The epidemiology of dengue outbreaks in 2016 and 2017 in Ouagadougou, Burkina Faso.

BACKGROUND: Dengue is prevalent in as many as 128 countries with more than 100 million clinical episodes reported annually and four billion people estimated to be at risk. While dengue fever is systematically diagnosed in large parts of Asia and South America, the disease burden in Africa is less well investigated. This report describes two consecutive dengue outbreaks in Ouagadougou, Burkina Faso in 2016 and 2017. METHODS: Blood samples of febrile patients received at Schiphra laboratory in Ouagadougou, Burkina Faso, were screened for dengue infection using SD Bioline Dengue Duo rapid diagnostic test kits (Standard Diagnostics, Suwon, Republic of Korea). RESULTS: A total of 1,397 and 1,882 cases were reported by a single laboratory in 2016 and 2017, respectively. Most cases were at least 15 years of age and the results corroborated reports from WHO indicating the circulation of three dengue virus serotypes in Burkina Faso. CONCLUSION: This study complements data from other, simultaneously conducted surveillance efforts, and indicates that the dengue disease burden might be underestimated in sub-Saharan African nations. Dengue surveillance should be enhanced in African settings to determine the burden more accurately, and accelerated efforts towards a dengue vaccine should be put in place

Projections of Excess Mortality Related to Diurnal Temperature Range Under Climate Change Scenarios: a multi-country modelling study

Various retrospective studies have reported on the increase of mortality risk due to higher diurnal temperature range (DTR). This study projects the effect of DTR on future mortality across 445 communities in 20 countries and regions

설사와 온도 및 강수량의 연관성. 사하라 사막 이남의 아프리카 10개 국가들을 대상으로.

