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Lohr, Wolfgang
Publications (8 of 8) Show all publications
Rocklöv, J., Tozan, Y., Ramadona, A. L., Sewe, M. O., Sudre, B., Garrido, J., . . . Semenza, J. C. (2019). Using Big Data to Monitor the Introduction and Spread of Chikungunya, Europe, 2017. Emerging Infectious Diseases, 25(6), 1041-1049
Open this publication in new window or tab >>Using Big Data to Monitor the Introduction and Spread of Chikungunya, Europe, 2017
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2019 (English)In: Emerging Infectious Diseases, ISSN 1080-6040, E-ISSN 1080-6059, Vol. 25, no 6, p. 1041-1049Article in journal (Refereed) Published
Abstract [en]

With regard to fully harvesting the potential of big data, public health lags behind other fields. To determine this potential, we applied big data (air passenger volume from international areas with active chikungunya transmission, Twitter data, and vectorial capacity estimates of Aedes albopictus mosquitoes) to the 2017 chikungunya outbreaks in Europe to assess the risks for virus transmission, virus importation, and short-range dispersion from the outbreak foci. We found that indicators based on voluminous and velocious data can help identify virus dispersion from outbreak foci and that vector abundance and vectorial capacity estimates can provide information on local climate suitability for mosquitoborne outbreaks. In contrast, more established indicators based on Wikipedia and Google Trends search strings were less timely. We found that a combination of novel and disparate datasets can be used in real time to prevent and control emerging and reemerging infectious diseases.

Place, publisher, year, edition, pages
Centers for Disease Control and Prevention (CDC), 2019
National Category
Infectious Medicine Public Health, Global Health, Social Medicine and Epidemiology
Identifiers
urn:nbn:se:umu:diva-161458 (URN)10.3201/eid2506.180138 (DOI)000470776900001 ()31107221 (PubMedID)
Funder
Swedish Research Council Formas, 2017-01300
Available from: 2019-07-09 Created: 2019-07-09 Last updated: 2019-09-05Bibliographically approved
Tissera, H., Gunasena, S., De Silva, D., Sessions, O., Palihawadana, P., Amarasinghe, A., . . . Gubler, D. (2017). Enhanced dengue sentinel surveillance in metropolitan Sri Lanka: 2012 to 2015. Paper presented at 65th Annual Meeting of the American-Society-of-Tropical-Medicine-and-Hygiene (ASTMH), NOV 13-16, 2016, Atlanta, GA. American Journal of Tropical Medicine and Hygiene, 95(5), 426-427
Open this publication in new window or tab >>Enhanced dengue sentinel surveillance in metropolitan Sri Lanka: 2012 to 2015
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2017 (English)In: American Journal of Tropical Medicine and Hygiene, ISSN 0002-9637, E-ISSN 1476-1645, Vol. 95, no 5, p. 426-427Article in journal, Meeting abstract (Other academic) Published
Place, publisher, year, edition, pages
American Society of Tropical Medicine and Hygiene, 2017
National Category
Public Health, Global Health, Social Medicine and Epidemiology
Identifiers
urn:nbn:se:umu:diva-141469 (URN)000412851502880 ()
Conference
65th Annual Meeting of the American-Society-of-Tropical-Medicine-and-Hygiene (ASTMH), NOV 13-16, 2016, Atlanta, GA
Note

Supplement: S, Meeting Abstract: 1357

Available from: 2017-12-11 Created: 2017-12-11 Last updated: 2018-06-09Bibliographically approved
Semenza, J. C., Trinanes, J., Lohr, W., Sudre, B., Löfdahl, M., Martinez-Urtaza, J., . . . Rocklöv, J. (2017). Environmental Suitability of Vibrio Infections in a Warming Climate: An Early Warning System. Journal of Environmental Health Perspectives, 125(10), Article ID UNSP 107004.
Open this publication in new window or tab >>Environmental Suitability of Vibrio Infections in a Warming Climate: An Early Warning System
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2017 (English)In: Journal of Environmental Health Perspectives, ISSN 0091-6765, E-ISSN 1552-9924, Vol. 125, no 10, article id UNSP 107004Article in journal (Refereed) Published
Abstract [en]

