umu.sePublications
Change search
Refine search result
1 - 19 of 19
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Ahlm, Clas
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Infectious Diseases.
    Eliasson, Mats
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Vapalahti, O.
    University of Helsinki and Helsinki University Central Hospital Laboratory, Finland.
    Evander, Magnus
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Virology.
    Seroprevalence of Sindbis virus and associated risk factors in northern Sweden2014In: Epidemiology and Infection, ISSN 0950-2688, E-ISSN 1469-4409, Vol. 142, no 7, p. 1559-1565Article in journal (Refereed)
    Abstract [en]

    Mosquito-borne Sindbis virus (SINV) cause disease characterized by rash, fever and arthritis which often leads to long-lasting arthralgia. To determine the seroprevalence of SINV and associated risk factors in northern Sweden, a randomly selected population aged between 25 and 74 years were invited to join the MONICA study. Serum from 1611 samples were analysed for specific IgG antibodies. Overall, 2·9% had IgG against SINV. More men (3·7%) than women (2·0%) were SINV seropositive (P = 0·047) and it was more common in subjects with a lower educational level (P = 0·013) and living in small, rural communities (P < 0·001). Seropositivity was associated with higher waist circumference (P = 0·1), elevated diastolic blood pressure (P = 0·037), and history of a previous stroke (P = 0·011). In a multiple logistic regression analysis, adjusting for known risk factors for stroke, seropositivity for SINV was an independent predictor of having had a stroke (odds ratio 4·3, 95% confidence interval 1·4–13·0,P = 0·011).

  • 2.
    Ahlm, Clas
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Infectious Diseases.
    Linderholm, Mats
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Infectious Diseases.
    Juto, Per
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Virology.
    Stegmayr, Birgitta
    Settergren, Bo
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Infectious Diseases.
    Prevalence of serum IgG antibodies to Puumala virus (haemorrhagic fever with renal syndrome) in northern Sweden.1994In: Epidemiology and Infection, ISSN 0950-2688, E-ISSN 1469-4409, Vol. 113, no 1, p. 129-36Article in journal (Refereed)
    Abstract [en]

    A stratified and randomly-selected population sample was identified in 1990 in order to study the seroprevalence of nephropathia epidemica (haemorrhagic fever with renal syndrome) in Northern Sweden. Sera from 1538 subjects (750 men, 788 women), 25-64 years of age, were analysed for the presence of Puumala virus (PUV) specific-IgG by the indirect immunofluorescence antibody test. Specific IgG was detected in sera from 83 subjects (5.4%). Men and women had similar seroprevalence rates. The highest seroprevalences were found in subjects 55 years or older (8.0%) and among farmers and forestry workers (15.9%). The geographic distribution of seropositive individuals was uneven and there were significantly more seropositive persons in rural than in urban areas (P < 0.05).

  • 3.
    Alexeyev, Oleg A
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Virology.
    Ahlm, Clas
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Infectious Diseases.
    Elgh, Fredrik
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Virology.
    Aava, Birgitta
    Skoglig Zooekologi, SLU, Umeå.
    Palo, Thomas
    Skoglig Zooekologi, SLU, Umeå.
    Settergren, Bo
    Tärnvik, Arne
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Infectious Diseases.
    Wadell, Göran
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Virology.
    Juto, Per
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Virology.
    A minority of seropositive wild bank voles (Clethrionomys glareolus) show evidence of current Puumala virus infection1998In: Epidemiology and Infection, ISSN 0950-2688, E-ISSN 1469-4409, Vol. 121, no 2, p. 419-425Article in journal (Refereed)
    Abstract [en]

