Serum type (IgG, IgM and IgA-class) and secretory type antibodies specific to Streptococcus pneumoniae (Pn), Haemophilus influenzae (Hi) and Branhamella catarrhalis (Br) were measured by enzyme-linked immunosorbent assay (ELISA) in 46 serum and 114 middle ear effusion (MEE) samples from 85 children with acute otitis media (AOM). The samples were obtained within 12 h from the onset of the ear symptoms. Serum (but not secretory) type antibodies to the infecting Pn serotype were found in 24% of the MEE samples of the patients with Pn AOM and, correspondingly, serum and/or secretory type antibodies to Hi and Br were seen in 54% and 63% of the MEE samples of the patients with Hi or Br AOM, respectively. Moreover, antibodies against bacteria other than the causative one could also be found in the MEE. The occurrence of the serum type antibodies against these bacteria in the MEE was closely correlated with their serum levels. The findings of this study indicate that during the very early phase of AOM, the MEE contains both serum type antibodies originating from the serum, and secretory antibodies of middle ear origin. Among them there are antibodies specific to the three most common bacteria causing AOM (Pn, Hi, and Br) regardless of the bacterial etiology of the AOM attack in question.
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.
A nation-wide survey of the prevalence of antimicrobial resistance in Haemophilus influenzae was conducted on isolates collected in 1988-90 from middle ear fluid (MEF), blood, or cerebrospinal fluid (CSF) in infected children or throat samples of healthy children. Altogether 885 strains were examined regarding capsular type b, beta-lactamase production and the minimal inhibitory concentration (MIC) of ampicillin, cefaclor, erythromycin, tetracycline, chloramphenicol, trimethoprim and trimethoprim-sulfamethoxazole for these strains was determined by the agar dilution method. 99% (578/585) of MEF isolates, 93% (112/121) of throat isolates, but only 6% (10/179) of blood/CSF isolates were not of type b (Hib). The rate of beta-lactamase production was 11.4% among Hib strains, 8.0% among non-type b MEF isolates, and 4.5% among non-type b throat isolates. No increase in the prevalence of beta-lactamase production in H. influenzae has taken place in Finland since the early 1980s. Resistance to ampicillin among strains that lacked beta-lactamase activity was rare (0.2%). Of the non-type b MEF and throat isolates, 5.9% and 2.7%, respectively, were resistant to trimethoprim and 3.6% and 2.7%, respectively, to trimethoprim-sulfamethoxazole. Resistance to other drugs was rare (
A nationwide survey of the prevalence of antimicrobial resistance among Streptococcus pneumoniae isolates from the middle ear fluid of children with acute otitis media (639 strains) and from throat-swab samples of healthy children (149 strains) was conducted in Finland during 1987-1990. The MICs of penicillin, cephalothin, cefaclor, erythromycin, trimethoprim, and co-trimoxazole were determined by the agar dilution method. Low-level resistance to penicillin (MIC, 0.1-1 microgram/mL) was found in 1.7% of the otitis-related and 1.3% of the healthy-carrier strains. No highly penicillin-resistant strains (MIC, > or = 2 micrograms/mL) were found. Six multiresistant strains were detected, three of them possibly belonging to a previously identified clone present in Finland since 1985. Eighty-five percent of the resistant otitis-related strains, including 9 of the 11 moderately penicillin-resistant strains (4 of which were multiresistant), belonged to the three most common serogroups (6, 19, and 23).
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.
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.
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).
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.
We performed field trials in the course of an epidemic in Finland to learn whether Group A memingococcal capsular polysaccharide vaccine protects infants and young children from meningitis. The first trial involved 130,178 children between the ages of three months and five years; 49,295 children received the vaccine, 48,977 received a control Haemophilus influenzae Type b polysaccharide vaccine, and 31.906 remained unvaccinated. No cases of meningitis or sepsis caused by Group A meningococci were seen in the first year of observation among the children vaccinated with meningococcal vaccine whereas six occurred among those vaccinated with the H. influenzae vaccine and 13 among those not vaccinated. In the second trial 21,007 children of the same ages received the meningococcal vaccine. No cases caused by Group A occurred among those vaccinated, although five to seven would have been expected within the year. Meningococcal Group A vaccine appears efficacious in young infants and children.
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.
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.
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.
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.
Development of Francisella tularensis antigen responses measured as T-lymphocyte proliferation and cytokine production (tumor necrosis factor alpha, gamma interferon, and interleukin-2 and -4) during human tularemia.
The lymphocyte immune reactivity of 12 tularemia patients to Francisella tularensis antigens prepared from the bacterial cell envelope was examined during a 14-week follow-up study. Lymphocyte blast transformation responses of peripheral blood mononuclear cells (PBMC) to different protein antigens appeared simultaneously 2 weeks after the first symptoms of tularemia, indicating that none of these antigens had any special role at the early phase of immunization. While the lymphocyte blast transformation responses of total lymphocytes to all bacterial antigens were negative in the week 1 samples, continuously growing F. tularensis-specific T-lymphocyte lines were obtained from PBMC at the same time, indicating that an immune response had already occurred. Later, the T-lymphocyte lines and lymphocyte blast transformation responses were similar. Lymphocyte activation among the PBMC was reflected in an increased number of HLA-DR antigen-expressing, CD4-positive T lymphocytes (CD4+ DR+). The mean secretion of soluble CD8 from F. tularemia antigen-stimulated PBMC increased 2 weeks after tularemia onset, but the mean number of CD8+ DR+ T lymphocytes did not vary during the study period and no correlation could be found between the soluble CD8 and number of CD8+ DR+ T lymphocytes. F. tularemia antigen-induced cytokine production was measured from the PBMC supernatants. High levels of tumor necrosis factor alpha were detected from the first week onwards. The highest levels of interleukin-2 and gamma interferon were recorded during the second and third weeks, respectively, after tularemia onset. Interleukin-4 could not be demonstrated in the lymphocyte supernatants.