Modelling multi-type transmission of pneumococcal carriage in Bangladeshi families.

The burden of pneumococcal carriage is largest in developing countries from which, however, detailed studies on pneumococcal transmission are missing. In this study we followed nasopharyngeal carriage in Bangladeshi infants (n=99) from birth, with 2-week sampling intervals until age 4 months, and monthly thereafter until age 1 year, and also their family members at the same intervals. We assessed the dependence of pneumococcal acquisition rates on age, serotype, serotype-specific exposure (i.e. transmission) and current state of carriage (yes/no). A statistical model of pneumococcal transmission, taking into account incompletely observed data, was applied to estimate rates of acquisition and clearance for a large number of serotypes at the same time. Serotypes that were common in the study population were more often acquired from the community than rarer serotypes. However, when conditioning on serotype-specific exposure within the family, transmission rates were similar between different serotypes. Exposure within families signified more than tenfold increase in the rate of acquisition.

The genus-specific antigen of Chlamydia: resemblance to the lipopolysaccharide of enteric bacteria.

A strong immunological cross-reaction between a major glycolipid antigen of Chlamydia and the innermost (Re) core of the lipopolysaccharide of enteric bacteria was demonstrated with the aid of mutants in which the Re structure is exposed. The chlamydial glycolipid resembled the Re lipopolysaccharide in molecular size, solubility, and endotoxic properties and may thus be functionally equivalent to lipopolysaccharide, an essential and characteristic component of the outer membrane of Gram-negative bacteria.

Vaccines, coming of age after 200 years.

An overview on the short, only 200 years, past history and future expectations in the field of vaccines is presented. The focus is on development trends and potential rather than individual vaccines. While the first vaccines were a result of keen observation, the further development has been tightly dependent on the development of microbiology to provide both the knowledge basis and the technology for new vaccines for new purposes. The post-genomic era just starting therefore promises an exponential increase of vaccine research and new vaccines, both improved vaccines with a greater efficacy and less adverse effects to replace old ones and vaccines for prevention of diseases for which no vaccines exist. Furthermore, fully new applications to prevention or treatment of chronic diseases not traditionally associated with infections are expected.

Prognosis after community-acquired pneumonia in the elderly: a population-based 12-year follow-up study.

BACKGROUND: Only a few studies have investigated the long-term effects of community-acquired pneumonia (CAP). These studies have focused on cases treated in the hospital, and, to our knowledge, no long-term survival studies that include all cases of CAP are available. METHODS: A prospective observational study on the survival rates in a population-based cohort of elderly inhabitants aged 60 years or older at baseline in 1 township in eastern Finland in 1983. A total of 4167 (99% of the total elderly population), 122 of whom survived CAP during a prospective pneumonia surveillance period from 1983 to 1985, were followed up for mortality from 1983 to 1994 for a median of 9.2 years. The relative risk (RR) of death in patients who survived CAP was compared with that in elderly inhabitants without CAP by Cox multivariate regression analysis. Data on causes of death were obtained from a central register based on death certificates. RESULTS: The long-term survival rate was significantly lower in persons who had survived CAP or pneumococcal CAP (PCAP) than in the rest of the study population. The RR of pneumonia-related mortality was 2.1 (95% confidence interval [CI], 1.3-3.4; P = .004) in all patients with CAP and 2.8 (95% CI, 1.5-5.3; P = .001) in patients with PCAP. The respective numbers for total mortality were 1.5 (95% CI, 1.2-1.9; P = .001) in all patients with CAP and 1.6 (95% CI, 1.1-2.2; P= .01) in those with PCAP. Also the risk of cardiovascular mortality was increased in persons with CAP (RR, 1.4; 95% CI, 1.0-1.9; P = .02) and in those with PCAP (RR, 1.6; 95% CI, 1.0-2.4; P= .04). CONCLUSIONS: The present results indicate that elderly patients treated for CAP are at high risk of subsequent mortality for several years. Based on the high incidence and negative long-term effects of pneumonia, it can be concluded that there is a clear need for prevention, eg, by influenza and pneumococcal immunization.

