African Journal of Malaria and Tropical Diseases

African Journal of Malaria and Tropical Diseases ISSN 2736-173X Vol. 14 (1), pp. 001-004, January, 2026. Available online at www.internationalscholarsjournals.org © International Scholars Journals

Full Length Research Paper

Long-term Stability and Bioactivity of Ocimum kilimandscharicum Extracts Against Anopheles gambiae s.s.

Eliningaya J. Kweka1*, Hassan M. Nkya2, Lucile Lyaruu1, Epiphania E. Kimaro1 Beda J. Mwang’onde1 and Aneth M. Mahande3

¹Tropical Pesticides Research Institute, Division of Livestock and Human Diseases Vector Control, P.O. Box 3024, Arusha, Tanzania.
²Tanzania Wildlife Research Institute, P. O. Box 661, Arusha, Tanzania.
³Tropical Pesticides Research Institute, Mabogini field station, Moshi, Tanzania.

Accepted 19 August, 2025

Reducing vector-human contact is of priority in breaking the transmission chain of malaria parasites. The use of plant extracts as repellents against malaria vectors have been advocated in different studies. The feeding inhibition of four years old Ocimum kilimandscharicum in liquid paraffin or glycerin was compared with N, N-diethyl-3-methylbenzamide (DEET) using cage evaluation method. The four years old extracts of O. kilimandscharicum performed similarly when mixed either in glycerine or liquid paraffin. Blood feeding succession was highest in negative control (glycerine/liquid paraffin alone) while low in OK and DEET. Therefore, promotion of plant extracts for commercialization is of priority in rural Tanzania where whole plants are currently used as repellents against malaria vectors.

Key words: Ocimum kilimandscharicum, DEET, Anopheles gambiae s.s, feeding inhibition.

African Journal of Malaria and Tropical Diseases ISSN 2736-173X Vol. 14 (1), pp. 001-006, January, 2026. Available online at www.internationalscholarsjournals.org © International Scholars Journals

Full Length Research Paper

Bioefficacy of Essential Oils Derived from Local Ethiopian Flora against Larval Stages of Major Mosquito Vectors

Fekadu Massebo¹, Mekuria Tadesse², Tesfaye Bekele², Meshesha Balkew¹ and Teshome Gebre-Michael¹*

¹Aklilu Lemma Institute of Pathobiology, Addis Ababa University, P. O. Box 1176, Addis Ababa, Ethiopia.
²Essential Oil Research Institute, Agricultural Research Institute of Ethiopia, Addis Ababa, Ethiopia.

Accepted 19 October, 2025

The concern for environmental safety and increased development of resistance to chemical insecticides by major arthropod vectors is rekindling interest in the search for botanical products that may be used against major vectors. Essential oils of 11 local plants were evaluated for larvicidal activities against laboratory colonies of Anopheles arabiensis and Aedes aegypti early fourth instar larvae. Those oils which induced higher larvicidal activities in the laboratory were also evaluated in the field. In the laboratory, the LC50 values of the oils ranged from 17.5 to 85.9 ppm against A. arabiensis and from 9.1 to 67.8 ppm against A. aegypti. Similarly, the LC90 values of the oils ranged from 33.2 to 128.4 ppm and from 14.3 to 96.4 ppm against the respective mosquito species. However, Chenopodium ambrosioides Linnaeus oil with LC50 of 17.5 and 9.1 ppm against A. arabiensis and A. aegypti, respectively, and Ocimum lamiifolium Hochst oil with LC 50 of 20.9 and 8.6 ppm against A. arabiensis and A. aegypti, respectively, were the most effective oils. A. aegypti, were more sensitive to most oils than A. arabiensis larvae. Of the five essential oils which exhibited relatively strong larvicidal effects in the laboratory and further tested in the field against wild-collected anopheline larvae, the LC50 and LC 90 values ranged from 35 to 110 ppm, and from 63.7 to 162.9 ppm, respectively. O. lamiifolium and C. ambrosioides still induced the highest larvicidal effects with LC50 = 34 ppm; LC90 = 97. 9 ppm and LC50 =
47.3 ppm; LC90 = 97.9 ppm, respectively. However, it was revealed that laboratory bred mosquito larvae were more sensitive to the essential oils than wild-collected larvae.

