BackgroundDengue is caused by an arthropod-borne flavivirus. Infection can be either primary or secondary based on serology, with each stage of the disease characterized by specific serological conversion and antibody formation. Further study is needed to fully identify the factors associated with and predisposing to dengue infection. The objective of this study was to identify socio-demographic factors associated with the prevalence of dengue serotypes in Kassala State in the eastern part of Sudan in 2011.MethodsThis was a cross-sectional community-based study with 530 participants who were randomly selected through multi-stage cluster sampling. Dengue serotype prevalence was determined using capture Enzyme-linked immunosorbent assay (ELISA). ELISA IgG. A multivariate logistic regression model was designed to measure the strength of associations between socio-demographic factors and dengue serotype prevalence. All participants who tested negative for dengue were used as the statistical reference group.ResultsFrom this study, the prevalence of dengue in Kassala was estimated to be 9.4 % (95 % CI: 7.1–12.3). Lack of knowledge about dengue fever disease (OR 2.8, 95 % CI: 1.24–6.53) and a household density of more than 3 people per room (OR 2.1, 95 % CI: 1.06–4.09) were the most important factors associated with dengue infection among the study population.ConclusionsCommunity-oriented interventions are needed to modify existing social behaviors to reduce the risk of dengue in the eastern part of Sudan. Additional studies are also required in this field.

Dengue fever is a vector-borne disease that is transmitted to humans by infected Aedes aegypti mosquitoes. The eastern part of the Sudan is one of the regions that is affected by dengue virus circulation. In this study, we estimated the prevalence of dengue infections in the Kassala state in the eastern part of the Sudan. The study objective was to estimate the sero-prevalence of dengue IgG/IgM antibodies in the Kassala locality in 2011. This was a cross sectional community-based study that utilized a multi-stage cluster sampling technique regarding the probability sampling the study participants. Capture ELISA serological techniques were used for both IgM and IgG, with the specific cut-offs for each set by the manufacturer. The prevalence of dengue infection was found to be 9.4% (95% CI: 7.1-12.3). In conclusion, there is evidence that the dengue virus is being transmitted in Kassala. Disease surveillance, including the clinical, serological and entomological components, should be strengthened, and additional epidemiological studies are needed to better understand of the disease burden and effects in the area.

Exploration and development wells are increasingly drilled to deeper depths and lower porosities, in hotter formations. These conditions increase the challenges for Formation Tester's (FT's) to acquire accurate formation pressures in a timely and cost efficient manner. One of the most important constraints on current FT acquisition is the downhole formation temperature. The Pattani and North Malay basins in the Gulf of Thailand (GoT) are known to be one of the highest temperature locations where FT data is routinely acquired. Successful exploitation of the hydrocarbon resources in these basins is strongly driven by cost efficiency and the characterization of the many individual sands that are part of the complex fluvial stratigraphic framework. Reservoir pressure, fluid type, inflow performance and sand-to-sand correlation are some of the objectives for acquiring FT data and are used to manage the many wells drilled each year in these basins. Chevron (Thailand) E&P and PTTEP are the main operators in the GoT, drilling roughly 450 wells each year and over 80% of the wells have bottomhole temperatures in excess of 320 degF. Roughly 80% of the wells drilled require FT logging in the data acquisition program. The main challenge in this high temperature environment for formation testing acquisition is that pressure gauges need to be stabilized to eliminate a transient effect due to high temperature, in order to obtain an accurate pressure measurement. This can lead to longer logging times with the current tools available and lost efficiencies, particularly for wells with many individual hydrocarbon bearing sands (high pay counts).To improve efficiency and the actual formation pressure management, a proposal was made to develop a High Temperature FT tool in early 2009. This paper discusses the development challenges for FT's in this high temperature area, including gauge selection, gauge limitation, gauge temperature transient effects and logging procedures. After an intensive working period, a specially-made flask to cover certain parts of the tool for heat transfer and mitigation was introduced. Since then, this new FT service has been deployed in more than 20 wells in the Gulf of Thailand. This paper also presents the actual field data from the new tool in terms of data quality and accuracy compared to previous generations of FT, and the resultant efficiency gains from rig time savings. With this development, it is currently possible to obtain accurate formation pressure data, even in the extreme high temperatures found in the GoT, where satisfactory results were not possible in the past.