Reduction in pediatric hospitalizations for varicella-related invasive group A streptococcal infections in the varicella vaccine era

OBJECTIVES: To assess changes in hospitalization rates for invasive group A streptococcal (IGAS) and varicella-associated IGAS (VA-IGAS) infections at a pediatric hospital over a period of 9 years, to characterize clinical features of patients with IGAS infections, and to assess frequency of macrolide-resistant IGAS isolates.Study design Medical records of all hospitalized patients with group A streptococcus isolated from a normally sterile site from 1993 to 2001 were reviewed. Data collected included demographics, clinical course, microbiologic features, outcome, and presence of streptococcal toxic shock syndrome (STSS) or necrotizing fasciitis (NF). Annual hospitalization rates for IGAS were determined. RESULTS: There were 144 patients with IGAS infections, including 11 (8%) with STSS or NF. Overall mortality rate was 2% (3/144) but 18% (2/11) among patients with STSS or NF. Preexisting varicella was present in 16% (23/144); 4 of 23 VA-IGAS cases had STSS or NF. Although there was no change in annual hospitalization rates for IGAS infections during the study period, the percentage of VA-IGAS hospitalizations decreased from 27% in the prevaccine era (1993 to 1995), to 16% during vaccine implementation (1996 to 1998) and 2% during widespread vaccine use (1999 to 2001) (linear-by-linear association, P=.001). Macrolide resistance was low in 1993 to 1995 (5%, 1/19) and 1996 to 1998 (0%, 0/42) among tested IGAS isolates and increased significantly in 1999 to 2001 (13%, 5/38) (Fisher exact, P=.035). CONCLUSIONS: A decline in pediatric varicella-related IGAS hospitalizations was temporally associated with utilization of varicella vaccine. These data reinforce the importance of universal varicella vaccination for children. Increasing macrolide resistance among IGAS isolates indicates a need for continued surveillance.     

Splenic abscess caused by group A beta-haemolytic streptococcus

A case of a pyoderma complicated with splenic abscess and bacteraemia caused by group A streptococcus was treated successfully with antibiotics alone for 4 weeks. To our knowledge, this is the first reported case of splenic abscess associated with group A streptococcal bacteraemia. Advances in antibiotic therapy and imaging techniques have improved the management and outcomes of splenic abscesses. Clinicians should be aware of the possibility of splenic abscess after a pyoderma or a sepsis-like episode. CONCLUSION: Splenic abscesses can be diagnosed by serial ultrasound or CT scan examinations and should be treated with antibiotics for 4-6 weeks.     

Early-onset group B streptococcal sepsis in a preterm infant with Kostmann syndrome

A preterm infant died of group B streptococcal sepsis 7 h after birth. The infant's complete blood count showed total agranulocytosis. Histopathology of the major organs showed significant bacterial invasion without infiltration of polymorphonuclear leucocytes. Examination of the bone marrow revealed normal cellularity of the granulocyte precursors with arrested maturation. These findings are consistent with Kostmann syndrome. CONCLUSION: It is suggested that in patients with deteriorating early-onset infection, underlying congenital abnormalities in host defence, such as Kostmann syndrome, should be considered.     

Invasive group B streptococcal infections in Finland: a population-based study

We analyzed surveillance data on group B streptococcus (GBS) infection in Finland from 1995 to 2000 and reviewed neonatal cases of early-onset GBS infection in selected hospitals in 1999 to 2000. From 1995 to 2000, 853 cases were reported (annual incidence 2.2-3.0/100,000 population). We found 32-38 neonatal cases of early-onset GBS disease per year (annual incidence 0.6-0.7/1,000 live births). In five hospitals, 35% of 26 neonatal cases of early-onset GBS infection had at least one risk factor: prolonged rupture of membranes, preterm delivery, or intrapartum fever. Five of eight mothers screened for GBS were colonized. In one case, disease developed despite intrapartum chemoprophylaxis. Although the incidence of early-onset GBS disease in Finland is relatively low, some geographic variation exists, and current prevention practices are suboptimal. Establishing national guidelines to prevent perinatal GBS is likely to reduce the incidence of the disease.     