Key words: Anopheles arabiensis, Aedes aegypti, essential oils, botanical larvicides.
 

African Journal of Malaria and Tropical Diseases ISSN 2736-173X Vol. 13 (6), pp. 001-006, June, 2025. Available online at www.internationalscholarsjournals.org © International Scholars Journals

Full Length Research Paper

Larvicidal Effects and Phytochemical Profile of Acacia nilotica Against Anopheles arabiensis

Amal Elsayed Edriss*, Abdalla Abdelrahim Satti and Zuhair Alfadil Alabjar

Sudan Academy of Science (SAS), P. O. Box 2404, Khartoum, Sudan.

Accepted 17 December, 2024

Acacia nilotica is a natural forest tree with many traditional uses in Sudan. Preliminary laboratory studies were conducted to analyze the phytochemical constituents of three extracts (water, ethanol and petroleum ether) prepared from A. nilotica (leaves and fruits), and to evaluate their larvicidal effects against the malaria vector mosquito, Anopheles arabiensis. The knockdown and residual effects of the extracts were tested in separate bioassay experiments, compared with two standard insecticides. The results showed wide range of secondary metabolites in water and ethanol extracts, mainly alkaloids, saponins, flavones and tannins, while the petroleum ether extracts were dominated by triterpenes and sterols. The fruits extracts seemed to be richer in active compounds than the leaves extracts. Therefore, the petroleum ether extracts exerted better mortality effects than other extracts, with fruits treatments being superior to leaves in all cases. Moreover, the fruits petroleum ether extract (0.5%) showed similar mortality percent (90.0%) as those of the two insecticides at 24 h post exposure. This treatment also manifested significantly the best residual actions up to three weeks, but lied next in order to both insecticides. Hence, the extract was recommended for further studies to indicate its toxic compound(s) and their possible usage for A. arabiensis control.

Key words: Acacia nilotica, Anopheles arabiensis, extracts, phytochemical analysis, larvicidal effect.
 

African Journal of Malaria and Tropical Diseases ISSN 2736-173X Vol. 13 (6), pp. 001-004, June, 2025. Available online at www.internationalscholarsjournals.org © International Scholars Journals

Full Length Research Paper

Distribution and Abundance of Female Anopheline Mosquitoes in Ugah, Nigeria

Ayanda, Opeyemi Isaac

Department of Biological Sciences, Covenant University, Ota, Nigeria. E-mail: [email protected]. Tel.:
+2348030661295.

Accepted 15 April, 2025

A study on the relative abundance of malaria vectors was investigated in Ugah, Nasarawa state, Nigeria between January and December 2004. A total of 2,276 mosquitoes were collected. The mosquitoes comprise three species - Anopheles gambiae sl, Anopheles funestus and Anopheles ardensis. Of the anophelines, Anopheles gambiae sl is the most abundant that is, 1087(47.76%) followed by Anopheles funestus and Anopheles ardensis with abundances of 863(37.92%) and 326(14.32%) respectively. Female anophelines were 1,670(73.37%). There was a significant difference in the relative abundance of mosquitoes with respect to season (P < 0.05). A number of factors (awareness, culture, proximity to water bodies) appear to be responsible for the abundance of the mosquitoes. The result suggests that concerted efforts should be made by stakeholders at reducing the abundance of malaria vectors in the rural areas in order to prevent outbreak.

Key words: Relative abundance, mosquitoes, Anopheles gambiae sl, Anopheles funestus, Anopheles ardensis.

African Journal of Malaria and Tropical Diseases ISSN 2736-173X Vol. 13 (5), pp. 001-006, May, 2025. Available online at www.internationalscholarsjournals.org © International Scholars Journals

Full Length Research Paper

Malaria Transmission Dynamics in Western Cameroon Highlands: A Seasonal Analysis of Entomological, Parasitological, and Clinical Factors

Jean Atangana1,2*, Etienne Fondjo1, Abraham Fomena3, Joseph Lebel Tamesse4, Salomon Patchoké1, Hamadou N. M. Ndjemaï 1,3 and Prosper A. Bessong Ndong1

1National Malaria Control Programme, Ministry of Public Health, Cameroon P.O. Box 14386, Yaoundé, Cameroon.
2Laboratory of Zoology, Faculty of Science, University of Yaoundé I P.O. Box 812, Yaoundé, Cameroon.
3Laboratory of Parasitology, Faculty of Science, University of Yaoundé I P.O. Box 812, Yaoundé, Cameroon.
4Laboratory of Zoology, Ecole Normale Supérieure, University of Yaoundé I, P.O. Box 614, Yaoundé, Cameroon.

