Dengue in Southeast Asia: epidemiological characteristics and strategic challenges in disease prevention.
ABSTRACT Dengue emerged as a public health burden in Southeast Asia during and following the Second World War and has become increasingly important, with progressively longer and more frequent cyclical epidemics of dengue fever/dengue hemorrhagic fever. Despite this trend, surveillance for this vector-borne viral disease remains largely passive in most Southeast Asian countries, without adequate laboratory support. We review here the factors that may have contributed to the changing epidemiology of dengue in Southeast Asia as well as challenges of disease prevention. We also discuss a regional approach to active dengue virus surveillance, focusing on urban areas where the viruses are maintained, which may be a solution to limited financial resources since most of the countries in the region have developing economies. A regional approach would also result in a greater likelihood of success in disease prevention since the large volume of human travel is a major factor contributing to the geographical spread of dengue viruses.
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ABSTRACT: Dengue fever is considered as a rapidly emerging arthropod-borne viral disease all over the world especially in the Philippines resulting in severe illness, possibly death, and economic burden to society and disruption of quality of life. In the absence of an available vaccine and specific treatment for use by the general population, dengue prevention is largely focused in controlling its main principal vector, Aedes aegypti and implicated secondary vector, Ae. albopictus. The biology and distribution of these mosquito vectors are greatly affected by several environmental determinants namely; (1) type of household (2) vegetation (3) climatic conditions (4) artificial water-holding containers (5) population density and (6) affected flood prone areas. Here we discuss the roles of each environmental or condition and its impact towards the spread and epidemiology of Dengue in Metro Manila. It also highlights modifiable measures of the environmental determinants that may be utilized in the prevention and control of Dengue.7th ASEAN Environmental Engineering Conference, Puerto Princesa, Palawan, Philippines; 10/2014
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ABSTRACT: Dengue disease is a major public health problem across the Asia-Pacific region for which there is no licensed vaccine or treatment. We evaluated the safety and immunogenicity of Phase III lots of a candidate vaccine (CYD-TDV) in children in Malaysia. In this observer-blind, placebo-controlled, Phase III study, children aged 2-11 years were randomized (4:1) to receive CYD-TDV or placebo at 0, 6 and 12 months. Primary endpoints included assessment of reactogenicity following each dose, adverse events (AEs) and serious AEs (SAEs) reported throughout the study, and immunogenicity expressed as geometric mean titres (GMTs) and distribution of dengue virus (DENV) neutralizing antibody titres. 250 participants enrolled in the study (CYD-TDV: n=199; placebo: n=51). There was a trend for reactogenicity to be higher with CYD-TDV than with placebo post-dose 1 (75.4% versus 68.6%) and post-dose 2 (71.6% versus 62.0%) and slightly lower post-dose 3 (57.9% versus 64.0%). Unsolicited AEs declined in frequency with each subsequent dose and were similar overall between groups (CYD-TDV: 53.8%; placebo: 49.0%). Most AEs were of Grade 1 intensity and were transient. SAEs were reported by 5.5% and 11.8% of participants in the CYD-TDV and placebo groups, respectively. No deaths were reported. Baseline seropositivity against each of the four DENV serotypes was similar between groups, ranging from 24.0% (DENV-4) to 36.7% (DENV-3). In the CYD-TDV group, GMTs increased post-dose 2 for all serotypes compared with baseline, ranging from 4.8 (DENV-1) to 8.1-fold (DENV-3). GMTs further increased post-dose 3 for DENV-1 and DENV-2. Compared with baseline, individual titre increases ranged from 6.1-fold (DENV-1) to 7.96-fold (DENV-3). This study demonstrated a satisfactory safety profile and a balanced humoral immune response against all four DENV serotypes for CYD-TDV administered via a three-dose regimen to children in Malaysia.Vaccine 10/2013; 31(49). DOI:10.1016/j.vaccine.2013.10.013 · 3.49 Impact Factor
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ABSTRACT: Dengue fever is a mosquito-borne viral disease affecting humans, results in about 50-100 million cases and 250,000 to 500,000 cases of more severe dengue hemorrhagic fever/dengue shock syndrome and about 20,000 deaths annually [1,2]. The development of vaccine against dengue is under the process of developing. With four different serotypes of the dengue virus that can cause the disease, the drug must immunize against all four types to be effective . Vaccination against only one serotype could possible lead to severe DHS when infected with another serotype due to Antibody-dependent enhancement. There is still limited information of how the disease typically behaves and how the virus interacts with the immune system.