Field Detection of Tembusu Virus in Western Thailand by RT-PCR and Vector Competence Determination of Select Culex Mosquitoes for Transmission of the Virus

Tembusu virus (TMUV; Ntaya serocomplex) was detected in two pools of mosquitoes captured near Sangkhlaburi, Thailand, as well as from sera from sentinel ducks from the same area. Although TMUV has been isolated from several mosquito species in Asia, no studies have ever shown competent vectors for this virus. Therefore, we allowed mosquitoes captured near Sangkhlaburi to feed on young chickens that had been infected with TMUV. These mosquitoes were tested approximately 2 weeks later to determine infection, dissemination, and transmission rates. Culex vishnui developed high viral titers after feeding on TMUV-infected chicks and readily transmitted virus to naïve chickens. In contrast, Cx. fuscocephala seemed less susceptible to infection, and more importantly, zero of five fuscocephala with a disseminated infection transmitted virus by bite, indicating a salivary gland barrier. These results provide evidence for the involvement of Culex mosquitoes in the transmission of TMUV in the environment.     

Evaluation of a Field-Portable DNA Microarray Platform and Nucleic Acid Amplification Strategies for the Detection of Arboviruses,Arthropods, and Bloodmeals

Highly multiplexed assays, such as microarrays, can benefit arbovirus surveillance by allowing researchers to screen for hundreds of targets at once. We evaluated amplification strategies and the practicality of a portable DNA microarray platform to analyze virus-infected mosquitoes. The prototype microarray design used here targeted the non-structural protein 5, ribosomal RNA, and cytochrome b genes for the detection of flaviviruses, mosquitoes, and bloodmeals, respectively. We identified 13 of 14 flaviviruses from virus inoculated mosquitoes and cultured cells. Additionally, we differentiated between four mosquito genera and eight whole blood samples. The microarray platform was field evaluated in Thailand and successfully identified flaviviruses (Culex flavivirus, dengue-3, and Japanese encephalitis viruses), differentiated between mosquito genera (Aedes, Armigeres, Culex, and Mansonia), and detected mammalian bloodmeals (human and dog). We showed that the microarray platform and amplification strategies described here can be used to discern specific information on a wide variety of viruses and their vectors.     

Caregivers Burden of Older Adults with Chronic Illnesses in the Community: A Cross-Sectional Study

A chronic physical/mental disease not only has direct consequences for the chronically-ill older adults but can also alter the caregiver’s life. The objectives of this study were to identify burdens of community-dwelling older adults, characteristics of caregivers, severity of caregiver burden, and to develop supportive strategies. Caregivers of community-dwelling older adults were randomly interviewed between February and March 2012. Information on baseline characteristics and caregiver burden using Zarit Burden Inventory (ZBI) was collected. One hundred-fifty caregivers were interviewed. The mean ZBI was 20.8 + 11.3 [95 % CI 19.0, 22.7]. The majority of caregiver burden was classified as no burden (52 %). The age of caregivers, self-reported health status and duration of care had a positive relationship with ZBI scores while self-reported income had a negative one. Caregiver burden among Thai community-dwelling elder persons was small as most of those cared for had uncomplicated illness but this might be underestimated. Caregiver-dependent factors were more strongly associated with high burden than patient characteristics. Healthcare providers should consider these factors for interventions to alleviate burden.     

Japanese encephalitis virus in culicine mosquitoes (Diptera: Culicidae) collected at Daeseongdong, a village in the demilitarized zone of the Republic of Korea

In total, 22,846 (17,793 culicines and 5,053 Anopheles spp.) female mosquitoes were captured by a Mosquito Magnet trap at Daeseongdong, a small village adjacent to the military demarcation line (center of the demilitarized zone) in northern Gyeonggi Province, Republic of Korea (ROK). Culicine mosquitoes were identified to species, placed in pools of up to 30 mosquitoes each, and screened for flavivirus using a SYBR Green I-based real-time polymerase chain reaction. In total, 51/660 pools positive for flaviviruses and confirmed by DNA sequencing of the NS5 region, were positive for Japanese encephalitis virus (family Flaviviridae, genus Flavivirus, JEV) (50 Culex tritaeniorhynchus Giles and one Culex bitaeniorhynchus Giles). The JEV maximum likelihood estimations (MLEs) (estimated number of viral RNA-positive mosquitoes per 1,000) for Cx. tritaeniorhynchus and Cx. bitaeniorhynchus were 9.7 and 0.9, respectively. This is the first report of a Cx. bitaeniorhynchus positive for JEV in the ROK. JEV is a local civilian and military health threat and a significant concern for nonimmune (unvaccinated) U.S. soldiers, civilians, and family members deployed to the ROK.     

