Invasive infections caused by Neisseria meningitidis, Haemophilus influenzae and Streptococcus pneumoniae among children in St Petersburg, Russia.

This study investigated the causes of invasive bacterial infections in children aged <15 years in St Petersburg, Russia, during 2001-2003, using culture and antigen detection methods (rapid antigen latex agglutination (RAL)) for normally sterile body fluids. A pathogen was detected in 90 cases (culture 50, RAL 40). Neisseria meningitidis was the most common pathogen (66%), followed by Haemophilus influenzae (19%) and Streptococcus pneumoniae (16%). Meningitis was the main clinical diagnosis (68/90, 76%), with N. meningitidis serogroup B, H. influenzae type b (Hib), and S. pneumoniae serogroup 1 being the most common isolates. Hib was less prevalent in St Petersburg than it was in industrialised countries before the introduction of Hib vaccinations.

Predictors of death from severe pneumonia among children 2-59 months old hospitalized in Bohol, Philippines: implications for referral criteria at a first-level health facility.

OBJECTIVE: To determine predictors of death among children 2-59 months old admitted to hospital with severe pneumonia. METHODS: Prospective observational study from April 1994 to May 2000 to investigate serious infections in children less than 5 years old admitted to a tertiary care government hospital in a rural province in central Philippines. The quality of clinical and laboratory work was monitored. The WHO classification for severe pneumonia was used for patient enrolment. RESULTS: There were 1249 children with severe pneumonia and no CNS infection. Thirty children died. Using univariate analysis, the following factors were significantly associated with death: age 2-5 months, dense infiltrates on chest radiography and presence of definite bacterial pathogens in the blood. Stepwise logistic regression analysis revealed the following independent predictors of death: age 2-5 months, weight for age z-score less than -2 SD, dense infiltrates on chest radiography and definite pathogens isolated in the blood. When the results of chest radiographs and blood cultures were not included to mimic facilities available at first-level facilities, age 2-5 months and weight for age z-score less than -2 SD remained independent predictors of death. CONCLUSION: When resources are limited, children with lower chest wall indrawing (severe pneumonia) who are 2-5 months old or moderately to severely malnourished should be referred for immediate higher-level care.

Streptococcus pneumoniae in nasopharyngeal secretions of healthy children: comparison of real-time PCR and culture from STGG-transport medium.

Precise methods for the detection of Streptococcus pneumoniae are needed for predicting the consequences of pneumococcal conjugate vaccines on nasopharyngeal carriage. In this study, 400 nasopharyngeal swab samples from children were analyzed using a real-time pneumolysin (ply)-PCR method. The specimens were originally collected into STGG-transport medium and cultured in 1999, after which they were stored at -80 degrees C until analyzed by real-time PCR in 2001. The sensitivities of real-time PCR and culture methods were also studied by analyzing 10-fold dilutions of a pneumococcal broth culture using both methods. Of the 400 nasopharyngeal swab samples, 158 (40%) were positive in culture and 276 (69%) by real-time PCR. A minor part (4%) of the culture-positive samples remained negative by PCR. There was a trend between the quantity of genome equivalents detected by PCR and the number of colonies found in culture. When analyzing 10-fold dilutions of a pneumococcal broth culture, a higher number of genome equivalents were detected using real-time PCR than the number of colonies detected by culture. Quantitative real-time PCR provides feasible means for quantifying pneumococcal carriage. Further studies are needed to confirm that positive PCR findings really indicate the presence of viable pneumococcus in nasopharyngeal specimens.

Evaluation of gene-technological and conventional methods in the identification of Streptococcus pneumoniae.

