complex, e.g. Actinomyces pyogenes, Stuart-Schwan coccus and strictly anaerobic bacteria such as Peptostreptococcus indolicus, Fusobacterium necrophorum and Bacteroides melaninogenicus were isolated at low frequencies (13.2, 6.3, 9.4, 3.8 and 1.3% respectively). When the cases of mastitis studied were restricted to those appearing in heifers pre partum, May 15 to October 14 (summer mastitis), these bacterial species were isolated at higher percentages (27.1, 14.4, 21.4, 13.5 and 5.2% respectively). These figures were, nevertheless, still lower than those published in reports from other countries. Whether considered up to 14 d post partum or only pre partum, there were no significant differences in the frequencies of A. pyogenes isolated at different seasons. There were geographical differences in bacterial incidence, e.g. Staphylococcus aureus was isolated significantly more often in northern regions whereas Str. dysgalactiae was more common in the south. This and other Swedish investigations support the theory that A. pyogenes and strictly anaerobic bacteria are 'secondary invaders' that depend on Str. dysgalactiae to cause a primary infection. It is stressed that the udders of all heifers should be examined daily so that cases of mastitis can be treated immediately.