Identification of essential containers for <i>Aedes</i> larval breeding to control dengue in Dhaka, Bangladesh

Dengue fever (DF), one of the mostimportant emerging arboviral diseases, is transmitted through the bite ofcontainer breeding mosquitoes <i>Aedesaegypti</i> and <i>Aedes albopictus</i>. Ahousehold entomological survey was conducted in Dhaka from August throughOctober 2000 to inspect water-holding containers in indoor, outdoor, androoftop for <i>Aedes</i> larvae. Theobjective of this study was to determine mosquito productivity of eachcontainer type and to identify some risk factors of the households to beinfested with <i>Aedes</i> larvae. Of 9222 households inspected, 1306(14.2%) were positive for <i>Aedes</i> larvae. Of 38 777wet containers examined, 2272 (5.8%)were infested with <i>Aedes</i> larvae. Containers used for reserving water,such as earthen jars, tanks, and drums were the most essential containers forlarval breeding. Tires in outdoor and rooftop of the households were alsoimportant for larval breeding. Although present in abundant, less importancewas indicated for buckets. Independent household, having water storage systemin the house, and having fully/partly shaded outdoor premise were foundsignificantly associated with household infestation of <i>Aedes</i> larvae. Identification and subsequent elimination of the most productive containers ina given area may potentially reduce mosquito density below a level at whichdengue transmission may be halted.

Identification of Essential Containers for <i>Aedes</i> Larval Breeding to Control Dengue in Dhaka, Bangladesh

Dengue fever (DF), one of the most important emerging arboviral diseases, is transmitted through the bite of container breeding mosquitoes <i>Aedes aegypti</i> and <i>Aedes albopictus</i>. A household entomological survey was conducted in Dhaka from August through October 2000 to inspect water-holding containers in indoor, outdoor, and rooftop locations for <i>Aedes</i> larvae. The objective of this study was to determine mosquito productivity of each container type and to identify some risk factors of households infested with <i>Aedes</i> larvae. Of 9,222 households inspected, 1,306 (14.2%) were positive for <i>Aedes</i> larvae. Of 38,777 wet containers examined, 2,272 (5.8%) were infested with <i>Aedes</i> larvae. Containers used to hold water, such as earthen jars, tanks, and drums were the most common containers for larval breeding. Tires in outdoor and rooftop locations of the households were also important for larval breeding. Although present in abundance, buckets were of less importance. Factors such as independent household, presence of a water storage system in the house, and fully/partly shaded outdoors were found to be significantly associated with household infestation of <i>Aedes</i> larvae. Identification and subsequent elimination of the most productive containers in a given area may potentially reduce mosquito density to below a level at which dengue transmission may be halted.

<i>Ascaris lumbricoids</i> infection as a risk factor for asthma and atopy in rural Bangladeshi children

Controversy persists as to whether helminth infections cause or protect against asthma and atopy. The aim of this study was to investigate the effects of helminth infection on asthma and atopy among Bangladeshi children. A total of 912 children aged 4.5 years (mean = 54.4, range = 53.5–60.8 months) participated in a cross-sectional study nested into a randomized controlled trial in Bangladesh. Ever-asthma, ever-wheezing and current wheezing were identified using the International Study of Asthma and Allergies in Childhood questionnaire. Current helminth infection was defined by the presence of helminth eggs in stools, measured by routine microscopic examination. Repeated <i>Ascaris</i> infection was defined by the presence of anti-<i>Ascaris</i> IgE≥0.70 UA/ml in serum measured by the CAP-FEIA method. Atopy was defined by specific IgE to house dust mite (anti-DP IgE) ≥0.70 UA/ml measured by the CAP-FEIA method and/or positive skin prick test (≥5 mm). Anti-<i>Ascaris</i> IgE was significantly associated with ever asthma (odds ratio (OR) = 1.86, 95% CI: 1.14–3.04, highest vs. lowest quartile; <i>P</i> for trend 0.016). Anti-<i>Ascaris</i> IgE was also significantly associated with positive anti-DP IgE (OR = 9.89, 95% CI: 6.52–15.00, highest vs. lowest; <i>P</i> for trend <0.001) and positive skin prick test (OR = 1.69, 95% CI: 1.01–2.81, highest vs. lowest, <i>P</i> for trend 0.076).These findings suggest that repeated <i>Ascaris</i> infection is a risk factor for asthma and atopy in rural Bangladeshi children. Further analysis is required to examine the mechanism of developing asthma and atopy in relation to helminth infection.

<i>Ascaris lumbricoids</i> Infection as a Risk Factor for Asthma and Atopy in Rural Bangladeshi Children

