More than time: travel time to the delivery ward and maternal outcomes - onset of labour, postpartum haemorrhage and obstetric anal sphincter injury.

BACKGROUND: Closing delivery units increases travel time for some women. Whether increased travel time is associated with maternal outcomes is important for understanding the consequences of such closures. Previous studies are limited in measuring travel time and restricted to the outcome of caesarean section. METHODS: Our population-based cohort includes data from the Swedish Pregnancy Register for women giving birth between 2014 and 2017 (N = 364,630). We estimated travel time from home to the delivery ward using coordinate pairs of actual addresses. The association between travel time and onset of labour was modelled using multinomial logistic regression, and logistic regression was used for the outcomes postpartum haemorrhage (PPH) and obstetric anal sphincter injury (OASIS). FINDINGS: Over three-quarters of women had ≤30 min travel time (median 13.9 min). Women who travelled ≥60 min arrived to care sooner and laboured there longer. Women with further to travel had increased adjusted odds ratio (aOR) of having an elective caesarean section (31-59 min aOR 1.11; 95% confidence interval [CI] 1.07-1.16; ≥60 min aOR 1.25; 95% CI 1.16-1.36) than spontaneous onset of labour. Women (at full term with spontaneous onset) living ≥60 min away had reduced odds of having a PPH (aOR 0.84; 95% CI 0.76-0.94) or OASIS (aOR 0.79; 95% CI 0.66-0.94). INTERPRETATION: Longer travel time increased the odds of elective caesarean section. Women with furthest to travel arrived sooner and spent more time in care; although they had a lower risk of PPH or OASIS, they also tended to be younger, have a higher body mass index and were Nordic born.

The changing epidemiology of community-acquired pneumonia: nationwide register-based study in Sweden.

BACKGROUND: There is limited evidence on the impact of pneumococcal conjugate vaccine childhood immunization programmes (PCV-CIP) on community-acquired pneumonia (CAP) in individuals with underlying diseases. METHODS: A nationwide cohort study using Swedish health registers to assess the incidence of hospitalization with all-cause (AC-CAP) and pneumococcal or lobar (PL-CAP) CAP between 2005 and 2015, in relation to PCV-CIP introduction in 2007-09. RESULTS: In total, 303 691 episodes of AC-CAP occurred, of which 14 225 were PL-CAP. Comparing before (2005-06) with after (2014-15) PCV-CIP, relative incidence reductions were 36% (95% Confidence Interval 32-40), 20% (14-25) and 16% (11-22) of AC-CAP for age groups < 2, 2-4 and 5-17 years, respectively, with similar reductions in young children with and without comorbidities. The reductions were more pronounced for PL-CAP. In the age groups 40-64, 65-74, 75-84 and ≥85 years there were relative increases of 11% (8-14), 18% (15-22), 15% (12-17) and 30% (27-34) of AC-CAP, respectively, but these increases were attenuated after adjustment for admittance practices using four control conditions. In adults with comorbidities, there was an increase in incidence of AC-CAP, and PL-CAP, in contrast to adults without reported underlying diseases where the incidence was stable or diminished for some age groups. Over the study period, there was an increased proportion of pneumonia patients with underlying diseases in all ages. CONCLUSION: This emphasizes that direct preventive interventions should be targeted towards individuals with underlying diseases. Future studies should investigate reasons for the observed increased risk in adults with comorbidities, for example due to pneumococcal nonvaccine serotypes, or other pathogens, preferentially affecting subjects with underlying diseases.

A coordinated cross-disciplinary research initiative to address an increased incidence of narcolepsy following the 2009-2010 Pandemrix vaccination programme in Sweden.

In response to the 2009-2010 influenza A(H1N1)pdm09 pandemic, a mass vaccination programme with the AS03-adjuvanted influenza A(H1N1) vaccine Pandemrix was initiated in Sweden. Unexpectedly, there were a number of narcolepsy cases amongst vaccinated children and adolescents reported. In this review, we summarize the results of a joint cross-disciplinary national research effort to investigate the adverse reaction signal from the spontaneous reporting system and to better understand possible causative mechanisms. A three- to fourfold increased risk of narcolepsy in vaccinated children and adolescents was verified by epidemiological studies. Of importance, no risk increase was observed for the other neurological and autoimmune diseases studied. Genetic studies confirmed the association with the allele HLA-DQB1*06:02, which is known to be related to sporadic narcolepsy. Furthermore, a number of studies using cellular and molecular experimental models investigated possible links between influenza vaccination and narcolepsy. Serum analysis, using a peptide microarray platform, showed that individuals who received Pandemrix exhibited a different epitope reactivity pattern to neuraminidase and haemagglutinin, as compared to individuals who were infected with H1N1. Patients with narcolepsy were also found to have increased levels of interferon-gamma production in response to streptococcus-associated antigens. The chain of patient-related events and the study results emerging over time were subjected to intense nationwide media attention. The importance of transparent communication and collaboration with patient representatives to maintain public trust in vaccination programmes is also discussed in the review. Organizational challenges due to this unexpected event delayed the initiation of some of the research projects, still the main objectives of this joint, cross-disciplinary research effort were reached, and important insights were acquired for future, similar situations in which a fast and effective task force may be required to evaluate vaccination-related adverse events.

