Community and School-Based Health Education for Dengue Control in Rural Cambodia: A Process Evaluation

Dengue fever continues to be a major public health problem in Cambodia, with significant impact on children. Health education is a major means for prevention and control of the National Dengue Control Program (NDCP), and is delivered to communities and in schools. Drawing on data collected in 2003–2004 as part of an ethnographic study conducted in eastern Cambodia, we explore the approaches used in health education and their effectiveness to control dengue. Community health education is provided through health centre outreach activities and campaigns of the NDCP, but is not systematically evaluated, is under-funded and delivered irregularly; school-based education is restricted in terms of time and lacks follow-up in terms of practical activities for prevention and control. As a result, adherence is partial. We suggest the need for sustained routine education for dengue prevention and control, and the need for approaches to ensure the translation of knowledge into practice

Dengue Incidence in Urban and Rural Cambodia: Results from Population-Based Active Fever Surveillance, 2006–2008

Dengue is a major public health problem in South-East Asia. Several dengue vaccine candidates are now in late-stage development and are being evaluated in clinical trials. Accurate estimates of true dengue disease burden will become an important factor in the public-health decision-making process for endemic countries once safe and effective vaccines become available. However, estimates of the true disease incidence are difficult to make, because national surveillance systems suffer from disease under-recognition and reporting. Dengue is mainly reported among children, and in some countries, such as Cambodia, the national case definition only includes hospitalized children. This study used active, community-based surveillance of febrile illness coupled with laboratory testing for DENV infection to identify cases of dengue fever in rural and urban populations. We found a high burden of dengue in young children and late adolescents in both rural and urban communities at a magnitude greater than previously described. The study also confirmed the previously observed focal nature of dengue virus transmission

An atlas of over 90.000 conserved noncoding sequences provides insight into crucifer regulatory regions

Despite the central importance of noncoding DNA to gene regulation and evolution, understanding of the extent of selection on plant noncoding DNA remains limited compared to that of other organisms. Here we report sequencing of genomes from three Brassicaceae species (Leavenworthia alabamica, Sisymbrium irio and Aethionema arabicum) and their joint analysis with six previously sequenced crucifer genomes. Conservation across orthologous bases suggests that at least 17% of the Arabidopsis thaliana genome is under selection, with nearly one-quarter of the sequence under selection lying outside of coding regions. Much of this sequence can be localized to approximately 90,000 conserved noncoding sequences (CNSs) that show evidence of transcriptional and post-transcriptional regulation. Population genomics analyses of two crucifer species, A. thaliana and Capsella grandiflora, confirm that most of the identified CNSs are evolving under medium to strong purifying selection. Overall, these CNSs highlight both similarities and several key differences between the regulatory DNA of plants and other species

Susceptibility of two cambodian population of Aedes aegypti mosquito larvae to temephos during 2001

Two population of Aedes aegypti, i.e Phnom Penh (temephos-treated area) and Kampong Cham (area untreated with temephos) were evaluated for their susceptibility to temephos. Larval bioassays were carried out in accordance with QHO standard methods. Results showed that, when compared with the WHO diagnostic dosage of 0.02 mg/l, the Phnom Penh population was resistant (LC95: 0.034mg/l) whereas that of Kampong Cham was susceptible (LC95: 0.015mg/l). 95% confidence intervals of 0.0298 - 0.0382 and 0.0115 - 0.0193, respectively, did not overlap, indicating that the difference in susceptibility between thw two populations was significant. Resistant of Ae. aegypti to temephos appears to be incipient in Camboida. More studies are reuqired with wider representations of localities

The use of ovitraps baited with hay infusion as a surveillance tool for Aedes aegypti mosquitoes in Cambodia

