Poul Christensen

Nasopharyngeal Carriage of Bacteria in Otitis-prone and Non-otitis-prone Children in Day-care Centres

During a 2-year period nasopharyngeal specimens were taken monthly on scheduled occasions as well as at episodes of acute otitis media (AOM) from a population of children attending day-care centres. The carriage rates of pneumococci, Haemophilus influenzae and Branhamella catarrhalis in 26 otitis-prone (OP) children when asymptomatic and at episodes of AOM were compared with the carriage rates in 36 non-otitis-prone (NOP) children. Pneumococci, H. influenzae and B. catarrhalis were found as frequently in NOP as in asymptomatic OP children. At AOM episodes only B. catarrhalis was found significantly more often than in the scheduled cultures. The frequencies of the six most commonly isolated pneumococcal types/groups (6, 23, 19, 14, 11, 18) were similar in the cultures taken from NOP and OP children on scheduled occasions as well as in cultures taken at AOM episodes. In contrast to the NOP children H. influenzae and B. catarrhalis were isolated less frequently in the 3-4-year-old than in the 2-3-year-old asymptomatic OP children. Our data indicated that the presence of pneumococci, H. influenzae or B. catarrhalis in the nasopharynx does not per se increase the risk for the development of AOM.

Isolation and Some Properties of an IgG Fc-Binding Protein from Group A Streptococci Type 15

An IgG Fc-binding protein was isolated from alkaline extracts of group A streptococci type 15 by ion-exchange chromatography and immunosorption on an IgG column. Ample use of protease inhibitors was necessary to achieve successful isolation. 600 micrograms protein was obtained from 60 g bacteria (wet weight). The protein appeared homogeneous on agarose gel and sodium dodecyl sulfate polyacrylamide gel electrophoresis and had an apparent molecular weight of 29,500. It contained appreciable amounts of the amino acids glutamic acid, alanine, leucine, aspartic acid and lysine, but little or no tyrosine, phenylalanine, proline, glucosamine or galactosamine. It precipitated human monoclonal IgG of all four sub-classes in agarose gels as well as polyclonal IgG, IgG Fc and normal human serum. It did not precipitate IgG Fab, IgA, IgM, IgD or free kappa or lambda chains.

Neonatal septicemia due to group B streptococci — Perinatal risk factors and outcome of subsequent pregnancies

All cases of early onset group B streptococcal (GBS) septicemia in infants born at Karolinska Hospital 1975-1986 were reviewed. GBS-septicemia was diagnosed in 40 infants within the first five days of life. The incidence was 1.24 per 1000 births. Fifty-five percent of the infants were preterm and 48% were born more than or equal to 12 hours after rupture of membranes. Prematurity and/or prolonged rupture of membranes were present in 83% of all neonates with fatal outcome. Case fatality was 22%. Deliveries by both cesarean section (31%) and vacuum extraction (26%) were increased in the mothers when compared to an overall incidence of 14 and 12% (p less than 0.01). Twenty-four (89%) of 27 mothers had low type specific IgG antibodies against the infecting GBS-serotype. Late onset GBS-septicemia was diagnosed in only two infants during the period. Seventeen mothers went through 24 subsequent pregnancies. In 11 of those the mothers were colonized with GBS and 10 received penicillin prophylaxis during pregnancy and/or delivery. None of the infants born after prophylaxis were colonized with GBS. Two were born prematurely and all had an uneventful course; whereas one infant delivered at 26 weeks gestation of a colonized untreated mother died of GBS-septicemia. Screening of parturients at risk and selective antibiotic prophylaxis may help to prevent early onset GBS-septicemia.

A Longitudinal Study of the Nasopharyngeal Carriage of Pneumococci as Related to Pneumococcal Vaccination in Children Attending Day-care Centres

A long-term study of nasopharyngeal carriership in 405 children, aged 6 months to 5 years, attending day-care centres was performed. The effect of pneumococcal vaccination was evaluated in a double-blind investigation where the children received either Pneumovax (a 14-valent pneumococcal vaccine) or saline. Nasopharyngeal cultures were taken monthly by a trained nurse during a 2-year follow-up period. No difference in pneumococcal carriage was found between vaccinees and controls. Pneumococci were found in 31.9% of all cultures. In day-care centres attended by greater than or equal to 45 children the carriage rate of pneumococci was significantly higher than in centres with less than 45 children. Spreading of pneumococci within day-care centres was common but rather short-lived. Children younger than 2 years showed the highest carriage rates. Pneumococci of group 6 were carried most frequently and for longer periods than groups 19 and 23.