Knowledge and understanding of antibiotic resistance and the risk of becoming a carrier when travelling abroad: a qualitative study of Swedish travellers.

BACKGROUND: Increasing globalisation, with the migration of people, animals and food across national borders increases the risk of the spread of antibiotic-resistant bacteria. To avoid becoming a carrier of antibiotic-resistant bacteria when travelling, knowledge about antibiotic resistance is important. MATERIALS AND METHODS: We aimed to describe the knowledge and understanding of antibiotic-resistant bacteria, and of the risk for becoming a carrier of such bacteria, among Swedish travellers before their travel to high-risk areas. A questionnaire with three open-ended questions was distributed to 100 individuals before departure. RESULTS: The travellers' answers were analysed using content analysis, resulting in the theme 'To be an insecure traveller who takes control over one's own journey'. Our results showed that the travellers were aware of what the term 'antimicrobial resistance' meant, but did not understand its real significance, nor the consequences for the individual nor for society. They also distanced themselves from the problem. Few thought that their travel would entail a risk of becoming a carrier of resistant bacteria. The lack of knowledge caused an uncertainty among the travellers, whom tried to master the situation by using coping strategies. They proposed a number of measures to prevent carriership. The measures were general and primarily aimed at avoiding illness abroad, particularly acute gastro-intestinal infection. CONCLUSIONS: In health care and vaccination clinics, there is a need for improved information for persons intending to travel to high-risk areas, both about the risks of contracting antibiotic-resistant bacteria and about effective preventive measures.

Individual maternal and child exposure to antibiotics in hospital - a national population-based validation study.

AIM: Exposure to antibiotics in early life may affect future health. Most antibiotics are prescribed in outpatient care, but inpatient exposure is also important. We estimated how specific diagnoses in hospitals corresponded to individual antibiotic exposure. METHODS: All pregnant women and children from birth to 5 years of age with infectious diseases and common inpatient diagnoses between July 2005 and November 2011 were identified from the Swedish National Patient Register. Random samples of individuals from predefined groups were drawn, and medical records received from the clinics were manually reviewed for antibiotics. RESULTS: Medical records for 4319 hospital visits were requested and 3797 (88%) were received. A quarter (25%) of children diagnosed as premature had received antibiotics, and in children from one to 5 years of age, diagnoses associated with bacterial infections were more commonly treated with antibiotics (62.4-90.6%) than those associated with viruses (6.3-22.2%). Pregnant women who had undergone a Caesarean section were more likely to be treated with antibiotics than those who had had a vaginal delivery (40.1% versus 11.1%). CONCLUSION: This study defines the proportion of new mothers and young children who received individual antibiotic treatment for specific inpatient diagnoses in Sweden and provides a useful basis for future studies focusing on antibiotic use.

Prevailing effectiveness of the 2009 influenza A(H1N1)pdm09 vaccine during the 2010/11 season in Sweden.

Sixty per cent of the Swedish population received the monovalent AS03-adjuvanted pandemic influenza vaccine in the autumn of 2009. We assessed the age-specific effectiveness of this pandemic vaccine against hospitalisation with laboratory-confirmed influenza A(H1N1)pdm09 during the season 2010/11, in the age group from six months to 64 years in Sweden. The screening method was applied to available surveillance data. Our results suggest a prevailing effectiveness of 72% (95% confidence interval (CI): 63­80%) with the highest effectiveness among children, six months to nine years-old (92%, 95%CI: 80­97%). However, there were limitations in data quality and study design due to the lack of systematic recording of administered vaccinations, which underline the importance of preparing for an evaluation when planning for large public health actions. Despite these limitations, we believe the results reflect true, high prevailing vaccine effectiveness. Indeed, there were fewer deaths caused by influenza and the impact of influenza on intensive care units was less severe during the 2010/11 season in Sweden than in countries with lower pandemic vaccination coverage. The association between the pandemic vaccine and narcolepsy has increased the importance of assessing the risks and benefits of the vaccination; studies on the effectiveness and the duration of protection are needed for this.

