Traditional medicinal plant knowledge and use by local healers in Sekoru District, Jimma Zone, Southwestern Ethiopia

The knowledge and use of medicinal plant species by traditional healers was investigated in Sekoru District, Jimma Zone, Southwestern Ethiopia from December 2005 to November 2006. Traditional healers of the study area were selected randomly and interviewed with the help of translators to gather information on the knowledge and use of medicinal plants used as a remedy for human ailments in the study area. In the current study, it was reported that 27 plant species belonging to 27 genera and 18 families were commonly used to treat various human ailments. Most of these species (85.71%) were wild and harvested mainly for their leaves (64.52%). The most cited ethnomedicinal plant species wasAlysicarpus quartinianus A. Rich., whose roots and leaves were reported by traditional healers to be crushed in fresh and applied as a lotion on the lesions of patients ofAbiato (Shererit). No significant correlation was observed between the age of traditional healers and the number of species reported and the indigenous knowledge transfer was found to be similar. More than one medicinal plant species were used more frequently than the use of a single species for remedy preparations. Plant parts used for remedy preparations showed significant difference with medicinal plant species abundance in the study area.     

Evaluation on potential of wild hosts as trap plants for managing gramineous stemborers in maize based-agroecosystem

As part of habitat management system to control cereal stemborers, various wild hosts used as trap plants were studied during the dry season from November 2003 to March 2004 at Melkassa, central Ethiopia. Five wild hosts of the family Poaceae [Pennisetum purpurum (Schumach), Sorghum vulgare variety sudanense (Pers.), Panicum coloratum L., Sorghum arundinaceum Stapf, and Hyperrhania rufa (Nees)] were evaluated as trap plants in maize, Zea mays L.,-based agroecosystem. The results of the study showed that maize plots surrounded by all tested wild hosts had significantly lower mean percentage of foliage damage and stemborer density than maize monocrop plots 15 m away from the treatment blocks. Interestingly, mean foliar damage and stemborer density between maize plots surrounded by wild hosts and maize monocrop plots within the treatment blocks was not significant. Percentage of tunneled stalks was significantly greater in maize monocrop plots 15 m away from the treatment blocks than in maize plots surrounded by all tested wild host plant species. Moreover, the highest mean percentage of parasitism (62%) of Chilo partellus (Swinhoe) by Cotesia flavipes (Cameron) was recorded in maize plots surrounded by P. purpureum. Therefore, the findings revealed that these wild hosts have considerable merit to be used as trap plants in the development of strategies for managing cereal stemborers in maize crops.     

Impact of Six Years Community Directed Treatment with Ivermectin in the Control of Onchocerciasis,Western Ethiopia

Background

The African Program for Onchocerciais Control (APOC) with a main strategy of community directed treatment with ivermectin (CDTI) was established with the aim of eliminating Onchocerciasis as a disease of public health and socio-economic importance. The study area was a hyper endemic area just before the implementation of CDTI. It has been implemented for six years in this district but yet not been evaluated. So, the objective of this study was to evaluate the impact of six years CDTI on parasitological and clinical indices of Onchocerciasis

Methods

This study employed a pre-post impact evaluation design. The minimum sample size for this study was 1318; the respondents were selected by multi-stage sampling technique. Data on socio-demographic characteristics using a semi-structured questionnaire, clinical examination for skin signs and symptoms of Onchocerciasis and two bloodless skin snips from each side of the gluteal fold were taken from the entire study participants. SPSS version 16.0 and Medcalc version 12.2.1.0 were used for analysis.

Result

The microfilaridermia reduced from the pre-intervention value of 74.8% to 40.7%, indicating a 45.6% reduction, mean intensity from 32.1(SD = 61.5) mf/mg skin snip to 18.7(SD = 28.7)indicating 41.75% reduction, CMFL from 19.6 mf/mg skin snip to 4.7 indicating 76% reduction. The result also showed that microfilaridermia and mean intensity decreased as the number of treatment taken increased. Pruritis, leopard skin, onchocercomata and hanging groin reduced by 54.4%, 61.3%, 77.7% and 88.5% respectively.

Conclusions

The implementation of CDTI significantly reduced the parasitological and clinical indices of Onchocerciasis, so, efforts should be made to improve the annual treatment coverage and sustainability of CDTI to drastically reduce the micro filarial load to the level the disease would no longer be a public health problem.     

Multiple insecticide resistance: an impediment to insecticide-based malaria vector control program

Background

Indoor Residual Spraying (IRS), insecticide-treated nets (ITNs) and long-lasting insecticidal nets (LLINs) are key components in malaria prevention and control strategy. However, the development of resistance by mosquitoes to insecticides recommended for IRS and/or ITNs/LLINs would affect insecticide-based malaria vector control. We assessed the susceptibility levels of Anopheles arabiensis to insecticides used in malaria control, characterized basic mechanisms underlying resistance, and evaluated the role of public health use of insecticides in resistance selection.

Methodology/Principal findings

Susceptibility status of An. arabiensis was assessed using WHO bioassay tests to DDT, permethrin, deltamethrin, malathion and propoxur in Ethiopia from August to September 2009. Mosquito specimens were screened for knockdown resistance (kdr) and insensitive acetylcholinesterase (ace-1^R) mutations using AS-PCR and PCR-RFLP, respectively. DDT residues level in soil from human dwellings and the surrounding environment were determined by Gas Chromatography with Electron Capture Detector. An. arabiensis was resistant to DDT, permethrin, deltamethrin and malathion, but susceptible to propoxur. The West African kdr allele was found in 280 specimens out of 284 with a frequency ranged from 95% to 100%. Ace-1^R mutation was not detected in all specimens scored for the allele. Moreover, DDT residues were found in soil samples from human dwellings but not in the surrounding environment.

Conclusion

The observed multiple-resistance coupled with the occurrence of high kdr frequency in populations of An. arabiensis could profoundly affect the malaria vector control programme in Ethiopia. This needs an urgent call for implementing rational resistance management strategies and integrated vector control intervention.     

Independent Origin and Global Distribution of Distinct Plasmodium vivax Duffy Binding Protein Gene Duplications

BackgroundPlasmodium vivax causes the majority of malaria episodes outside Africa, but remains a relatively understudied pathogen. The pathology of P. vivax infection depends critically on the parasite’s ability to recognize and invade human erythrocytes. This invasion process involves an interaction between P. vivax Duffy Binding Protein (PvDBP) in merozoites and the Duffy antigen receptor for chemokines (DARC) on the erythrocyte surface. Whole-genome sequencing of clinical isolates recently established that some P. vivax genomes contain two copies of the PvDBP gene. The frequency of this duplication is particularly high in Madagascar, where there is also evidence for P. vivax infection in DARC-negative individuals. The functional significance and global prevalence of this duplication, and whether there are other copy number variations at the PvDBP locus, is unknown.Conclusions/SignificancePvDBP duplications are much more widespread and complex than previously thought, and at least two distinct duplications are circulating globally. The same duplication boundaries were identified in parasites from three continents, and were found at high prevalence in human populations where DARC-negativity is essentially absent. It is therefore unlikely that PvDBP duplication is associated with infection of DARC-negative individuals, but functional tests will be required to confirm this hypothesis.