BACKGROUND: Some Vibrio spp. are pathogenic and ubiquitous in marine waters with low to moderate salinity and thrive with elevated sea surface temperature (SST). OBJECTIVES: Our objective was to monitor and project the suitability of marine conditions for Vibrio infections under climate change scenarios. METHODS: The European Centre for Disease Prevention and Control (ECDC) developed a platform (the ECDC Vibrio Map Viewer) to monitor the environmental suitability of coastal waters for Vibrio spp. using remotely sensed SST and salinity. A case-crossover study of Swedish cases was conducted to ascertain the relationship between SST and Vibrio infection through a conditional logistic regression. Climate change projections for Vibrio infections were developed for Representative Concentration Pathway (RCP) 4.5 and RCP 8.5. RESULTS: The ECDC Vibrio Map Viewer detected environmentally suitable areas for Vibrio spp. in the Baltic Sea in July 2014 that were accompanied by a spike in cases and one death in Sweden. The estimated exposure response relationship for Vibrio infections at a threshold of 16 degrees C revealed a relative risk (RR) = 1.14 (95% CI: 1.02, 1.27; p=0.024) for a lag of 2 wk; the estimated risk increased successively beyond this SST threshold. Climate change projections for SST under the RCP 4.5 and RCP 8.5 scenarios indicate a marked upward trend during the summer months and an increase in the relative risk of these infections in the coming decades. CONCLUSIONS: This platform can serve as an early warning system as the risk of further Vibrio infections increases in the 21st ritui due to climate change.

Place, publisher, year, edition, pages
National Institute of Environmental Health Sciences (NIEHS), 2017
National Category
Public Health, Global Health, Social Medicine and Epidemiology Pharmacology and Toxicology
Identifiers
urn:nbn:se:umu:diva-141822 (URN)10.1289/EHP2198 (DOI)000413793300016 ()29017986 (PubMedID)
Available from: 2017-11-27 Created: 2017-11-27 Last updated: 2018-06-09Bibliographically approved
Jönsson, A. K., Lövborg, H., Lohr, W., Ekman, B. & Rocklöv, J. (2017). Increased Risk of Drug-Induced Hyponatremia during High Temperatures. International Journal of Environmental Research and Public Health, 14(7), Article ID 827.
Open this publication in new window or tab >>Increased Risk of Drug-Induced Hyponatremia during High Temperatures
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2017 (English)In: International Journal of Environmental Research and Public Health, ISSN 1661-7827, E-ISSN 1660-4601, Vol. 14, no 7, article id 827Article in journal (Refereed) Published
Abstract [en]

Purpose: To investigate the relationship between outdoor temperature in Sweden and the reporting of drug-induced hyponatremia to the Medical Products Agency (MPA). Methods: All individual adverse drug reactions (ADR) reported to MPA from 1 January 2010 to 31 October 2013 of suspected drug-induced hyponatremia and random controls were identified. Reports where the ADR had been assessed as having at least a possible relation to the suspected drug were included. Information on administered drugs, onset date, causality assessment, sodium levels, and the geographical origin of the reports was extracted. A case-crossover design was used to ascertain the association between heat exposure and drug-induced hyponatremia at the individual level, while linear regression was used to study its relationship to sodium concentration in blood. Temperature exposure data were obtained from the nearest observation station to the reported cases. Results: During the study period, 280 reports of hyponatremia were identified. More cases of drug-induced hyponatremia were reported in the warmer season, with a peak in June, while other ADRs showed an opposite annual pattern. The distributed lag non-linear model indicated an increasing odds ratio (OR) with increasing temperature in the warm season with a highest odds ratio, with delays of 1-5 days after heat exposure. A cumulative OR for a lag time of 1 to 3 days was estimated at 2.21 at an average daily temperature of 20 degrees C. The change in sodium per 1 degrees C increase in temperature was estimated to be -0.37 mmol/L (95% CI: -0.02, -0.72). Conclusions: Warm weather appears to increase the risk of drug-induced hyponatremia.

