Long-term follow-up of a vaccination program for infants born to HBsAg-positive mothers in Stockholm County, Sweden.

We investigated the long-term antibody response to hepatitis B virus (HBV) vaccination in babies born to chronically infected mothers. They received one dose of monovalent HBV vaccination at birth and one month of age, followed by 3 doses of hexavalent vaccine including an HBV component at ages 3, 5, and 12 months, respectively, with a very high percentage of protective anti-HBs levels at 13 months. At the age of 8-12 years, 56 out of 68 children (82%) had protective levels of anti-HBs, two had signs of anti-HBc seroconversion without any history of clinical disease and none had ongoing infection. A small subgroup was retested after one booster dose, in all resulting in increase in anti-HBs from below 10 IU/L to levels corresponding to protective immunity. We conclude that this vaccination strategy is effective throughout the first decade of life in avoiding chronic infection and in maintaining a good serological response.

Six-week follow-up after HIV-1 exposure: a position statement from the Public Health Agency of Sweden and the Swedish Reference Group for Antiviral Therapy.

In 2014 the Public Health Agency of Sweden and the Swedish Reference Group for Antiviral Therapy (RAV) conducted a review and analysis of the state of knowledge on the duration of follow-up after exposure to human immunodeficiency virus (HIV). Up until then a follow-up of 12 weeks after exposure had been recommended, but improved tests and new information on early diagnosis motivated a re-evaluation of the national recommendations by experts representing infectious diseases and microbiology, county medical officers, the RAV, the Public Health Agency, and other national authorities. Based on the current state of knowledge the Public Health Agency of Sweden and the RAV recommend, starting in April 2015, a follow-up period of 6 weeks after possible HIV-1 exposure, if HIV testing is performed using laboratory-based combination tests detecting both HIV antibody and antigen. If point-of-care rapid HIV tests are used, a follow-up period of 8 weeks is recommended, because currently available rapid tests have insufficient sensitivity for detection of HIV-1 antigen. A follow-up period of 12 weeks is recommended after a possible exposure for HIV-2, since presently used assays do not include HIV-2 antigens and only limited information is available on the development of HIV antibodies during early HIV-2 infection. If pre- or post-exposure prophylaxis is administered, the follow-up period is recommended to begin after completion of prophylaxis. Even if infection cannot be reliably excluded before the end of the recommended follow-up period, HIV testing should be performed at first contact for persons who seek such testing.

Coexistence of two clades of enterovirus D68 in pediatric Swedish patients in the summer and fall of 2014.

In 2014, an outbreak of enterovirus D68 (EV-D68) was observed in North America, with cases of severe respiratory illness and a possible etiological link to cases of acute flaccid paralysis. EV-D68 has also been reported from European countries, but no data from Sweden are available. This study investigated respiratory specimens collected during July-October 2014 from 30 Swedish children aged 0-9 years who were positive for enterovirus and/or rhinovirus in routine clinical PCR. Seven samples were typed as EV-D68 by VP4/VP2 sequencing. Two genetically distinct EV-D68 variants coexisted. Six viruses belonged to clade B, the variant involved in the North American outbreak, and one virus belonged to clade A. Respiratory illness was the major symptom among EV-D68 infected patients and all fully recovered. This is the first report of EV-D68 in Sweden. Considering the current epidemiological situation, genotyping and specific EV-D68 testing should be considered in patients with severe respiratory illness who test positive for enterovirus or rhinovirus in routine diagnostics.

Evaluation of bio-rad geenius HIV-1 and -2 assay as a confirmatory assay for detection of HIV-1 and -2 antibodies.

The performance of the new Bio-Rad Geenius HIV-1/2 confirmatory assay was compared with that of the Chiron RIBA HIV-1/HIV-2 strip immunoblot assay using 166 samples from HIV-1-, HIV-2-, or HIV-1/2-positive and HIV-negative individuals and two quality control panels. Our results indicate that the Geenius assay is a suitable alternative for confirmatory HIV testing.

Antigenic relationships between six genotypes of the small hydrophobic protein gene of mumps virus.

Six different genotypes of mumps virus, A, C, D, G, H and I, genotyped on the basis of the small hydrophobic protein gene sequence, were subjected to antigenic comparison. Monoclonal antibodies directed against the haemagglutinin-neuraminidase protein of the SBL-1 strain of genotype A were used in immunofluorescence tests with different mumps virus strains. In addition, the six virus genotypes were compared by cross-neutralization tests with human post-vaccination sera after vaccination with the Jeryl Lynn (JL) strain of mumps virus and with rabbit hyperimmune sera directed against the A or D genotypes of mumps virus. Genotypes C, D, G, H and I could not be antigenically separated. In contrast, three different virus strains of genotype A, SBL-1, JL and Kilham, were distinct and were found to represent three different serotypes within the A genotype of mumps virus. Vaccination of Swedish children with the JL strain of mumps virus resulted in clearly lower neutralization titres against the SBL-1 strain, which is endemic in Sweden, compared to the homologous vaccine titres.

Development and evaluation of nucleic acid sequence based amplification (NASBA) for diagnosis of enterovirus infections using the NucliSens Basic Kit.

BACKGROUND: Molecular methods based on RNA amplification are needed for sensitive detection of enteroviruses in clinical samples. Many 'in house' methods based on reverse-transcribed PCR (RT-PCR) could be difficult to use in the routine diagnostic laboratory since they tend to be time-consuming, use reagents from many different suppliers and include non-routine procedures. OBJECTIVES: The aim of this study was to develop and evaluate methods based on nucleic acid sequence based amplification (NASBA) for detection of enterovirus sequences. STUDY DESIGN: 'In house' prepared and commercially available reagents were utilised to develop enterovirus-specific NASBA assays. Optimised methods were evaluated using clinical samples (cerebrospinal fluid, respiratory and stool samples), titred virus controls and in vitro produced synthetic RNA. Results for NASBA were compared with RT-PCR and virus culture. RESULTS: Kit-based reagents gave an equivalent sensitivity to the more laborious 'in house' molecular assays (NASBA and RT-PCR) on clinical material and controls. All molecular methods picked up enterovirus positive clinical samples that were not identified by culture. End point detection sensitivity for the NASBA assay based on the NucliSens Basic Kit was