6 research outputs found
The combined impact of LLINs, house screening, and pull‑push technology for improved malaria control and livelihoods in rural Ethiopia : study protocol for household randomised controlled trial
ADDITIONAL FILE 1. Ethics Review approval letter.ADDITIONAL FILE 2. Ethics information sheet and consent form.BACKGROUND : The combined application of long-lasting insecticidal nets (LLINs) and indoor residual spraying (IRS) are
commonly used malaria interventions that target indoor Anopheles vectors. Recent studies on the effects of house
screening (HS) and LLINs have demonstrated a reduction in indoor vector densities and malaria when the interventions
are combined. In addition, complementary interventions are needed to curb co-occurring pest populations
which pose menace to agricultural crop productivity and food security. However, interventions that impact malaria
mainly centre on public health strategies, overlooking subtle but important component of agricultural measures.
Addressing the coexisting risks of malaria and crop pests could contribute to improved livelihood of communities.
METHODS : A four-armed household, cluster-randomized, controlled study will be conducted to assess the combined
impact of HS, LLINs and push-pull agricultural technology (PPT) against clinical malaria in children in Ethiopia. The
unit of randomization will be the household, which includes a house and its occupants. A total of 838 households will
be enrolled in this study. In this trial 246 households will receive LLINs and HS, 250 will receive LLINs, HS and PPT, 175
households will receive LLINs and PPT. The remaining 167 houses which receive LLINs only will be used as control.
One child aged ≤14 years will be enrolled per household in each treatment and followed for clinical malaria using
active case detection to estimate malaria incidence for two malaria transmission seasons.
DISCUSSION : Episodes of clinical malaria, density of indoor biting malaria vectors, sporozoite infection rate, improved
crop infestation rate, crop yield gain, livestock productivity and cost effectiveness analysis will be the end points of
this study. Socio-economic, social demographic, cost-effectiveness analysis will be conducted using qualitative and
participatory methods to explore the acceptability of HS and PPT. Documenting the combined impact of LLINs, HS
and PPT on the prevalence of clinical malaria and crop pest damage will be the first of its kind.
TRIAL REGISTRATION : Pan African Clinical Trials Registry, PACTR202006878245287. 24/06/2020.Norwegian Agency for Development Cooperation (NORAD) through the
project Combating Arthropod Pests for Better Health, Food and Resilience to Climate Change (CAP-Africa).http://www.biomedcentral.com/bmcpublichealtham2023School of Health Systems and Public Health (SHSPH)UP Centre for Sustainable Malaria Control (UP CSMC
Observing the distribution of mosquito bites on humans to inform personal protection measures against malaria and dengue vectors
Background Understanding mosquito biting behaviours is important for designing and evaluating protection methods against nuisance biting and mosquito-borne diseases (e.g. dengue, malaria and zika). We investigated the preferred biting sites by Aedes aegypti and Anopheles arabiensis on adult volunteers in standing or sleeping positions; and estimated the theoretical protection limits affordable from protective clothing or repellent-treated footwear. Methods Adult volunteers dressed in shorts and t-shirts were exposed to infection-free laboratory-reared mosquitoes inside screened chambers from 6am to noon (for day-biting Ae. aegypti) or 6pm to midnight (night-biting An. arabiensis). Attempted bites on different body parts were recorded. Comparative observations were made on same volunteers while wearing sandals treated with transfluthrin, a vapour-phase pyrethroid that kills and repels mosquitoes. Results An. arabiensis bites were mainly on the lower limbs of standing volunteers (95.9% of bites below the knees) but evenly-distributed over all exposed body surfaces when the volunteers were on sleeping positions (only 28.8% bites below knees). Ae. aegypti bites were slightly concentrated on lower limbs of standing volunteers (47.7% below knees), but evenly-distributed on sleeping volunteers (23.3% below knees). Wearing protective clothing that leave only hands and head uncovered (e.g. socks + trousers + long-sleeved shirts) could theoretically prevent 78–83% of bites during sleeping, and at least 90% of bites during non-sleeping hours. If the feet are also exposed, protection declines to as low as 36.3% against Anopheles. The experiments showed that transfluthrin-treated sandals reduced An. arabiensis by 54–86% and Ae. aegypti by 32–39%, but did not change overall distributions of bites. Conclusion Biting by An. arabiensis and Ae. aegypti occur mainly on the lower limbs, though this proclivity is less pronounced in the Aedes species. However, when hosts are on sleeping positions, biting by both species is more evenly-distributed over the exposed body surfaces. High personal protection might be achieved by simply wearing long-sleeved clothing, though protection against Anopheles particularly requires covering of feet and lower legs. The transfluthrin-treated footwear can reduce biting risk, especially by An. arabiensis. These findings could inform the design and use of personal protection tools (both insecticidal and non-insecticidal) against mosquitoes and mosquito-borne diseases