Risk factors for pneumonia in the elderly.

PURPOSE: To investigate the prevalence of certain chronic conditions among the elderly and to estimate the relative risk for pneumonia associated with each condition. PATIENTS AND METHODS: Medical records of all inhabitants aged 60 years or more (4,175 persons) in one township (population 24,716) in Finland were reviewed, seeking 15 chronic conditions. Which patients had pneumonia in the same population was prospectively ascertained over a period of 3 years (185 patients). RESULTS: Hypertension was the most frequent chronic condition (36.4%) in the study population. Other common conditions were heart disease (23.7%, with chronic compensated heart failure in 96.3% of these), other cardiovascular disease (13.1%), and diabetes (13.1%). The prevalence of any other condition was less than 5%. The following conditions were significantly more common among pneumonia patients than among control subjects: heart disease (38.4% versus 23.0%), lung disease (13.0% versus 3.8%), bronchial asthma (11.9% versus 3.1%), immunosuppressive therapy (2.7% versus 0.8%), alcoholism (2.2% versus 0.3%), and institutionalization (8.6% versus 3.9%). By multivariate logistic regression analysis, independent risk factors for pneumonia were alcoholism (relative risk [RR] = 9.0, confidence interval [CI] = 5.1 to 16.2), bronchial asthma (RR = 4.2, CI = 3.3 to 5.4), immunosuppressive therapy (RR = 3.1, CI = 1.9 to 5.1), lung disease (RR = 3.0, CI = 2.3 to 3.9), heart disease (RR = 1.9, CI = 1.7 to 2.3), institutionalization (RR = 1.8, CI = 1.4 to 2.4), and age (70 years or more versus 60 to 69 years; RR = 1.5, CI = 1.3 to 1.7). One third of the study population and 57% of the pneumonia patients had one or more of these risk factors. Diabetes, chronic pyelonephritis, and malignancies of sites other than the lungs were not associated with increased risk for pneumonia. CONCLUSION: We found which elderly persons have an increased risk for pneumonia. Although the highest relative risk was associated with alcoholism, that condition was rare in this elderly population. Chronic obstructive lung diseases were more common and were also associated with a high relative risk. Heart disease had the highest public health impact because it was very common among the elderly and increased the risk of contracting pneumonia almost twofold; it also increased the risk of pneumonia-related death. These population-based data confirm and extend previous findings derived from selected patient groups and are useful for designing cost-effective pneumonia prevention programs.

Clinical efficacy of pneumococcal vaccine in the elderly: a randomized, single-blind population-based trial.

PURPOSE: To study the efficacy of pneumococcal capsular polysaccharide vaccine among the elderly by use of a population-based intervention in one township, Varkaus, Eastern Finland. PATIENTS AND METHODS: A randomized, controlled trial in which elderly inhabitants (aged 60 years or older) of the catchment area were randomized to receive either pneumococcal and influenza vaccines (PI group = vaccinated) or influenza vaccine alone (I group = controls) and offered participation. The response rate was 67.4%. The PI group consisted of 1,364 persons and the I group of 1,473 persons. The vaccinations were performed in the municipal health center in the fall of 1982, and all elderly inhabitants were followed for 3 years for the development of radiologically confirmed pneumonia. Pneumococcal etiology was identified by serological methods. RESULTS: The incidence of pneumonia was 18.8 per 1,000 person-years in the PI group (73 pneumonia episodes) and 16.6 per 1,000 person-years in the I group (69 episodes). Pneumococcal etiology was found in 27 episodes in the PI group (incidence 7.0 per 1,000 person-years) and in 36 episodes in the I group (incidence 8.6 per 1,000 person-years). In controls (I group) the incidence of pneumococcal pneumonia was significantly higher among persons with increased risk for contracting pneumonia (19 per 1,000 person-years) than among controls with low risk status (4 per 1,000 person-years). No significant protection from pneumococcal pneumonia was found in the study group as a whole (vaccine efficacy 15%, 95% CI -43% to 50%). However, in persons with medical risk factors for contracting pneumonia, there was a statistically significant protective efficacy of 59% (95% CI, 6% to 82%). CONCLUSION: Pneumococcal vaccination significantly reduced the incidence of pneumococcal pneumonia in elderly persons at increased risk for contracting pneumonia. This increased/high-risk category comprised 34% of the population aged 60 years or older. Because targeted vaccination of this large group may be difficult to organize in an efficient manner, vaccinating all elderly persons may be the best strategy to prevent this rather common and often fatal disease.