Fetal growth and risk of childhood asthma and allergic disease.

INTRODUCTION: Early genetic and environmental factors have been discussed as potential causes for the high prevalence of asthma and allergic disease in the western world, and knowledge on fetal growth and its consequence on future health and disease development is emerging. OBJECTIVE: This review article is an attempt to summarize research on fetal growth and risk of asthma and allergic disease. Current knowledge and novel findings will be reviewed and open research questions identified, to give basic scientists, immunologists and clinicians an overview of an emerging research field. METHODS: PubMed-search on pre-defined terms and cross-references. RESULTS: Several studies have shown a correlation between low birth weight and/or gestational age and asthma and high birth weight and/or gestational age and atopy. The exact mechanism is not yet clear but both environmental and genetic factors seem to contribute to fetal growth. Some of these factors are confounders that can be adjusted for, and twin studies have been very helpful in this context. Suggested mechanisms behind fetal growth are often linked to the feto-maternal circulation, including the development of placenta and umbilical cord. However, the causal link between fetal growth restriction and subsequent asthma and allergic disease remains unexplained. New research regarding the catch-up growth following growth restriction has posited an alternative theory that diseases later on in life result from rapid catch-up growth rather than intrauterine growth restriction per se. Several studies have found a correlation between a rapid weight gain after birth and development of asthma or wheezing in childhood. CONCLUSION AND CLINICAL RELEVANCE: Asthma and allergic disease are multifactorial. Several mechanisms seem to influence their development. Additional studies are needed before we fully understand the causal links between fetal growth and development of asthma and allergic diseases.

Impaired fetal growth decreases the risk of childhood atopic eczema: a Swedish twin study.

BACKGROUND: Studies have found associations between birth weight and risk of atopic eczema or allergic rhinitis (AR), although this could be due to confounding. OBJECTIVE: We sought to evaluate associations between fetal growth and the risk of atopic eczema or AR in childhood, controlling for gestational age (GA), shared (familial) environmental and genetic factors. METHODS: Data on atopic eczema, AR, birth characteristics and confounders were collected from registers and telephone interviews with the parents of 9- and 12-year-old twins. Firstly, cohort analyses on all twins (eczema n=10 132 and AR n=10 896) were performed. Secondly, to control for genetic and shared environment, co-twin-control analyses were performed in twin pairs discordant for atopic eczema (n=480) and AR (n=332). RESULTS: The rate of atopic eczema increased with birth weight, from 12.6% in twin children <2000 g to 17.3% in children >or=3500 g. The rate of AR varied between 7.8% and 8.8%. In the cohort analyses, the odds ratio (OR) for atopic eczema was 1.62 (95% CI: 1.27-2.06) for 500 g increase in birth weight and 1.00 (95% CI: 0.75-1.33) for AR. In co-twin-control analyses on atopic eczema, OR was 3.93 (95% CI: 1.55-9.98) for 500 g increase in birth weight, with no significant difference between monozygotic and dizygotic twins (P=0.84). CONCLUSIONS: We found a positive association between fetal growth and childhood atopic eczema, but not AR, independent of GA, shared environmental and genetic factors. This indicates fetal growth affects the immune system, and supports further studies on early mechanisms.

Validity of routine surveillance data: a case study on Swedish notifications of methicillin-resistant Staphylococcus aureus.

Surveillance of communicable diseases is a public health corner stone. Routine notification data on communicable diseases are used as a basis for public health action as well as for policy making. While there are agreed standards for evaluating the performance of surveillance systems, it is rarely possible to analyse the validity of the data entered into these systems. In this study we compared data on all Swedish cases of methicillin-resistant Staphylococcus aureus (MRSA) routinely notified between 2000 and 2003 with follow-up information collected for each of these cases as part of a public health project. The variables Reason for testing (clinical sample, contact tracing, screening of risk group), Clinical presentation (disease, colonisation), Transmission setting (healthcare-acquired, community-acquired), Country of acquisition (Sweden, abroad) and Risk-occupation (yes, no) were analysed for sensitivity, positive predictive value and completeness of answers. The sensitivity varied between 23% and 83%, the positive predictive values were generally higher (55% to 97%), while missing answers varied from 11% to 59%. The proportion of community-acquired cases was markedly higher when excluding either cases of MRSA colonisation or cases found through public health-initiated activities (contact tracing or screening of risk groups). We conclude that the quality of routine surveillance data may be inadequate for in-depth epidemiological analyses. This should be taken into account when interpreting routine surveillance figures. Whether or not the case definition includes cases of MRSA colonisation may have a significant impact on population-wide estimates of MRSA occurrence.