    Bank voles (Clethrionomys glareolus) serve as the reservoir for Puumala (PUU) virus, the aetiologic agent of nephropathia epidemica. The animals are believed to be persistently infected and the occurrence of serum antibodies is usually taken as an evidence of active infection. We found serum antibodies to PUU virus in 42 of 299 wild bank voles captured in a PUU virus endemic area. PUU virus RNA was demonstrated in lung specimens of 11 of these 42 animals and in 2 of them antigen was also found. Thus in the lungs of 31 of 42 seropositive animals neither PUU virus RNA nor antigen was detected. In 2 of 257 seronegative animals, lung specimens showed presence of PUU virus antigen and RNA. Isolation of PUU virus from lung tissue was successful in all 4 antigen-positive bank voles but in none of 16 tested antigen-negative animals. In conclusion, only a minority of bank voles with serum antibodies to PUU virus showed evidence of current infection.

  • 4. Alqahtani, F. Y.
    et al.
    Aleanizy, F. S.
    Mohamed, R. Ali El Hadi
    Alanazi, M. S.
    Mohamed, Nahla
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Virology. College of Medicine, Princess Nourah bint Abdulrahman University, Riyadh 12484, Saudi Arabia.
    Alrasheed, M. M.
    Abanmy, N.
    Alhawassi, T.
    Prevalence of comorbidities in cases of Middle East respiratory syndrome coronavirus: a retrospective study2019In: Epidemiology and Infection, ISSN 0950-2688, E-ISSN 1469-4409, Vol. 147, article id UNSP e35Article in journal (Refereed)
    Abstract [en]

    The Middle East respiratory syndrome coronavirus (MERS-CoV) is a life-threatening respiratory disease with a high case fatality rate; however, its risk factors remain unclear. We aimed to explore the influence of demographic factors, clinical manifestations and underlying comorbidities on mortality in MERS-CoV patients. Retrospective chart reviews were performed to identify all laboratory-confirmed cases of MERS-COV infection in Saudi Arabia that were reported to the Ministry of Health of Saudi Arabia between 23 April 2014 and 7 June 2016. Statistical analyses were conducted to assess the effect of sex, age, clinical presentation and comorbidities on mortality from MERS-CoV. A total of 281 confirmed MERS-CoV cases were identified: 167 (59.4%) patients were male and 55 (20%) died. Mortality predominantly occurred among Saudi nationals and older patients and was significantly associated with respiratory failure and shortness of breath. Of the 281 confirmed cases, 160 (56.9%) involved comorbidities, wherein diabetes mellitus, hypertension, ischemic heart disease, congestive heart failure, end-stage renal disease and chronic kidney disease were significantly associated with mortality from MERS-CoV and two or three comorbidities significantly affected the fatality rates from MERS-CoV. The findings of this study show that old age and the existence of underlying comorbidities significantly increase mortality from MERS-CoV.

  • 5. Amaku, M
    et al.
    Azevedo, F
    Burattini, M N
    Coelho, G E
    Coutinho, F A B
    Greenhalgh, D
    Lopez, L F
    Motitsuki, R S
    Wilder-Smith, Annelies
    Massad, E
    Magnitude and frequency variations of vector-borne infection outbreaks using the Ross-Macdonald model: explaining and predicting outbreaks of dengue fever2016In: Epidemiology and Infection, ISSN 0950-2688, E-ISSN 1469-4409, Vol. 144, no 16, p. 3435-3450Article in journal (Refereed)
    Abstract [en]

    The classical Ross-Macdonald model is often utilized to model vector-borne infections; however, this model fails on several fronts. First, using measured (or estimated) parameters, which values are accepted from the literature, the model predicts a much greater number of cases than what is usually observed. Second, the model predicts a single large outbreak that is followed by decades of much smaller outbreaks, which is not consistent with what is observed. Usually towns or cities report a number of recurrences for many years, even when environmental changes cannot explain the disappearance of the infection between the peaks. In this paper, we continue to examine the pitfalls in modelling this class of infections, and explain that, if properly used, the Ross-Macdonald model works and can be used to understand the patterns of epidemics and even, to some extent, be used to make predictions. We model several outbreaks of dengue fever and show that the variable pattern of yearly recurrence (or its absence) can be understood and explained by a simple Ross-Macdonald model modified to take into account human movement across a range of neighbourhoods within a city. In addition, we analyse the effect of seasonal variations in the parameters that determine the number, longevity and biting behaviour of mosquitoes. Based on the size of the first outbreak, we show that it is possible to estimate the proportion of the remaining susceptible individuals and to predict the likelihood and magnitude of the eventual subsequent outbreaks. This approach is described based on actual dengue outbreaks with different recurrence patterns from some Brazilian regions.