학위논문 (석사) -- 서울대학교 대학원 : 보건대학원 보건학과, 2020. 8. Ho KimAndrea Haselbeck.Background: Climate change affects not only the economy and ecosystem but also health and its social and environmental determinants. Lower- and middle-income countries, which comprise most of the African continent, are more vulnerable to climatic changes and its effects. Various diseases, particularly water and vector-borne, have already started to see an increase in prevalence (i.e cholera) as well as a geographical displacement (i.e malaria). Comprised of a wide variety of climatic zones and already suffering from malnutrition and a variety of infectious diseases, the African continent sees major shifts under a climate change scenario. Particularly, diarrheal diseases, which are a major leading cause of morbidity and mortality, especially in children under five years of age. This study aimed to evaluate the association between temperature and precipitation on all- cause diarrhea for ten different countries in Sub-Saharan Africa. Method: To analyze the association between the climatic drivers and diarrhea; firstly non-linear exposure-response functions using a natural cubic spline with 2 degrees of freedom were modeled, followed by three different quasi-Poisson generalized linear models for each country and all countries combined; 1- average temperature-diarrhea cases, 2-precipitation-diarrhea cases (controlled for temperature), 3- interaction term of temperature and precipitation -diarrhea cases. Seasonality was controlled for in all models, using a natural cubic spline of time (month of the study period) with 2 df per year. Secondly, group analysis based on geographical location and annual average temperature were conducted for both temperature-diarrhea and precipitation-diarrhea associations. Finally, subgroup analysis was conducted for age and gender. Results: Three countries showed statistically significant association between temperature and diarrhea cases (Burkina Faso, Ethiopia, Sudan). Burkina Faso showed a protective effect for temperature (12% reduction of diarrhea cases per unit increase of average temperature), whereas Ethiopia and Sudan showed an increased risk (53 and 19 percent increase in diarrhea cases per unit increase of temperature). The precipitation-diarrhea model generally showed positive associations, with statistically significant estimates for Ethiopia and Kenya and for the pooled estimate for all countries (six percent increase in diarrhea for both Ethiopia and Kenya and three percent increase for all countries, per unit increase of precipitation). All age groups showed statistically significant increased (Ethiopia) or reduced risk (Burkina Faso) of diarrhea for average temperature-diarrhea models whereas only the under-five age group showed statistically significant increased risk of diarrhea per unit change of precipitation (Senegal, Kenya, Ethiopia). Conclusion: The results are consistent with other publications investigating such associations and expand to new study sites previously not investigated. The importance of such results is highlighted when making informed decisions in resource management and allocation, policy, and education programs.배경: 기후 변화는 경제와 생태계뿐만 아니라, 건강 및 건강의 사회적, 환경적 결정요인에도 영향을 미친다. 아프리카 대륙의 대부분을 차지하는 중하위권 국가들은 기후 변화와 그 영향에 더 취약한 것으로 알려져 있다. 각종 질병, 특히 물과 벡터 매개 질병은 이미 유병률 (즉 콜레라)뿐만 아니라 지리적 변위(즉 말라리아)도 증가하기 시작했다. 다양한 기후 지역으로 구성되어 있고 이미 영양실조와 다양한 전염병으로 고통 받고 있는 아프리카 대륙은 기후 변화 시나리오 하에서 주요한 변화를 겪고 있다. 특히, 5세 미만 아동에게 질병과 사망의 주요 원인으로는 설사 질환이 제시되고 있다. 본 연구는 사하라 이남 아프리카 10개국의 설사에 대한 온도와 강수량 사이의 연관성을 평가하는 것을 목표로 했다. 방법: 기후 요인와 설사 사이의 연관성 분석; 먼저 자유도가 2도인 natural cubic spline을 이용한 비선형 노출-반응 함수를 준-포아송 일반화 선형 모형을 사용하여 모델링 한 다음, 각 나라 및 모든 국가를 합친 결과를 제시한다; 1-평균 온도-설사 사례, 2-강수량과 설사 사례(온도가 제어된), 3-온도 및 강수량의 설사 사례에 대한 교호작용. 계절성은 연간 2df의 natural cubic spline(연구 기간의 월)을 사용하여 모든 모델에서 고려되었다. 둘째, 지리적 위치와 연평균 온도에 기초한 group별 분석은 온도-지질 및 강수-지질 연관성 모두에 대해 실시되었다. 마지막으로 연령과 성별에 대한 Sub-group 분석을 실시했다. 결과: 3개국은 기온과 설사 환자 사이에 통계적으로 유의미한 연관성을 보였다(부르키나파소, 에티오피아, 수단). 부르키나파소는 기온에 대한 protective한 관계(온도 상승당 12%의 설사환자 감소)를 보인 반면 에티오피아와 수단은 위험성이 증가(온도 상승당 설사환자 각 53%, 19% 증가)했다. 강수-지질 모형은 일반적으로 양의 연관성을 보여주었는데, 통계적으로 유의한 추정치는 에티오피아와 케냐와 모든 국가에 대한 합동 추정치였다(강수량 단위 증가 당 이티오피아와 케냐의 경우 설사가 6% 증가, 모든 국가의 경우 3% 증가). 결론: 본 연구의 결과는 온도- 및 강수량과 설사 사례의 연관성을 조사하는 다른 기존 연구들과 일치하며, 이전에 조사되지 않았던 새로운 연구 지역을 포함하여 확장되어 수행되었다. 본 연구 결과는 자원 관리와 할당, 정책 및 교육 프로그램에서 정보에 입각한 의사결정을 내릴 때 중요하게 사용될 수 있다.1. Introduction 11 2. Methods 13 2.1 Datasets & Descriptive statistics 2.2 Statistical analysis 3. Results 19 3.1 Descriptive results 3.2 Statistical analysis results 4. Discussion 30 Limitations Strengths Conclusion 5. Appendix 39 6. References 49 Index of Figures Figure 1.Map of Africa, highlighting study sites and the yearly diarrhea cases per each study year 22 Figure 2. Map of the Africa, highlighting the study sites and 7-year averages of climate drivers 23 Figure 3. Non-linear exposure-response plots of temperature and relative risk of diarrhea 25 Figure 4. Non-linear exposure-response plots of precipitation and relative risk of diarrhea 27 Fig A- 1. Time -Series plots of average temperature, precipitation, and diarrhea cases per country 41 Fig A-2. Non-linear exposure-response plots of temperature and relative risk of diarrhea for under 5 years old age group 46 Fig A- 3.Non-linear exposure-response plots of temperature and relative risk of diarrhea for over 5 years old age group 46 Fig A- 4. Non-linear exposure-response plots of temperature and relative risk of diarrhea for males 47 Fig A- 5.Non-linear exposure-response plots of temperature and relative risk of diarrhea for females 47 Fig A- 6. Non-linear exposure-response plots of precipitation and relative risk of diarrhea for under 5 years old 48 Fig A- 7. Non-linear exposure-response plots of precipitation and relative risk of diarrhea for over 5 years age group 48 Fig A- 8. Non-linear exposure-response plots of precipitation and relative risk of diarrhea for males 49 Fig A- 9. Non-linear exposure-response plots of precipitation and relative risk of diarrhea for females 49 Index of Tables Table 1. List of TSAP study sites, study period and number of diarrhea cases 16 Table 2.NOAA Climate indicator coverage for 2009-2015. 16 Table 3. Diarrhea cases per country by age and gender 21 Table 4.Relative Risk of diarrhea per unit increase of temperature 25 Table 5.Relative risk of diarrhea per unit increase of precipitation 27 Table 6. Results of risk ratio for diarrhea by interactions between precipitation and temperature 28 Table A- 1. Distribution of diarrhea cases for each country by study year 40 Table A- 2. Climate characteristics & seasons by country 42 Table A- 3.Seasonal temperature characteristic by country 43 Table A- 4. Risk ratio of diarrhea for average temperature for grouped countries 43 Table A- 5. Risk ratio of diarrhea for precipitation for geographically grouped countries 44 Table A- 6. Risk ratio of diarrhea for interaction of temperature and precipitation 44 Table A- 7. Risk ratio of diarrhea for average temperature per age group 44 Table A- 8.Risk ratio of diarrhea for precipitation per age group 44 Table A- 9.Risk ratio of diarrhea for temperature per gender 45 Table A- 10. Risk ratio of diarrhea for precipitation per gender 45Maste

