View clinical trials related to Epidemiology.
Filter by:The epidemiology and ecology of malaria in humans includes complex interactions between human hosts and mosquito vectors. These interactions are spatio-temporal in nature and are heavily dependent on transportation capabilities and seasonal conditions. Where and when infections are acquired is not well understood in the Greater Mekong Subregion (GMS), where there are numerous vectors, many with different behaviours and habitats. For example, many infections appear to be associated with forests or forest edges and some of the most important mosquito vectors in the region are forest dwellers (Obsomer, Defourny, and Coosemans 2007). Interventions that target houses at night-time (e.g. mosquito nets), have had limited success in the GMS, most likely because at least some infections are acquired during the day or outside of the home (Dolan et al. 1993; Luxemburger et al. 1994). While overall malaria incidence in the region appears to be declining, the disease remains persistent in small subregions, for example along international borders joining Thailand with Myanmar. It will be crucial for elimination efforts to address the persistent malaria in these regions, most likely requiring the use of novel and spatially targeted approaches. Increasingly, spatial data and analyses are used in disease research (Linard and Tatem 2012; Pybus et al. 2016; Tatem et al. 2012), however most spatial analyses are at aggregate scales, using data from provincial or state levels. More detailed studies have a single geographic reference point per individual in the study, frequently the home (Mosha et al. 2014; Parker et al. 2015). These studies allow researchers to investigate potential clustering of cases within and between houses ("hotspots") (Bejon et al. 2014; Bousema et al. 2012; Mosha et al. 2014). Even these detailed studies typically ignore the spaces in which people spend time outside of their home and where they may acquire infection: schools; places of worship and work; forest camps and temporary shelters. Given that many malaria infections in the GMS are acquired outside of the home, in areas that are not usually mapped, this information is important for developing strategies to prevent transmission and will be crucial for achieving elimination. Researchers in other substantive areas have already begun mapping the movement patterns of study subjects so that exposure to a variety of environmental exposures outside of the home can be assessed (Matthews and Yang 2013; Vazquez-Prokopec et al. 2010). Early approaches relied on travel surveys or travel diaries, both having bias of unknown magnitude. Modern wearable global positioning satellite (GPS) instruments (loggers or trackers) and geographic information science (GIS) enable detailed mapping and quantification of human movement patterns. Through analysing differences in the movement patterns between humans who do versus those that do not acquire infectious diseases, it may be possible to identify a narrower set of geographic spaces in which disease transmission is occurring. Public health interventions could then target those risk areas. Most of these detailed studies have been done in economically developed settings and urban environments. Infectious diseases such as malaria remain persistent in resource-poor, rural, and remote areas - the very regions that are least likely to be studied with detailed approaches (Sachs and Malaney 2002).
This is an observational study (case-control study) aiming to identify risk factors for malaria infection in health centers or malaria posts or district hospitals in Buntharik District and Nachalui District, Ubon Ratchathani Province, Thailand. This study expects to recruit 330 cases (malaria positive) and 330 control (negative cases) subject. One-to-one matching of cases (malaria positive) and controls (malaria negative) will be done at each study site. CASE (Malaria positive) subject will go through the following; 1. Enrollment visit (Day 0) 1.1 Blood collection of three dried blood spots, and malaria slide. In district hospitals in individuals >14 kg: additional 10ml venous blood will be collected. 1.2 A survey questionnaire which includes patient demographics, information on malaria treatment, bed net use and possible risk factors for acquiring malaria, as well as questions about their travel and usage of mobile phones will be administered. 2. Follow up visits (if fever plus Day 42 (+/-3)) 2.1 Blood collection of three dried blood spots and malaria slide. In district hospitals: additional 0.5ml venous blood will be collected. 2.2 Short survey questionnaire including questions on symptoms, travel and possible risk behaviors since enrollment will be administered. CONTROL (Malaria negative) subject will go through the following; 1. Enrollment visit (Day 0) 1.1 Blood collection to confirm negative malaria slide. In district hospitals: additional 0.5ml venous blood will be collected. 1.2 A survey questionnaire including patient demographics, information on any recent malaria treatment they may have taken, bed net use and possible risk factors for acquiring malaria, as well as questions about their travel and usage of mobile phones will be administered. 2. Follow up visit: No follow up visit
The investigators will conduct a population-based study using health administrative data to evaluate the impact of preoperative geriatric consultation on postoperative outcomes in older patients having elective, non-cardiac surgery
AVIRON study aims at estimating the burden of various causes of death and morbidity in the Reunion Island population.
