Indicators and vectors related to malaria transmission in the Kozah and Doufel gou (Kara region, North Togo)

Malaria is a vector-borne disease transmitted by Anopheles mosquitoes, in particular Anopheles gambiae s.l. To identify malaria vectors and establish a link between the presence of malaria vectors and malaria prevalence, a study was carried out in 7 localities of the Kara region: Lassa-Bas, Sarakawa, and Kpindi in the Kozah prefecture and Siou, Défalé, Ténéga and Broukou in the Doufelgou prefecture. Two malaria indicators were evaluated including the prevalence rate as well as consultation rate among children aged under 5 and pregnant women in the above-mentioned areas. Additionally, adult mosquitoes were collected using Human Landing Catch and Spray Catch techniques in the following localities: Lassa-Bas, Sarakawa, Siou, and Ténéga. Malaria prevalence rate was globally > 70%, the consultation rate was also > 50% among children under 5 years in the two prefectures. In pregnant women, the prevalence was > 60% while the consultation rate was 45%. A total of 592 mosquitoes were collected, divided into 3 genera: Anopheles, 521 (88%); Culex, 54 (9%); and Aedes, 17 (3%). Of the overall Anopheles mosquitoes collected, Anopheles gambiae s.l. represented 100% in all the localities (Lassa-Bas, 140; Sarakawa, 62; Ténéga, 303; and Siou, 16), followed by Aedes aegypti, Aedes sp, and Culex spp. The high rate of malaria prevalence could be potentially linked to the abundance of Anopheles mosquitoes

Building the capacity of West African countries in Aedes surveillance: inaugural meeting of the West African Aedes Surveillance Network (WAASuN)

Arboviral diseases such as dengue, Zika and chikungunya transmitted by Aedes mosquitoes have been reported in 34 African countries. Available data indicate that in recent years there have been dengue and chikungunya outbreaks in the West Africa subregion, in countries including Côte d’Ivoire, Burkina Faso, Gabon, Senegal, and Benin. These viral diseases are causing an increased public health burden, which impedes poverty reduction and sustainable development. Aedes surveillance and control capacity, which are key to reducing the prevalence of arboviral infections, need to be strengthened in West Africa, to provide information essential for the formulation of effective vector control strategies and the prediction of arboviral disease outbreaks. In line with these objectives, the West African Aedes Surveillance Network (WAASuN) was created in 2017 at a meeting held in Sierra Leone comprising African scientists working on Aedes mosquitoes. This manuscript describes the proceedings and discusses key highlights of the meeting

First report of the presence of L1014S Knockdown-resistance mutation in Anopheles gambiae s.s and Anopheles coluzzii from Togo, West Africa [version 1; referees: 2 approved, 1 approved with reservations]

Background: To optimize the success of insecticide-based malaria control intervention, knowledge of the distribution of Anopheles gambiae species and insecticide resistance mechanisms is necessary. This paper reported an updated data on pyrethroids/DDT resistance in the An. gambiae s.l population from Togo.  Methods: From December 2013 to April 2015, females of indoor-resting An. gambiae s.l were captured in three locations belonging to three different ecological zones. Resistance to DDT, permethrin and deltamethrin was screened in F1 progeny of collected mosquitoes using WHO susceptibility tests. The identification of species of An. gambiae complex and the detection of kdr and ace.1R allele were carried out using DNA-based molecular techniques. Results: An. gambiae from Kovié and Nangbéto were highly resistant to DDT and permethrin with mortalities rate ranging from 0.83% to 1.58% for DDT and zero to 8.54% for permethrin. Mosquitoes collected in Nangbéto displayed 81.53% mortality with deltamethrin. An. coluzzii and An. gambiae s.s were found in sympatry in Nangbéto and Mango. The allelic frequency of L1014F was high, ranging from 66 to 100% in both An. coluzzii and An. gambiae s.s. For the first time we detected the L1014S allele in both An. coluzzii and An. gambiae s.s. from Togo at the frequency ranging from 5% to 13% in all the sites. The kdr N1575Y was present at various frequencies in both species ranging from 10% to 45%. Both An. gambiae s.s. and An. coluzzii shared the ace1R mutation in all investigated sites with allelic frequency ranging from 4% to 16%. Conclusion: These results showed that multiple mutations are involved in insecticides resistance in An. gambiae populations from Togo including the kdr L1014F, L1014S, and N1575Y and ace.1R G119S mutations

Building the capacity of West African countries in Aedes surveillance: inaugural meeting of the West African Aedes Surveillance Network (WAASuN).

Funder: Centers for Disease Control and PreventionArboviral diseases such as dengue, Zika and chikungunya transmitted by Aedes mosquitoes have been reported in 34 African countries. Available data indicate that in recent years there have been dengue and chikungunya outbreaks in the West Africa subregion, in countries including Côte d'Ivoire, Burkina Faso, Gabon, Senegal, and Benin. These viral diseases are causing an increased public health burden, which impedes poverty reduction and sustainable development. Aedes surveillance and control capacity, which are key to reducing the prevalence of arboviral infections, need to be strengthened in West Africa, to provide information essential for the formulation of effective vector control strategies and the prediction of arboviral disease outbreaks. In line with these objectives, the West African Aedes Surveillance Network (WAASuN) was created in 2017 at a meeting held in Sierra Leone comprising African scientists working on Aedes mosquitoes. This manuscript describes the proceedings and discusses key highlights of the meeting