Place, publisher, year, edition, pages
MDPI AG, 2017
Keywords
average daily temperature, hyponatremia, adverse drug reaction
National Category
Public Health, Global Health, Social Medicine and Epidemiology Occupational Health and Environmental Health
Identifiers
urn:nbn:se:umu:diva-139162 (URN)10.3390/ijerph14070827 (DOI)000407370700159 ()
Available from: 2017-09-11 Created: 2017-09-11 Last updated: 2018-06-09Bibliographically approved
Tissera, H., Amarasinghe, A., Gunasena, S., DeSilva, A. D., Yee, L. W., Sessions, O., . . . Wilder-Smith, A. (2016). Laboratory-Enhanced Dengue Sentinel Surveillance in Colombo District, Sri Lanka: 2012-2014. PLoS Neglected Tropical Diseases, 10(2), Article ID e0004477.
Open this publication in new window or tab >>Laboratory-Enhanced Dengue Sentinel Surveillance in Colombo District, Sri Lanka: 2012-2014
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2016 (English)In: PLoS Neglected Tropical Diseases, ISSN 1935-2727, E-ISSN 1935-2735, Vol. 10, no 2, article id e0004477Article in journal (Refereed) Published
Abstract [en]

INTRODUCTION: Dengue has emerged as a significant public health problem in Sri Lanka. Historically surveillance was passive, with mandatory dengue notifications based on clinical diagnosis with only limited laboratory confirmation. To obtain more accurate data on the disease burden of dengue, we set up a laboratory-based enhanced sentinel surveillance system in Colombo District. Here we describe the study design and report our findings of enhanced surveillance in the years 2012-2014.

METHODS: Three outpatient clinics and three government hospitals in Colombo District that covered most of the Colombo metropolitan area were selected for the sentinel surveillance system. Up to 60 patients per week presenting with an undifferentiated fever were enrolled. Acute blood samples from each patient were tested by dengue specific PCR, NS1 ELISA and IgM ELISA. A sub-set of samples was sent to Duke-NUS Singapore for quality assurance, virus isolation and serotyping. Trained medical research assistants used a standardized case report form to record clinical and epidemiological data. Clinical diagnoses by the clinicians-in-charge were recorded for hospitalized cases.

RESULTS: Of 3,127 febrile cases, 43.6% were PCR and/or NS1 positive for dengue. A high proportion of lab confirmed dengue was observed from inpatients (IPD) (53.9%) compared to outpatient (clinics in hospitals and general practice) (7.6%). Dengue hemorrhagic fever (DHF) was diagnosed in 11% of patients at the time of first contact, and the median day of illness at time of presentation to the sentinel sites was 4. Dengue serotype 1 was responsible for 85% of the cases and serotype 4 for 15%. The sensitivity and specificity of the clinicians' presumptive diagnosis of dengue was 84% and 34%, respectively.

CONCLUSION: DENV-1, and to a lesser degree DENV-4, infection were responsible for a high proportion of febrile illnesses in Colombo in the years 2012 to 2014. Clinicians' diagnoses were associated with high sensitivity, but laboratory confirmation is required to enhance specificity.

Place, publisher, year, edition, pages
Public library science, 2016
National Category
Public Health, Global Health, Social Medicine and Epidemiology
Identifiers
urn:nbn:se:umu:diva-117587 (URN)10.1371/journal.pntd.0004477 (DOI)000372567300076 ()26927901 (PubMedID)
Available from: 2016-03-02 Created: 2016-03-02 Last updated: 2018-06-07Bibliographically approved
Kittayapong, P., Olarantmanee, P., Maskao, P., Byass, P., Lohr, W., Gubler, D. & Wilder-Smith, A. (2015). A school-based intervention trial using insecticide-treated school uniforms to reduce dengue infections in school-aged children. Paper presented at The 9th European Congress on Tropical Medicine and International Health (ECTMIH), Basel, Switzerland, September 6-10, 2015. Tropical medicine & international health, 20(Suppl. 1), 114-114
Open this publication in new window or tab >>A school-based intervention trial using insecticide-treated school uniforms to reduce dengue infections in school-aged children
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2015 (English)In: Tropical medicine & international health, ISSN 1360-2276, E-ISSN 1365-3156, Vol. 20, no Suppl. 1, p. 114-114Article in journal, Meeting abstract (Other academic) Published
Abstract [en]

Background: There is an urgent need to enhance our armamentarium to prevent dengue infections in children. Since dengue vectors (Aedes mosquitoes) are active mainly during the day, a potential target for control should be schools where children spend a considerable amount of their day. School uniforms are the cultural norm in most developing countries, worn throughout the day. We hypothesized that insecticide-treated school uniforms will  reduce the incidence of dengue infection in school-aged children. Our objective was to determine the impact of impregnated school uniforms on dengue incidence.

