Integrated participatory approach reveals perceived local availability of wild edible plants in Northwestern Kenya

Availability is a crucial aspect of wild edible plants (WEPs) consumption by indigenous communities. Understanding the local perception of this availability helps to determine, which contribution WEPs can make to rural communities. We used an integrated participatory approach to investigate important parameters and themes that infuenced the perception of availability of woody WEPs. We demonstrate the approach in three communities in Turkana County, Kenya. By availability, we referred to the ease of accessing, harvesting, transporting, and processing WEPs for consumption. We conducted three focus group discussions (FGDs). We asked FGD participants to list, score, and discuss availability. We used logistic regression and mixed-content analysis to identify important parameters and themes, respectively. The most important WEPs were the toothbrush tree (Salvadora persica L.), Indian jujube (Ziziphus mauritiana Lam.), and mbamba ngoma (Balanites rotundifolia (Tiegh.) Blatt.). Distance, seasonality, price, and adequacy of harvested WEPs for household consumption were important parameters. Culture and tradition, distribution of WEPs, seasonality, and climate change emerged as important themes. We showed the importance of using an integrated participatory approach when assessing the perception of WEPs’ availability by local communities and could be used in comparable arid and semi-arid areas with semi-nomadic pastoralists across Africa

Ecology: a prerequisite for malaria elimination and eradication

* Existing front-line vector control measures, such as insecticide-treated nets and residual sprays, cannot break the transmission cycle of Plasmodium falciparum in the most intensely endemic parts of Africa and the Pacific * The goal of malaria eradication will require urgent strategic investment into understanding the ecology and evolution of the mosquito vectors that transmit malaria * Priority areas will include understanding aspects of the mosquito life cycle beyond the blood feeding processes which directly mediate malaria transmission * Global commitment to malaria eradication necessitates a corresponding long-term commitment to vector ecolog

Shifts in malaria vector species composition and transmission dynamics along the Kenyan coast over the past 20 years

BACKGROUND: Over the past 20 years, numerous studies have investigated the ecology and behaviour of malaria vectors and Plasmodium falciparum malaria transmission on the coast of Kenya. Substantial progress has been made to control vector populations and reduce high malaria prevalence and severe disease. The goal of this paper was to examine trends over the past 20 years in Anopheles species composition, density, blood-feeding behaviour, and P. falciparum sporozoite transmission along the coast of Kenya. METHODS: Using data collected from 1990 to 2010, vector density, species composition, blood-feeding patterns, and malaria transmission intensity was examined along the Kenyan coast. Mosquitoes were identified to species, based on morphological characteristics and DNA extracted from Anopheles gambiae for amplification. Using negative binomial generalized estimating equations, mosquito abundance over the period were modelled while adjusting for season. A multiple logistic regression model was used to analyse the sporozoite rates. RESULTS: Results show that in some areas along the Kenyan coast, Anopheles arabiensis and Anopheles merus have replaced An. gambiae sensu stricto (s.s.) and Anopheles funestus as the major mosquito species. Further, there has been a shift from human to animal feeding for both An. gambiae sensu lato (s.l.) (99% to 16%) and An. funestus (100% to 3%), and P. falciparum sporozoite rates have significantly declined over the last 20 years, with the lowest sporozoite rates being observed in 2007 (0.19%) and 2008 (0.34%). There has been, on average, a significant reduction in the abundance of An. gambiae s.l. over the years (IRR = 0.94, 95% CI 0.90–0.98), with the density standing at low levels of an average 0.006 mosquitoes/house in the year 2010. CONCLUSION: Reductions in the densities of the major malaria vectors and a shift from human to animal feeding have contributed to the decreased burden of malaria along the Kenyan coast. Vector species composition remains heterogeneous but in many areas An. arabiensis has replaced An. gambiae as the major malaria vector. This has important implications for malaria epidemiology and control given that this vector predominately rests and feeds on humans outdoors. Strategies for vector control need to continue focusing on tools for protecting residents inside houses but additionally employ outdoor control tools because these are essential for further reducing the levels of malaria transmission

Protecting cows in small holder farms in East Africa from tsetse flies by mimicking the odor profile of a non-host bovid

<div><p>Background</p><p>For the first time, differential attraction of pathogen vectors to vertebrate animals is investigated for novel repellents which when applied to preferred host animals turn them into non-hosts thereby providing a new paradigm for innovative vector control. For effectively controlling tsetse flies (<i>Glossina</i> spp.), vectors of African trypanosomosis, causing nagana, repellents more powerful than plant derived, from a non-host animal the waterbuck, <i>Kobus ellipsiprymnus defassa</i>, have recently been identified. Here we investigate these repellents in the field to protect cattle from nagana by making cattle as unattractive as the buck.</p><p>Methodology/Principal findings</p><p>To dispense the waterbuck repellents comprising guaiacol, geranylacetone, pentanoic acid and δ-octalactone, (patent application) we developed an innovative collar-mounted release system for individual cattle. We tested protecting cattle, under natural tsetse challenge, from tsetse transmitted nagana in a large field trial comprising 1,100 cattle with repellent collars in Kenya for 24 months. The collars provided substantial protection to livestock from trypanosome infection by reducing disease levels >80%. Protected cattle were healthier, showed significantly reduced disease levels, higher packed cell volume and significantly increased weight. Collars >60% reduced trypanocide use, 72.7% increase in ownership of oxen per household and enhanced traction power (protected animals ploughed 66% more land than unprotected). Land under cultivation increased by 73.4%. Increase in traction power of protected animals reduced by 69.1% acres tilled by hand per household per ploughing season. Improved food security and household income from very high acceptance of collars (99%) motivated the farmers to form a registered community based organization promoting collars for integrated tsetse control and their commercialization.</p><p>Conclusion/Significance</p><p>Clear demonstration that repellents from un-preferred hosts prevent contact between host and vector, thereby preventing disease transmission: a new paradigm for vector control. Evidence that deploying water buck repellents converts cattle into non-hosts for tsetse flies—<i>‘cows in waterbuck clothing’</i>.</p></div

Average number of <i>G</i>. <i>pallidipes</i> flies caught per trap per day (apparent densities) with various tsetse repellent (WRC) treatments over the trial period.

<p>Average number of <i>G</i>. <i>pallidipes</i> flies caught per trap per day (apparent densities) with various tsetse repellent (WRC) treatments over the trial period.</p

Trypanosome infection in cattle with waterbuck repellent compounds (WRC).

<p>Estimates obtained from the generalized estimating equations model. The 95% Confidence Intervals (CI) were constructed using empirically corrected standard errors.</p

Cattle with repellent collars grazing in bush with natural tsetse challenge.

<p>(Picture R.K. Saini).</p

Farmers perceptions of the effectiveness of the new repellent collar technology.

<p>Farmers perceptions of the effectiveness of the new repellent collar technology.</p

Target used to attract and kill the flies (pull).

<p>(Picture R.K. Saini).</p

Randomized four treatment regimes for the eight trial sites^*.

<p>Randomized four treatment regimes for the eight trial sites^{<a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0005977#t001fn001" target="_blank">*</a>}.</p