Quantifying transmission of norovirus during an outbreak

Healthcare workers are thought to play a role in nosocomial transmission of norovirus, but the level and direction of norovirus transmission between patients and healthcare workers in sustaining transmission during an outbreak have not been quantified.

Molecular epidemiology of a large community-based outbreak of hepatitis B in Bristol, U.K.

A large outbreak of hepatitis B virus (HBV) infection in the U.K. occurred between 2001 and 2005 in Bristol, U.K.

Investigation of a large community-based outbreak of hepatitis B infection in the United Kingdom

We describe the largest outbreak of hepatitis B virus infection reported to date in the UK. Between July 2001 and December 2005, 237 cases were identified in Avon, South West England. The likely route of transmission was injecting drug use in 44% (104/237) and heterosexual intercourse in 30% (71/237) of cases. A case-control study in injectors showed that injecting crack cocaine [adjusted odds ratio (aOR) 23·8, 95% confidence interval (CI) 3·04-186, P<0·001] and sharing injecting paraphernalia in the year before diagnosis (aOR 16·67, 95% CI 1·78-100, P=0·010) were strongly associated with acute hepatitis B. In non-IDUs number of sexual partners and lack of consistent condom use were high compared to a national sample. We describe the control measures implemented in response to the outbreak. This outbreak has highlighted the problems associated with the low uptake from the national hepatitis B vaccination policy which targets high-risk groups, the difficulties of identifying those at risk of acquiring hepatitis B infection through heterosexual sex, and injecting crack cocaine as a risk factor for hepatitis B.

H1N1 outbreak in a Swiss military boot camp--observations and suggestions

The A(H1N1)pdm09 influenza virus is a highly contagious pathogen which caused the 2009 influenza pandemic. The virus is known to affect mainly younger people and may be a problem in crowded living conditions. The aim of the study was to describe a major A(H1N1)pdm09 outbreak in a Swiss military boot camp and to develop suggestions for similar future situations.

Effect of immune pressure on hepatitis C virus evolution: insights from a single-source outbreak

The host's immune response to hepatitis C virus (HCV) can result in the selection of characteristic mutations (adaptations) that enable the virus to escape this response. The ability of the virus to mutate at these sites is dependent on the incoming virus, the fitness cost incurred by the mutation, and the benefit to the virus in escaping the response. Studies examining viral adaptation in chronic HCV infection have shown that these characteristic immune escape mutations can be observed at the population level as human leukocyte antigen (HLA)-specific viral polymorphisms. We examined 63 individuals with chronic HCV infection who were infected from a single HCV genotype 1b source. Our aim was to determine the extent to which the host's immune pressure affects HCV diversity and the ways in which the sequence of the incoming virus, including preexisting escape mutations, can influence subsequent mutations in recipients and infection outcomes. Conclusion: HCV sequences from these individuals revealed 29 significant associations between specific HLA types within the new hosts and variations within their viruses, which likely represent new viral adaptations. These associations did not overlap with previously reported adaptations for genotypes 1a and 3a and possibly reflected a combination of constraint due to the incoming virus and genetic distance between the strains. However, these sites accounted for only a portion of the sites in which viral diversity was observed in the new hosts. Furthermore, preexisting viral adaptations in the incoming (source) virus likely influenced the outcomes in the new hosts.

Distinct proteinase K-resistant prion protein fragment in goats with no signs of disease in a classical scrapie outbreak

Considerable efforts have been directed toward the identification of small-ruminant prion diseases, i.e., classical and atypical scrapie as well as bovine spongiform encephalopathy (BSE). Here we report the in-depth molecular analysis of the proteinase K-resistant prion protein core fragment (PrP(res)) in a highly scrapie-affected goat flock in Greece. The PrP(res) profile by Western immunoblotting in most animals was that of classical scrapie in sheep. However, in a series of clinically healthy goats we identified a unique C- and N-terminally truncated PrP(res) fragment, which is akin but not identical to that observed for atypical scrapie. These findings reveal novel aspects of the nature and diversity of the molecular PrP(res) phenotypes in goats and suggest that these animals display a previously unrecognized prion protein disorder.

European outbreak of atypical myopathy in the autumn 2009

BACKGROUND: Atypical myopathy is an acute, severe rhabdomyolysis occurring in grazing horses. In the beginning of October 2009, a new outbreak occurred in several European countries. Geographic, demographic and clinical data of the reported cases in the month October 2009 are described. KEY FINDINGS: The survival rate in this outbreak was 25%. The most frequently observed clinical signs were congested mucous membranes, dyspnea, tachycardia, depression, weakness, stiffness, recumbency, trembling, sweating, and myoglobinuria. Nonsurvivors were significantly more likely to be recumbent than survivors. Prognostic factors, symptomatic treatment, and preventive measures are discussed. SIGNIFICANCE: Differences were encountered during the described outbreak of atypical myopathy in October 2009 compared with previous outbreaks reported. Equine practitioners should be aware that previous epidemiological studies have shown that after a high prevalence in the autumn, new cases are likely to occur in the following spring.

