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- Ahmed Hassan Ahmed, Osama, 1972-
(författare)
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Rift Valley fever : challenges and new insights for prevention and control using the “One Health” approach
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Rift Valley fever (RVF) is an emerging viral zoonosis that causes frequent outbreaks in east Africa and on the Arabian Peninsula. The likelihood of RVF global expansion due to climate change and human anthropogenic factors is an important issue. The causative agent, RVF virus, is an arbovirus that is transmitted by several mosquito species and is able to infect a wide range of livestock as well as people. The infection leads to mass abortions and death in livestock and a potentially deadly hemorrhagic fever in humans. RVF has severe socio-economic consequences such as animal trade bans between countries, disruption of food security, and economic disaster for farmers and pastoralists as well as for countries. Human behavior such as direct contact with infected animals or their fluids and exposure to mosquito bites increases the risk for contracting the disease.To better understand the challenges associated with RVF outbreaks and to explore prevention and control strategies, we used the One Health approach. The local community had to be involved to understand the interaction between the environment, animals, and humans. We focused on Sudan, Saudi Arabia, and Kenya. First, we systematically reviewed the literature and then we performed cross sectional community-based studies using a special One Health questionnaire. Climatic and remote sensing data were used in combination with statistics to develop a sub-region predictive model for RVF.For both Saudi Arabia and Sudan, the ecology and environment of the affected areas were similar. These areas included irrigation canals and excessive rains that provide an attractive habitat for mosquito vectors to multiply. The surveillance systems were unable to detect the virus in livestock before it spread to humans. Ideally, livestock should serve as sentinels to prevent loss of human lives, but the situation here was reversed. Differences between countries regarding further spread of RVF was mainly determined by better economic and infrastructure resources.In Sudan, there was a lack of knowledge and appropriate practices at the studied community regarding RVF disease symptoms and risk factors for both animals and humans. The community was hesitant in notifying the authorities about RVF suspicion in livestock due to the lack of a compensation system. The perceived role of the community in controlling RVF was fragmented, increasing the probability of RVF transmission and disease.In Kenya, our study found that better knowledge about RVF does not always translate to more appropriate practices that avoid exposure to the disease. However, the combination of good knowledge, attitudes, and practices may explain why certain communities were less affected. Strategies to combat RVF should consider socio-cultural and behavioral differences among communities. We also noticed that RVF outbreaks in Kenya occurred in regions with high livestock density exposed to heavy rains and wet soil fluxes, which could be measured by evapotranspiration and vegetation seasonality variables. We developed a RVF risk map on a sub-regional scale. Future outbreaks could be better managed if such relevant RVF variables are integrated into early warning systems.To confront RVF outbreaks, a policy is needed that better incorporates ecological factors and human interactions with livestock and environment that help the RVF pathogen spread. Early detection and notification of RVF is essential because a delay will threaten the core of International Health Regulations (IHR), which emphasizes the share of information during a transboundary disease outbreak to avoid unnecessary geographical expansion.
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- Muindi, Kanyiva, 1973-
(författare)
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Air pollution in Nairobi slums : sources, levels and lay perceptions
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- BackgroundAir quality in Africa has remained a relatively under-researched field. Most of the African population is dependent on biomass for cooking and heating, with most of the combustion happening in low efficiency stoves in unvented kitchens. The resulting high emissions are compounded by ingress from poor outdoor air in a context of poor emissions controls. The situation is dire in slum households where homes are crowded and space is limited, pushing households to cook in the same room that is used for sleeping. This study assessed the levels of particulate matter with aerodynamic diameter £ 2.5 microns (PM2.5) in slum households and people's perceptions of and attitudes towards air pollution and health risks of exposure in two slum areas, Viwandani and Korogocho, in the Nairobi city.Methods The study employed both qualitative and quantitative methods. For the quantitative study, we used structured questionnaires to collect data about the source of air pollution among adults aged 18 years and above and pregnant women residing in the two study communities. We used the DustTrak™ air samplers to monitor the indoor PM2.5 levels in selected households. We also collected data on community perceptions on air pollution, annoyance and associated health risks. We presented hotspot maps to portray the spatial distribution of perceptions on air pollution in the study areas. For the qualitative study, we conducted focus group discussions with adult community members. Groups were disaggregated by age to account for different languages used to communicate with the younger and older people. We analysed the qualitative data using thematic analysis.Results Household levels of PM2.5 varied widely across households and ranged from 1 to 12,369μg/m3 (SD=287.11). The household levels of PM2.5 levels were likely to exceed the WHO guidelines given the high levels observed in less than 24 hours of monitoring periods (on average 10.4 hours in Viwandani and 11.8 hours in Korogocho). Most of the respondents did not use ventilation use in the evening which coincided with the use of cookstove and lamp, mostly burning kerosene. The levels of PM2.5 varied by the type of fuels, with the highest emissions in households using kerosene for cooking and lighting. The PM2.5 levels spiked in the evenings and during periods of cooking using charcoal/wood. Despite these high levels, residents perceived indoor air to be less polluted compared with the outdoor air, possibly due to the presence of large sources of emissions near the communities such as dumpsites and industries. The community had mixed perceptions on the health impacts of air pollution, with respiratory illnesses perceived as the main consequence while vector or sanitation related diseases such as diarrhoea was also perceived to be related to air pollution.ConclusionsWith poor housing and reliance on dirty fuels, households in slums face potentially high levels of exposure to PM2.5 with dire implications on health. To address the poor perception on air pollution and knowledge gaps on the health effects of air pollution, education programs need to be developed and tailored. These programs should aim to provide residents with information on air quality and its impact on the health; what they can do as communities as well as empower them to reach out to government/stakeholders for action on outdoor sources of pollution such as emissions from dumpsites or industries. The government has a larger role in addressing some of the key pollution sources through policy formulation and strong implementation/enforcement.