Controversy persists as to whether helminth infections cause or protect against asthma and atopy. The aim of this study was to investigate the effects of helminth infection on asthma and atopy among Bangladeshi children. A total of 912 children aged 4.5 years (mean = 54.4, range = 53.5–60.8 months) participated in a cross-sectional study nested into a randomized controlled trial in Bangladesh. Ever-asthma, ever-wheezing and current wheezing were identified using the International Study of Asthma and Allergies in Childhood questionnaire. Current helminth infection was defined by the presence of helminth eggs in stools, measured by routine microscopic examination. Repeated <i>Ascaris</i> infection was defined by the presence of anti-<i>Ascaris</i> IgE ≥ 0.70 UA/ml in serum measured by the CAP-FEIA method. Atopy was defined by specific IgE to house dust mite (anti-DP IgE) ≥ 0.70 UA/ml measured by the CAP-FEIA method and/or positive skin prick test (≥ 5 mm). Anti-<i>Ascaris</i> IgE was significantly associated with ever asthma (odds ratio (OR) = 1.86, 95% CI: 1.14–3.04, highest vs. lowest quartile; <i>P</i> for trend 0.016). Anti-<i>Ascaris</i> IgE was also significantly associated with positive anti-DP IgE (OR = 9.89, 95% CI: 6.52–15.00, highest vs. lowest; <i>P</i> for trend < 0.001) and positive skin prick test (OR = 1.69, 95% CI: 1.01–2.81, highest vs. lowest, <i>P</i> for trend 0.076). These findings suggest that repeated <i>Ascaris</i> infection is a risk factor for asthma and atopy in rural Bangladeshi children. Further analysis is required to examine the mechanism of developing asthma and atopy in relation to helminth infection.

Visceral Leishmaniasis Eradication is a Reality: Data from a Community-based Active Surveillance in Bangladesh

More than 20 million people in Bangladesh are considered at risk of developing visceral leishmaniasis (VL). A community-based active surveillance was conducted in eight randomly selected villages in a highly endemic area of Bangladesh from 2006 to 2008. A total of 6,761 individuals living in 1,550 mud-walled houses were included in the active surveillance. Rapid rK39 dipstick tests were conducted throughout the study period to facilitate the case diagnosis. Individuals with previous or current clinical leishmaniasis were identified on the basis of the case definition of the VL elimination program. Untreated cases of suspected VL were referred to the hospital for treatment. Socioeconomic and environmental information including bed net use was also collected. In 2006, the annual incidence of clinical leishmaniasis in the study area was 141.9 cases per 10,000 population, which was significantly increased by the following year owing to community-based active surveillance for case detection and reporting. However, early case detection and early referral for treatment led to a significant decrease in incidence in 2008. This study suggests that community-based active surveillance using a simple diagnostic tool might play a role in achieving the goal of the VL elimination program.

Trends in dietary intake of folate, vitamins B6, and B12 among Japanese adults in two rural communities from 1974 through 2001.

BACKGROUND: The 5th edition of the Japanese food composition table enables us to evaluate intakes of folate and vitamins B6 and B12, which are associated with risk of chronic diseases. METHODS: We investigated long-term trends in dietary intake of those nutrients in two rural communities; Ikawa from1974 through 2000, and Kyowa from 1982 through 2001. The 24-hour recall method was adopted. Intake of green tea interviewed from 1994 was used to examine food sources for these nutrients in the latest period, but not to evaluate long-term trends. Reduced intakes of nutrients due to cooking were not taken into account. RESULTS: Age-adjusted mean folate intake increased by 30% in Ikawa between the 1970's and 1980's, and then leveled off to the latest survey, while that in Kyowa did not change throughout the survey periods. The increased folate intake was primarily due to green/yellow vegetables. Mean vitamin B6 intake did not change except that it increased for Ikawa women in the 1980's and decreased for Kyowa men in the latest period. No secular trend was found for mean vitamin B12 intake. The largest source for folate intake was total vegetables (38-58% of total intake) and the second largest source was alcohol/beverages including green tea (11-24%). Fish/shellfish was the largest source for vitamins B6 (16-23%) and B12 (77-84%). CONCLUSIONS: Dietary intakes of folate, vitamins B6 and B12 showed no notable long-term trend, except for an increased folate intake between the 1970's and 1980's due to an increased intake of green/yellow vegetables.

Activity of the enzymes of the antioxidative system in cadmium-treated Oxya chinensis (Orthoptera Acridoidae).

One purpose in this research was to determine the toxic effects of Cd on antioxidant enzymes of Oxya chinensis (Orthoptera: Acridoidae). Changes in the activities of the antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), and guaiacol peroxidase (GPx) were measured in O. chinensis insects injected with Cd(2+). Fifth-nymphs of O. chinensis insects were injected with Cd(2+) at different concentrations (0, 0.55×10(-4), 1.10×10(-4), 1.65×10(-4), 2.20×10(-4), and 2.75×10(-4)gg(-1)). An increase in SOD activity in O. chinensis was observed at 1.10×10(-4) to 2.75×10(-4)gg(-1) Cd(2+). The SOD activity was lower at 2.20×10(-4)and 2.75×10(-4)gg(-1) than that at 1.10×10(-4) and 1.65×10(-4)gg(-1). It appears that SOD had a positive protective effect at low Cd(2+) concentrations, and that this effect disappeared at high Cd(2+) concentrations. CAT activity was accelerated to varying degrees at 1.10×10(-4) to 2.75×10(-4)gg(-1) for males and at 1.10×10(-4), 2.20×10(-4), and 2.75×10(-4)gg(-1) for females. CAT showed a strong detoxification effect with all treatments. GPx activity decreased with increasing Cd(2+) concentration with all treatments for males and at 2.20×10(-4) and 2.65×10(-4)gg(-1) for females. We showed that GPx activity had a weak detoxification function with all treatments for males and at high Cd(2+) for females. Thus, CAT had a strong detoxification effect, whereas SOD had a medium and GPx had a weak detoxification effect. Among the three enzymes, CAT played an important role in the damaging mechanisms of reactive oxygen species in O. chinensis insects. Alterations of the antioxidant enzyme level under environmental stresses are suggested as indicators of biotic and abiotic stress.