Bamboo stumps that are artificially in use put pressure on dengue and chikungunya vector control in Dhaka city, Bangladesh.

BACKGROUND OBJECTIVES: Aedes aegypti and Ae. albopictus mosquitoes breed in natural and artificial containers, and they transmit dengue and chikungunya. A study was conducted to identify the contribution of bamboo stumps to these disease vectors that were used in the flower garden as pillars to hold the bamboo flex fence. METHODS: Two sizes of whole bamboo were used to hold fences around gardens at Dhaka University, Bangladesh, and were painted red and green. Mosquito larvae and pupae were collected from bamboo stumps between July and August, and vectors were identified up to the species level. The data were analyzed using the STATA/MP 14.2 version. RESULTS: 83.5% and 0.2% were Ae. albopictus and Ae. aegypti, respectively, and the remaining were Culex and Ar-migeres species. Ae. albopictus, Ae. aegypti, and both species-positive bamboo stumps were 46.9, 0.7, and 47.1%, respectively. 54.5% of the bamboo stumps had at least one mosquito species. The average stump depth for Aedes positive stumps (mean=11.7 cm, SE = 0.5) was significantly (p <0.001) higher than the Aedes negative stumps (mean = 9.5 cm, SE = 0.4). 53.8% and 38.0% stumps were found Aedes positive on the ground and upper sides of fences, respectively, and found significant (p<0.01) differences between both sides. A zero-inflated negative binomial count model is significant at a 5% level of significance, χ2(4) = 11.8, p = 0.019 (<0.05) for Ae. albopictus. Stump depth is found to have a significant positive effect on the number of Aedes-positive stumps. INTERPRETATION CONCLUSION: Artificially used natural containers are adding pressure to current mosquito control activities as mosquitoes are breeding on them, which needs additional attention.

Bamboo stumps that are artificially in use put pressure on Dengue and Chikungunya vector control in Dhaka City, Bangladesh.

BACKGROUND OBJECTIVES: Aedes aegypti and Ae. albopictus mosquitoes breed in natural and artificial containers, and they transmit dengue and chikungunya. Therefore, a study was conducted to identify the contribution of bamboo stumps to these disease vectors that were used in the flower garden as pillars to hold the bamboo flex fence. METHODS: Two sizes of whole bamboo were used to hold fences around gardens at Dhaka University, Bangladesh, and they were painted red and green. Mosquito larvae and pupae were collected from bamboo stumps between July and August, and vectors were identified up to the species level. The data were analyzed using the STATA/MP 14.2 version. RESULTS: We found 83.5% and 0.2% were Ae. albopictus and Ae. aegypti, respectively, and the rest were Culex and Armigeres species. Ae. albopictus, Ae. aegypti, and both species-positive bamboo stumps were 46.9, 0.7, and 47.1 percent, respectively. 54.5% of bamboo stumps had at least one mosquito species. The average stump depth for Aedes positive stumps (mean =11.7 cm, SE = 0.5) was significantly (p <0.001) higher than the Aedes negative stumps (mean = 9.5 cm, SE = 0.4). 53.8% and 38.0% stumps were found Aedes positive on the ground and upper sides of fences, respectively, and found significant (p<0.01) differences between both sides. A zero-inflated negative binomial count model is significant at a 5% level of significance, χ2(4) = 11.8, p = 0.019 (<0.05) for Ae. albopictus. Stump depth is found to have a significant positive effect on the number of Aedes-positive stumps. INTERPRETATION CONCLUSION: Artificially used natural containers are adding pressure to current mosquito control activities as mosquitoes are breeding on them, which needs additional attention.

Impact of various extraction methods on fatty acid profile, physicochemical properties, and nutritional quality index of Pangus fish oil.

Marine fish are high in essential omega-3 fatty acids, which are important for human health. This study evaluated the effects of four extraction methods (soxhlet extraction, SE; wet rendering, WR; acid silage, AS; microwave-assisted extraction, MAE) on the oil yield, physicochemical properties, fatty acid profile, and nutritional quality index (NQI) of pangus fish oil. The oil yield ranged from 13.50% to 21.80%, with MAE having the highest yield. Furthermore, MAE oil has the lowest free fatty acid (0.70%), peroxides (2.08 Meq/kg), and saponification (287.27 mg/g KOH) value. There were no significant differences (p > .05) in the refractive index and melting point of oils among extraction techniques. A total of 25 fatty acids were identified. However, the maximum PUFA, MUFA, and SFA recovery was observed in the SE (19.15 mg/100 g), MAE (7.99 mg/100 g), and AS (17.33 mg/100 g), respectively. In terms of NQI, SE had higher PUFA/SFA, HH, and LA/ALA ratios, while AS had higher EPA + DHA, n-3/n-6, AI, TI, and FLQ indices. Furthermore, the MAE approach yielded better ratios of n-3/n-6 and HPI index, whereas the WR method yielded a higher AI index. Therefore, MAE would be the most efficient method for extracting pangus fish oil by considering both technical feasibility and quality indices including extraction yield, best physical properties, oxidative stability, and fatty acid contents.

Optimization of Drying Parameters for Total Phenolic Content of Papaya Using Response Surface Methodology.

An optimum condition of the drying process can minimize nutrient losses and maximize the shelf life of food products. Thus, this study is aimed at developing an optimized system for the process conditions to determine the total phenolic content (TPC) of oven-dried papaya slices. The response surface method and central composite design were used to design the experiment, and it was found that the drying conditions had a significant impact on the total phenolic content of papaya slices. TPC was determined in relation to their interactions with the independent variables that include time, temperature, sample thickness, and stage of ripeness. The optimum drying conditions are those with the maximum content of TPC. In order to fit the experimental data, a quadratic polynomial model is created for the output variable, and an analysis of variance is carried out to determine whether or not the model is compatible to determine the optimal drying conditions. Time (10 h), temperature (62.02°C), thickness (9.75 mm) and stages (ripe) were found to be the optimal drying conditions. It was found that temperature had more effect on the amount of TPC than other factors. The numerical findings showed a good agreement with experimental data, with R 2 = 0.9237. It is hoped that the findings will make a contribution to the process of drying food.

Insecticide-treated bed nets in rural Bangladesh: their potential role in the visceral leishmaniasis elimination programme.

OBJECTIVE: To analyse the feasibility, acceptability and effectiveness of insecticide-treated bed nets with slow-release insecticides (KO Tab 123) as an option for kala-azar vector management in Bangladesh. METHODS: Intervention study involving an insecticide dipping programme through village health workers supervised by public health officers covering 6967 households in Mymensingh and 8287 in Rajshahi district. In a subsample of households, sandfly densities at baseline, 1, 12 and 18 months were measured with CDC light traps both in intervention and control areas. Bioassays were performed for determining the bioavailability of the insecticide and tests of chemical residues in the treated bed nets were undertaken. Satisfaction surveys and direct observation of use of treated bed net use were conducted. RESULTS: The dipping programme was feasible with the help of communities and public health staff, was well accepted, reached a coverage of 98.2% and 96.2% in the two study sites within 4 weeks and was effective in terms of a significant reduction in sandfly densities (approximately 60%) for a period of 18 months. Bioassay results were satisfactory (>80% sandfly mortality) and the average chemical content of the treated bed nets was sufficient for killing sand flies at the end of the observation period. CONCLUSION: Bed nets treated with slow-release insecticides can be an important complementary measure for sandfly control in the visceral leishmaniasis elimination programme.