  • 6.
    Andersson, T
    et al.
    Department of Mathematics, Stockholm University, Sweden and Swedish Institute for National Food Agency (SLV), Sweden and Communicable Disease Control (SMI), Solna, Sweden.
    Bjelkmar, P
    Swedish Institute for Communicable Disease Control (SMI), Solna, Sweden, and Inera AB, Sweden.
    Hulth, A
    Swedish Institute for Communicable Disease Control (SMI), Solna, Sweden.
    Lindh, J
    Department of Microbiology, Tumour and Cell Biology, Karolinska Institutet, Sweden and Swedish Institute for Communicable Disease Control (SMI), Solna, Sweden.
    Stenmark, Stephan
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Infectious Diseases. County Medical Officer, Västerbotten, Sweden.
    Widerström, Micael
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Clinical Bacteriology. Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Infectious Diseases.
    Syndromic surveillance for local outbreak detection and awareness: evaluating outbreak signals of acute gastroenteritis in telephone triage, web-based queries and over-the-counter pharmacy sales2014In: Epidemiology and Infection, ISSN 0950-2688, E-ISSN 1469-4409, Vol. 142, no 2, p. 303-313Article in journal (Refereed)
    Abstract [en]

    For the purpose of developing a national system for outbreak surveillance, local outbreak signals were compared in three sources of syndromic data - telephone triage of acute gastroenteritis, web queries about symptoms of gastrointestinal illness, and over-the-counter (OTC) pharmacy sales of antidiarrhoeal medication. The data sources were compared against nine known waterborne and foodborne outbreaks in Sweden in 2007-2011. Outbreak signals were identified for the four largest outbreaks in the telephone triage data and the two largest outbreaks in the data on OTC sales of antidiarrhoeal medication. No signals could be identified in the data on web queries. The signal magnitude for the fourth largest outbreak indicated a tenfold larger outbreak than officially reported, supporting the use of telephone triage data for situational awareness. For the two largest outbreaks, telephone triage data on adult diarrhoea provided outbreak signals at an early stage, weeks and months in advance, respectively, potentially serving the purpose of early event detection. In conclusion, telephone triage data provided the most promising source for surveillance of point-source outbreaks.

  • 7. Burattini, M N
    et al.
    Coutinho, F A B
    Lopez, L F
    Ximenes, R
    Quam, Mikkel
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Epidemiology and Global Health.
    Wilder-Smith, Annelies
    Massad, E
    Potential exposure to Zika virus for foreign tourists during the 2016 Carnival and Olympic Games in Rio de Janeiro, Brazil2016In: Epidemiology and Infection, ISSN 0950-2688, E-ISSN 1469-4409, Vol. 144, no 9, p. 1904-1906Article in journal (Refereed)
  • 8.
    De, Rituparna
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology. Division of Bacteriology, National Institute of Cholera and Enteric Diseases, P-33 C. I. T. Road, Scheme XM, Beleghata, Kolkata-700010, India.
    Ramamurthy, T.
    Sarkar, B. L.
    Mukhopadhyay, A. K.
    Pazhani, G. P.
    Sarkar, S.
    Dutta, S.
    Nair, G. B.
    Retrospective genomic analysis of Vibrio cholerae O1 El Tor strains from different places in India reveals the presence of ctxB-7 allele found in Haitian isolates2017In: Epidemiology and Infection, ISSN 0950-2688, E-ISSN 1469-4409, Vol. 145, no 11, p. 2212-2220Article in journal (Refereed)
    Abstract [en]