Serum antibodies after vaccination with Haemophilus influenzae type b capsular polysaccharide and responses to reimmunization: no evidence of immunologic tolerance or memory.

Haemophilus influenzae type b capsular polysaccharide vaccine was given in Finland in 1974 to approximately 50,000 infants and children, whose serum anti-H influenzae type b capsular polysaccharide levels have been followed for 3 1/2 years. The serum antibodies induced by the vaccination proved short-lived (less than 6 months) in the infants younger than 18 months. Elevated serum antibody levels were detectable for 1 1/2 years but less than 3 1/2 years in the children who were vaccinated when 18 to 35 months old. In the children who were 3 to 5 years old when vaccinated, the elevated anti-H influenzae type b capsular polysaccharide levels persisted for at least 3 1/2 years. Therefore, children vaccinated at the age of 18 months may need a new dose of vaccine 1 to 1 1/2 years after the first dose in order to be protected for the period of high susceptibility, until the age of approximately 7 years. Some of the vaccinated children were reimmunized 3 1/2 years after the first dose, and the anti-H influenzae type b capsular polysaccharide levels in their sera were studied in a similar manner. At no time did the anti-H influenzae type b capsular polysaccharide levels after the reimmunization differ from the anti-H influenzae type b capsular polysaccharide levels seen after the first vaccination in children of the same age.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical experience with Haemophilus influenzae type b conjugate vaccines.

The importance of Haemophilus influenzae type b as the main cause of serious bacteremic infections in young children and the consequent need for preventive measures have been widely appreciated since the 1970s. The knowledge that serum antibodies to the polysaccharide capsule of H influenzae type b increase with age and correlate with resistance to this infection encouraged work toward a vaccine based on the H influenzae type b polysaccharide. Such a vaccine was used in 1974 in a field trial in Finland. Two important lessons were learned. First, vaccine-induced antibodies to the polyribosylribitol-phosphate (PRP) polysaccharide correlated with protection from disease caused by H influenzae type b, so that the serum anti-PRP concentration predicting protection could be estimated as 1 microgram/mL. Second, the vaccine was not effective in infancy; protection and serum antibody concentrations above 1 microgram/mL were not observed before 18 to 24 months of age. The poor immunogenicity of PRP in infancy has been observed in a large number of studies and is shared by other bacterial polysaccharides. Although the reason for this is not known, the most likely hypothesis associates poor immunizing ability in infancy with the "T-independent" nature of these polysaccharide antigens. Such antigens would be unable to stimulate T lymphocytes; therefore, immunity to them would depend exclusively on B cells and antibodies produced by them. If infants, by and large, lack B cells that could be stimulated directly by a polysaccharide antigen, they cannot respond to the polysaccharide vaccine. This hypothesis immediately suggests possibilities for improvement of the vaccine.(ABSTRACT TRUNCATED AT 250 WORDS)

Immunogenicity of Haemophilus influenzae oligosaccharide-protein and polysaccharide-protein conjugate vaccination of children at 4, 6, and 14 months of age.