To find reliable methods able to identify the "difficult" Streptococcus pneumoniae isolates, an in-house polymerase chain reaction (PCR) for pneumolysin gene (Ply-PCR) and a commercial RNA hybridisation test (AccuProbe) were evaluated. Selected isolates of suspected pneumococci, sent for confirmation of identification and for serotyping, were classified into four groups based on their optochin sensitivity and capsule reaction. All isolates in Group 1, which consisted of 24 typical, optochin-sensitive, encapsulated pneumococcal strains, were positive in the Ply-PCR and AccuProbe tests. In Group 2, which consisted of 25 optochin-sensitive, but unencapsulated pneumococcal strains, all the isolates were positive in the Ply-PCR test, and 23 were positive in the AccuProbe test. In Group 3, which consisted of 15 atypical, optochin-resistant but encapsulated pneumococci, 12 of the isolates were positive in the Ply-PCR and 12 in the AccuProbe test, and 11 of these 12 strains were positive in both tests. In Group 4, which consisted of 36 equivocal optochin-resistant, unencapsulated isolates, 15 strains were positive in the Ply-PCR test and 8 strains in the AccuProbe test. As a conclusion, the Ply-PCR and AccuProbe tests identified similarly typical optochin-sensitive pneumococci, but gave partly controversial results about atypical pneumococci. Thus, they did not reliably help in the identification of suspected pneumococcal isolates lacking the conventional characteristics of pneumococcus.

Negative pressure tympanograms in children less than 2 years of age--different bacterial findings in otitis media by tympanometric results.

OBJECTIVE: The interpretation of negative pressure tympanograms as indicators of the presence of middle ear fluid has been ambiguous. Our purpose was to assess the occurrence and implications of negative pressure tympanograms and to study their association with bacterial pathogens in otitis media. METHODS: Altogether 329 infants were enrolled at a well-baby clinic for the Finnish Otitis Media Cohort Study, a longitudinal prospective cohort study. The children were closely followed in a special study clinic from 2 to 24 months of age for respiratory diseases, especially acute otitis media. Children were examined at the study clinic with tympanometry and pneumatic otoscopy whenever visiting the study clinic for respiratory disease. Myringotomy with aspiration was performed if middle ear fluid was suspected in otoscopy. Occurrence of middle ear fluid in ears with negative pressure tympanograms (less than -100 daPa) was assessed. Nested case control design matched by visit type (acute or follow-up visit) and month of visit was used for analysis of association of bacterial pathogens and tympanometric results. RESULTS: Middle ear fluid was encountered in 15% of ears with negative tympanometric peak pressure, a lower proportion than described previously. In otitis media with a negative tympanometric peak pressure, 71% of bacterial cultures remained negative for the main pathogens, compared to 36% in matched controls (P<0.001). Especially Streptococcus pneumoniae but also Haemophilus influenzae were rarely found in samples from negative pressure ears. Moraxella catarrhalis was equally often found. CONCLUSIONS: Negative pressure tympanogram is a poor indicator for the presence of middle ear fluid. Furthermore, if otitis media is diagnosed with negative tympanometric peak pressure negative middle ear bacterial culture for the main pathogens is highly probable. Expectant follow-up might be more appropriate than routine antibiotic treatment.

Nasopharyngeal carriage of Streptococcus pneumoniae in Finnish children younger than 2 years old.

To describe the natural course of nasopharyngeal carriage of Streptococcus pneumoniae and its relationship to acute otitis media (AOM), 329 Finnish children were followed from ages 2 to 24 months. In total, 3024 nasopharyngeal (NP) swabs (obtained at 10 scheduled healthy visits) and 2007 NP aspirates (obtained during respiratory infections) were cultured. Carriage during health increased gradually (9%-43%) with age. Within 4 age intervals, carriage was lower during health (13%-43%) than during respiratory infection without AOM (22%-45%). Higher proportions of positive samples were found during AOM (45%-56%), in particular during pneumococcal AOM (97%-100%). Antimicrobial treatment reduced carriage only temporarily. The most frequent NP serotypes were 6B, 6A, 11, 19F, and 23F. Both age and health status were important determinants of NP carriage of S. pneumoniae and these features should be considered carefully during analysis of carriage rates.

Bacteriology of acute otitis media in a cohort of Finnish children followed for the first two years of life.