    A total of 45 strains of Vibrio cholerae O1 isolated from 10 different places in India where they were associated with cases of cholera between the years 2007 and 2008 were examined by molecular methods. With the help of phenotypic and genotypic tests the strains were confirmed to be O1 El Tor biotype strains with classical ctxB gene. Polymerase chain reaction (PCR) analysis by double - mismatch amplification mutation assay PCR showed 16 of these strains carried the ctxB-7 allele reported in Haitian strains. Sequencing of the ctxB gene in all the 45 strains revealed that in 16 strains the histidine at the 20th amino acid position had been replaced by asparagine and this single nucleotide polymorphism did not affect cholera toxin production as revealed by beads enzyme-linked immunosorbent assay. This study shows that the new ctxB gene sequence was circulating in different places in India. Seven representatives of these 45 strains analysed by pulsed - field gel electrophoresis showed four distinct Not I digested profiles showing that multiple clones were causing cholera in 2007 and 2008.

  • 9.
    Desvars-Larrive, Amélie
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Clinical Bacteriology. Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS).
    Liu, X.
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Clinical Bacteriology. Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS).
    Hjertqvist, M.
    Sjöstedt, A.
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Clinical Bacteriology. Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS).
    Johansson, A.
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Clinical Bacteriology. Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS).
    Ryden, Patrik
    Umeå University, Faculty of Science and Technology, Department of Mathematics and Mathematical Statistics.
    High-risk regions and outbreak modelling of tularemia in humans2017In: Epidemiology and Infection, ISSN 0950-2688, E-ISSN 1469-4409, Vol. 145, no 3, p. 482-490Article in journal (Refereed)
    Abstract [en]

    Sweden reports large and variable numbers of human tularemia cases, but the high-risk regions are anecdotally defined and factors explaining annual variations are poorly understood. Here, high-risk regions were identified by spatial cluster analysis on disease surveillance data for 1984-2012. Negative binomial regression with five previously validated predictors (including predicted mosquito abundance and predictors based on local weather data) was used to model the annual number of tularemia cases within the high-risk regions. Seven high-risk regions were identified with annual incidences of 3.8-44 cases/100 000 inhabitants, accounting for 56.4% of the tularemia cases but only 9.3% of Sweden's population. For all high-risk regions, most cases occurred between July and September. The regression models explained the annual variation of tularemia cases within most high-risk regions and discriminated between years with and without outbreaks. In conclusion, tularemia in Sweden is concentrated in a few high-risk regions and shows high annual and seasonal variations. We present reproducible methods for identifying tularemia high-risk regions and modelling tularemia cases within these regions. The results may help health authorities to target populations at risk and lay the foundation for developing an early warning system for outbreaks.

  • 10. Earnest, A
    et al.
    Tan, S B
    Wilder-Smith, Annelies
    Institute of Public Health, University of Heidelberg, Germany.
    Meteorological factors and El Niño Southern Oscillation are independently associated with dengue infections2012In: Epidemiology and Infection, ISSN 0950-2688, E-ISSN 1469-4409, Vol. 140, no 07, p. 1244-1251Article in journal (Refereed)
    Abstract [en]

    Our objective was to determine the association between temperature, humidity, rainfall and dengue activity in Singapore, after taking into account lag periods as well as long-term climate variability such as the El Niño Southern Oscillation Index (SOI). We used a Poisson model which allowed for autocorrelation and overdispersion in the data. We found weekly mean temperature and mean relative humidity as well as SOI to be significantly and independently associated with dengue notifications. There was an interaction effect by periods of dengue outbreaks, but periods where El Niño was present did not moderate the relationship between humidity and temperature with dengue notifications. Our results help to understand the temporal trends of dengue in Singapore, and further reinforce the findings that meteorological factors are important in the epidemiology of dengue.

