Laboratory-based efficacy evaluation of Bacillus thuringiensis var. israelensis and temephos larvicides against larvae of Anopheles stephensi in ethiopia.

BACKGROUND: Malaria, transmitted by the bite of infective female Anopheles mosquitoes, remains a global public health problem. The presence of an invasive Anopheles stephensi, capable of transmitting Plasmodium vivax and Plasmodium falciparum parasites was first reported in Ethiopia in 2016. The ecology of An. stephensi is different from that of Anopheles arabiensis, the primary Ethiopian malaria vector, and this suggests that alternative control strategies may be necessary. Larviciding may be an effective alternative strategy, but there is limited information on the susceptibility of Ethiopian An. stephensi to common larvicides. This study aimed to evaluate the efficacy of temephos and Bacillus thuringiensis var. israelensis (Bti) larvicides against larvae of invasive An. stephensi. METHODS: The diagnostic doses of two larvicides, temephos (0.25 ml/l) and Bti (0.05 mg/l) were tested in the laboratory against the immature stages (late third to early fourth stages larvae) of An. stephensi collected from the field and reared in a bio-secure insectary. Larvae were collected from two sites (Haro Adi and Awash Subuh Kilo). For each site, three hundred larvae were tested against each insecticide (as well as an untreated control), in batches of 25. The data from all replicates were pooled and descriptive statistics prepared. RESULTS: The mortality of larvae exposed to temephos was 100% for both sites. Mortality to Bti was 99.7% at Awash and 100% at Haro Adi site. CONCLUSIONS: Larvae of An. stephensi are susceptible to temephos and Bti larvicides suggesting that larviciding with these insecticides through vector control programmes may be effective against An. stephensi in these localities.

Resistance of Anopheles stephensi to selected insecticides used for indoor residual spraying and long-lasting insecticidal nets in Ethiopia.

BACKGROUND: Malaria, transmitted by the bite of infective female Anopheles mosquitoes, remains a global public health problem. The presence of invasive Anopheles stephensi, capable of transmitting Plasmodium vivax and Plasmodium falciparum, was first reported in Ethiopia in 2016. The ecology of this mosquito species differs from that of Anopheles arabiensis, the primary malaria vector in Ethiopia. This study aimed to evaluate the efficacy of selected insecticides, which are used in indoor residual spraying (IRS) and selected long-lasting insecticidal nets (LLINs) for malaria vector control against adult An. stephensi. METHODS: Anopheles stephensi mosquitoes were collected as larvae and pupae from Awash Subah Kilo Town and Haro Adi village, Ethiopia. Adult female An. stephensi, reared from larvae and pupae collected from the field, aged 3-5 days were exposed to impregnated papers of IRS insecticides (propoxur 0.1%, bendiocarb 0.1%, pirimiphos-methyl 0.25%), and insecticides used in LLINs (alpha-cypermethrin 0.05%, deltamethrin 0.05% and permethrin 0.75%), using diagnostic doses and WHO test tubes in a bio-secure insectary at Aklilu Lemma Institute of Pathobiology, Addis Ababa University. For each test and control tube, batches of 25 female An. stephensi were used to test each insecticide used in IRS. Additionally, cone bioassay tests were conducted to expose An. stephensi from the reared population to four brands of LLINs, MAGNet™ (alpha-cypermethrin), PermaNet® 2.0 (deltamethrin), DuraNet© (alpha-cypermethrin) and SafeNet® (alpha-cypermethrin). A batch of ten sugar-fed female mosquitoes aged 2-5 days was exposed to samples taken from five positions/sides of a net. The data from all replicates were pooled and descriptive statistics were used to describe features of the data. RESULTS: All An. stephensi collected from Awash Subah Kilo Town and Haro Adi village (around Metehara) were resistant to all tested insecticides used in both IRS and LLINs. Of the tested LLINs, only MAGNet™ (alpha-cypermethrin active ingredient) caused 100% knockdown and mortality to An. stephensi at 60 min and 24 h post exposure, while all other net brands caused mortality below the WHO cut-off points (< 90%). All these nets, except SafeNet®, were collected during LLIN distribution for community members through the National Malaria Programme, in December 2020. CONCLUSIONS: Anopheles stephensi is resistant to all tested insecticides used in IRS and in the tested LLIN brands did not cause mosquito mortality as expected, except MAGNet. This suggests that control of this invasive vector using existing adult malaria vector control methods will likely be inadequate and that alternative strategies may be necessary.

Physiochemical Properties, Lipid Breakdown, ß-Carotenoids, Tocopherols, Vitamins, Amino and Fatty Acid Profiles of Soxhlet Extracted Oil from Different Garden Cress Seed (Lepidium sativum L.) Genotypes in Ethiopia.

Physiochemical properties, lipid breakdown, ß-carotenoids, tocopherols, and vitamins as well as amino and fatty acid profiles of Soxhlet-extracted oil from five different garden cress (Lepidium sativum L.) seed genotypes (namely: CG8, CG7, CG17, CG4, and 207910) across Ethiopia regions were investigated. Results showed that despite the seeds' proximate peak and least values, the extraction yield, viscosity, specific gravity, refractive index, lipid breakdown, and boiling point of garden cress seed oil across the genotypes noticeably varied with promising amino and fatty acid profiles. Further, the genotype CG17 obtained greater quantities of ß-carotenoids, tocopherols and vitamin values compared to the other genotypes.

Malaria vector feeding, peak biting time and resting place preference behaviors in line with Indoor based intervention tools and its implication: scenario from selected sentinel sites of Ethiopia.