Water quality and breeding habitats of anopheline mosquito in northwestern Thailand

Malaria transmission is dependent upon many hydrology-driven ecological factors that directly affect the vectorial competence, including the presence of suitable habitats for the development of anopheline larvae. Larval habitats were identified and characterized at three malaria endemic villages (Ban Khun Huay, Ban Pa Dae, and Ban Tham Seau) in Mae Sot district, Tak Province, in northwestern Thailand between July 2002 and June 2003. The Global Positioning System (GPS) was used to provide precise locational data for the spatial distribution of anopheline mosquito larvae and their habitats. Ten habitat categories were identified. Eighteen adult Anopheles species were identified from larvae in all the surveyed habitats. An. minimus was the most common species throughout the year. The relationship between eight abiotic variables (temperature, hardness, carbon dioxide, dissolved oxygen, nitrate, phosphate, silica and pH) and the abundance of four major species of malaria vectors (An. (Cel.) dirus, An. (Cel.) minimus, An. (Cel.) maculatus, and An. (Cel.) sawadwongporni), and six species of non-vectors (An. (Cel.) kochi, An. (Cel.) jamesii, An. (Ano.) peditaeniatus, An. (Ano.) barbirostris, An. (Ano.) campestris, and An (Cel.) vagus) larvae was investigated. The results from the multiple regression models suggest that hardness, water temperature and carbon dioxide are the best predictor variables associated with the abundance of An. minimus larvae (p < 0.001); water pH for An. dirus larvae (p < 0.001); temperature and pH for An. kochi larvae (p < 0.01); temperature and silica concentration for An. jamesii larvae (p < 0.001); dissolved oxygen and silica concentration for An. campestris larvae (p < 0.001); and pH and silica concentration for An. vagus larvae (p < 0.001). We could not identify key environmental variables for An. maculatus, An. sawadwongporni, An. peditaeniatus, and An. barbirostris.     

Can a multidisciplinary approach slow renal progression in CKD patients?

Background: Several randomized controlled trials have examined the benefits of multidisciplinary CKD care on estimated glomerular filtration rate (eGFR). But, the results are inconclusive.Purpose: This study aimed to evaluate whether or not multidisciplinary CKD care was beneficial in terms of CKD progression.Methods: This is a randomized controlled trial and conducted at community hospital, Thailand. The inclusion criteria were patients with age of 18 years or older and diagnosed with up to stage 3b CKD based on the KDIGO guidelines. Eligible patients divided into two groups: intervention and control group. The intervention group received a type of multidisciplinary treatment, while patients in the control group received the standard treatment administered at the outpatient clinic. The primary outcome was eGFR outcomes at three months after enrollment.Results: During the study period, there were 334 patients who met the study criteria. Eligible patients were divided into two groups: intervention (166 patients; 49.70%) and control (168 patients; 50.30%). There were three outcomes that differed significantly between the two groups at 3 months: mean difference of eGFR from baseline, proportion of patients with eGFR decline greater than 4 mL/min/1.73 m², and difference in CKD stage from baseline. A significantly higher percentage of patients in the intervention group experienced CKD improvement by one stage (24.10% vs 5.95%), and a significantly lower percentage experienced decline by one stage (8.43% vs 35.12%) than in the control group.Conclusion: Slower renal progression in patients with up to stage 3b CKD was shown in patients who were treated by a multidisciplinary approach.     

Morphological variations of Anopheles minimus A in Tak Province, Thailand

Anopheles minimus Theobald is one of the major vectors of malaria throughout the Oriental Region, and it's complex consists of at least 2 sibling species (A and C) in Thailand. This study aimed to determine the morphological variations of wings of An. minimus A and to clarify the specific status of An. minimus in Ban Khun Huay, Ban Pa Dae, and Ban Tham Seau, Mae Sot district, Tak Province, Thailand. Anopheline larvae were collected from the fields between October 2002 and September 2003, allowed to emerge into adults in the laboratory and identified by morphological and molecular characterization. About 1,715 of female An. minimus A were separated into 8 groups based on their wing scale patterns. Polymerase Chain Reaction Restriction Fragment Length Polymorphism (PCR-RFLP) assay (ribosomal DNA ITS2) confirmed the identification of An. minimus A in all 8 groups.