  • 11. Liese, J. G.
    et al.
    Silfverdal, Sven-Arne
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Paediatrics.
    Giaquinto, C.
    Carmona, A.
    Larcombe, J. H.
    Garcia-Sicilia, J.
    Fuat, A.
    Garces-Sanchez, M.
    Arroba Basanta, M. L.
    Munoz Hiraldo, E.
    Cantarutti, L.
    Kroeniger, W.
    Vollmar, J.
    Holl, K.
    Pircon, J. Y.
    Rosenlund, M. R.
    Incidence and clinical presentation of acute otitis media in children aged < 6 years in European medical practices2014In: Epidemiology and Infection, ISSN 0950-2688, E-ISSN 1469-4409, Vol. 142, no 8, p. 1778-1788Article in journal (Refereed)
    Abstract [en]

    We conducted an epidemiological, observational cohort study to determine the incidence and complications of acute otitis media (AOM) in children aged <6 years. Data on physician-diagnosed AOM were collected from retrospective review of medical charts for the year preceding enrolment and then prospectively in the year following enrolment. The study included 5776 children in Germany, Italy, Spain, Sweden, and the UK. AOM incidence was 256/1000 person-years [95% confidence interval (CI) 243-270] in the prospective study period. Incidence was lowest in Italy (195, 95% CI 171-222) and highest in Spain (328, 95% CI 296-363). Complications were documented in < 1% of episodes. Spontaneous tympanic membrane perforation was documented in 7% of episodes. Both retrospective and prospective study results were similar and show the high incidence during childhood in these five European countries. Differences by country may reflect true differences and differences in social structure and diagnostic procedures.

  • 12. Massad, E.
    et al.
    Nascimento Burattini, M.
    Khan, K.
    Struchiner, C. J.
    Coutinho, F. A. B.
    Wilder-Smith, Annelies
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Epidemiology and Global Health. Institute of Public Health, University of Heidelberg, Germany; Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore.
    On the origin and timing of Zika virus introduction in Brazil2017In: Epidemiology and Infection, ISSN 0950-2688, E-ISSN 1469-4409, Vol. 145, no 11, p. 2303-2312Article in journal (Refereed)
    Abstract [en]

    The timing and origin of Zika virus (ZIKV) introduction in Brazil has been the subject of controversy. Initially, it was assumed that the virus was introduced during the FIFA World Cup in June-July 2014. Then, it was speculated that ZIKV may have been introduced by athletes from French Polynesia (FP) who competed in a canoe race in Rio de Janeiro in August 2014. We attempted to apply mathematical models to determine the most likely time window of ZIKV introduction in Brazil. Given that the timing and origin of ZIKV introduction in Brazil may be a politically sensitive issue, its determination (or the provision of a plausible hypothesis) may help to prevent undeserved blame. We used a simple mathematical model to estimate the force of infection and the corresponding individual probability of being infected with ZIKV in FP. Taking into account the air travel volume from FP to Brazil between October 2013 and March 2014, we estimated the expected number of infected travellers arriving at Brazilian airports during that period. During the period between December 2013 and February 2014, 51 individuals travelled from FP airports to 11 Brazilian cities. Basing on the calculated force of ZIKV infection (the per capita rate of new infections per time unit) and risk of infection (probability of at least one new infection), we estimated that 18 (95% CI 12-22) individuals who arrived in seven of the evaluated cities were infected. When basic ZIKV reproduction numbers greater than one were assumed in the seven evaluated cities, ZIKV could have been introduced in any one of the cities. Based on the force of infection in FP, basic reproduction ZIKV number in selected Brazilian cities, and estimated travel volume, we concluded that ZIKV was most likely introduced and established in Brazil by infected travellers arriving from FP in the period between October 2013 and March 2014, which was prior to the two aforementioned sporting events.

