Quantification of the efficiency of treatment of Anopheles gambiae breeding sites with petroleum products by local communities in areas of insecticide resistance in the Republic of Benin

<p>Abstract</p> <p>Background</p> <p>The emergence of <it>Anopheles </it>populations capable of withstanding lethal doses of insecticides has weakened the efficacy of most insecticide based strategies of vector control and, has highlighted the need for developing new insecticidal molecules or, improving the efficacy of existing insecticides or abandoning those to which resistance has emerged. The use of petroleum products (PP) against mosquito larvae had an immense success during early programmes of malaria control, but these compounds were abandoned and replaced in the 1950s by synthetic insecticides probably because of the high performances given by these new products. In the current context of vector resistance, it is important to elucidate the empirical use of PP by quantifying their efficiencies on resistant strains of <it>Anopheles</it>.</p> <p>Methods</p> <p>Larvae of <it>Anopheles </it>Ladji a local resistant strain were exposed to increasing concentrations of various PP (kerosene, petrol and engine oils) for 24 hours and the lethal activities recorded. The highest concentration (HiC) having no lethal activity (also referred as the NOEL or no effect level) and the lowest concentration (LoC₁₀₀) yielding 100% mortality were rated for each PP on the Ladji strain. Prior to laboratory analysis, KAP studies were conducted in three traditional communities were insecticide resistance is clearly established to confirm the use of PP against mosquitoes.</p> <p>Results</p> <p>Laboratory analysis of petrol, kerosene and engine oils, clearly established their lethal activities on resistant strains of <it>Anopheles </it>larvae. Contrary to existing references, this research revealed that exposed larvae of <it>Anopheles </it>were mostly killed by direct contact toxicity and not by suffocation as indicated in some earlier reports.</p> <p>Conclusion</p> <p>This research could serve as scientific basis to backup the empirical utilisation of PP on mosquito larvae and to envisage possibilities of using PP in some traditional settings where <it>Anopheles </it>have developed resistance to currently used insecticides.</p

Does the spillage of petroleum products in Anopheles breeding sites have an impact on the pyrethroid resistance?

<p>Abstract</p> <p>Background</p> <p>The emergence of <it>Anopheles </it>populations capable of withstanding lethal doses of insecticides has weakened the efficacy of most insecticide based strategies of vector control and, has highlighted the need for further studies on the mechanisms of insecticide resistance and the various factors selecting resistant populations of mosquitoes. This research targeted the analysis of breeding sites and the oviposition behaviour of susceptible and resistant populations of <it>Anopheles </it>in localities of spilled petroleum products. The aim was to establish the possible contribution of oil spillage in the selection of pyrethroid resistance in malaria vectors.</p> <p>Methods</p> <p><it>Anopheles </it>breeding sites were identified and the insecticide susceptibility of the <it>Anopheles gambiae </it>populations mapped in 15 localities of South Western Nigeria. The presence of oil particles as well as the turbidity, the dissolved oxygen and the pH of each identified breeding site was recorded. Data were cross-analysed to correlate the habitat types and the insecticide susceptibility status of emerging mosquitoes. The second phase of this study was basically a laboratory model to provide more information on the implication of the spillage of petroleum on the selection of pyrethroid resistance in <it>An. gambiae</it>.</p> <p>Results</p> <p>Moderate levels of resistance following exposure to permethrin-impregnated papers were recorded with the majority of <it>An. gambiae </it>samples collected in the South Western Nigeria. Data from this study established a link between the constituency of the breeding sites and the resistance status of the emerging <it>Anopheles</it>.</p> <p>Conclusion</p> <p>This study has revealed the segregational occupation of breeding habitats by pyrethroid resistant and susceptible strains of <it>An. gambiae </it>in south-western Nigeria. Compiled results from field and laboratory research point out clear relationships between oil spillage and pyrethroid resistance in malaria vectors. The identification of this factor of resistance could serve as strong information in the management of insecticide resistance in some West African settings.</p

Comparative study of the effectiveness of combination therapies based on atemisinine in Dassa Zounme and Parakou: case of Artemether lumefantrine and Artesunate amodiaquine

The National Malaria Control Program recommended in 1993, the use of Chloroquina (CQ) as first line drug for malaria treatment, and sulfadoxin pyrimethamin as second drug. After years, Benin knows resistance about these antimalarials. Quinina was to treat gravities. In 2004, the strategy of treatment changed. Treatment of malaria cases is based on use of arteminisinia therapeutic combination. The goal of this study is to be sure that these drugs are efficace before general use in the country and in some regions as Dassa Zounmè where the resistance is up (61. 3% for Chloroquina CQ and 45.9% for SP in 2002).The study is based on: comparison of therapeutic efficacy of artemether Lumefantrine and Artesunate Amodiaquine. Results show that all of the tested drugs have good therapeutic efficacy. Most important rate failure is in Dassa Zounmè (33, 86%) than Parakou (23, 44%). They are parasitologic failure and are probably due to the reinfestation of children. Two drugs have a good parasitological clearance and eliminate fever after 2 days of treatment. Published by the International journal of Microbiology and Mycology (IJMM

Number of eggs laid by susceptible and resistant strains of in oily and non oily breeding sites

<p><b>Copyright information:</b></p><p>Taken from "Does the spillage of petroleum products in breeding sites have an impact on the pyrethroid resistance?"</p><p>http://www.malariajournal.com/content/6/1/159</p><p>Malaria Journal 2007;6():159-159.</p><p>Published online 3 Dec 2007</p><p>PMCID:PMC2222605.</p><p></p

Mapping of susceptibility to pyrethroid (permethrin) in the South Western Nigeria

<p><b>Copyright information:</b></p><p>Taken from "Does the spillage of petroleum products in breeding sites have an impact on the pyrethroid resistance?"</p><p>Malaria Journal 2007;6():159-159.</p><p>Published online 3 Dec 2007</p><p>PMCID:PMC2222605.</p><p></p

Hatching rate of eggs laid by resistant and susceptible strains of in oily and non-oily breeding sites

<p><b>Copyright information:</b></p><p>Taken from "Does the spillage of petroleum products in breeding sites have an impact on the pyrethroid resistance?"</p><p>http://www.malariajournal.com/content/6/1/159</p><p>Malaria Journal 2007;6():159-159.</p><p>Published online 3 Dec 2007</p><p>PMCID:PMC2222605.</p><p></p