Pyruvate oxidase in Streptococcus sanguis under various growth conditions

Streptococcus sanguis ATCC 10556 was grown in batch culture under aerobic and anaerobic conditions. The organism was also kept in aerated nitrogen- and sugar-limited continuous cultures. Pyruvate oxidase was induced under aerobic conditions and the highest specific activity of the enzyme was found in aerated batch cultures in the early phase of exponential growth. A steady-state growth of the organism could not be established in aerated continuous culture, unless catalase was included in the culture medium. In aerated nitrogen-limited continuous culture with an excess of sugar there was very low pyruvate oxidase activity, and lactate was the only fermentation product. In aerated sugar-limited continuous culture there was high pyruvate oxidase activity, and acetate was the main fermentation product. This indicated that pyruvate oxidase was the key enzyme in converting pyruvate into fermentation products in the aerated sugar-limited continuous culture. The pyruvate oxidase reaction requires high concentrations of pyruvate, phosphate and oxygen for maximum velocity. These concentrations are probably never reached intracellularly. The limited supply of substrates may thus be the most important factor in modulating the activity of the enzyme. The enzyme is hysteretic and this may also contribute to the adaptation of the enzyme activity to the metabolic processes of the cell. The combination of pyruvate oxidase and NAD(P)H-OSCN-oxidoreductase in S. sanguis and the presence of thiocyanate and salivary peroxidase in saliva may provide an ecological advantage to S. sanguis in habitats exposed to saliva.     

Prediction of caries increment in Scottish adolescents

Salivary, clinical, and microbiological factors were compared with subsequent 2-yr caries increment in a group of 372 Scottish adolescents. The caries increment was significantly correlated with previous caries experience, salivary buffering capacity and counts of lactobacilli, mutans streptococci and candida. Veillonella levels and salivary flow rate were not correlated with caries increment. Significant improvements in the predictions were obtained when the results of more than one test were included using stepwise regression analysis. On an individual basis, using stepwise discriminant analysis, the caries increment group (low, medium, or high) was identified correctly in 49% of all subjects, but this was reduced to 45% if previous caries experience was excluded from the analysis.     

Group A Streptococcus vulvovaginitis in breastfeeding women

Group A beta-hemolytic streptococcus-associated vulvovaginitis is uncommon in adult women. Clinicians should include group A beta-hemolytic streptococcus as a possible cause of vulvovaginal symptoms in breastfeeding women. Along with appropriate antibiotic therapy, vaginal estrogen therapy may be considered to diminish susceptibility to recurrent infection in women with vaginal atrophy.     

Evaluation of Group B Streptococcus Differential Agar for detection and isolation of Streptococcus agalactiae

In total, 320 vaginal or rectal swabs were cultured on Granada medium (GM) or Group B Streptococcus Differential Agar (GBSDA), and were also inoculated into LIM broth (Todd-Hewitt broth supplemented with selective antibiotics), for detection of group B Streptococcus (GBS). Overall, GBS isolates were detected on 53 of the 320 swabs; 47 of these isolates grew on both GM and GBSDA, five only on GBSDA, and one only following subculture from LIM broth. GBSDA appears to be a valid alternative to GM for the growth of GBS isolates from pregnant women.     

Group A β-hemolytic streptococcal pharyngitis in children

Group A β-hemolytic streptococcus (GABHS) is the most common bacterial cause of acute pharyngitis in children. Because clinical findings can be nonspecific, even experienced physicians cannot reliably diagnose GABHS pharyngitis solely on the basis of clinical presentation. Suspected cases should be confirmed by a throat culture or a rapid antigen detection test before antibiotic therapy is initiated. Microbiologic testing is generally not necessary in patients with pharyngitis whose clinical and epidemiologic findings are not suggestive of GABHS. Clinical score systems have been developed to help physicians decide which patients should undergo diagnostic testing and to reduce the unnecessary use of antibiotics. Antibiotic therapy should be initiated as soon as the diagnosis is confirmed. Penicillin V remains the drug of choice. Alternative therapy, eg, with cephalosporin or macrolide, is often sought because of penicillin allergy, noncompliance, and treatment failure.