Beneficial effect of pneumococcal vaccination on otitis media in children over two years old

The effect of immunization with a 14-valent pneumococcal vaccine (Pneumovax) was studied in a double-blind trial in which 405 children between the ages of 6 months and 5 years were matched in vaccine/control pairs according to age and history of otitis media. The fact that all the children attended day-care centres ensured that both vaccinees and controls were similarly exposed to upper respiratory tract pathogens. The total incidence of acute otitis media was reduced during a 2-year follow-up period by 24% (P less than 0.05) among those vaccinated between the ages of 2 and 5. For recurrent episodes a decrease by 40% was noted. Protective efficacy was demonstrable during the first post-vaccinational year, but not when more than 1 year had lapsed after the vaccination. These findings suggest that, while the vaccine had not effect on children under 2 years old, it may be a useful aid in preventing recurrent attacks of otitis media in children between 2 and 5 years of age.

Obstetrical care in future pregnancies after fetal loss in group B streptococcal septicemia. A prevention program based on bacteriological and immunological follow-up

Among 22 mothers of infants infected with group B streptococci (GBS), 19 showed markedly low levels of antibodies against the infecting type. Three of the patients with low antibody levels went through a new pregnancy within 1 yr after they had lost an infant (2 patients) or experienced fetal death due to GBS (1 patient). They were still urogenital carriers of the type of GBS causing the previous infection, and their serum levels of type-specific antibodies remained low. All three went through a successful pregnancy following a prevention program comprising antibiotic treatment from the 28th wk of pregnancy.

Chlorhexidine for prevention of neonatal colonization with group B streptococci. II. Chlorhexidine concentrations and recovery of group B streptococci following vaginal washing in pregnant women

The effect of a single washing of the urogenital tract with 0.5 g/l chlorhexidine was studied in 6 women in weeks 38-40 of pregnancy, among whom 5 were carriers of group B streptococci in urethra and/or cervix. The chlorhexidine concentrations varied between 25 and 200 mg/l during the first hour after washing in 5 of the 6 women, whereas one patient showed concentrations below 25 mg/l. With the exception of one patient, all individuals showed concentrations less than 25 mg/l at 3-24 h after washing. A clear suppression of the number of colony-forming units of GBS was already apparent after 60 min and was still evident 6 h after chlorhexidine washing.

The effect of intravenous immunoglobulin treatment in recurrent acute otitis media

The effect of serial intravenous infusion of human immunoglobulin on the frequency of acute otitis media (AOM) episodes and on other upper respiratory tract infections was prospectively studied in a group of 22 otitis-prone children, 1-4 years old. After pair-matching, the children were allocated to immunoglobulin treatment or to a control group. Increased specific IgG antibody activities against pneumococcal types associated with recurrent AOM (rAOM) were generally achieved, but no significant difference was noted in the frequency of AOM attacks or other respiratory tract infections between the immunoglobulin-treated children and their pair-matched untreated controls. The results indicate that, although serum antibody activities against bacteria associated with AOM are increased by immunoglobulin infusions, this does not prevent the development of AOM in children suffering from rAOM.

Nosocomial Klebsiella pneumoniae Infection: Clinical and Hygienic Measures in a Neonatal Intensive Care Unit

An outbreak in a neonatal intensive care nursery of severe infections caused by Klebsiella pneumoniae type K-17 has been studied. Over a 9-month period 20 epidemiologically linked cases of severe septicemia, meningitis and pneumonia were diagnosed. The specific epidemic strain could be identified. After introduction of a policy of hygienic measures the nosocomial infection could be eradicated although colonization still occurred. Thorough handwashing before and after the nursing care of each infant, individual gowning and disposable gloves in the care of infants below 1 500 g were important. The changing bacterial ecology of a neonatal unit should be followed closely by weekly routine throat cultures as well as by cultures of incubators and ventilation equipment. The present investigation has shown the importance of this procedure, which is mandatory for appropriate choice of antimicrobial agents when treating infections in critically ill or very low birth weight infants in the neonatal intensive care unit. Prophylactic antimicrobial treatment is not indicated. Control of K. pneumoniae nosocomial infections can only be achieved by maintaining a high standard of hygiene in the neonatal care.

Age-related variations in anti-streptococcal antibody levels

The present study was undertaken to determine the upper 95% confidence limits (CL) for titres of antibodies to streptolysin O (ASO) and streptococcal DNase B (ADNB) using 741 sera from a general population. The ASO titres in sera from children increased abruptly with increasing age, from a mean of 21 (CL 67) in infants of 3 years or less to 211 (CL 462) in children 7 to 8 years old. In children 9 to 12 years of age titres exhibited a plateau with mean values of 168–258 (CL436–611). In individuals over 20 years the mean ASO titre diminished with increasing age, individuals of 70 years or more showing a mean titre of 83 (CL 169). A similar variation was seen for ADNB. Infants 3 years of age or younger exhibited no detectable ADNB whereas individuals 70 years or more had a mean titre of 11 (CL 91). A maximal mean ADNB titre of 184 (CL 706) was detected in 9-year-old-children. It was concluded that age-related reference values for anti-streptococcal antibodies increase the clinical relevance of the tests.