Measles outbreak in Gothenburg urban area, Sweden, 2017 to 2018: low viral load in breakthrough infections.

In an outbreak of measles in Gothenburg, Sweden, breakthrough infections (i.e. infections in individuals with a history of vaccination) were common. The objective of this study was to compare measles RNA levels between naïve (i.e. primary) and breakthrough infections. We also propose a fast provisional classification of breakthrough infections. Medical records were reviewed and real-time PCR-positive samples genotyped. Cases were classified as naïve, breakthrough or vaccine infections. We compared clinical symptoms and measles RNA cycle threshold (Ct) values between breakthrough and naïve infections. Sixteen of 28 confirmed cases of measles in this outbreak were breakthrough infections. A fast provisional classification, based on previous history of measles vaccination and detectable levels of measles IgG in acute serum, correctly identified 14 of the 16 breakthrough infections, confirmed by IgG avidity testing. Measles viral load was significantly lower in nasopharyngeal samples from individuals with breakthrough compared with naïve infections (median Ct-values: 32 and 19, respectively, p < 0.0001). No onward transmission from breakthrough infections was identified. Our results indicate that a high risk of onward transmission is limited to naïve infections. We propose a fast provisional classification of breakthrough measles that can guide contact tracing in outbreak settings.

Core mutations, IL28B polymorphisms and response to peginterferon/ribavirin treatment in Swedish patients with hepatitis C virus genotype 1 infection.

BACKGROUND: Patients infected with hepatitis C virus (HCV) genotype 1 respond poorly to standard treatment with 50% or less achieving sustained virologic response. Predicting outcome is essential and could help avoid unnecessary treatment and reduce health cost. Recently, an association of amino acid substitutions in the core region and treatment outcome was observed in Japanese patients. In the present study, the impact of these mutations on response kinetics and treatment outcome was explored in Caucasian patients. METHODS: The core region of HCV pre-treatment samples obtained from 50 patients treated with peginterferon/ribavirin in a previous Swedish clinical trial with genotype 1 infection were sequenced. The alleles at rs12979860, a single nucleotide polymorphism (SNP), were assessed in order to identify any co-association with this strong response predictor. RESULTS: No association between treatment response and substitutions of core residue 91 was found. In contrast, substitutions of core residue 70 were observed in 6/21 (29%) non-responders, but only in one of 29 responders (p = 0.03), and were more common in subgenotype 1b (R70Q in 6 of 13 strains) than in 1a (R70P in 1 of 37 strains, p = 0.004). The rs12979860 SNP upstream of the IL28B gene was overall the strongest response predictor (p = 0.0001). Core 70 substitutions were associated with poorer response kinetics in patients carrying the CT genotype at rs12979860. CONCLUSIONS: The results indicate that substitutions of core residue 70 are related to treatment response in Caucasian patients with HCV-1b infection, but are of less importance than IL28B polymorphism.

Response prediction and treatment tailoring for chronic hepatitis C virus genotype 1 infection.

We monitored early viral response during the treatment of hepatitis C virus (HCV) infection with the aim of identifying predictors of treatment outcome. We studied 53 patients with genotype 1 infection who received 180 microg/week pegylated interferon alfa-2a and 1,000 or 1,200 mg/day ribavirin depending on body weight and serially assessed HCV RNA in serum, using the Cobas TaqMan assay. Thirty-one patients (58%) achieved sustained viral response (SVR). SVR was obtained in 100% (10/10) of patients with pretreatment viremia concentrations below 400,000 IU/ml, in 100% (14/14) of patients with more than 1.5 log reduction of HCV RNA after 4 days of treatment, and in 95% (22/23) of patients with a rate of decline in viremia higher than 0.70 log units/week during the second phase. Non-SVR was seen in all patients with a second-phase decline rate lower than 0.35 log units/week. Patients with slopes between 0.50 and 0.80 log units/week achieved SVR (4/4) unless the treatment dose was modified (3/3). We conclude that the second-phase slope appears to be an accurate and useful predictor of treatment response. On the basis of these findings, we propose a model of tailored treatment which takes into account the second-phase slope and the amount of HCV RNA after 21 days of treatment.

The epidemiology of and risk factors for invasive Staphylococcus aureus infections in western Sweden.

We conducted a prospective study of all cases of invasive Staphylococcus aureus infections (ISA) in the catchment area of Skaraborg Hospital (population 255,109) in western Sweden from March 2003 to February 2005. The annual incidence was 33.9 cases/100,000 population. Of these, 49% were classified as community-acquired, 32% as nosocomial and 19% as health care-associated. The mean age was 65 y. We registered children (age < or = 18 y) in 13 episodes. The most common predisposing illnesses/conditions were persons undergoing haemodialysis (relative risk 291), peritoneal dialysis (relative risk 204), persons with rheumatoid arthritis (relative risk 9), diabetes mellitus (relative risk 8), and cancer (relative risk 7). The patients were treated at various departments; only 18% of the episodes were primarily cared for at a department of infectious diseases. The most common diagnosis was soft tissue infection (27% of the episodes), bacteraemia without focus (19%), arthritis (15%), and line-associated infection (14%). A total of 197 invasive isolates was obtained, the vast majority from blood, in 141 of 170 episodes. We documented the wide spectrum of signs and symptoms. One- quarter of the patients had no history of fever, and one-third of the bacteraemia patients had normal white blood cell count (<10 x 10(9)/l) at presentation. All cases were of MSSA (methicillin-sensitive Staphylococcus aureus).

[Hepatitis B--sexually transmitted disease among young people. Outbreak in Skaraborg could have resulted in an epidemic]. / Hepatit B--sexuellt överförd sjukdom bland unga. Utbrott i Skaraborg kunde lett till en epidemi.

An outbreak of sexually transmitted hepatitis B among teenagers is reported. A complicated pattern of contacts was discovered among those involved. The young people involved were tested for hepatitis B, an offer of vaccination was given and contact tracing was undertaken. This was done by a nurse with good knowledge of local circumstances and this is presumed to have helped to contain the outbreak. The connection between the cases was further proven by hepatitis B DNA analysis.