CS MQP - TCP Congestion Control over a Satellite Network

Dynamic Adaptive Streaming over HTTP (DASH) is a popular, modern method for streaming media. Adaptive bitrate (ABR) functionality allows DASH to adjust to changing network conditions during the course of the stream. However, little work has assessed DASH's performance over geostationary satellite networks, where high latencies cause many network protocols to perform poorly. This paper presents results from experiments that evaluate DASH over a commercial geostationary satellite connection, comparing performance when adjusting two different configuration settings of the stream: The length of video segments, and the ABR algorithm used to make decisions. Results show that: 1) longer segment lengths are more stable but fail to adjust bitrate, staying at a low video quality; and 2) the buffer-based BOLA ABR algorithm has fewer stalls and better video quality than either a throughput-based approach or a hybrid approach

CS MQP - Analyzing DASH Video Streaming over Geostationary Satellite Networks

Dynamic Adaptive Streaming over HTTP (DASH) is a popular, modern method for streaming media. Adaptive bitrate (ABR) functionality allows DASH to adjust to changing network conditions during the course of the stream. However, little work has assessed DASH's performance over geostationary satellite networks, where high latencies cause many network protocols to perform poorly. This paper presents results from experiments that evaluate DASH over a commercial geostationary satellite connection, comparing performance when adjusting two different configuration settings of the stream: The length of video segments, and the ABR algorithm used to make decisions. Results show that: 1) longer segment lengths are more stable but fail to adjust bitrate, staying at a low video quality; and 2) the buffer-based BOLA ABR algorithm has fewer stalls and better video quality than either a throughput-based approach or a hybrid approach

Improving Outdoors Literacy For Children At Turn Back Time

Studies show that exposure to nature and play-based learning are critical to early childhood development. Turn Back Time Inc. (TBT) provides the opportunity of outdoors learning to children through various daily activities and experiential play in nature. While TBT possesses a rudimentary trail for outdoors literacy, the lack of long-term structural units stunts the efficacy of their outdoors literature process. The purpose of this study was to research, construct and analyze nature-based literacy stations to improve TBT’s outdoor learning facilities and to enhance the literature experience of TBT students

Serology as a Tool to Assess Infectious Disease Landscapes and Guide Public Health Policy.

Understanding the local burden and epidemiology of infectious diseases is crucial to guide public health policy and prioritize interventions. Typically, infectious disease surveillance relies on capturing clinical cases within a healthcare system, classifying cases by etiology and enumerating cases over a period of time. Disease burden is often then extrapolated to the general population. Serology (i.e., examining serum for the presence of pathogen-specific antibodies) has long been used to inform about individuals past exposure and immunity to specific pathogens. However, it has been underutilized as a tool to evaluate the infectious disease burden landscape at the population level and guide public health decisions. In this review, we outline how serology provides a powerful tool to complement case-based surveillance for determining disease burden and epidemiology of infectious diseases, highlighting its benefits and limitations. We describe the current serology-based technologies and illustrate their use with examples from both the pre- and post- COVID-19-pandemic context. In particular, we review the challenges to and opportunities in implementing serological surveillance in low- and middle-income countries (LMICs), which bear the brunt of the global infectious disease burden. Finally, we discuss the relevance of serology data for public health decision-making and describe scenarios in which this data could be used, either independently or in conjunction with case-based surveillance. We conclude that public health systems would greatly benefit from the inclusion of serology to supplement and strengthen existing case-based infectious disease surveillance strategies

Projections of excess mortality related to diurnal temperature range under climate change scenarios: a multi-country modelling study

Summary Background Various retrospective studies have reported on the increase of mortality risk due to higher diurnal temperature range (DTR). This study projects the effect of DTR on future mortality across 445 communities in 20 countries and regions. Methods DTR-related mortality risk was estimated on the basis of the historical daily time-series of mortality and weather factors from Jan 1, 1985, to Dec 31, 2015, with data for 445 communities across 20 countries and regions, from the Multi-Country Multi-City Collaborative Research Network. We obtained daily projected temperature series associated with four climate change scenarios, using the four representative concentration pathways (RCPs) described by the Intergovernmental Panel on Climate Change, from the lowest to the highest emission scenarios (RCP 2.6, RCP 4.5, RCP 6.0, and RCP 8.5). Excess deaths attributable to the DTR during the current (1985–2015) and future (2020–99) periods were projected using daily DTR series under the four scenarios. Future excess deaths were calculated on the basis of assumptions that warmer long-term average temperatures affect or do not affect the DTR-related mortality risk. Findings The time-series analyses results showed that DTR was associated with excess mortality. Under the unmitigated climate change scenario (RCP 8.5), the future average DTR is projected to increase in most countries and regions (by −0·4 to 1·6°C), particularly in the USA, south-central Europe, Mexico, and South Africa. The excess deaths currently attributable to DTR were estimated to be 0·2–7·4%. Furthermore, the DTR-related mortality risk increased as the long-term average temperature increased; in the linear mixed model with the assumption of an interactive effect with long-term average temperature, we estimated 0·05% additional DTR mortality risk per 1°C increase in average temperature. Based on the interaction with long-term average temperature, the DTR-related excess deaths are projected to increase in all countries or regions by 1·4–10·3% in 2090–99. Interpretation This study suggests that globally, DTR-related excess mortality might increase under climate change, and this increasing pattern is likely to vary between countries and regions. Considering climatic changes, our findings could contribute to public health interventions aimed at reducing the impact of DTR on human health.Peer reviewe

Projections of excess mortality related to diurnal temperature range under climate change scenarios:a multi-country modelling study

Abstract Background: Various retrospective studies have reported on the increase of mortality risk due to higher diurnal temperature range (DTR). This study projects the effect of DTR on future mortality across 445 communities in 20 countries and regions. Methods: DTR-related mortality risk was estimated on the basis of the historical daily time-series of mortality and weather factors from Jan 1, 1985, to Dec 31, 2015, with data for 445 communities across 20 countries and regions, from the Multi-Country Multi-City Collaborative Research Network. We obtained daily projected temperature series associated with four climate change scenarios, using the four representative concentration pathways (RCPs) described by the Intergovernmental Panel on Climate Change, from the lowest to the highest emission scenarios (RCP 2.6, RCP 4.5, RCP 6.0, and RCP 8.5). Excess deaths attributable to the DTR during the current (1985–2015) and future (2020–99) periods were projected using daily DTR series under the four scenarios. Future excess deaths were calculated on the basis of assumptions that warmer long-term average temperatures affect or do not affect the DTR-related mortality risk. Findings: The time-series analyses results showed that DTR was associated with excess mortality. Under the unmitigated climate change scenario (RCP 8.5), the future average DTR is projected to increase in most countries and regions (by −0·4 to 1·6°C), particularly in the USA, south-central Europe, Mexico, and South Africa. The excess deaths currently attributable to DTR were estimated to be 0·2–7·4%. Furthermore, the DTR-related mortality risk increased as the long-term average temperature increased; in the linear mixed model with the assumption of an interactive effect with long-term average temperature, we estimated 0·05% additional DTR mortality risk per 1°C increase in average temperature. Based on the interaction with long-term average temperature, the DTR-related excess deaths are projected to increase in all countries or regions by 1·4–10·3% in 2090–99. Interpretation: This study suggests that globally, DTR-related excess mortality might increase under climate change, and this increasing pattern is likely to vary between countries and regions. Considering climatic changes, our findings could contribute to public health interventions aimed at reducing the impact of DTR on human health