Methods: A randomised controlled trial was conducted in 10 schools in eastern Thailand in 2012. Pre-fabricated school uniforms were commercially treated to ensure consistent high quality of insecticide impregnation with permethrin. The 1-h-knock-down effect and 24 h mortality of Aedes mosquitoes by the impregnated cloth was tested at baseline and then once per month using WHOPES cone test. Blood samples were taken at baseline and at the end of the school-term for the hemagglutination-inhibition assay to identify serologically confirmed dengue infections during the study period. Students were randomized into intervention schools (all students wearing impregnated uniforms) versus control schools (uniforms had the same appearance and odor, but were not impregnated).

Results: A total of 1808 students in 10 schools were enrolled, mean age 10.07 years. Of these, 1651 had paired blood samples taken, which showed an incidence of new dengue infection of 3.3 % over the school term (5  months). There was no difference in the incidence of dengue infections in intervention versus control schools. Both the knock-down and mortality at baseline were close to 100%, but rapidly waned after only 8 washes to 20% e.g. after only 1 month of wearing the uniform.

Conclusion: Although the results of mosquitoes’ knock-down and mortality of impregnated schools looked very promising, we did not see a protective effect of impregnated uniforms on reducing dengue infections in this school-based trial. The most likely reason for the apparent failure was the rapid waning efficacy of impregnation after washing. New technologies need to be developed to overcome rapid waning efficacy of impregnated clothing.

Disclosure: This research was funded by the European Commission 7th Framework and was conducted by ‘DengueTools’ partners.

Place, publisher, year, edition, pages
Wiley-Blackwell, 2015
National Category
Public Health, Global Health, Social Medicine and Epidemiology
Identifiers
urn:nbn:se:umu:diva-109944 (URN)000360758800278 ()
Conference
The 9th European Congress on Tropical Medicine and International Health (ECTMIH), Basel, Switzerland, September 6-10, 2015
Available from: 2015-10-15 Created: 2015-10-09 Last updated: 2018-06-07Bibliographically approved
Tissera, H., Gunasena, S., da Silva, D., Sessions, O., Palihawadana, P., Amarasinghe, A., . . . Gubler, D. (2015). Enhanced dengue sentinel surveillance in Sri Lanka. Paper presented at The 9th European Congress on Tropical Medicine and International Health (ECTMIH), Basel, Switzerland, September 6-10, 2015. Tropical medicine & international health, 20(Suppl. 1), 133-133
Open this publication in new window or tab >>Enhanced dengue sentinel surveillance in Sri Lanka
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2015 (English)In: Tropical medicine & international health, ISSN 1360-2276, E-ISSN 1365-3156, Vol. 20, no Suppl. 1, p. 133-133Article in journal, Meeting abstract (Other academic) Published
Abstract [en]

Introduction: Dengue poses a significant socioeconomic and disease burden in Sri Lanka, where the geographic spread, incidence and severity of disease has been increasing since the first dengue hemorrhagic fever (DHF) epidemic occurred in 1989. Periodic epidemics have become progressively larger, peaking in 2012 with 44 456 cases. Passive surveillance was established nationwide more than a decade ago but dengue notifications have been based on clinical diagnosis, with infrequent laboratory confirmation. To obtain more accurate data on the disease burden, a laboratory-based enhanced sentinel surveillance system was established in Colombo Municipality, the area with the highest dengue incidence. Here we describe the study design and the results of the first 2 years (2012–2014).

Methods: Three government hospitals and two outpatient clinics in Colombo District were selected for the sentinel surveillance. All patients presenting with undifferentiated fever were enrolled, if consent given, capped at a maximum of 60 patients per week. Acute blood samples were taken from all enrolled subjects and tested by dengue-specific PCR, and NS1, and IgM – ELISA at the time of first presentation. A sub-set of 536 samples was sent to Duke-NUS Singapore for quality assurance, virus isolation and serotyping.

Results: Between 1 April, 2012 and 31 March, 2014, 3127 patients were enrolled, 964 (30.9%) as outpatients and 2160 (69.1%) as inpatients. The mean age was 22.3 years (SD = 17.5) and the time of first presentation was at day 4 of illness. For inpatients, 1687 (78.1%) of all febrile cases had laboratory-confirmed dengue. For outpatients, the proportion of confirmed dengue was 237 (24.6%). The mean duration of hospitalization was 4.1 days (SD = 1.85). The proportion of DHF in lab-confirmed hospitalized dengue cases was 22.1% and 4 patients (0.21%) died. Serotypes 1 and 4 were the only viruses detected in this sample (serotype 1: 85%; serotype 4: 15%). The clinicians’ diagnosis for dengue at time of first presentation had a sensitivity of 92% and specificity of 23%.

