Application of eco-friendly tools and eco-biosocial strategies to control dengue vectors in urban and peri-urban settings in Thailand

Background: Dengue is considered one of the most important vector-borne diseases in Thailand. Its incidence is increasing despite routine implementation of national dengue control programmes. This study, conducted during 2010, aimed to demonstrate an application of integrated, community-based, eco-biosocial strategies in combination with locally-produced eco-friendly vector control tools in the dengue control programme, emphasizing urban and peri-urban settings in eastern Thailand. Methodology: Three different community settings were selected and were randomly assigned to intervention and control clusters. Key community leaders and relevant governmental authorities were approached to participate in this intervention programme. Ecohealth volunteers were identified and trained in each study community. They were selected among active community health volunteers and were trained by public health experts to conduct vector control activities in their own communities using environmental management in combination with eco-friendly vector control tools. These trained ecohealth volunteers carried out outreach health education and vector control during household visits. Management of public spaces and public properties, especially solid waste management, was efficiently carried out by local municipalities. Significant reduction in the pupae per person index in the intervention clusters when compared to the control ones was used as a proxy to determine the impact of this programme. Results: Our community-based dengue vector control programme demonstrated a significant reduction in the pupae per person index during entomological surveys which were conducted at two-month intervals from May 2010 for the total of six months in the intervention and control clusters. The programme also raised awareness in applying eco-friendly vector control approaches and increased intersectoral and household participation in dengue control activities. Conclusion: An eco-friendly dengue vector control programme was successfully implemented in urban and peri-urban settings in Thailand, through intersectoral collaboration and practical action at household level, with a significant reduction in vector densities

First evidence of dengue infection in domestic dogs living in different ecological settings in Thailand.

Dengue is a vector-borne disease transmitted by Aedes mosquitoes. It is considered an important public health problem in many countries worldwide. However, only a few studies have been conducted on primates and domestic animals that could potentially be a reservoir of dengue viruses. Since domestic dogs share both habitats and vectors with humans, this study aimed to investigate whether domestic dogs living in different ecological settings in dengue endemic areas in Thailand could be naturally infected with dengue viruses.Serum samples were collected from domestic dogs in three different ecological settings of Thailand: urban dengue endemic areas of Nakhon Sawan Province; rubber plantation areas of Rayong Province; and Koh Chang, an island tourist spot of Trat Province. These samples were screened for dengue viral genome by using semi-nested RT-PCR. Positive samples were then inoculated in mosquito and dog cell lines for virus isolation. Supernatant collected from cell culture was tested for the presence of dengue viral genome by semi-nested RT-PCR, then double-strand DNA products were double-pass custom-sequenced. Partial nucleotide sequences were aligned with the sequences already recorded in GenBank, and a phylogenetic tree was constructed. In the urban setting, 632 domestic dog serum samples were screened for dengue virus genome by RT-PCR, and six samples (0.95%) tested positive for dengue virus. Four out of six dengue viruses from positive samples were successfully isolated. Dengue virus serotype 2 and serotype 3 were found to have circulated in domestic dog populations. One of 153 samples (0.65%) collected from the rubber plantation area showed a PCR-positive result, and dengue serotype 3 was successfully isolated. Partial gene phylogeny revealed that the isolated dengue viruses were closely related to those strains circulating in human populations. None of the 71 samples collected from the island tourist spot showed a positive result.We concluded that domestic dogs can be infected with dengue virus strains circulating in dengue endemic areas. The role of domestic dogs in dengue transmission needs to be further investigated, i.e., whether they are potential reservoirs or incidental hosts of dengue viruses

Map of Thailand highlighting locations of three sampling sites in the three different ecological settings: Urban city, rubber plantation area and an island tourist spot.

<p>Map of Thailand highlighting locations of three sampling sites in the three different ecological settings: Urban city, rubber plantation area and an island tourist spot.</p

Phylogenetic analysis of DENV-positive dog serum isolates.

<p>The phylogenetic tree was derived from the partial nucleotide sequences of C/prM gene using maximum likelihood method with 1,000 bootstrap value. (A) DENV serotype 2 and 3, (B) DENV serotype 2, (C) DENV serotype 3. Domestic dog sequences are indicated in red circles.</p

Antimicrobial resistance profiles in bacterial species isolated from fecal samples of free-ranging long-tailed macaques (Macaca fascicularis) living in Lopburi Old Town, Thailand