BACKGROUND: Timely information on the bacteriology of primary, noncomplicated acute otitis media (AOM) may today be needed more than ever, because of the increasing antimicrobial resistance of its major bacterial causes and because of the potential of new pneumococcal and other bacterial vaccines for prevention of AOM. METHODS: The study followed 329 children from 2 to 24 months of age at scheduled healthy visits and sick visits at the study clinic. Whenever AOM was diagnosed during the follow-up, myringotomy was performed and middle ear fluid was aspirated for bacterial culture. RESULTS: At least one middle ear fluid sample was available from 772 AOM events; Streptococcus pneumoniae (Pnc) was isolated in 201 (26%), Moraxella catarrhalis (Mc) in 177 (23%) and Haemophilus influenzae (Hi) in 174 events (23%). The incidence of Pnc AOM peaked at 12 months of age, whereas the incidence of Mc AOM showed the first peak at 6 months and Hi AOM at 20 months. Pnc AOM showed less prominent seasonality in occurrence than Mc and Hi AOM. Hi was a rare cause of the first 2 AOM episodes (13%) but became increasingly common from the third episode on (32% on average). CONCLUSIONS: Pnc, Mc and Hi were almost equally common findings in AOM. Pnc seems to be the most pathogenic of these three, the role of Mc is increasing and Hi is clearly associated with recurrent AOM.

Efficacy of a pneumococcal conjugate vaccine against acute otitis media.

BACKGROUND: Ear infections are a common cause of illness during the first two years of life. New conjugate vaccines may be able to prevent a substantial portion of cases of acute otitis media caused by Streptococcus pneumoniae. METHODS: We enrolled 1662 infants in a randomized, double-blind efficacy trial of a heptavalent pneumococcal polysaccharide conjugate vaccine in which the carrier protein is the nontoxic diphtheria-toxin analogue CRM197. The children received either the study vaccine or a hepatitis B vaccine as a control at 2, 4, 6, and 12 months of age. The clinical diagnosis of acute otitis media was based on predefined criteria, and the bacteriologic diagnosis was based on a culture of middle-ear fluid obtained by myringotomy. RESULTS: Of the children who were enrolled, 95.1 percent completed the trial. With the pneumococcal vaccine, there were more local reactions than with the hepatitis B vaccine but fewer than with the combined whole-cell diphtheria-tetanus-pertussis and Haemophilus influenzae type b vaccine that was administered simultaneously. There were 2596 episodes of acute otitis media during the follow-up period between 6.5 and 24 months of age. The vaccine reduced the number of episodes of acute otitis media from any cause by 6 percent (95 percent confidence interval, -4 to 16 percent [the negative number indicates a possible increase in the number of episodes]), culture-confirmed pneumococcal episodes by 34 percent (95 percent confidence interval, 21 to 45 percent), and the number of episodes due to the serotypes contained in the vaccine by 57 percent (95 percent confidence interval, 44 to 67 percent). The number of episodes attributed to serotypes that are cross-reactive with those in the vaccine was reduced by 51 percent, whereas the number of episodes due to all other serotypes increased by 33 percent. CONCLUSIONS: The heptavalent pneumococcal polysaccharide-CRM197 conjugate vaccine is safe and efficacious in the prevention of acute otitis media caused by the serotypes included in the vaccine.

Blood culture confirmed typhoid fever in a provincial hospital in the Philippines.

