Habitat Characterization and Spatial Distribution of Anopheles Sp Mosquito Larvae in Luanda, Angola
Total Page:16
File Type:pdf, Size:1020Kb
Central Annals of Community Medicine and Practice Short Communication *Corresponding author María del Carmen Marquetti Fernández, Department Vector Control, Institute of Tropical Medicine Pedro Habitat Characterization Kourí, La Habana, Cuba. Cuban Medical Cooperation in Angola, Email: and Spatial Distribution of Submitted: 07 December 2016 Accepted: 30 December 2016 Anopheles Sp Mosquito Larvae Published: 02 January 2017 Copyright in Luanda, Angola © 2017 del Carmen Marquetti Fernández et al. OPEN ACCESS María del Carmen Marquetti Fernández1*, Yoenys Hidalgo Flores2, and Duniarliz Lamothe Nuviola2 Keywords 1Department Vector Control, Instituto de Medicina Tropical Pedro Kourí, Cuba • Anopheles sp 2Cuban Control Programanti-Larval Malaria Vectors with Biolarvicides in Angola, • Habitat characterization Cuba • Malaria • Luanda • Angola Abstract Anophelesgambiae and Anophelesfunestus are the main vectors of malaria in Angola. The objective of this work was to obtain information about the habitat characterization of Anopheles sp. Mosquito larvae in Luanda. Mosquito larvae sampling was conducted to determine the presence or absence of Anopheles mosquito larvae during January and March 2015. A total of 512 potential mosquito breeding sites were sampled, 437 (85,3%) were productive for mosquitos About 135 of 179 (75,4%) of all available Anopheles sp. habitats were man-made. Anopheles sp. Larvae presence was much more likely to found in ground drains, concrete drains, puddles, ground wells and concrete wells than other habitats. Breeding sites with sunlit presence and semi-polluted and clear water were more likely to contain Anopheles sp. larvae than others. This results combined with improved knowledge of mosquito ecology and their interactions with humans, is crucial to understand the epidemiology of urban malaria in the capital of Angola. INTRODUCTION Estrategico Nacionalpara o Control da Malaria em Angola 2015 In the Afro tropical Region, where Malaria is transmitted topopulational 2020). though to date coverage is insufficient (Plano mainly by Anopheles funestus and members of the Anopheles gambiae complex, gaps in information on larval ecology and the Anophelesgambiae and Anophelesfunestus are the main vectors ability of An. gambiaes.l. To exploit a wide variety of larval habitats of malaria in Angola, but other species such as Anophelesarabiensis, have discouraged efforts to develop and implement larval control Anopheles nili, Anophelesmelas and Anophelespharoensis are also strategies [1]. reported [4]. In recent years there is increasing interest in the Studies carried out in Luanda founded low Malaria Implementation of the reduction and management of larval populations of mosquito vectors of Malariain Africa, highlighting parasitaemia (5.5%) in children under5 years compared with the use of two bacteria Bacillus thuringiensis and Bacillussphaericus because these are highly effective against mosquito larvae [2,3]. increased29% in neighboring with distance provinces from the [5],city whilecenter a [6]. low However, prevalence the provinceof confirmed of Luanda cases was reported the most with cases Malariain of Malaria Luanda,reported whichin the In Angola Malaria vector control is directed primarily to the Bacillusthuringiensis most of these cases were clinically diagnosed and no information ® ® ) and Bacillussphaericus ), which are applied iscountry available with on over where 30% they and were 3% acquired.mortality during 2013, although byanti-larval brigades fight anti larvalusing struggle,these larvicides at the level ( of municipalities, created(Bactivec to support Cuban cooperation,(Griselesf which has been developing The objective of this work was to obtain information about this activity within the Program of National Malaria Control since the habitat characterization of Anopheles sp. Mosquito larvae in 2009, in addition limited actions of intra household spraying Luanda, Angola. This work was carried out in order to collect with use of pyrethroids and more over since 2006 has increased base line information for to improve the larval control mosquito the distribution of impregnated mosquito net sare made in the through the biolarvicides application implemented in Luanda. Cite this article: del Carmen