Association of serotypes of Streptococcus pneumoniae with disease severity and outcome in adults: an international study.

BACKGROUND: The introduction of conjugate pneumococcal vaccination for children has reduced the burden of invasive disease due to pneumococcal conjugate vaccine (PCV) types (i.e., serotypes 9V, 14, 6B, 18C, 23F, 19F, and 4) in adults. As nonvaccine serotypes become predominant causes of invasive disease among adults, it is necessary to evaluate the disease severity and mortality associated with infection due to nonvaccine serotypes, compared with PCV serotypes, in adults. METHODS: The association of pneumococcal serotype and host-related variables with disease severity and mortality was statistically examined (with multivariable analysis) in 796 prospectively enrolled, hospitalized adult patients with bacteremia due to Streptococcus pneumoniae. RESULTS: In multivariate analyses of risk in patients with invasive pneumococcal disease, older age (age, > or = 65 years; P = .004), underlying chronic disease (P = .025), immunosuppression (P = .035), and severity of disease (P < .001) were significantly associated with mortality; no association was found between nosocomial infection with invasive serotypes 1, 5, and 7 and mortality. The risk factors meningitis (P = .001), suppurative lung complications (P < or = .001), and preexisting lung disease (P = .051) were significantly associated with disease severity, independent of infecting serotype. No differences were seen in disease severity or associated mortality among patients infected with PCV serotypes, compared with patients infected with nonvaccine serotypes. CONCLUSIONS: Our data support the notion that host factors are more important than isolate serotype in determining the severity and outcome of invasive pneumococcal disease and that these outcomes are unlikely to change in association with nonvaccine serotype infection in the post-conjugate vaccine era.

Clonal and capsular types decide whether pneumococci will act as a primary or opportunistic pathogen.

BACKGROUND: Streptococcus pneumoniae is a major cause of morbidity and mortality worldwide. The role of the different capsular and clonal types in invasive disease severity remains to be defined. METHODS: Disease severity and disease type were correlated to age, underlying disease, capsular serotype, and clonal type of the causative agent for 494 adult patients with invasive pneumococcal disease. RESULTS: Pneumococcal isolates of serotypes 1 and 7F were genetically homogenous, had the highest potential to infect previously healthy individuals, and were not causing deaths. Also, type 1 isolates were only found among younger adults, whereas other serotypes were mainly found among elderly persons (e.g., type 23F). Some serotypes and/or clones were more prone to cause more-severe disease, as observed by high APACHE II scores calculated at admission, and were also associated with a high mortality (e.g., clones of type 3 and 11A). We found no evidence of an impact of penicillin resistance on disease severity and disease type. CONCLUSIONS: We suggest that clones with capsular types 1 and 7F, which are known to have a high invasive disease potential, behave as primary pathogens, whereas clones with other capsular types with a lower relative risk of causing invasive disease are more opportunistic, primarily affecting patients with underlying disease. Disease caused by the latter group, however, was more severe, even in previously healthy individuals.

Endocarditis and pericarditis complicating pneumococcal bacteraemia, with special reference to the adhesive abilities of pneumococci: results from a prospective study.

The incidence of pneumococcal cardiac infections is unknown and the pathogenicity of such complications is poorly understood. In a prospective, international, observational study, eight of 844 patients hospitalised with Streptococcus pneumoniae bacteraemia developed endocarditis (n = 5) or pericarditis (n = 3). The clinical and microbiological characteristics of these patients were compared with those of control patients. The corresponding incidence of pneumococcal endocarditis was c. 1-3/1 million inhabitants/year. There was no common pattern in the medical history of patients with an infectious cardiac complication. The severity of illness upon admission was comparable with that for patients without infectious cardiac complications, as was the 14-day mortality rate (25% and 17%, respectively). For encapsulated S. pneumoniae, no significant differences were found between patients with infectious cardiac complications and controls in adherence assays. However, non-encapsulated S. pneumoniae showed higher hydrophobicity and increased adherence to human epithelial cells.

Antibody response to pneumococcal vaccine in middle-aged and elderly patients recently treated for pneumonia.