Epidemiological features of blood culture confirmed typhoid fever and antibiotic sensitivity of isolated Salmonella typhi strains were investigated in Bohol Province in Central Philippines from where no earlier information of these was avialable. Typhoid fever is endemic elsewhere in the Philippines (eg Metropolitan Manila and surroundings) where also multidrug resistant S. typhi strains have been detected. A laboratory for surveillance of invasive bacterial infections was established in a tertiary care government hospital, in Bohol, Central Philippines, in 1994. Patients with suspected typhoid fever or other serious infection were managed and blood cultures from them were taken according to clinicians' judgment. Blood cultures were processed and the isolated bacteria identified using generally accepted methods. S. typhi and other Salmonella isolates were identified using commercial antisera. Patient data were collected from hospital records. Of a total of 4,699 blood cultures done during a period of 3 3/4 years, 1,530 (32%) were requested for suspected typhoid fever. S. typhi was the most common pathogen isolated from 422 patients (8.9%), followed by S. paratyphi A from 55 patients (1%). Most patients were young adults (43%) and school age children (28%). Male:female ratio was 1.5:1. Among the 422 patients, there were 9 (2%) deaths due to typhoid fever, all with complications. All S. typhi isolates were sensitive to chloramphenicol, cotrimoxazole, and ampicillin. Our observation on blood culture confirmed typhoid fever demonstrates its importance as a major infectious disease in Bohol and gives a sound basis for treatment of typhoid patients and for further clinical and epidemiologic studies of typhoid fever and for following antibiotic sensitivity of S. typhi in Bohol and elsewhere in the Philippines.

Treatment of acute otitis media with an antiadhesive oligosaccharide: a randomised, double-blind, placebo-controlled trial.

BACKGROUND: Antiadhesive compounds are promising candidates for prevention or treatment of infections. We have investigated the efficacy of such an agent, 3'-sialyllacto-N-neotetraose (NE-1530), given intranasally for prophylaxis of acute otitis media and for effect on nasopharyngeal carriage of bacteria. METHODS: We did a randomised, double-blind placebo-controlled study at one study site. 507 healthy children were randomly assigned either NE-1530 (n=254) or placebo (253) as intranasal sprays twice daily during 3 months. The children were examined by the study physicians once a month and during illness. Treatment efficacy was estimated from Cox proportional hazards model. A sample of nasopharyngeal secretion was taken at every visit for culture of Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis. Adverse events were recorded in study diaries. FINDINGS: At least one event of acute otitis media was diagnosed in 108 (43%) of 254 children in the NE-1530 group and in 86 (34%) of 253 children in the placebo group. The efficacy of treatment was negative, -27% (95% CI -68 to 5; p=0.10). The nasopharyngeal carriage of S pneumoniae, H. influenzae, and M. catarrhalis was not affected by treatment, and the adverse event profiles were almost identical for NE-1530 and placebo. INTERPRETATION: NE-1530 did not have a beneficial effect on the occurrence of acute otitis media or on the nasopharyngeal carriage of bacteria in children.

Invasive bacterial infections of children in a rural province in the central Philippines.

The etiology of invasive bacterial infections was studied among 956 Filipino children less than five years old who fulfilled the World Health Organization criteria for severe or very severe pneumonia or had suspected meningitis or sepsis. The most common invasive infections were due to Streptococcus pneumoniae (12 [1.3%]) and Haemophilus influenzae (12 [1.3%]); including four cases of pneumococcal meningitis and 11 cases of H. influenzae meningitis. Type 1 was the most common (six of the 12 isolates) of the pneumococcal serotypes. Serotypes/groups 1, 6, 14, and 23 accounted for 91.7% of the invasive isolates. The majority of the H. influenzae strains from blood (10 out of 10) and cerebrospinal fluid (6 out of 7) were type b. Almost all of the invasive S. pneumoniae (9 out of 12) and H. influenzae (11 out of 12) infections were seen before one year of age, which stresses the need to investigate early immunization of children for H. influenzae type b and S. pneumoniae, as well as maternal immunization to maximize the potential of immunoprophylaxis.

Establishing a laboratory for surveillance of invasive bacterial infections in a tertiary care government hospital in a rural province in the Philippines.