  • 13. Massad, E
    et al.
    Rocklöv, Joacim
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Epidemiology and Global Health.
    Wilder-Smith, Annelies
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Epidemiology and Global Health.
    Dengue infections in non-immune travellers to Thailand2013In: Epidemiology and Infection, ISSN 0950-2688, E-ISSN 1469-4409, Vol. 141, no 2, p. 412-417Article in journal (Refereed)
    Abstract [en]

    Dengue is the most frequent arboviral disease and is expanding geographically. Dengue is also increasingly being reported in travellers, in particular in travellers to Thailand. However, data to quantify the risk of travellers acquiring dengue when travelling to Thailand are lacking. Using mathematical modelling, we set out to estimate the risk of non-immune persons acquiring dengue when travelling to Thailand. The model is deterministic with stochastic parameters and assumes a Poisson distribution for the mosquitoes' biting rate and a Gamma distribution for the probability of acquiring dengue from an infected mosquito. From the force of infection we calculated the risk of dengue acquisition for travellers to Thailand arriving in a typical year (averaged over a 17-year period) in the high season of transmission. A traveller arriving in the high season of transmission and remaining for 7 days has a risk of acquiring dengue of 0.2% (95% CI 0.16-0.23), whereas the risk for travel of 15 and 30 days' duration is 0.46% (95% CI 0.41-0.50) and 0.81% (95% CI 0.76-0.87), respectively. Our data highlight that the risk of non-immune travellers acquiring dengue in Thailand is substantial. The incidence of 0.81% after a 1-month stay is similar to that reported in prospective seroconversion studies in Israeli travellers to Thailand, highlighting that our models are consistent with actual data. Risk estimates based on mathematical modelling offer more detailed information depending on various travel scenarios, and will help the travel medicine provider give better evidence-based advice for travellers to dengue-endemic countries.

  • 14. Massad, Eduardo
    et al.
    Bezerra Coutinhol, Francisco Antonio
    Wilder-Smith, Annelies
    Umeå University, Faculty of Medicine, Department of Epidemiology and Global Health. Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Section of Medicine.
    Modelling an optimum vaccination strategy against ZIKA virus for outbreak use2019In: Epidemiology and Infection, ISSN 0950-2688, E-ISSN 1469-4409, Vol. 147, article id UNSP e196Article in journal (Refereed)
    Abstract [en]

    We present a model to optimise a vaccination campaign aiming to prevent or to curb a Zika virus outbreak. We show that the optimum vaccination strategy to reduce the number of cases by a mass vaccination campaign should start when the Aedes mosquitoes' density reaches the threshold of 1.5 mosquitoes per humans, the moment the reproduction number crosses one. The maximum time it is advisable to wait for the introduction of a vaccination campaign is when the first ZIKV case is identified, although this would not be as effective to minimise the number of infections as when the mosquitoes' density crosses the critical threshold. This suboptimum strategy, however, would still curb the outbreak. In both cases, the catch up strategy should aim to vaccinate at least 25% of the target population during a concentrated effort of 1 month immediately after identifying the threshold. This is the time taken to accumulate the herd immunity threshold of 56.5%. These calculations were done based on theoretical assumptions that vaccine implementation would be feasible within a very short time frame.

  • 15.
    Palmgren, Helena
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Infectious Diseases.
    Aspán, Anna
    SVA.
    Broman, Tina
    Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine). Umeå University, Faculty of Medicine, Department of Clinical Microbiology.
    Bengtsson, Kennet
    Blomquist, Lennart
    Bergström, Sven
    Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine).
    Sellin, Mats
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Clinical Bacteriology.
    Wollin, Ralf
    SVA.
    Olsen, Björn
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Infectious Diseases.
    Salmonella in Black-headed gulls ( Larus ridibundus); prevalence, genotypes and influence on Salmonella epidemiology.2006In: Epidemiology and Infection, ISSN 0950-2688, E-ISSN 1469-4409, Vol. 134, no 3, p. 635-644Article in journal (Refereed)
    Abstract [en]

