Respiratory tract infections during the 2011 Mycoplasma pneumoniae epidemic.

In 2011, Norway experienced a surge in community acquired Mycoplasma pneumoniae infections. Norway also has one of the highest rates of reported Bordetella pertussis infections, despite high vaccine coverage. We aimed to determine the prevalence of upper respiratory tract pathogens in patients attending primary care physicians for respiratory illness during the 2011 M. pneumoniae epidemic period. A retrospective analysis of data from 26,039 patients that have had nasopharyngeal swabs analysed by nucleic acid amplification testing (NAAT) for M. pneumoniae, C. pneumoniae and B. pertussis was performed. Subsets of samples were tested for additional pathogenic bacteria, including B. parapertussis and B. holmesii, as well as influenza virus. M. pneumoniae, C. pneumoniae and B. pertussis were detected in 2,484 (9.5 %), 261 (1.0 %) and 821 (3.2 %) patients, respectively. Co-infection of M. pneumoniae and B. pertussis was found in 50 (0.19 %) patients, C. pneumoniae and B. pertussis in 4 (0.02 %). Influenza virus was found in 899 (24.5 %) of 3,661 nasopharyngeal swabs. Co-infection of influenza virus and bacterial pathogens was common, although influenza virus co-infection with B. pertussis occurred significantly more often than with C. pneumoniae and M. pneumoniae (20.4 % versus 2.9 % and 9.1 %, respectively; p<0.005). Testing for Bordetella species genes IS1001, IS1002 and recA showed that B. holmesii was most likely misdiagnosed as B. pertussis in 5.8 % of cases. The most prevalent respiratory tract pathogen in the general population in 2011 was M. pneumoniae. B. pertussis was also found frequently as was B. pertussis and influenza virus co-infections.

[Respiratory syncytial virus infections in hospitalized children in Akershus]. / Infeksjon med respiratorisk syncytialvirus hos hospitaliserte barn i Akershus.

INTRODUCTION: The study describes hospitalisations for RSV infections among children < 15 years. MATERIAL AND METHODS: The study is a population-based retrospective analysis of admission data from February 1993 through January 2000 of children who tested positive for RSV in nasopharyngeal aspirates. RESULTS: 1,002 cases were identified of which 69.5% were < 1 year old children. Estimated annual incidence of RSV infection requiring hospitalisation was 2.1/1,000 Children < 15 years, 24.9/1,000 infants < 1 year, and 28.4/1,000 infants < 6 months old. Males were more likely to be hospitalised than females. The overall mortality was 0.5%. Premature infants with birthweight < or = 1,000 g had the highest hospitalisation rates, the longest hospital stay and most complications. However, surprisingly many complications occurred among previously healthy infants. INTERPRETATION: Recommendations for RSV prophylaxis among preterm infants should be investigated in a larger study. Development of an RSV vaccine should be a priority.

Evaluation of 12 commercial tests for detection of Epstein-Barr virus-specific and heterophile antibodies.

Ten microbiological departments in Norway have participated in a multicenter evaluation of the following commercial tests for detection of Epstein-Barr virus (EBV)-specific and heterophile antibodies: CAPTIA Select viral capsid antigen (VCA)-M/G/EBNA (Centocor Inc.), Enzygnost anti-EBV/immunoglobulin M (IgM) and IgG (Dade Behring), Vironostika EBV VCA IgM/IgG/EBNA enzyme-linked immunosorbent assay (ELISA) (Organon Teknika), SEROFLUOR immunofluorescence assay and EBV Combi-Test (Institute Virion Ltd.), anti-EBV recombinant IgM- and IgG-early antigen/EBNA IgG ELISA (Biotest Diagnostics), EBV IgM/IgG/EBNA ELISA (Gull Laboratories), Paul-Bunnell-Davidsohn test (Sanofi Diagnostics Pasteur), Monosticon Dri-Dot (Organon Teknika), Avitex-IM (Omega Diagnostics Ltd.), Alexon Serascan infectious mononucleosis test (Alexon Biomedical Inc. ), Clearview IM (Unipath Ltd.), and Cards+/-OS Mono (Pacific Biotech, Inc.). The test panel included sera from patients with primary EBV infection, immunocompromised patients with recent cytomegalovirus infection, healthy persons (blood donors), and EBV-seronegative persons. Among the tests for EBV-specific antibodies the sensitivity was good, with only small differences between the different assays. However, there was a greater variation in specificity, which varied between 100% (Enzygnost) and 86% (Biotest). Tests for detection of heterophile antibodies based on purified or selected antigen (Avitex, Alexon, Clearview IM, and Cards+/-OS Mono) were more sensitive than the Paul-Bunnell-Davidsohn and Monosticon tests.