A clinical bacteriologic laboratory was established in a tertiary care government hospital in The Philippines, where expert bacteriologic laboratories do not usually exist at this level of health care. The laboratory was jointly established by the Research Institute for Tropical Medicine (RITM) (Manila, The Philippines) and the National Public Health Institute (KTL) (Helsinki, Finland). The laboratory was planned, its personnel were trained, and its functioning was continuously supported by the RITM and KTL. The following aspects were of utmost importance in establishing the laboratory and launching its work: 1) the support of the RITM bacteriologic laboratory, with back-up and consultations from KTL; 2) creation and maintenance of personal contacts between clinicians and laboratory staff with an emphasis on clinical relevance and rapid reporting of laboratory results; 3) the consideration of the quality aspects of the work from the start; and 4) keen follow-up of the bacteriologic results and their clinical significance and use, of practical laboratory work, and of quality assurance aspects. In the first two years of its operation, the laboratory identified Streptococcus pneumoniae and Haemophilus influenzae as the most important causes of severe pneumonia, sepsis or meningitis in children less than two years of age, and Salmonella typhi as the most frequent significant isolate from the blood cultures, being found most often in school age children and young adults.

Incremental effectiveness of pneumococcal vaccine on simultaneously administered influenza vaccine in preventing pneumonia and pneumococcal pneumonia among persons aged 65 years or older.

The effectiveness of simultaneously administered influenza and pneumococcal vaccines vs. influenza vaccine alone in preventing pneumonia, pneumococcal pneumonia and pneumococcal bacteraemia among the elderly was studied. The vaccines were offered to all persons aged 65 years or older (N=43,500) living in 35 administrative districts in Northern Finland. A total of 26,925 persons (62%) decided to participate. Allocation to the vaccination groups took place by year of birth (odd/even). The total follow-up of those vaccinated consisted of 38,037 person years. The incremental effectiveness of the pneumococcal vaccine was -20 (95% CI -50- + 10%) for pneumonia, -20 (95% CI -90- + 20%) for pneumococcal pneumonia and + 60% (95% CI -40- +90%) for pneumococcal bacteraemia. Thus the pneumococcal polysaccharide vaccine did not offer any additional protection from pneumonia among elderly people in Finland although it reduced the incidence of bacteraemia.

Epidemiology of invasive Streptococcus pneumoniae infections in adults in Finland.

Laboratory-based surveillance of invasive pneumococcal infections in adults in Finland from 1983 to 1992 identified 862 episodes of pneumococcal bacteraemia and 97 episodes of meningitis. The overall incidence of invasive pneumococcal infections was 9.1 per 100,000 for all adults per year, but 27.1, 35.8, and 44.5 per 100,000 in those aged 65 years or over, 75 years or over, and 85 years or over, respectively. Most (99.7%) of the pneumococcal strains were sensitive to penicillin. Ninety-five percent of the strains belonged to serogroups/types present in the 23-valent pneumococcal polysaccharide vaccine. Group/type distribution was different in patients aged 16-64 years compared to those 65 years or over (P < 0.001), in bacteraemia compared to meningitis (P < 0.001), and in the years 1983-7 compared to 1988-92 (P < 0.05).

Rapid HLA-DQB1 genotyping for four alleles in the assessment of risk for IDDM in the Finnish population. The Childhood Diabetes in Finland (DiMe) Study Group.

OBJECTIVE: To study the effectiveness of MHC genotyping in the assessment of risk for IDDM based on the identification of alleles that are significantly associated with risk for IDDM (DQB1 *0302 and *0201) and protection from it (DQB1 *0602/*0603 and *0301). RESEARCH DESIGN AND METHODS: A long series of 649 index cases of IDDM, together with their healthy siblings and 756 healthy blood donors, was collected in Finland. The samples were analyzed using a large-scale assay procedure that was developed for rapid screening purposes. The method utilizes time-resolved fluorometry to detect the hybridization of lanthanide-labeled allele-specific oligonucleotide probes with amplified gene product. RESULTS: A total of 61.9% of IDDM index cases had high risk (DQB1 *0201/*0302) or moderate risk (DQB1 *0302/x [x meaning DQB1 *0302 or a nondefined allele]) genotypes compared with 14.3% of the reference population. In patients and control subjects, the frequencies of low risk genotypes were 28.0 and 22.1%, respectively, and those of decreased risk genotypes, 10.0 and 63.6%. The relative risk of a *0201/*0302 genotype was 53.5 (31.1-92.8) compared with the decreased risk genotypes (63.6% of controls). The graded risk estimation was equally efficient in assessing the risk of IDDM in siblings of child with IDDM. CONCLUSION: The near-automatic typing procedure developed is attractive for large-scale screening projects, such as diabetes prevention and intervention trials.