BACKGROUND: A substantial proportion of patients admitted to the hospital for pneumonia have been treated in a hospital during the preceding 4 to 5 years, and patients previously treated in a hospital for pneumonia seem to be at an especially high risk for another episode of pneumonia. Many cases of pneumococcal infection might therefore be prevented by immunizing admitted patients with pneumococcal vaccine at discharge or at follow-up. The aim of this study was to investigate the type-specific antibody response to pneumococcal vaccine in middle-aged and elderly patients at follow-up 8 weeks after hospital treatment for pneumonia. METHODS: A total of 92 individuals, 50 to 85 years old, participated in the study. One group consisted of 65 individuals treated in the hospital for pneumonia 8 weeks before vaccination (mean age, 67 years), and another group consisted of 27 individuals who had not recently been treated for pneumonia (mean age, 67 years). All 92 individuals received a single dose of a 23-valent pneumococcal vaccine. The type-specific antibody responses to six pneumococcal capsular polysaccharide antigens included in the vaccine as well as antibodies against the 23-valent pneumococcal vaccine were measured before and 3 to 4 weeks after vaccination by use of an enzyme-linked immunosorbent assay. RESULTS: The antibody concentrations before and after vaccination were comparable in the two groups, as were antibody fold increases from prevaccination to postvaccination serum. No serious adverse events were recorded. CONCLUSIONS: Pneumococcal vaccination at follow-up 8 weeks after treatment in the hospital for pneumonia seems to elicit an adequate antibody response without notable adverse reactions.

Hypoalbuminemia in hospitalized patients with community-acquired pneumonia.

BACKGROUND: Hypoalbuminemic patients admitted to the hospital for community-acquired pneumonia have increased mortality and morbidity. The aim of this study was to investigate the reasons for hypoalbuminemia in these patients. METHODS: During a 12-month period, all patients aged 50 to 85 years (with the exception of immunocompromised patients) with community-acquired pneumonia who were admitted to the Department of Infectious Diseases at Danderyd Hospital, Stockholm, Sweden, were included in a prospective study. The population studied consisted of 97 patients with a mean age of 69.6 years. The patients' nutritional status, including weight, history of weight loss, body mass index, and triceps skinfold thickness, was assessed on admission, as well as at two follow-up visits 8 weeks and 6 months after discharge from the hospital. Blood samples were drawn on admission, during the time in the hospital, and at the follow-up visits. Laboratory tests performed included the following: plasma proteins, albumin, transthyretin and transferrin, alpha 1-antitrypsin, orosomucoid, haptoglobin, C-reactive protein, and interleukin-6. RESULTS: No correlation was found between the serum albumin levels and the nutritional measurements. The serum albumin levels correlated positively with the transthyretin and transferrin levels, and inversely with the acute-phase proteins. CONCLUSIONS: The inflammatory reaction is the main reason for depressed serum albumin levels in elderly patients with pneumonia. The study results do not support the use of nutritional supplementation to alter the clinical outcome in these patients.

Pneumococcal disease in Sweden: experiences and current situation.

During the last decade, the incidence of invasive pneumococcal disease in Sweden has risen, seemingly due chiefly to an increasing incidence of pneumococcal bacteremia among the elderly. On the other hand, mortality due to invasive disease in Sweden is low, approximately 10% for bacteremic pneumococcal pneumonia. Beta-lactam resistance in Streptococcus pneumoniae is still a relatively minor problem in Sweden, with only 3%-4% of strains demonstrating decreased susceptibility to penicillin. However, local outbreaks of pneumococcal disease with up to 10% resistance have occurred among children, especially in southern Sweden.

Diagnostic fiberoptic bronchoscopy and protected brush culture in patients with community-acquired pneumonia.

A model for performing fiberoptic bronchoscopy as a supplement to noninvasive diagnostic methods, in patients with community-acquired pneumonia, was prospectively studied. Twenty-four patients underwent bronchoscopy, seven pilot patients and 17 of 277 (6 percent) consecutive patients with CAP. Indications for FOB were early therapy failure (less than or equal to 72h)(n = 7), late therapy failure (greater than 72h)(n = 11), or before start of antibiotic therapy in severely ill or immunocompromised patients (n = 6). Samples were obtained by aspiration of bronchial secretion and with a protected brush catheter from which quantitative cultures with a detection level of 10(4) colony forming units per ml were performed. Results concluded that FOB, with the use of quantitative PB-cultures, offered a safe and specific diagnostic tool, which on special indications, can be of great value in the management of patients with CAP.