[Infectious bovine rhinotracheitis (IBR) in the canton of Jura: an epidemiological outbreak investigation]

Following an abortion in a beef herd in the summer of 2009, three outbreaks of infectious bovine rhinotracheitis (IBR) were diagnosed in the cantons of Jura and Neuchatel. An epidemiological outbreak investigation was conducted with the aims to identify the source of introduction of the bovine herpes virus 1 (BoHV-1) into the affected herds and to prevent further spread of the disease. The attack rates in the three outbreak farms were 0.89, 0.28 and 0, respectively. BoHV-1 could be isolated from nasal swabs of two animals originating from one of the affected farms. Comparative restriction enzyme analysis revealed slight differences between the isolates of the two animals, but a high similarity to previous BoHV-1 isolates from the canton of Jura, as well as to a French BoHV-1 isolate. This IBR outbreak has shown the importance of reporting and analyzing abortions. The current disease outbreaks recall the main risk factors for the spread of IBR in Switzerland: purchase and movement of bovines and semen of often unknown IBR status.

Pseudomonas aeruginosa outbreak in a pediatric oncology care unit caused by an errant water jet into contaminated siphons

We analyzed an outbreak of invasive infections with an exotoxin U positive Pseudomonas aeruginosa strain within a pediatric oncology care unit. Environmental sampling and molecular characterization of the Pseudomonas aeruginosa strains led to identification of the outbreak source. An errant water jet into the sink within patient rooms was observed. Optimized outbreak management resulted in an abundance of further Pseudomonas aeruginosa infections within the pediatric oncology care unit.

Juvenile spring eruption: an outbreak report and systematic review of the literature

Juvenile spring eruption of the helices of the ears is a distinctive sun-induced condition appearing on the light-exposed skin of the ears, typically in boys and young men in early spring.

Outbreak among drug users caused by a clonal strain of group A streptococcus

We describe an outbreak among drug users of severe soft-tissue infections caused by a clonal strain of group A streptococcus of M-type 25. Cases (n = 19) in drug users were defined as infections (mainly needle abscesses) due to the outbreak strain. Comparison with controls showed that infected drug users bought drugs more often at a specific place. Drug purchase and use habits may have contributed to this outbreak.

Scabies outbreak in an intensive care unit with 1,659 exposed individuals--key factors for controlling the outbreak

OBJECTIVE: To investigate a large outbreak of scabies in an intensive care unit of a university hospital and an affiliated rehabilitation center, and to establish effective control measures to prevent further transmission. DESIGN: Outbreak investigation. SETTING: The intensive care unit of a 750-bed university hospital and an affiliated 92-bed rehabilitation center. METHODS: All exposed individuals were screened by a senior staff dermatologist. Scabies was diagnosed on the basis of (1) identification of mites by skin scraping, (2) identification of mites by dermoscopy, or (3) clinical examination of patients without history of prior treatment for typical burrows. During a follow-up period of 6 months, the attack rate was calculated as the number of symptomatic individuals divided by the total number of exposed individuals. INTERVENTIONS: All exposed healthcare workers (HCWs) and their household members underwent preemptive treatment. Initially, the most effective registered drug in Switzerland (ie, topical lindane) was prescribed, but this prescription was switched to topical permethrin or systemic ivermectin as a result of the progression of the outbreak. Individuals with any signs or symptoms of scabies underwent dermatological examination. RESULTS: Within 7 months, 19 cases of scabies were diagnosed, 6 in children with a mean age of 3.1 years after exposure to the index patient with HIV and crusted scabies. A total of 1,640 exposed individuals underwent preemptive treatment. The highest attack rate of 26%-32% was observed among HCWs involved in the care of the index patient. A too-restricted definition of individuals at risk, noncompliance with treatment, and the limited effectiveness of lindane likely led to treatment failure, relapse, and reinfestation within families. CONCLUSIONS: Crusted scabies resulted in high attack rates among HCWs and household contacts. Timely institution of hygienic precautions with close monitoring and widespread, simultaneous scabicide treatment of all exposed individuals are essential for control of an outbreak.

Measles outbreak in Germany: clinical presentation and outcome of children hospitalized for measles in 2006

In 2006, 115 children hospitalized with measles in Germany were reported. Detailed information could be obtained for 96 cases from a pediatric hospital surveillance system. The most frequent symptoms and complications were pneumonia, respiratory insufficiency, other respiratory disorders, otitis media, feeding problems, and other gastrointestinal symptoms. Two children died of measles inclusion body encephalitis.

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.