At 4 and 6 months of age, 118 infants were vaccinated with either one of two Haemophilus influenzae type b capsular polysaccharide-protein conjugate vaccines: 72 infants received the polysaccharide coupled to diphtheria toxoid (PRP-D group), and 46 infants received polysaccharide-derived oligosaccharides coupled to CRM197 protein, a nontoxic mutant form of diphtheria toxin (HbOC group). A third dose of the same vaccine was given to 40 children in the PRP-D group and 25 children in the HbOC group at 14 months of age. Antibodies to the H influenzae type b capsular polysaccharide were measured by Farr-type radioimmunoassay in serum samples taken before each vaccination and 1 month after the second and the third doses. Adverse reactions monitored by a questionnaire were mild. After two vaccine doses, the geometric mean concentration of antibodies to H influenzae type b polysaccharide increased from 0.07 micrograms/mL in the prevaccination samples to 0.63 micrograms/mL in the PRP-D group and to 4.32 micrograms/mL in the HbOC group. In the following 7 months, the geometric mean concentrations declined to 0.38 and 1.12 micrograms/mL, respectively. The booster dose given at 14 months elicited a strong antibody response in both groups (to geometric mean concentrations of 29.7 and 58.3 micrograms/mL, respectively). Both vaccines appear to be capable of immunologic priming by immunization in infancy.

Neonatal immunization: response to Haemophilus influenzae type b-tetanus toxoid conjugate vaccine.

OBJECTIVE: To study the immunogenicity and tolerability of Haemophilus influenzae type b (Hib) conjugate vaccine administered in the neonatal period. DESIGN: Hib capsular polysaccharide (PS)-tetanus toxoid conjugate vaccine (PRP-T) was given to 120 neonates at 2 days of age, followed by PRP-T or the Hib PS vaccine at 4 months and a PRP-T booster at 14 months. Their anti-Hib PS concentrations were compared with those in children receiving PRP-T at 2 and 4 months or at 4 months. RESULTS: No serious adverse reactions were noted. The geometric mean concentration of anti-Hib PS at the age of 2 days was 0.34 micrograms/mL and at 4 months was 0.12 micrograms/mL. This was significantly more than the concentration in unimmunized infants at this age and 3.5 times more than expected, taking into account the natural decay of transplacentally acquired antibodies. Such a response was not seen in infants with a high (greater than 3.0 micrograms/mL) neonatal antibody concentration. The PRP-T vaccine given at 4 months elicited an antibody response in all infants and Hib PS in 62%, indicating immunologic priming. At 14 months, a higher percentage of the infants who had received PRP-T at 2 days and 4 months than of those who had received PRP-T at 4 months only had anti-Hib PS concentrations greater than 0.15 micrograms/mL. All infants responded well to the booster at 14 months. There was no evidence of immunologic tolerance. CONCLUSIONS: Neonatal immunization with PRP-T was safe and well tolerated in Finnish infants, and it would be worthwhile to further study its effects in higher risk populations.

Salmonella, complement and mouse macrophages.

The structure of the polysaccharide chains that constitute the O antigen on the surface of Salmonella bacteria determines the rate of complement activation and C3b deposition on the bacteria. A fast-activating O antigen causes rapid C3-dependent opsonization of the bacteria injected intraperitoneally; as a consequence, the bacteria are taken up and killed by the resident peritoneal macrophages, and their virulence is low. A slow-activating O antigen protects the bacteria from opsonization in the peritoneal cavity, and is associated with higher virulence. However, if injected intravenously bacteria with either O-antigenic type are equally virulent; in the high complement concentration of the blood they become opsonized and taken up by macrophages in the liver and spleen, which are unable to kill them but instead provide a protected site for multiplication.

Bacterial coinfection in children hospitalized with respiratory syncytial virus infections.