Conclusions: Dengue infection was responsible for a high proportion of febrile illnesses during 2012–2014, with serotypes 1 and 4 circulating. A significant proportion (22%) of hospitalized dengue cases developed DHF, but the case fatality rate was low. Clinicians’ judgment was associated with good sensitivity, but to enhance specificity it is important to add laboratory confirmation of dengue.

Disclosure: This research was funded by the European Commission under the 7th Framework and conducted by DengueTools partners (www.denguetools.net).

Place, publisher, year, edition, pages
[Tissera, H.; Palihawadana, P.; Amarasinghe, A.; Muthukuda, C.; Botheju, C.] Minist Hlth, Epidemiol it, Colombo, Sri Lanka. [Tissera, H.] Natl Dengue Control Unit, Colombo, Sri Lanka. [Gunasena, S.] Med Res Inst, Colombo, Sri Lanka. [da Silva, D.] Genentech Res Inst, Colombo, Sri Lanka. [Sessions, O.] Nanyang Technol Univ, Duke NUS Grad Med Sch, Singapore 639798, Singapore. [Leong, W. -Y.; Wilder-Smith, A.] Nanyang Technol Univ, Lee Kong Chian Sch Med, Singapore 639798, ngapore. [Lohr, W.; Byass, P.; Wilder-Smith, A.] Umea Univ, Umea, Sweden. [Gubler, D.] Duke NUS Grad Med Sch, Colombo, Sri Lanka.: , 2015
National Category
Public Health, Global Health, Social Medicine and Epidemiology
Identifiers
urn:nbn:se:umu:diva-109928 (URN)000360758800324 ()
Conference
The 9th European Congress on Tropical Medicine and International Health (ECTMIH), Basel, Switzerland, September 6-10, 2015
Available from: 2015-10-16 Created: 2015-10-09 Last updated: 2018-06-07Bibliographically approved
Rocklöv, J., Lohr, W., Hjertqvist, M. & Wilder-Smith, A. (2014). Attack rates of dengue fever in Swedish travellers. Scandinavian Journal of Infectious Diseases, 46(6), 412-417
Open this publication in new window or tab >>Attack rates of dengue fever in Swedish travellers
2014 (English)In: Scandinavian Journal of Infectious Diseases, ISSN 0036-5548, E-ISSN 1651-1980, Vol. 46, no 6, p. 412-417Article in journal (Refereed) Published
Abstract [en]

Background: Dengue is endemic in many countries visited by Swedish travellers. We aimed to determine the attack rate of dengue in Swedish travellers and analyse the trends over time and the geographical variation. Methods: We obtained the following data from the Swedish Institute for Communicable Disease Control for the y 1995-2010: number of Swedish residents with confirmed dengue, the country and year of infection. We also obtained registers on the Swedish annual air traveller arrivals to dengue endemic areas from the United Nations World Tourist Organization for the time period. We estimated attack rates with 95% confidence intervals (CI). Results: In total, 925 Swedish travellers with confirmed dengue were reported. We found an increasing trend over time for most destinations. The majority of the dengue cases were acquired in Thailand (492 out of 925 travellers; 53%), with an attack rate of 13.6 (95% CI 12.7, 14.4) per 100,000 travellers. However, the 2 highest attack rates per 100,000 travellers were found for Sri Lanka (45.3, 95% CI 34.3, 56.4) and Bangladesh (42.6, 95% CI 23.8, 61.5). Conclusions: Information on attack rates in travellers is more helpful in guiding travel medicine practitioners than reports of absolute numbers, as the latter reflect travel preferences rather than the true risk. Although the majority of dengue infections in Swedish travellers were acquired in Thailand, the attack rates for dengue in travellers to Sri Lanka and Bangladesh were much higher. These data aid in refining information on the risk of dengue in travellers.

National Category
Public Health, Global Health, Social Medicine and Epidemiology
Identifiers
urn:nbn:se:umu:diva-88055 (URN)10.3109/00365548.2014.887222 (DOI)000336454800002 ()24716463 (PubMedID)
Available from: 2014-04-22 Created: 2014-04-22 Last updated: 2018-06-08Bibliographically approved
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