This study was conducted to test (a) if a modified version of the CDC-enhanced would attract more gravid female Aedes aegypti mosquitoes than standard ovitraps for more frequent monitoring of oviposition activity, and (b) the placement of ovitraps indoors or outdoors affected their performance. Paired ovitraps were placed in 25 strategically houses in Toul Kouk, a village on the outskirts of Phnom Penh, Cambodia's capital city. Each pair consisted of one ovitrap with 10% hay infusion and the other with plain tap water, one pair placed inside each house and the other outside the same house. Collections were made every other day for four weeks. The number of positive ovitraps was recorded and egg counts made. Thirteen collections made over a 4-week period yielded a total of 7758 eggs, of which 5396 were collected in ovitraps with hay infusion. Ovitraps with hay infusion had a higher positivity (weekly range 15.56-54.55%) than ovitraps with plain water (weekly range 6.67 - 34.88%) (t = 4.92; df 12; p 0.5 and t = 0.06; df 12; p >0.5, respectively) or for plain water traps (t= 1.97; df 12; 0.05 < p < 0.1 and t = 1.03; df 12; 0.2 < p < 0.5, respectively). Overall results indicate that, in the study site (a) hay infusion-baited ovitraps are a more sensitive indicator of the presence and numbers of Aedes aegypti than those with plain water and are suitable for frequent monitoring of Aedes aegypti oviposition activity, and (b) the location of ovitraps, indoors or outdoors, does not influence the performance of the traps

Secondary Evolution of a Self-Incompatibility Locus in the Brassicaceae Genus Leavenworthia

International audienceSelf-incompatibility (SI) is the flowering plant reproductive system in which self pollen tube growth is inhibited, thereby preventing self-fertilization. SI has evolved independently in several different flowering plant lineages. In all Brassicaceae species in which the molecular basis of SI has been investigated in detail, the product of the S-locus receptor kinase (SRK) gene functions as receptor in the initial step of the self pollen-rejection pathway, while that of the S-locus cysteine-rich (SCR) gene functions as ligand. Here we examine the hypothesis that the S locus in the Brassicaceae genus Leavenworthia is paralogous with the S locus previously characterized in other members of the family. We also test the hypothesis that self-compatibility in this group is based on disruption of the pollen ligand-producing gene. Sequence analysis of the S-locus genes in Leavenworthia, phylogeny of S alleles, gene expression patterns, and comparative genomics analyses provide support for both hypotheses. Of special interest are two genes located in a non-S locus genomic region of Arabidopsis lyrata that exhibit domain structures, sequences, and phylogenetic histories similar to those of the S-locus genes in Leavenworthia, and that also share synteny with these genes. These A. lyrata genes resemble those comprising the A. lyrata S locus, but they do not function in self-recognition. Moreover, they appear to belong to a lineage that diverged from the ancestral Brassicaceae S-locus genes before allelic diversification at the S locus. We hypothesize that there has been neo-functionalization of these S-locus-like genes in the Leavenworthia lineage, resulting in evolution of a separate ligand-receptor system of SI. Our results also provide support for theoretical models that predict that the least constrained pathway to the evolution of self-compatibility is one involving loss of pollen gene function. Citation: Chantha S-C, Herman AC, Platts AE, Vekemans X, Schoen DJ (2013) Secondary Evolution of a Self-Incompatibility Locus in the Brassicaceae Genus Leavenworthia. PLoS Biol 11(5): e1001560

Lal2/SRK alignment for S-domain coding sequence

Nexus-formatted alignment of the S-domain coding sequence for SRK and Lal2 sequences included in Figure S3-A. Includes commands used for phylogenetic inference in mrbayes

Lal2/SRK alignment for entire coding sequence

Nexus-formatted alignment of the full coding sequence for SRK and Lal2 sequences included in Figure 2-A. Includes commands used for phylogenetic inference in mrbayes

Lal2/SRK alignment for coding sequence excluding S-domain

Nexus-formatted alignment of the coding sequence excluding the S-domain for SRK and Lal2 sequences included in Figure S3-B. Includes commands used for phylogenetic inference in mrbayes