Observing the distribution of mosquito bites on humans to inform personal protection measures against malaria and dengue vectors
Background Understanding mosquito biting behaviours is important for designing and evaluating protection methods against nuisance biting and mosquito-borne diseases (e.g. dengue, malaria and zika). We investigated the preferred biting sites by Aedes aegypti and Anopheles arabiensis on adult volunteers in standing or sleeping positions; and estimated the theoretical protection limits affordable from protective clothing or repellent-treated footwear. Methods Adult volunteers dressed in shorts and t-shirts were exposed to infection-free laboratory-reared mosquitoes inside screened chambers from 6am to noon (for day-biting Ae. aegypti) or 6pm to midnight (night-biting An. arabiensis). Attempted bites on different body parts were recorded. Comparative observations were made on same volunteers while wearing sandals treated with transfluthrin, a vapour-phase pyrethroid that kills and repels mosquitoes. Results An. arabiensis bites were mainly on the lower limbs of standing volunteers (95.9% of bites below the knees) but evenly-distributed over all exposed body surfaces when the volunteers were on sleeping positions (only 28.8% bites below knees). Ae. aegypti bites were slightly concentrated on lower limbs of standing volunteers (47.7% below knees), but evenly-distributed on sleeping volunteers (23.3% below knees). Wearing protective clothing that leave only hands and head uncovered (e.g. socks + trousers + long-sleeved shirts) could theoretically prevent 78–83% of bites during sleeping, and at least 90% of bites during non-sleeping hours. If the feet are also exposed, protection declines to as low as 36.3% against Anopheles. The experiments showed that transfluthrin-treated sandals reduced An. arabiensis by 54–86% and Ae. aegypti by 32–39%, but did not change overall distributions of bites. Conclusion Biting by An. arabiensis and Ae. aegypti occur mainly on the lower limbs, though this proclivity is less pronounced in the Aedes species. However, when hosts are on sleeping positions, biting by both species is more evenly-distributed over the exposed body surfaces. High personal protection might be achieved by simply wearing long-sleeved clothing, though protection against Anopheles particularly requires covering of feet and lower legs. The transfluthrin-treated footwear can reduce biting risk, especially by An. arabiensis. These findings could inform the design and use of personal protection tools (both insecticidal and non-insecticidal) against mosquitoes and mosquito-borne diseases
Temperature-Dependent Transport Properties of a Redox-Active Ionic Liquid with a Viologen Group
A redox-active ionic liquid (IL),
1-butyl-1′-heptyl-4,4′-bipyridinium
bisÂ(trifluoromethanesulfonyl)Âimide, has been synthesized and its transport
processes were investigated. The conductivity and viscosity of the
IL, as well as the diffusion coefficients of its components were studied
over a 50 °C wide temperature range: for the diffusivity studies,
both the pulsed-gradient spin–echo (PGSE)–NMR technique
and voltammetric measurements have been applied. The measured data
are presented in the paper and are compared to each other. It was
found that the diffusion coefficients determined by means of NMR and
chronoamperometry measurements are, within the range of experimental
error, equalî—¸and they are (in accordance with other ionic liquid
studies) higher than what the conductivity or viscosity measurements
indicate. The results are interpreted in the light of the existing
theories. The measured diffusion coefficients and bulk conductivities
can be well interrelated based on the “ionicity” concept
(that is, by treating the ionic liquid as a weak electrolyte). In
agreement with the empirical Walden rule, a direct comparison between
the measured conductivities and viscosities is also possible, for
which a hole conduction model is utilized. Based on the fact that
both the electrochemical and the NMR measurements yield practically
the same diffusion coefficients in the system, there is no evidence
that interpretations based in other redox-active IL systems on “homogeneous
electron transfer” apply to the system studied here