In Ethiopia, malaria incidence has significantly reduced in the past decade through the combined use of conventional vector control approaches and treatment using antimalarial drugs. However, the sustainability of this achievement is threatened by the shift in biting and resting behaviors and emergence of insecticide resistance by the primary malaria vector. Therefore, continuous monitoring of the behaviour of malaria mosquitoes in different sentinel sites is crucial to design effective prevention and control methods in the local context. Entomological investigations were conducted in three sentinel sites for five consecutive months during the major malaria transmission season. The species composition, population dynamics, biting and resting behaviours of malaria vectors were determined using center for disease control and prevention (CDC) light trap, human landing catch (HLC), pyrethrum spray catch (PSC) and Pitfall shelter collection (PFS). Accordingly, 10 households for CDC, 10 households for PSC, 10 households for PFS and 5 households for HLC from each site were randomly enrolled for mosquito collection. A total of 8,297 anopheline mosquitoes were collected from the three sites, out of which 4,525 (54.5 %) were An. gambiae, s.l. 2,028 (24.4 %) were An. pharoensis, 160 (1.9 %) were An. funestus and the rest 1,584 (19 %) were other anophelines (An. coustani, An. cinerus and An. tenebrosus). No significant variation (P = 0.476) was observed between indoor (25.2/trap-night and outdoor collections (20.1/trap-night). Six hundred seventy six (43.3%) of An. gambiae s.l. (primary vector) were collected between 18:00 and 22:00 h. Biting activity declined between 00:00 and 02:00 h. The national malaria control program should pay close attention to the shifting behavior of vector mosquitoes as the observed outdoor feeding tendency of the vector population could pose challenges to the indoor intervention tools IRS and LLINs.

Changes in care-seeking for common childhood illnesses in the context of Integrated Community Case Management (iCCM) program implementation in Benishangul Gumuz region of Ethiopia.

BACKGROUND: Integrated Community Case Management (iCCM) is a strategy for promoting access of under-served populations to lifesaving treatments through extending case management of common childhood illnesses to trained frontline health workers. In Ethiopia iCCM is provided by health extension workers (HEWs) deployed at health posts. We evaluated the association between the implementation of iCCM program in Assosa Zuria zone, Benishangul Gumuz region and changes in care-seeking for common childhood illnesses. METHODS: We conducted a pre-post study without control arm to evaluate the association of interest. The iCCM program that incorporated training, mentoring and supportive supervision of HEWs with community-based demand creation activities was implemented for two years (2017-18). Baseline, midline and endline surveys were completed approximately one year apart. Across the surveys, children aged 2-59 months (n = 1,848) who recently had cough, fever or diarrhea were included. Data were analysed using mixed-effects logistic regression model. RESULTS: Over the two-year period, care-seeking from any health facility and from health posts significantly increased by 10.7 and 17.4 percentage points (PP) from baseline levels of 64.5 and 34.1%, respectively (p<0.001). Care sought from health centres (p = 0.420) and public hospitals (p = 0.129) did not meaningfully change while proportion of caregivers who approached private (p = 0.003) and informal providers (p<0.001) declined. Caregivers who visited health posts for the treatment of diarrhea (19.2 PP, p<0.001), fever (15.5 PP, p<0.001), cough (17.8 PP, p<0.001) and cough with respiratory difficulty (17.3 PP, p = 0.038) significantly increased. After accounting for extraneous variables, we observed that care-seeking from iCCM providers was almost doubled (adjusted odds ratio = 2.32: 95% confidence interval; 1.88-2.86) over the period. CONCLUSION: iCCM implementation was associated with a meaningful shift in care-seeking to health posts.

Building district-level capacity for continuous improvement in maternal and newborn health.

INTRODUCTION: The Maternal and Newborn Health in Ethiopia Partnership (MaNHEP) adapted a collaborative improvement strategy to develop woreda (district) leadership capacity to support and facilitate continuous improvement of community maternal and neonatal health (CMNH) and to provide a model for other woredas, dubbed "lead" woredas. Community-level quality improvement (QI) teams tested solutions to improve CMNH care supported by monthly coaching and regular meetings to share experiences. This study examines the extent of the capacity built to support continuous improvement in CMNH care. METHODS: Surveys and in-depth interviews assessed the extent to which MaNHEP developed improvement capacity. A survey questionnaire evaluated woreda culture, leadership support, motivation, and capacity for improvement activities. Interviews focused on respondents' understanding and perceived value of the MaNHEP improvement approach. Bivariate analyses and multivariate linear regression models were used to analyze the survey data. Interview transcripts were organized by region, cadre, and key themes. RESULTS: Respondents reported significant positive changes in many areas of woreda culture and leadership, including involving a cross-section of community stakeholders (increased from 3.0 to 4.6 on 5-point Likert scale), using improvement data for decision making (2.8-4.4), using locally developed and tested solutions to improve CMNH care (2.5-4.3), demonstrating a commitment to improve the health of women and newborns (2.6-4.2), and creating a supportive environment for coaches and QI teams to improve CMNH (2.6-4.0). The mean scores for capacity were 3.7 and higher, reflecting respondents' agreement that they had gained capacity in improvement skills. Interview respondents universally recognized the capacity built in the woredas. The themes of community empowerment and focused improvement emerged strongly from the interviews. DISCUSSION: MaNHEP was able to build capacity for continuous improvement and develop lead woredas. The multifaceted approach to building capacity was critical for the success in creating lead woredas able to serve as models for other districts.