    During a period of 3 years, 1998-2000, 1047 faecal swabs from Black-headed gulls were sampled at one location in Southern Sweden. Salmonella spp. was found in 28 individuals (2.7%) and the dominating serotype found was S. Typhimurium (83%). Twenty-five per cent of the Salmonella-infected gulls were later recaptured and re-sampled. We found that Salmonella infection in Black-headed gulls was of short duration, and that infection in this bird species was predominantly expressed as carriage without disease manifestations. All S. Typhimurium isolates were subjected to antibiotic resistance profiling and molecular characterization by pulsed-field gel electrophoresis and IS200 polymerase chain reaction. The S. Typhimurium gull isolates were compared to human and domestic animal isolates of the same serotype and phage type. We found genetic relatedness of S. Typhimurium DT195 isolates from gulls, domestic animals and humans, indicating that Black-headed gulls might play a role in the spread of S. Typhimurium in Sweden.

  • 16.
    Palmgren, Helena
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Infectious Diseases.
    McCafferty, D.
    British Antarctic SurŠey, National EnŠironment Research Council, Cambridge, UK.
    Aspán, A.
    Department of Bacteriology, National Veterinary Institute, Uppsala, Sweden.
    Broman, Tina
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Infectious Diseases. Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Clinical Bacteriology.
    Sellin, Mats
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Clinical Bacteriology.
    Wollin, R.
    Department of Bacteriology, Swedish Institute for Infectious Disease Control, Solna, Sweden.
    Bergström, Sven
    Umeå University, Faculty of Medicine, Microbiology.
    Olsen, Björn
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Infectious Diseases. Department of Infectious Diseases, Kalmar County Hospital, S-381 95 Kalmar, Sweden.
    Salmonella in sub-Antarctica: low heterogeneity in salmonella serotypes in South Georgian seals and birds2000In: Epidemiology and Infection, ISSN 0950-2688, E-ISSN 1469-4409, Vol. 125, no 2, p. 257-262Article in journal (Refereed)
    Abstract [en]

    The number of human visitors to Antarctica is increasing rapidly, and with it a risk of introducing infectious organisms to native animals. To study the occurrence of salmonella serotypes in sub- Antarctic wildlife, faecal samples were collected from gentoo penguins, macaroni penguins, gray-headed albatrosses, black-browed albatrosses and Antarctic fur seals on Bird Island in the South Georgian archipelago during the austral summer of 1996 and 1998. In 1996, S. havana, S. typhimurium and S. enteritidis were isolated from 7% of gentoo penguins and 4% of fur seals. In 1998, however, 22% of fur seals were found to be infected with S. havana, S. enteritidis and S. newport. All isolates, except one, showed identical pulsed-field gel electrophoresis-patterns within each serotype, irrespective of sampling year and animal reservoir. No significant antibiotic resistance was found. The very low heterogeneity in the salmonella isolates found could either indicate a high genetic adaptation of the bacteria to the environment or a recent introduction of salmonella into the area.

  • 17. Steptoe, A
    et al.
    Gylfe, Åsa
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Shamaei-Tousi, A
    Bergström, Sven
    Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine).
    Henderson, B
    Pathogen burden and cortisol profiles over the day2009In: Epidemiology and Infection, ISSN 0950-2688, E-ISSN 1469-4409, Vol. 137, no 12, p. 1816-1824Article in journal (Refereed)
    Abstract [en]