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- Santosa, Ailiana, 1976-
(författare)
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Where are the world’s disease patterns heading? : The challenges of epidemiological transition
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- INTRODUCTION: Epidemiological transition theory, first postulated by Omran in 1971, provides a useful framework for understanding cause-specific mortality changes and may contribute usefully to predictions about cause-specific mortality. However, understandings of mortality transitions and associated epidemiological changes remain poorly defined for public health practitioners due to lack of evidence from low- and middle-income countries. Therefore, understanding of the concept and development of epidemiological transition theory as well as population burden of premature mortality attributable to risk factors is needed.OBJECTIVES: This thesis aims to understand how epidemiological transition theory has been applied in different contexts, using available evidence on mortality transitions from high, middle- and low- income countries, as well as the contribution of risk factors to mortality transitions, particularly for premature mortality.METHODS: A Medline literature search from 1971 to 2013 was conducted to synthesise published evidence on mortality transition (paper I). A descriptive analysis of trends in cause of death using INDEPTH data was conducted, focusing on specific causes of death in 12 INDEPTH sites in Africa and Asia, using the INDEPTH 2013 standard population structure for appropriate comparisons across sites (paper II). A retrospective dynamic cohort database was constructed from Swedish population registers for the age range 30-69 years during 1991-2006, to measure reductions in premature non-communicable disease mortality using a life table method (paper III). Prospective cohort data from Västerbotten Intervention Programme from 1990 to 2006 were used to measure the magnitude of premature non-communicable disease mortality reductions associated with risk factor changes for each period of time (paper IV).FINDINGS: There were changes in emphasis in research on epidemiological transition over the four decades from 1971 to 2013, from cause of death to wide-ranging aspects of the determinants of mortality with increasing research interests in low-and middle-income countries, with some unconsidered aspects of social determinants contributing to deviations from classic theoretical pathways. Mortality rates declined in most sites, with the annual reductions in premature adult mortality varied across INDEPTH sites, Sweden, which now is at late stage of epidemiological transition stage, achieved a 25% reduction in premature mortality during 1991-2006. Overall downward trends in risk factors have helped to reduce premature mortality in the population of Västerbotten County, but some benefits were offset by other increasing risks. The largest mortality changes accrued from reductions in smoking, hypertension and hypercholesterolaemia.CONCLUSIONS: This thesis established patterns of current epidemiological transition in high, middle-and low-income countries (Asia and Africa), where the theory fits the transition patterns in some countries, but with some needs for further adjustments in other settings, as well as deviations from the classical ET theory in the last four decades. It highlights the need to identify the burden of mortality and morbidity, particularly for reducing mortality occurring before the age of 70 years and its attribution to risk factors, which are a major public health challenge. This informs shifting of public health priorities and resources towards prevention and control of chronic non-communicable disease risk factors.
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- Trang, Phan Minh, 1974-
(författare)
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Weather and extreme heat in association to mental disorders : The case of Hanoi, Vietnam
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: Vietnam suffers consequences of global warming. There is limited data of the relationship between weather, extreme heat and potential mental health problems. It is therefore crucial to study heat-related mental illnesses and to establish good solutions with relevant adaptations to global warming. The adaptation measures should give attention to people that live in areas facing annual extreme weather, and protecting health in general and more specifically mental health of citizens. The study aimed to examine relationships between weather patterns, extreme heat or heatwaves, and mental disorders, and to investigate factors contributing to increased vulnerability and susceptibility.Methods: The thesis includes a systematic review and a hospital-based study using data from the Hanoi Mental Hospital for five years (2008 – 2012), with mental disorders diagnosed by ICD10 (F00-99) to estimate the effects of weather variation, seasonality, increased temperatures, and heatwaves on hospital admissions for depression and other mental disorders. A negative binomial regression model accounting for yearly study period, time trends, and day of the week was used to analyze the relationship between seasonality, heatwaves, and monthly and daily mental disorder hospitalizations.Results: Our findings showed (i) a general tendency for more admissions between May and December, with a seasonal bi-annual high between May-June and November-December, and elevated ambient temperature was significantly related to increasing admissions for depressive disorders; (ii) the number of hospital cases for mental disorders increased in the summer seasone specially in June, and two percent of cases emerged during elevated temperature of one degree Celsius; and (iii) when compared with non-heatwave periods, heatwaves amounted to increasing risks for admission for the whole group of mental disorders (F00-79), and admissions for mental disorders among residents in rural communities and in the elderly population increased significantly during heatwaves.Conclusion: There were associations between hospital admissions for depression and other mental disorders and seasonality, weather patterns, elevated temperatures, and heatwaves. The associations grew stronger with the length of the heatwaves and particularly the elderly appeared more sensitive to seasonality, hot weather and heatwaves.
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