Malaria is the most widespread parasitic illness in the world, and it is endemic to Guiana. Although the number of cases has decreased since 2005, sources of infection still remain, particularly within illegal gold mines. These malaria carriers/sufferers often use self-medication to deal with malaria symptoms, resulting in a risk of resistance to anti-malarial treatments, and particularly to artemisinine. The mobility of this population across the Guiana Shield increases both the risk of malaria spreading and the resistance of this illness to treatment in the region, and puts the population at risk of new outbreaks of this disease despite the great efforts put into anti-malarial policy in this region. Fighting malaria within this population is therefore a dual public health challenge: on the one hand, make it possible for the WHO to eliminate malaria from the Guiana Shield by 2017, on the other to limit resistance to artemisinine in this region. However, Guiana's particular context - namely the illegal status of gold mines and the difficult geographical access, the Harpie military operations, the illegality of carrying out malarial diagnosis tests and treating cases without the presence of a health professional - prevents us from achieving this goal using the same tools as our neighbours in Suriname, whose " Looking for Gold, Finding Malaria " programme was a success. A better understanding of the malarial epidemiology in this population will enable us to propose innovative, more adapted measures to combat malaria within these guyanese populations. This is an transversal, multicentric observational study.
National, prospective, multicentre, non-interventional epidemiological study, conducted among oncologists and breast surgeons in community and university hospitals, from the public sector in Algeria. The study will collect information on the characteristics, and breast carcinomas patterns of patients whose breast cancer diagnosis was confirmed by an anatomopathologist. The study will be conducted over a representative, but not exhaustive sample of Algerian female patients.
Aims of the study: - to study the incidence rate of juvenile idiopathic arthritis (JIA) and it's clinical subtypes in Estonia for the years 1998-2000; - to examine the course and short-term clinical outcome of JIA. Method: a prospective population-based study carried on in 14 counties of Estonia
The purpose of this study is to evaluate the incidence, prevalence, clinical characteristics and prognosis of Crohn's disease and ulcerative colitis over time in a district of Seoul, Korea.
Background: - Research suggests that occupational exposure to formaldehyde is associated with increased risk for myeloid leukemia, but the significance of these findings is uncertain because of inconsistencies among studies and lack of knowledge of how formaldehyde can cause leukemia. - Damage to the DNA of myeloid cells (type of white blood cell) or an environmental factor not affecting the cell genetic machinery may be involved. Objective: To determine if formaldehyde exposure is associated with genetic or other changes in myeloid cells. Eligibility: Workers exposed to high levels of formaldehyde and unexposed workers in Guangdong Province, China. Design: - 40 exposed workers and 40 unexposed workers will be enrolled. - Subjects wear small instruments at work that measure chemicals in the air for 1 or 2 days. - Subjects have a brief physical examination and provide blood, urine, and mouth rinse samples. - Subjects answer a questionnaire about work, smoking and drinking, use of medicines, medical history, general health, exposure to radiation and exposure to various substances at home.
With an estimated 2.5 million HIV-infected persons, India is home to one of the largest populations of HIV-infected persons in the world. Yet, it is estimated that less than 20% of the people living with HIV in India are aware of their status. Andhra Pradesh (AP), situated in south India, is the state with the highest HIV burden in India. Reports from AP suggest usage of voluntary counseling and testing (VCT) is low, especially among high-risk groups. VCT has been shown to have many benefits in addition to diagnosis of HIV infection such as reduction in risk behavior, partner referral, and serving as an entry point to the health care system. Community mobilization and VCT vans have been shown in the past to play a role in increasing utilization of VCT services in various developing countries similar to India. The primary objective of this protocol is to arrive at an effect size of community mobilization alone, and both community mobilization and VCT vans, on the adoption of VCT services in Andhra Pradesh, India. Secondary objectives include identifying barriers to VCT, assessing stigma in the community, and establishing a specimen repository at the YRGCARE infectious disease laboratory in Chennai, India. We will achieve these objectives by conducting a cluster randomized clinical trial with 3 arms: ARM 1: standard of care with pre-existing VCT centers (SVCT); ARM 2: community mobilization in the setting of pre-existing VCT centers (CVCT); ARM 3: community mobilization plus VCT van in addition to the pre-existing VCT centers (MCVCT). The overall study duration will be 6 months from randomization. To our knowledge, this is the first study to examine the role of community mobilization and VCT vans on the adoption of VCT in the Indian context. It will provide us with vital data that will be used to plan a larger powered study to evaluate the effectiveness of these interventions including sites from other parts of India. Additionally, this study will also provide us with important information on barriers to VCT in these communities.