    Hypothalamic-pituitary-adrenocortical (HPA) regulation in adults is influenced by early psychosocial adversity, but the role of infectious disease history is poorly understood. We studied the association between cumulative pathogen burden and cortisol profile over the day in a sample of 317 healthy men and women aged 51-72 years. Cumulative pathogen burden was defined as positive serostatus for Chlamydia pneumoniae, cytomegalovirus (CMV) and herpes simplex virus 1 (HSV-1). Salivary cortisol was sampled repeatedly over the day. The cortisol slope was defined as the decrease across the day and evening. Age, gender, grade of employment, body mass index, smoking status, self-rated health, cardiovascular medication, depressed mood and time of waking were included as covariates. The pathogen burden averaged 1.76 (S.D. = 0.92). The cortisol slope was inversely associated with pathogen burden after controlling for covariates. When individual pathogens were studied, only CMV was associated with flatter cortisol rhythms in isolation. We conclude that pathogen burden is independently associated with flatter cortisol slopes over the day, and may contribute to disturbed neuroendocrine regulation.

  • 18.
    Strömgren, Magnus
    et al.
    Umeå University, Faculty of Social Sciences, Department of Geography and Economic History, Economic and social geography.
    Holm, Einar
    Umeå University, Faculty of Social Sciences, Department of Geography and Economic History, Economic and social geography.
    Dahlström, Örjan
    Ekberg, Joakim
    Eriksson, Henrik
    Spreco, Armin
    Timpka, Toomas
    Place-based social contact and mixing: a typology of generic meeting places of relevance for infectious disease transmission2017In: Epidemiology and Infection, ISSN 0950-2688, E-ISSN 1469-4409, Vol. 145, no 12, p. 2582-2593Article in journal (Refereed)
    Abstract [en]

    This study aims to develop a typology of generic meeting places based on social contact and mixing of relevance for infectious disease transmission. Data was collected by means of a contact diary survey conducted on a representative sample of the Swedish population. The typology is derived from a cluster analysis accounting for four dimensions associated with transmission risk: visit propensity and its characteristics in terms of duration, number of other persons present and likelihood of physical contact. In the analysis, we also study demographic, socioeconomic and geographical differences in the propensity of visiting meeting places. The typology identifies the family venue, the fixed activity site, the family vehicle, the trading plaza and the social network hub as generic meeting places. The meeting place typology represents a spatially explicit account of social contact and mixing relevant to infectious disease modelling where the social context of the outbreak can be highlighted in light of the actual infectious disease.

  • 19. Timpka, Toomas
    et al.
    Eriksson, Henrik
    Holm, Einar
    Umeå University, Faculty of Social Sciences, Department of Geography and Economic History, Economic and social geography.
    Strömgren, Magnus
    Umeå University, Faculty of Social Sciences, Department of Geography and Economic History, Economic and social geography.
    Ekberg, Joakim
    Spreco, Armin
    Dahlström, Örjan
    Relevance of workplace social mixing during influenza pandemics: an experimental modelling study of workplace cultures2016In: Epidemiology and Infection, ISSN 0950-2688, E-ISSN 1469-4409, Vol. 144, no 10, p. 2031-2042Article in journal (Refereed)
    Abstract [en]

    Workplaces are one of the most important regular meeting places in society. The aim of this study was to use simulation experiments to examine the impact of different workplace cultures on influenza dissemination during pandemics. The impact is investigated by experiments with defined social-mixing patterns at workplaces using semi-virtual models based on authentic sociodemographic and geographical data from a North European community (population 136 000). A simulated pandemic outbreak was found to affect 33% of the total population in the community with the reference academic-creative workplace culture; virus transmission at the workplace accounted for 10·6% of the cases. A model with a prevailing industrial-administrative workplace culture generated 11% lower incidence than the reference model, while the model with a self-employed workplace culture (also corresponding to a hypothetical scenario with all workplaces closed) produced 20% fewer cases. The model representing an academic-creative workplace culture with restricted workplace interaction generated 12% lower cumulative incidence compared to the reference model. The results display important theoretical associations between workplace social-mixing cultures and community-level incidence rates during influenza pandemics. Social interaction patterns at workplaces should be taken into consideration when analysing virus transmission patterns during influenza pandemics.

1 - 19 of 19
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf