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L Matter

Publications and source records attributed to L Matter.

At least 37 records · Page 2Linked to original sources
PubMed1997

[Vaccinations: the necessary and the desirable].

Most routine childhood vaccinations are well established in Switzerland. The high rate of protection must be maintained as long as the corresponding infectious agents have not been eradicated. The implementation of the measles, mumps, and rubella (MMR) vaccination scheme for boys and girls must be improved, with special emphasis on the timely application of the first dose during the second year of life as well as the catch-up dose at school age. The current low MMR vaccination rates carry the risk of increased age-dependent complications in the future. The potential for a substantial reduction in morbidity and mortality by recommended vaccinations for adults, particularly for influenza and pneumococcal infections in the elderly, deserves increased attention and commitment. Every medical consultation should be considered an opportunity to update immunity and to cope with gaps in the implementation of the vaccination schedule, in order to achieve optimal protection for the individual as well as for the population. The need for improved, as well as new, types of vaccines should not deter us from the use of currently available vaccines.

Adult↗
PubMed1997

Age-stratified seroprevalence of measles, mumps and rubella (MMR) virus infections in Switzerland after the introduction of MMR mass vaccination.

We have performed age-stratified seroprevalence studies for MMR to evaluate these vaccinations. Serum samples submitted for diagnostic testing were randomly selected for unlinked anonymous panels. IgG antibodies were tested by ELISA and indirect immunofluorescence. In the vaccination cohort (age 1.5 to 6.5 years), seroprevalence attained 80%. For measles and mumps it continued to increase to 95%, while for rubella it declined transiently to 60% between 7 and 12 years of age. We observed no differences according to gender in any age group in 1991-1992. (Semi)quantitative values of the IgG antibodies against all three viruses increased during adolescence, suggesting wild virus circulation. In 1992, MMR vaccination has reached < 80% of the children during their second year of age. Due to previous monovalent measles and mumps vaccinations in pre-school children and due to endemic and epidemic activity, particularly of mumps virus, a trough of the seroprevalence in adolescents was evident only for rubella. MMR vaccination campaigns performed at school since 1987 have increase seroprevalence in this population segment and have probably over-compensated for the expected shift to the right of the seroprevalence curves. A more compulsive implementation of the recommended childhood vaccination schedule and continued efforts at catchup vaccinations during school age especially for rubella are necessary to avoid the accumulation of susceptible young adults during the forthcoming decades.

Adolescent↗
PubMed1997

Familial transmission of a serious disease--producing group A streptococcus clone: case reports and review.

Invasive group A streptococcus (GAS) infections are emerging diseases; however, person-to-person transmission of invasive GAS producing life-threatening infection has been observed rarely. We report a small intrafamilial cluster of life-threatening GAS infections. A previously healthy 47-year-old father developed necrotizing fasciitis of the neck. Two days later, his 16-year-old daughter developed streptococcal angina, pneumonia, and pleural empyema. Both patients had signs of streptococcal toxic shock syndrome. Pulsed field gel electrophoresis revealed that the M6 strains of GAS isolated from the father and daughter had identical patterns. Cases of person-to-person transmission of invasive GAS infection reported in the literature are also reviewed.

Adolescent↗
PubMed1997

Serum levels of rubella virus antibodies indicating immunity: response to vaccination of subjects with low or undetectable antibody concentrations.

To define the concentration of anti-rubella virus (RV) antibodies discriminating nonimmune from immune persons and to characterize immune responses to rubella vaccination, serologic studies were performed after rubella vaccination in persons with low or undetectable antibody concentrations. Thirty-six subjects with primary immune responses had prevaccination anti-RV IgG concentrations <15 IU/mL by ELISA and negative results by radial hemolysis. Eighty-three subjects with secondary immune responses had mean IgG increases of 9 IU/mL within 2 weeks. Eight of them had initial IgG levels <15 IU/mL, and 2 were negative by radial hemolysis. Both groups attained similar antibody levels after 1-3 months. Secondary immune responses to rubella vaccination were delayed by >2 weeks and thus resembled the time course of primary immunization, but IgM responses and IgG avidity were distinct between subjects with primary or secondary immune responses. Thresholds for immunity <15 IU/mL entail the risk of withholding rubella vaccination from susceptible persons.

Adult↗
PubMed1997

Evaluation of the COBAS AMPLICOR MTB system.

A panel of 1,012 respiratory sediments was retrospectively tested by PCR amplification to detect Mycobacterium tuberculosis with the COBAS AMPLICOR MTB system. The sensitivities and specificities of COBAS and fluorescence microscopy compared to culture were 92.6 versus 95.6% and 99.6 versus 95.3%, respectively. Inhibition occurred in 48 (4.7%) specimens.

Bronchoalveolar Lavage Fluid↗
PubMed1997

Evaluation of 2-SP transport medium for detection of Chlamydia trachomatis and Neisseria gonorrhoeae by two automated amplification systems and culture for chlamydia.

AIMS: To assess the performance of 2-sucrose-phosphate based transport medium (2-SP) for the detection of Chlamydia trachomatis and Neisseria gonorrhoeae by an automated commercial polymerase chain reaction (PCR) and ligase chain reaction (LCR) compared to centrifugation culture on McCoy cells for C trachomatis. Second, to compare both amplification systems for initial diagnostic testing of a low prevalence population for sexually transmitted diseases. METHODS: Four hundred and eighty one consecutive urogenital and conjunctival specimens were examined. All tests were performed on the same specimen collected with a dacron swab and transported in 2-SP medium. Samples that were positive by culture or by both PCR and LCR were considered to be true positives. RESULTS: The prevalences of C trachomatis and of N gonorrhoeae were 2.7% and 0.4%, respectively. PCR had a resolved sensitivity and specificity of 100% and 99.8%, respectively, for C trachomatis, and 100% and 98.9%, respectively, for N gonorrhoeae. LCR was 100% sensitive and specific for both pathogens. The resolved sensitivity of the shell vial assay was 85%. No culture positive sample would have been missed by PCR or LCR. The inhibition rate for PCR was 4.8%. CONCLUSIONS: 2-SP medium proved to be suitable for both PCR and LCR. It is not limited to any one test manufacturer and allows the performance of amplification techniques and viral and chlamydia culture from the same specimen. The LCR was more reliable than PCR on initial testing. However, hands on time is longer, and no amplification control is available for LCR.

Bacteriological Techniques↗
PubMed1996

Effects of antibiotic treatment in the subset of common-cold patients who have bacteria in nasopharyngeal secretions.

BACKGROUND: Upper-respiratory-tract infection is one of the main causes of overuse of antibiotics. We have found previously that bacteria such as Haemophilus influenzae, Moraxella catarrhalis, and Streptococcus pneumoniae can be isolated from the nasopharyngeal secretions of a substantial proportion of adults with upper-respiratory-tract infections. We have assessed the efficacy of co-amoxiclav in patients with common colds but no clinical signs of sinusitis or other indications for antibiotics. METHODS: Between January, 1992 and March, 1994, 314 patients who presented to our outpatient clinic with common colds were enrolled in the double-blind, placebo-controlled study. They were randomly assigned 5 days' treatment with co-amoxiclav (375 mg three times daily) or identical placebo. Clinical examinations were done at enrolment and on day 5-7 to assess outcome (cured, persistent symptoms, worse symptoms). Seven patients were excluded after randomisation, seven did not have nasopharyngeal aspiration, and 12 did not return for followup assessment. FINDINGS: Of 300 patients with nasopharyngeal aspirates, 72 had negative bacterial cultures, 167 had cultures positive only for bacteria unrelated to respiratory infections, and 61 had cultures positive for H influenzae, M catarrhalis, or S pneumoniae. At 5-day follow-up of these culture-positive patients, the distribution of outcome was significantly better among co-amoxiclav-treated (n=30) than placebo-treated (n=28) patients (cured 27 vs 4%; persistent symptoms 70 vs 60%; worse symptoms 3 vs 36%; p=0.001). Patients on co-amoxiclav also scored their symptoms significantly lower than patients on placebo (p=0.008). Among culture-negative patients (n=230), the outcome distribution did not differ between the treatment groups (p=0.392). INTERPRETATION: The majority of patients with upper-respiratory-tract infection do not benefit from antibiotics and side-effects are frequent. However, for the subgroup whose nasopharyngeal secretions contain H influenzae, M catarrhalis, or S pneumoniae, antibiotics are clinically beneficial.

Adult↗
PubMed1996

IgM-specific serodiagnosis of acute human cytomegalovirus infection using recombinant autologous fusion proteins.

Portions of three human cytomegalovirus (HCMV) polypeptides, which were shown previously to be highly reactive with patient sera, were expressed in Escherichia coli as autologous fusion proteins. Purified recombinant polypeptides were used as antigens in enzyme linked immunosorbent assay (ELISA) and compared against assays which use natural viral antigen from cell culture for their ability to improve IgM-specific serology of acute HCMV-infection. A fusion protein (CM2) which contained two copies of the C-terminal portion of pUL44 (p52, aa 297-433) and one copy of a highly reactive fragment of the major DNA-binding protein pUL57 (aa 545-601) proved to be superior in sensitivity and specificity compared to assays which use culture derived antigen. A construct expressing one copy of the fragments from pUL44 and pUL57 in fusion with the 54 amino terminal residues of pUL32 (pp150, aa 994-1048) did not lead to an improved sensitivity compared to CM2. Adversely, this polypeptide reacted with a number of sera from asymptomatic blood donors infected latently with HCMV indicating low specificity of this antigen for the detection of acute infection. Concordant results were obtained with an antigen that combined only the C-terminal portions of pUL44 and pUL32 (CM3). ELISA experiments with sequential sera from renal transplant recipients demonstrated that detection of IgM-antibodies using CM2 as antigen correlated closely with acute infection, whereas high levels of IgM-antibodies against CM1 and CM3 persisted for a month following acute HCMV-infection. These results indicate that the application of a single autologous fusion protein like CM2 as antigen for recombinant ELISAs can improve significantly IgM-serodiagnosis of acute HCMV infection.

Antibodies, Viral↗
PubMed1996

Immunoglobulin A-specific serodiagnosis of acute human cytomegalovirus infection by using recombinant viral antigens.

The immunoglobulin A-specific reactivities of recombinant viral proteins from nine different reading frames of human cytomegalovirus were evaluated in enzyme-linked immunosorbent assay experiments. Antigen fragments of reading frames pUL32, pUL44, and pUL57 were identified as preferable antigens for immunoglobulin A serodiagnosis. Application of autologous fusion proteins which combine these polypeptides may be useful especially for the early detection of acute secondary human cytomegalovirus infection.

Acute Disease↗
PubMed1996

Diagnostic implications of kinetics of immunoglobulin M and A antibody responses to Toxoplasma gondii.

We evaluated immunoglobulin M (IgM) and IgA assays that could improve the predictive value for recently acquired toxoplasma infection for patients with positive screening test results. Follow-up sera were collected from 82 patients whose initial serum specimen had a reactive anti-Toxoplasma gondii IgM result. According to the evolution of the immune response, patients were divided retrospectively into two groups: one in which a recent infection was unlikely and the other one with an evolving immune response suggestive of recent toxoplasma infection. All IgM and one of three IgA assays used in the study are suitable for screening pregnant patients, with a negative predictive value of 100%. The predictive value of positive results is much lower because of the low prevalence of acute toxoplasmosis in pregnant women and the long persistence of IgM after acute infection. In the present study, all except one IgM enzyme immunoassay remained positive well beyond 6 months after the initial sample was tested. The IgM immunofluorescence test had the shortest persistence of positivity in most cases. IgA tests were either too insensitive or remained reactive too long to be useful for screening pregnant patients. Interpreting enzyme immunoassays with modified cutoff values and the combination of two tests could improve the predictive value of positive results to about 80% in terms of recent infection.

Adolescent↗
PubMed1996

An outbreak of mumps in a population partially vaccinated with the Rubini strain.

Since 1991, 6 years after the recommendation of universal childhood triple vaccination against measles, mumps and rubella (M + M + R), Switzerland has been confronted with an increasing number of mumps cases affecting both vaccinated and unvaccinated children. The M + M + R vaccine mainly used in the Swiss population after 1986 contains the highly attenuated Rubini strain of mumps virus. We analysed an outbreak of 102 suspected mumps cases by virus isolation, determination of IgM antibodies to mumps virus in 27 acute phase sera, and verification of vaccination histories. Mumps was confirmed by virus isolation in 88 patients, of whom 72 had previously received the Rubini vaccine strain. IgM antibodies to mumps virus were detected in 24/27 acute phase serum samples. A group of 92 subjects from the same geographic area without signs of mumps virus infection served as controls. IgG antibodies to mumps virus and vaccination status were assessed in these children. The vaccination rate in these controls was 61%, with equal seropositivity for unvaccinated and Rubini-vaccinated subjects. These data support other recent reports which indicate an insufficient protective efficacy of current mumps vaccines.

Adolescent↗
PubMed1995

[Current developments in Mycobacteria diagnosis].

The reemergence of tuberculosis in the industrialized countries has hastened the development of new laboratory techniques. Hence, well-known shortcomings of traditional techniques such as the lack of a rapid and specific detection system, the delayed availability of species identification and drug susceptibility results, and the lack of a reliable method for determining strain identity for epidemiological purposes, have become immediate targets for implementing molecular biology techniques. In particular, nucleic acid amplification techniques, restriction fragment-length polymorphism and single-strand conformation polymorphism analyses have dramatically improved diagnostic timeliness and accuracy of mycobacteriology laboratory results. Our paper reviews recent developments and comments on the diagnostic applications of the new tools as compared to traditional techniques.

Amino Acid Sequence↗
PubMed1995

The incidence of rubella virus infections in Switzerland after the introduction of the MMR mass vaccination programme.

We have collected data on the incidence of rubella in Switzerland from 1987 to 1992 to help evaluating the impact of the measles, mumps and rubella (MMR) mass vaccination programme which started in 1985 in this country. We used detailed informations on samples submitted for diagnostic testing in conjunction with anonymous laboratory notifications to the Swiss Federal Office for Public Health, and data from the Swiss sentinel network of general practitioners to find trends in the incidence of rubella after the introduction of mass vaccination. We observed an unabated seasonal oscillation without decreasing trend during the observation period and were unable to detect a shift in the age distribution of cases. An important proportion of laboratory-confirmed rubella occurred in women of childbearing age. Immigrants from regions with low endemicity of rubella were at increased risk of contracting rubella and transmitting it to their offspring. We conclude, that MMR mass vaccination has not interrupted the circulation of rubella virus in Switzerland, and that improvements in the implementation and surveillance of the MMR vaccination campaign are necessary in order to avoid untoward effects of it.

Adolescent↗
PubMed1995

Isolation of Coxiella burnetii from heart valves of patients treated for Q fever endocarditis.

Coxiella burnetii was isolated from the valve material of two patients who underwent valvectomy because of progressive congestive heart failure due to endocarditis. In each case antibiotic therapy was administered for several months prior to valvectomy. Classical histopathological examination of the valves did not reveal an etiology. However, coxiella-like organisms were demonstrated in valvular material with Köster, Stamp, and Giemsa stains, and the organisms were grown in cell culture. Antibody titers were consistent with the diagnosis of chronic C. burnetii infection. This report illustrates the advantage of simple and fast staining techniques and cell culture for the demonstration and isolation of C. burnetii in the heart valve tissue of patients with Q fever endocarditis.

Antibodies, Bacterial↗
PubMed1995

The DNA-binding protein pUL57 of human cytomegalovirus is a major target antigen for the immunoglobulin M antibody response during acute infection.

A small polypeptide from pUL57 of human cytomegalovirus was identified as a major target for the immunoglobulin M antibody response. This antigen seems to be superior to antigenic fragments from pp150 and p52 in the identification of sera from acutely infected patients. It may therefore represent an essential antigen for recombinant immunoglobulin M antibody tests for human cytomegalovirus.

Acute Disease↗
PubMed1995

Detection of human immunodeficiency virus (HIV) type 1 antibodies by new automated microparticle enzyme immunoassay for HIV types 1 and 2.

We compared an automated microparticle double-antigen sandwich enzyme immunoassay (EIA) for the IMx test system recently developed by Abbott with two established assays (the automated indirect Vidas IgG EIA and the double-antigen sandwich EIA from Murex/Wellcome) devised for the detection of human immunodeficiency virus type 1 (HIV-1) and HIV-2 antibodies. A total of 1,078 consecutive serum samples were tested prospectively with the three assays. In addition, we used retrospectively selected panels of serum samples with discrepant results in two different screening tests and with indeterminate or positive Western immunoblot (WB) results, as well as five commercially available HIV-1 seroconversion panels. The new assay showed excellent discriminatory characteristics for the separation of samples from HIV-1-positive and HIV-1-negative persons according to Centers for Disease Control and Prevention WB criteria. The sensitivities were 98.1, 92.9, and 96.1% for the new test and the two other assays, respectively, and the specificities were 99.7, 97.9, and 98.1%, respectively. With the seroconversion panels this new test was positive several days earlier than the two other assays; i.e., seroconversion was evident at the peak of p24 antigenemia and often several weeks before WB became positive by the most stringent criteria.

HIV Antibodies↗