Clinical and bacterial findings were prospectively studied in 90 children hospitalized because of middle or lower respiratory tract infection caused by respiratory syncytial virus (RSV) during a surveillance period of 12 months. The results were compared with those of RSV-negative children hospitalized with identical indications during the 3 peak months of the RSV epidemic (N = 91) or for the 3 months after the outbreak (N = 99). A high frequency of pneumonia and acute otitis media were found in both RSV-positive and RSV-negative children during the epidemic, but not in control patients after the epidemic. Bacterial infection, based on a significant rise of antibody titer and/or on detection of pneumococcal antigen in serum or urine, was observed in 39% of the children with RSV infection. The respective figures were 24% in RSV-negative children hospitalized during the epidemic and 8% after the epidemic. Our observations stress the role of RSV as a predisposing agent for secondary bacterial infection in the airways of children. The most common bacteria involved in the mixed RSV-bacterial infections were Streptococcus pneumoniae and Haemophilus influenzae, the latter being found only in pneumonic patients. The presence or absence of pneumonia or acute otitis media was not significantly correlated with evidence of pneumococcal infection. We conclude that a bacterial pathogen should be actively sought when managing patients with lower respiratory tract syndromes, especially in those who have evidence of RSV infection.

Antibody response to the pneumococcal proteins pneumococcal surface adhesin A and pneumolysin in children with acute otitis media.

BACKGROUND: Pneumococcal surface adhesin A (PsaA) and pneumolysin (Ply) are common to virtually all Streptococcus pneumoniae isolates, and they are immunogenic and protective against pneumococcal challenge in experimental animals. We have recently shown production of antibodies to PsaA and Ply in young children, but data on the immune response to these antigens during culture-confirmed pneumococcal infection are lacking. OBJECTIVES: To evaluate whether young children respond to S. pneumoniae by producing antibodies to PsaA and Ply during acute otitis media (AOM). SUBJECTS AND METHODS: A cohort of 329 children was followed prospectively from the age of 2 months to the age of 2 years. Paired sera were obtained during episodes of AOM and used to measure antibodies to PsaA and Ply by enzyme-linked immunosorbent assay. S. pneumoniae cultured from the middle ear fluid was taken as evidence of pneumococcal AOM. The presence of S. pneumoniae in the nasopharyngeal aspirate collected in connection of AOM or any other respiratory infection or in the nasopharyngeal swab collected at scheduled visits was taken to indicate pneumococcal carriage and thus a history of previous contact with S. pneumoniae. RESULTS: Children with previous pneumococcal contacts had high anti-PsaA and anti-Ply concentrations in the acute phase sera regardless of the nature (AOM or carriage) of the current pneumococcal contact. Of the children with no previous pneumococcal contact, those with current pneumococcal AOM had lower antibody concentrations than those with current pneumococcal carriage only. Anti-PsaA and anti-Ply responses were found in children with current pneumococcal contact. The antibody response was strongly associated with low acute phase antibody concentration, but not significantly with age and the nature of the current pneumococcal contact. CONCLUSIONS: We showed that infants are capable of developing a specific antibody response to the pneumococcal proteins PsaA and Ply during AOM.

Epidemiology of invasive Haemophilus influenzae type b disease among children in Finland before vaccination with Haemophilus influenzae type b conjugate vaccine.

On the basis of intensified surveillance in Finland we report the epidemiology of invasive Haemophilus influenzae type b disease based on 333 consecutive culture-proved cases recorded during 1985 and 1986. The annual incidence rate among children younger than 5 years of age was 52/100,000; 46% of patients had meningitis, 29% had epiglottitis and 25% had other forms of invasive disease. The median age of patients was 27 months, with 45% younger than 2 years of age. Meningitis and epiglottitis were found more often among boys than among girls, whereas the opposite was found among patients with other types of invasive disease (P = 0.015). Among the latter 68% of children with pneumonia or septicemia were 2 years or older compared with 32% of patients with arthritis, cellulitis or pyelonephritis (P = 0.009). These background data are essential for correct interpretation and application of results from trials with H. influenzae type b conjugate vaccines that are currently ongoing in Finland.

