Analysis of the Physicochemical and Biological Parameters of the Larvae Bridges of Malaria Vectors in the Commune of Lemba-Kinshasa, Democratic Republic of Congo (DRC)

Background and objective: The objective of this study was to evaluate the influence of environmental factors on the distribution and proliferation of breeding sites and larvae of Anopheles gambiae and Anopheles funestus in the commune of Lemba. Methods: 351 larval breeding sites including were identified and studied from April 15 to June 15, 2019. Five physicochemical parameters (pH, temperature, conductivity, turbidity and oxygen dissolved) were measured using a HI 9812-S brand Combo multiparametric probe. Results: The commune of Lemba is generally characterized by water with a basic pH (pH > 7). The pH amplitude of the waters of the Super-Lemba deposits is 2.06, with an average of 8.17 ± 0.42, while in Mbanza-Lemba (ML) the pH amplitude is 2.02, with an average of 7.87 ± 0.51. The breeding grounds of Super-Lemba (SL) larvae (29.12°C ± 1.5°C), with an amplitude of 6.60°C. Turbidity varies with an amplitude of 814 in SL with an average of (328.19 ± 13.3) and 499.00 in ML with an average of (306.06 ± 11.6). Dissolved oxygen has a relatively low amplitude in ML, i.e., 19.80 mg/l. Only the first factorial axis is explained because it expresses 100% of the total inertia. This implies that the abundance of anophelinae larvae in prospected breeding sites at SL can be explained by high values of conductivity, pH, turbidity and dissolved oxygen; while the proliferation of culicinae larvae in ML is linked to a high temperature of the waters of the breeding places. Conclusion: The temperature of the roosts, the PH of the roosts greater than 7 and the conductivity are at the basis of the proliferation of mosquito larvae in these two districts studied in the commune of Lemba.