Candida norvegensis: a fluconazole-resistant species.

Candida norvegensis has been an unusual cause of infections in humans. In Norway this species was isolated from eight patients from 1990 to 1996 and was of probable pathogenic significance in four of them. All isolates were resistant to fluconazole. The same was true for two C. norvegensis isolates from before 1940, and it is therefore assumed that the fluconazole resistance is inherent.

Meningococcal phenotypic and genotypic characteristics and human antibody levels.

During a 2-month period in 1984, throat and blood samples were collected from 1,102 healthy persons of different ages living in the city of Tromsø, Norway. One hundred and eight persons (9.8%) were meningococcal carriers, but the carrier rate varied with sex and age. Twenty-nine isolates (26.9%) were of serogroup B, and 31 (28.7%) isolates contained the serotype 15 antigen. Sixty-eight (63.0%) isolates were nontypable, 49 (45.4%) were nongroupable, and 21 (19.4%) were sulfonamide resistant. All nine serotype 2a isolates and eight (25.8%) of the serotype 15 isolates were sulfonamide resistant. Only these eight serotype 15, sulfonamide-resistant isolates had a DNA fingerprint similar to that of the majority of systemic isolates of Neisseria meningitidis in Norway. The average level of antimeningococcal immunoglobulin G antibodies, as determined by a whole-bacterium enzyme immunoassay with a systemic B:15 meningococcal strain as the antigen, was low until 12 to 15 years of age and then steadily increased.

Evaluation of ten commercial heterophile antibody tests for infectious mononucleosis.

Ten rapid slide agglutination tests for infectious mononucleosis were evaluated. The quality of the technical information included with the kits was found to differ considerably, as did the composition of the tests and the principles of test specificity. Furthermore, large variation was found in the shelf life and price of the different kits. Thirty-nine serum samples were selected according to titre in the Paul-Bunnell-Davidsohn differential absorption test, largely from the low titre area, since this is where most diagnostic problems can be expected. The sera were tested blindly using the ten rapid slide agglutination tests. Considerable differences were found in specificity and sensitivity. When compared with the results obtained from PBD, the tests could be divided into two groups. The first group consisted of three kits, all of which gave false negative, but no false positive results. The remaining seven tests gave false negative and false positive results, but were more sensitive than the tests in the first group. The large variation in the results obtained when using the different kits under controlled conditions indicates that such tests may give even less satisfactory results in practice.

An ELISA study of the antibody response after vaccination with a combined meningococcal group B polysaccharide and serotype 2 outer membrane protein vaccine.

The antibody response of a group of adult volunteers given a combined meningococcal group B polysaccharide and serotype 2 outer membrane protein vaccine, has been studied by the ELISA technique. The antigen was an outer membrane preparation from a non-capsular strain of Neisseria meningitidis (the vaccine strain). The vaccination was performed as a double-blind experiment where one group of 27 persons was given the vaccine and a similar group of 28 persons was given a placebo. In addition, five volunteers from the laboratory staff were given the vaccine. Two weeks after the primary vaccination, 31 of the 32 vaccinated persons demonstrated a significant increase of specific IgG antibodies. The number with significant IgA and IgM increase was 21 and 12, respectively. A booster effect after revaccination four weeks later was found in 18 persons for IgG, in 10 for IgA and in one for IgM. Twenty-five weeks after the primary vaccination the ELISA values were significantly reduced, mostly for IgM antibodies. The mean values for IgG, IgM and IgA were then 150%, 130% and 110%, respectively, of the values before vaccination. A new way of analysing the data has also been tried for IgG determination. Instead of comparing OD values, we calculate the expression: B = D/2 . In(1 + OD/A)/(1-OD/A), where A is an experimental constant and D is the serum dilution. B then becomes linearly proportional to the antibody concentration. This way of expressing the results shows the geometric mean IgG titer 25 weeks after vaccination to be three times higher for the vaccinated than for the placebo group.