Deaths in bacteremic pneumococcal pneumonia. A comparison of two populations--Huntington, WVa, and Stockholm, Sweden.

The case fatality rate in bacteremic pneumococcal pneumonia (Pnb) has been reported to be lower in Sweden than in the United States. We retrospectively compared 231 adult Pnb patients in Stockholm (STO), Sweden, with 107 patients infected with the same serotypes or groups in Huntington, WVa (HWV). The total case fatality rate was 11/231 (5 percent) in STO versus 28/107 (26 percent) in HWV (p < 0.001), being significantly lower in STO for all age groups. Patients from HWV more often had preexisting chronic diseases, while alcoholism was more prevalent in STO. The case fatality rate was similar among alcoholics in STO and HWV, while it was much higher in nonalcoholic patients with chronic diseases in HWV (22/73;30 percent) than in STO (2/88;2 percent) (p < 0.001). No bias was found that could account for more than a small part of the higher case fatality rate in HWV. Thus, underlying chronic diseases in HWV accounted for some of the increased risk of death in this patient group. However, the major part of the difference in death rates between HWV and STO remains unexplained.

Oral empiric treatment of community-acquired pneumonia. A multicenter, double-blind, randomized study comparing sparfloxacin with roxithromycin. The Scandinavian Sparfloxacin Study Group.

STUDY OBJECTIVE: Comparison of efficacy and safety of sparfloxacin (Spfx) vs roxithromycin (ROXI) for treatment of community-acquired pneumonia (CAP). DESIGN: Multicenter, double-blind, randomized study. SETTING: Twenty-three university and community hospitals in Scandinavia. PATIENTS: Three hundred four adults (> or = 18 years of age) with CAP treated as outpatients (25%) or inpatients (75%). INTERVENTIONS: Randomization 1:1 to Spfx, 400 mg on day 1, then 200 mg once daily, or ROXI, 150 mg twice daily, 10 to 14 days. Safety and efficacy analyses in intention-to-treat (ITT) and evaluable populations. RESULTS: Three hundred three of 304 patients were included in the ITT and safety analyses and 260 (86%) were evaluable at the end of follow-up. Streptococcus pneumoniae was the cause of pneumonia in 62 (20%) patients (11 with bacteremia), Chlamydia pneumoniae in 40 (13%), and Mycoplasma pneumoniae in 38 (13%) patients. The success rates for Spfx and ROXI at the end of follow-up were 82% and 72%, respectively, in the ITT population, and 94% and 79%, respectively, in the evaluable population. The odds ratio Spfx/ROXI for success was 4.5 (95% confidence interval, 1.9, 10.8) for the evaluable population. Both drugs were, overall, equally safe. GI symptoms were the most common adverse experiences in both groups. Prolongation of QTc, without clinical symptoms, was seen in 3% of Spfx patients and in 1% of ROXI patients, and photosensitivity, mostly mild to moderate, was seen in 5% of the Spfx group. CONCLUSIONS: Oral treatment with Spfx was superior to ROXI for the treatment of moderately severe CAP. Spfx was effective for all isolated pathogens, including S pneumoniae, and may be an alternative for empiric treatment of CAP, especially in areas with a high incidence of beta-lactam-resistant pneumococci.

The role of IgA determination by ELISA in the early serodiagnosis of Mycoplasma pneumoniae infection, in relation to IgG and mu-capture IgM methods.

Enzyme-linked immunosorbent assay (ELISA) for IgA, IgG and IgM was evaluated with sera from 50 adult patients with pneumonia, selected on the basis of a positive complement fixation (CF) test for diagnosis of Mycoplasma pneumoniae infection and with sera from 105 healthy blood donors. The ELISA antigen for IgG and IgA was a sonicated suspension of M. pneumoniae solubilised by deoxycholate. For the IgM assay, the same antigen was directly conjugated to alkaline phosphatase and used in a mu-capture format. ELISA gave positive results with high or rising titres for one or several antibody classes in 47 (94%) patients. In two of the three ELISA-negative cases, the diagnosis of M. pneumoniae infection indicated by the CF test seemed unlikely on clinical grounds. Specific IgA antibodies was developed more regularly and more rapidly than IgM. IgA titres also started to decrease earlier than IgM or the late-peaking IgG response. Thus, the determination of IgA antibodies was found to be valuable for the early diagnosis of M. pneumoniae infection. The study also demonstrated that the determination of all three antibody classes is necessary to obtain an optimal level of serodiagnosis.