Efficacy of 3D screens for sustainable mosquito control: a semi-field experimental hut evaluation in northeastern Tanzania.

BACKGROUND: A three-dimensional window screen (3D-Screen) has been developed to create a window double-screen trap (3D-WDST), effectively capturing and preventing the escape of mosquitoes. A 2015 laboratory study demonstrated the 3D-Screen's efficacy, capturing 92% of mosquitoes in a double-screen setup during wind tunnel assays. To further evaluate its effectiveness, phase II experimental hut trials were conducted in Muheza, Tanzania. METHODS: Three experimental hut trials were carried out between 2016 and 2017. Trial I tested two versions of the 3D-WDST in huts with open or closed eaves, with one version using a single 3D-Screen and the other using two 3D-Screens. Trial II examined the 3D-WDST with two 3D-Screens in huts with or without baffles, while Trial III compared handmade and machine-made 3D structures. Mosquito capturing efficacy of the 3D-WDST was measured by comparing the number of mosquitoes collected in the test hut to a control hut with standard exit traps. RESULTS: Trial I showed that the 3D-WDST with two 3D-Screens used in huts with open eaves achieved the highest mosquito-capturing efficacy. This treatment captured 33.11% (CI 7.40-58.81) of female anophelines relative to the total collected in this hut (3D-WDST and room collections) and 27.27% (CI 4.23-50.31) of female anophelines relative to the total collected in the control hut (exit traps, room, and verandahs collections). In Trial II, the two 3D-Screens version of the 3D-WDST captured 70.32% (CI 56.87-83.77) and 51.07% (CI 21.72-80.41) of female anophelines in huts with and without baffles, respectively. Compared to the control hut, the capturing efficacy for female anophelines was 138.6% (37.23-239.9) and 42.41% (14.77-70.05) for huts with and without baffles, respectively. Trial III demonstrated similar performance between hand- and machine-made 3D structures. CONCLUSIONS: The 3D-WDST proved effective in capturing malaria vectors under semi-field experimental hut conditions. Using 3D-Screens on both sides of the window openings was more effective than using a single-sided 3D-Screen. Additionally, both hand- and machine-made 3D structures exhibited equally effective performance, supporting the production of durable cones on an industrial scale for future large-scale studies evaluating the 3D-WDST at the community level.

Genome-wide analyses disclose the distinctive HLA architecture and the pharmacogenetic landscape of the Somali population.

African populations are underrepresented in medical genomics studies. For the Somali population, there is virtually no information on genomic markers with significance to precision medicine. Here, we analyzed nearly 900,000 genomic markers in samples collected from 95 unrelated individuals in the North Eastern Somalia. ADMIXTURE program for estimation of individual ancestries revealed a homogenous Somali population. Principal component analysis with PLINK software showed approximately 60% East African and 40% West Eurasian genes in the Somali population, with a close relation to the Cushitic and Semitic speaking Ethiopian populations. We report the unique features of human leukocyte antigens (HLA) in the Somali population, which seem to differentiate from all other neighboring regions compared. Current study identified high prevalence of the diabetes type 1 (T1D) predisposing HLA DR-DQ haplotypes in Somalia. This finding may explain the increased T1D risk observed among Somali children. In addition, ethnic Somalis were found to host the highest frequencies observed thus far for several pharmacogenetic variants, including UGT1A4*2. In conclusion, we report that the Somali population displays genetic traits of significance to health and disease. The Somali dataset is publicly available and will add more information to the few genomic datasets available for African populations.

Visceral Leishmaniasis, Northern Somalia, 2013-2019.

We identified visceral leishmaniasis caused by Leishmania donovani in a previously unknown focus in northern Somalia. Clinical and epidemiologic characteristics of 118 cases during 2013-2019 in Bosaso, the region's commercial capital, have raised suspicion of visceral leishmaniasis endemicity status there.

3D mosquito screens to create window double screen traps for mosquito control.

BACKGROUND: Mosquitoes are vectors for many diseases such as malaria. Insecticide-treated bed nets and indoor residual spraying of insecticides are the principal malaria vector control tools used to prevent malaria in the tropics. Other interventions aim at reducing man-vector contact. For example, house screening provides additive or synergistic effects to other implemented measures. We used commercial screen materials made of polyester, polyethylene or polypropylene to design novel mosquito screens that provide remarkable additional benefits to those commonly used in house screening. The novel design is based on a double screen setup made of a screen with 3D geometric structures parallel to a commercial mosquito screen creating a trap between the two screens. Owing to the design of the 3D screen, mosquitoes can penetrate the 3D screen from one side but cannot return through the other side, making it a unidirectional mosquito screen. Therefore, the mosquitoes are trapped inside the double screen system. The permissiveness of both sides of the 3D screens for mosquitoes to pass through was tested in a wind tunnel using the insectary strain of Anopheles stephensi. RESULTS: Among twenty-five tested 3D screen designs, three designs from the cone, prism, or cylinder design groups were the most efficient in acting as unidirectional mosquito screens. The three cone-, prism-, and cylinder-based screens allowed, on average, 92, 75 and 64% of Anopheles stephensi mosquitoes released into the wind tunnel to penetrate the permissive side and 0, 0 and 6% of mosquitoes to escape through the non-permissive side, respectively. CONCLUSIONS: A cone-based 3D screen fulfilled the study objective. It allowed capturing 92% of mosquitoes within the double screen setup inside the wind tunnel and blocked 100% from escaping. Thus, the cone-based screen effectively acted as a unidirectional mosquito screen. This 3D screen-based trap design could therefore be used in house screening as a means of avoiding infective bites and reducing mosquito population size.