Clinical picture of community-acquired Chlamydia pneumoniae pneumonia requiring hospital treatment: a comparison between chlamydial and pneumococcal pneumonia.

BACKGROUND: The importance of Chlamydia pneumoniae as a cause of pneumonia has remained controversial. The clinical picture of C pneumoniae and Streptococcus pneumoniae in patients admitted to hospital with community-acquired pneumonia was compared during a C pneumoniae epidemic in Finland. METHODS: Group I consisted of 24 patients in whom serological testing and bacterial culture indicated an association with C pneumoniae only, group II comprised nine patients with both C pneumoniae and S pneumoniae, and group III consisted of 13 patients with S pneumoniae only. RESULTS: The patients with C pneumoniae suffered from headache more frequently than the other patients (group I, 46%; group II, 11%; and group III, 15%) and had received antimicrobial treatment more often before admission to hospital (group I, 54%; groups II and III, 0%). The patients with C pneumoniae produced few good sputum samples and had suffered from respiratory symptoms longer than those with S pneumoniae (group I, 10 days; groups II and III, 4 days). C reactive protein values on admission were lowest in group I and highest in group II. The antimicrobial treatment provided in hospital covered C pneumoniae in 36% of cases in group I and 0% in group II, while S pneumoniae was covered in all patients. C pneumoniae and S pneumoniae together were associated with more severe disease and a longer stay in hospital. CONCLUSIONS: Pneumonia caused by C pneumoniae was milder but clinically resembled that caused by S pneumoniae, and required hospital treatment even among young patients. Mixed infections were common and should be taken into account when planning antimicrobial treatment for community-acquired pneumonia. Further studies with more patients are needed to evaluate the severity of C pneumoniae pneumonia.

Antibody response to pneumococcal capsular polysaccharide vaccine in the elderly.

Antibody response to 23-valent pneumococcal vaccine was assessed in 350 subjects (131 men, 219 women) aged 65-91 years. IgG antibodies to pneumococcal serotypes 4, 6B, 9V, 14, 19F, and 23F were measured by EIA after blocking of antibodies to cell wall polysaccharide. Antibody concentrations in both pre- and postvaccination sera (mean interval, 35 days) were higher in elderly men than women; in the women, the concentrations decreased significantly with increasing age, but not in the men. Antibody fold increases were good in the elderly, including those > or = 85 years old. The overall percentage of the elderly with antibody concentrations > 1 microgram/mL to the 6 antigens increased by vaccination from 61% to 87%, but in the women > or = 85 years old, only to 75%. Antibody response to 23-valent pneumococcal vaccine was satisfactory in the elderly.

The etiology of community-acquired pneumonia among hospitalized patients during a Chlamydia pneumoniae epidemic in Finland.

The etiology of community-acquired pneumonia during a Chlamydia pneumoniae epidemic was studied among 125 hospitalized patients. Etiologic investigations included blood and sputum cultures, pneumococcal antigen detection, and serologic investigations for common respiratory viruses and for Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, Mycoplasma pneumococcal antigen detection, and serologic investigations for common and for Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, Mycoplasma pneumoniae, and Chlamydia species. A specific microbial agent was identified in 110 patients (88%). Some 48% of the patients had mixed infections. S. pneumoniae was the most common pathogen (55%), followed by C. pneumoniae (43%). C. pneumoniae was found both as a single etiologic agent and as a mixed infection, most often with S. pneumoniae. In conclusion, S. pneumoniae is the most common cause of community-acquired pneumonia, even during a C. pneumoniae epidemic. The organism, alone or with other pathogens (especially S. pneumoniae), may cause community-acquired pneumonia that requires hospital treatment.