Background and Aim: At present, increasing in long-tailed macaques (Macaca fascicularis) population in Lopburi old town caused several problems in its community, in particular with sanitation problem. The present study aimed to explore species distribution and antimicrobial resistance patterns in bacteria isolated from feces of the free-ranging long-tailed macaques (Macaca fascicularis) in Lopburi Old Town, Thailand. Materials and Methods: Fresh fecal samples were collected from October 2018 to July 2019 from seven troops of macaques. Bacterial colonies were identified based on Gram stain and standard biochemical techniques. Sensitivity toward eight different antibiotics, including amoxicillin, amoxicillin-clavulanate, cephalexin, clindamycin, doxycycline, enrofloxacin, erythromycin, and gentamicin, was analyzed using the disk diffusion method. Results: A total of 1050 fecal samples were collected. Five unique bacterial species were identified, including Escherichia coli, Enterobacter spp., Proteus spp., Salmonella Group B, and Citrobacter spp. in 100%, 25.71%, 18%, 1.71%, and 0.57% of the fecal specimens, respectively. Among 70 distinct isolates of E. coli, 63 (93%) were resistant to multiple drugs, including amoxicillin, cephalexin, clindamycin, and erythromycin; one isolate (6%) was resistant to clindamycin only. Furthermore, 17 isolates (94%) of Salmonella Group B were resistant to both clindamycin and erythromycin. Five of the six Citrobacter spp. isolates (83%) were also multidrug-resistant (to cephalexin, clindamycin, and erythromycin); the one remaining Citrobacter spp. isolate (6%) was resistant to both clindamycin and erythromycin. However, a high percentage of E. coli, Salmonella Group B and Citrobacter spp. remained susceptible to amoxicillin-clavulanate, enrofloxacin, and doxycycline. Conclusion: Our findings provide the basic information for the selection of empirical therapy and for the evaluation of the scale of antibiotic resistance associated with macaques living in Lopburi Old Town

Application of eco-friendly tools and eco-biosocial strategies to control dengue vectors in urban and peri-urban settings in Thailand

Background: Dengue is considered one of the most important vector-borne diseases in Thailand. Its incidence is increasing despite routine implementation of national dengue control programmes. This study, conducted during 2010, aimed to demonstrate an application of integrated, community-based, eco-biosocial strategies in combination with locally-produced eco-friendly vector control tools in the dengue control programme, emphasizing urban and peri-urban settings in eastern Thailand. Methodology: Three different community settings were selected and were randomly assigned to intervention and control clusters. Key community leaders and relevant governmental authorities were approached to participate in this intervention programme. Ecohealth volunteers were identified and trained in each study community. They were selected among active community health volunteers and were trained by public health experts to conduct vector control activities in their own communities using environmental management in combination with eco-friendly vector control tools. These trained ecohealth volunteers carried out outreach health education and vector control during household visits. Management of public spaces and public properties, especially solid waste management, was efficiently carried out by local municipalities. Significant reduction in the pupae per person index in the intervention clusters when compared to the control ones was used as a proxy to determine the impact of this programme. Results: Our community-based dengue vector control programme demonstrated a significant reduction in the pupae per person index during entomological surveys which were conducted at two-month intervals from May 2010 for the total of six months in the intervention and control clusters. The programme also raised awareness in applying eco-friendly vector control approaches and increased intersectoral and household participation in dengue control activities. Conclusion: An eco-friendly dengue vector control programme was successfully implemented in urban and peri-urban settings in Thailand, through intersectoral collaboration and practical action at household level, with a significant reduction in vector densities

A participatory epidemiological and One Health approach to explore the community's capacity to detect emerging zoonoses and surveillance network opportunities in the forest region of Guinea.

The Ebola virus disease epidemic that threatened West Africa between 2013 and 2016 was of unprecedented health magnitude. After this health crisis, studies highlighted the need to introduce community-based surveillance systems and to adopt a One Health approach. This study aimed to provide preparatory insights for the definition of a community-based surveillance system for emerging zoonoses such as viral hemorrhagic fevers in Guinea. The objective was to explore the disease detection capacity and the surveillance network opportunities at the community level in two pilot areas in the forest region of Guinea, where the epidemic emerged. Based on a participatory epidemiological and One Health approach, we conducted Focus Group Discussions with human, animal and ecosystem health actors. We used a range of participatory tools, included semi-structured interviews, ranking, scoring and flow diagram, to estimate the local knowledge and perception of diseases and clinical signs and to investigate the existing health information exchange network and its related strengths and weaknesses. The results showed that there is heterogeneity in knowledge of diseases and perception of the clinical signs among actors and that there are preferred and more effective health communication channels opportunities. This preparatory study suggests that it is necessary to adapt the case definitions and the health communication channels to the different actors who can play a role in a future community-based surveillance system and provides recommendations for future surveillance activities to be carried out in West Africa