Accepted 14 March, 2025

A cross-sectional study on malaria transmission was carried out in Mangoum, a village situated in the western highland region of Cameroon in October 2005 and May 2006, to assess malaria parasite prevalence in a cohort of children and vectors biting habits and entomological inoculation rate. Mosquitoes were collected by landing catches on volunteers. Members of the Anopheles gambiae complex and molecular forms were identified using Polymerase Chain Reaction method. Infection intensity was determined by counting the number of infected red blood cells against 200 leucocytes. A total of 1195 Anopheles were collected, 183 and 1012 respectively in the dry and rainy seasons. Two Anopheles species were identified: A. gambiae s.l. and Anopheles funestus. A. gambiae s.s. was the only member of the A. gambiae complex found and the main malaria vector in this region. The sporozoïte rate of A. gambiae was higher in the rainy season (9%). The average inoculation rate was 90 infective bites per man per year. A total of 699 children were examined. Two parasites species were identified: Plasmodium falciparum and Plasmodium malariae. The mean parasite rate was 41. 3%. In the age range of 2 - 9 years, the parasite rates were 49% in the dry season and 34.7% in the rainy season. The mean spleen rate of the age range 2 - 9 years varies from 26. 7% in rainy season to 22. 3% in the dry season, and was not significantly different (p = 0, 3). The Western highlands region can be considered as an area of high malaria transmission intensity.

Key words: Malaria, transmission, Anopheles vectors, biting habits, sporozoite rate, parasites species, western Cameroon highlands.
 

African Journal of Malaria and Tropical Diseases ISSN 2736-173X Vol. 13 (5), pp. 001-005, May, 2025. Available online at www.internationalscholarsjournals.org © International Scholars Journals

Full Length Research Paper

Anti-Malarial and Mosquito Repellent Activities of Tithonia diversifolia: Insights from Leaf Extracts

Oyewole I. O. 1*, Ibidapo, C. A. 2, Moronkola, D. O.3, Oduola, A. O.4, Adeoye G. O.5, Anyasor G. N.6 and Obansa J. A. 7

1, 6Department of Basic and Applied sciences, Babcock University, Ilisan-Remo, Nigeria.
2Zoology Department, Lagos State University, Ojo, Lagos, Nigeria.
3Olabisi Onabanjo University, Ago Iwoye;
5University of Lagos, Lagos, Nigeria.
4, 7Public Health Division, Nigerian Institute of Medical Research, Yaba, Lagos, Nigeria.

Accepted 10 April, 2025

Extracts from the leaf of Tithonia diversifolia used in folk medicine for treatment of various ailments were tested for antimalaria and mosquito repellency properties in experimental animals and human volunteers, under the laboratory conditions. Comparison of the effectiveness of Chloroquine with the aqueous and methanolic extracts from the plant (T. diversifolia) showed that Chloroquine was 100% effective in clearing the parasite while the aqueous and methanolic extracts were 50 and 74% effective in clearing the parasites respectively. Both aqueous and methanolic extracts were more effective when administered before the onset of the infection, probably indicating the time-dependency of the antimalaria effects. Earlier application of the extracts at the onset of the malaria symptoms was more effective in reducing the parasitemia within a few days. The administration of the plant extracts during the malaria episode was also effective with longer period of administration. The LC50 of the aqueous extract in mice was 1.2ml/100g body weight while the Maximum Tolerated Dose (MTD) was found to be 1.0ml/g. The repellent activity of volatile oil at different concentrations was measured by protection period against the bites of Anopheles gambiae, Aedes aegypti and Culex quinquefasciatus. The volatile oil extract showed higher repellent effect on A. gambiae at higher concentrations however its repellent and protective effects at various concentrations on all other species of mosquito tested can not be underestimated.

Key words: Tithonia diversifolia, aqueous, methanolic, volatile oil extracts, chloroquine, Plasmodium berghei, mosquitoes.