Invasive Escherichia coli infections in children: bacterial characteristics in different age groups and clinical entities.

Escherichia coli isolates from blood or cerebrospinal fluid of 135 children were characterized for serotype, adhesin and hemolysin production and compared with 94 fecal isolates from healthy children. Capsular type K1, sero-group O18 and rough-type lipopolysaccharide were predominant in neonatal infections (49, 16 and 16%, respectively) and also in meningitis and septicemia of infants from 7 days to 23 months of age (39, 17 and 13%). S-fimbriated strains were common in neonatal infections (23%) but rare (< or = 5%) in all other clinical groups. Pyelonephritis was the most common diagnosis in infants (49 of 72); it was associated with P-fimbriation (63%); serogroups O1, O2, O4, O6 or O7 (41%), and hemolysin production (37%). Invasive infections in older children (age > or = 2 years) were associated with predisposing factors and were caused by strains resembling fecal isolates; the only exception was hemolysin production which was detected in 40% of the disease but only 9% of the fecal isolates. Eight O:K:H serotypes were associated with invasive infections; they usually had K1 or K5 capsule and either P, S or type 1C fimbriae.

Vaccination with Haemophilus influenzae type b meningococcal protein conjugate vaccine reduces oropharyngeal carriage of Haemophilus influenzae type b among American Indian children.

The effect of Haemophilus influenzae type b (Hib) meningococcal protein conjugate vaccine (Hib-OMPC; Merck, Sharp & Dohme) on oropharyngeal (OP) carriage of Hib was evaluated in Navajo and Apache Indian children, who are known to be at high risk for invasive Hib disease. We obtained 1423 OP swabs at well child visits from 1321 children 3 months to 4 years of age: 293 of the swabs were obtained from children before the administration of any Hib-OMPC; 1119 were taken after the primary vaccination series; and 11 after the booster dose. Swabs were tested for the presence of Hib capsular polysaccharide antigen by enzyme-linked immunosorbent assay. Forty of 1423 swabs were positive for Hib. Among the 40 positive swabs 5 (13%) were obtained from children who had received Hib-OMPC vaccine appropriate for age at swabbing, compared with 500 of 1383 (36%) of negative swabs. Children who were OP carriers of Hib were older than noncarriers (mean age, 13 and 9 months, respectively) and a greater proportion of carriers (48%) had symptoms of respiratory infection at the time of swabbing than noncarriers (30%). These variables were significantly related to increased risk of OP carriage of Hib when incorporated jointly in a logistic regression model: not vaccinated according to age (odds ratio 2.7, 95% confidence interval 1.00 to 7.05); increase of age in months (odds ratio 1.1, 95% confidence interval 1.02-1.10); and respiratory infection symptoms present (odds ratio 2.0, 95% confidence interval 1.06-3.77). Thus besides preventing invasive Hib disease, appropriate vaccination with Hib-OMPC appears to reduce OP carriage of Hib.

Preceding respiratory infection predisposing for primary and secondary invasive Haemophilus influenzae type b disease.

Cases (117) with invasive Haemophilus influenzae type b (Hib) disease and their family members reported symptoms of respiratory infection during the 4-week period before the onset of Hib disease significantly more often than age-, sex- and residence-matched controls (225) and their family members during the same time period. Viral (adenovirus; influenza A and B; parainfluenza types 1, 2 and 3; and respiratory syncytial virus) and Mycoplasma pneumoniae serology was performed in 84 paired sera from cases and 112 paired sera from controls, who were healthy children matched to the cases by age, year and season. Viral or M. pneumoniae infection was diagnosed equally often among cases and controls (18% for both groups). However, patients who were associated cases of Hib disease (i.e. either the primary or secondary case of a case pair) had a diagnostic viral serology more often (50%) than did sporadic cases (13%) (odds ratio, 7.0; 95% confidence interval, 1.6 to 33; P = 0.006). These results suggest that some infectious agent(s) caused symptoms among the patients and circulated among the patients' closest contacts immediately before their development of Hib disease and possibly predisposed for invasive Hib disease. For the development of associated Hib disease among close contacts of an index case, adenovirus, influenza A, respiratory syncytial virus or para-influenza type 1, 2 and 3 infections may be important.

Etiology of childhood pneumonia: serologic results of a prospective, population-based study.

BACKGROUND: To investigate the etiology of pediatric community-acquired pneumonia, we conducted a prospective, population-based study covering the total population <15 years of age (n = 8851) in 4 municipalities in eastern Finland. MATERIALS AND METHODS: The number of patients was 201; chest radiographs were available for all cases and paired sera for serologic assays were available for >90% of cases. The methods included assays for antibody response to 3 pneumococcal antigens, specific pneumococcal immune complex assays and conventional antibody tests for mycoplasmal, chlamydial and viral infections. RESULTS: Serologic evidence of specific microbial etiology was obtained in 133 (66%) of the pneumonia patients. Bacterial infection was diagnosed in 102 cases (51%) and viral infection in 51 cases (25%). Streptococcus pneumoniae was the most common agent (57 cases; 28%), followed by Mycoplasma pneumoniae (44; 22%), respiratory syncytial virus (43; 21%) and Chlamydia spp. (29; 14%). Haemophilus influenzae was identified in only 6% and Moraxella catarrhalis in only 3% of the children. More than one specific infection was found in 51 patients (25%). The proportion of pneumococcal cases varied from 24 to 36% by age. Mycoplasma infections were seen mostly in patients > or =5 years and Chlamydia infections in patients > or =10 years of age. CONCLUSIONS: The results of our prospective, strictly population-based study confirm the importance of S. pneumoniae in the etiology of community-acquired pneumonia in children of all ages. M. pneumoniae and Chlamydia pneumoniae are important from the age of 5 years onwards.

Radioimmunoassay of capsular polysaccharide antigens of groups A and C meningococci and Haemophilus influenzae type b in cerebrospinal fluid.

Sensitive radioimmunoassays capable of measuring 0-5 ng/ml of the Haemophilus influenzae type b polysaccharide and 2 ng/ml of the groups A and C meningococcal polysaccharides were developed and used to detect these substances in cerebrospinal fluid (CSF). Polysaccharide of the causative agent was detected in the CSF of 14 out of 15 patients with Haemophilus influenzae type b meningitis, in 18 out of 23 patients with group A, and in two out of four patients with group C meningococcal meningitis. In some cases the antigen could be detected even after three days of antibacterial treatment. No false positive reactions were seen. The assay procedure could be shortened to approximately three hours. These assays could be useful in routine diagnostic work and epidemiological investigations.

Comparative sensitivity of different serological tests for detecting chlamydial antibodies in perihepatitis.

The value of several serological tests was assessed by studying sera from 30 women with clinical findings of perihepatitis and a high chlamydial antibody titre in the indirect immunofluorescence antibody test (IFAT). The other tests included the complement fixation test and enzyme immunoassays in which the antigen comprised either partially purified particles (EIA kit) or purified major outer membrane protein (MOMP EIA) of Chlamydia trachomatis L2 or lipopolysaccharide isolated from an Re mutant of Salmonella (Re LPS EIA). High IgG titres were noted in most (88-96%) of the patients by MOMP EIA and EIA kit, and in fewer patients (50%) by Re LPS EIA or complement fixation test. Seroconversion was found in 11-44% of the patients for IgG and in 28-36% for IgM; high IgG titre was thus the best diagnostic indicator for each test. The enzyme immunoassay tests have the advantage of being automated either with partially purified corpuscular or purified MOMP antigen and would allow a sensitive easy screening for chlamydial aetiology of women with pain of the right upper quadrant.