Marquetti Fernández M, Flores YH, Nuviola DL (2017) Habitat Characterization and Spatial Distribution of Anopheles Sp Mos- quito Larvae in Luanda, Angola. Ann Community Med Pract 3(1): 1016. del Carmen Marquetti Fernández et al. (2017) Email: [email protected]; [email protected] Central The study was carried out in Luanda, the capital of Angola, The majority of the breeding sites with Anopheles sp. larvae presence were founded in the most urban municipality Census data conducted from 15-31of May, 2014; National Instituteas a population of Statistics). estimated A oflarge 6 542 proportion 944 inhabitants of the (Nationalresidents of Luanda live in densely populated urban slums. The city is (Luanda) 100 (55,9%) of the total. Icolo de Bengo and Quissama showed the most low percentages (4,5%) and (5,6%). The rest of the municipalities Viana, Cacuaco, Cazenga y Belas showed thedivided same in name 7 municipalities as the province Belas, and Cacuaco, conformed Cazenga, by Ingombota, Icolo de Presence/absencepercentages between 7,2% of Anopheles to 9,5%. sp. Larvae Maianga,Bengo, Quissama, Rangel, Samba, Viana Sambizanga and Luanda and municipality Kilamba Kiaxi which districts has respectively. Each municipality is divided into comunes and concrete wells were much more likely to contain Anopheles sp. these in neighborhoods. The rainy season is between November- larvaeGround than otherdrains, habitats, concrete drains, puddles, ground wells and May but the most accumulation of rain in Luanda occurs in presence and semi-polluted water and clear water were more March- April. Luanda had an annual rainfall of 323 millimeters likely to contain Anopheles (Figuresp. larvae. 1). HoweverBreeding Anophelessites with larvaesunlit during 2013 with values of 27,9 millimeters for November and presence not showed predilection for presence or absence of 12,7 millimeters in April with a peak of rainfall in April 116,8 vegetation at the breeding sites. Despite the study was carried out Average Climatic Conditions Luanda, Angola; Anopheles sp breeding Weather, 2013). The data collection was conducted from January millimetersto March 2015 ( belonging to rainy season. Each area was visited BBC in rainy season 148 (82,7%) of the total of only once time of breeding sites in all municipalities of Luanda. sites were classifies as permanent breeding sites. Aboutpurposes 135 of 179 (75,4%). of all available habitats were man-made, of them 48 in all municipalities for to sampling with the mainly objective to (35,5%) for drainages and 66 (48,8%) for water storage Anopheles mosquitoes in general can be determineOpen natural the and presence artificial or absencewater bodies of Anopheles were selected mosquito randomly larvae (Table 1) using standard procedures. A total of 512 were selected; 185 in amongBreeding them the sites lagoons of , streams, back waters of rivers, irrigation Luanda municipality conformed by Ingombota, Maianga, Rangel, natural or artificial permanently or semi-permanent prominent Samba, Sambizanga and Kilamba Kiaxi districts; 95 for Cacuaco y ofVianaperi the province urban and municipalities; 25 for Cazenga 52 for situated Belas coastal in the municipality;center of the province.30 for Icolo From de Bengo every and potential Quissama breeding the most site rural up to municipalities 5 dips were characterization only was carried out in the breeding sites with Anophelestaken with mosquito’s a standard presence.white 350 ml dipper (WHO 1992). Habitat to the malaria program established in the province and trained for theThe activitystaff (5 by persons) Cuban specialistthat performed in vector the control. sampling All belongssample included different parameters: location of breeding sites; man– made or not breeding sites; presence/absence of Anopheles larvae; presence/absence of sunlit; sun receives only part of the day) and shaded; presence/absence of any Totals of larvae presence in different breeding vegetation, partly sunny ( Figure 1 Anopheles sp sites in Luanda, January- March 2015. appreciation semi permanentwater breedingturbidity (pollute,sites. The semi-pollute sampled mosquito or clear water)larvae (qualitative ) and the classification in permanent or was transferred to small labelled vials and sent to the entomology Table 1: Number and percentage of different parameters analyzed in laboratory belonging to Malaria Control Program at the Ministry Anopheles sp. breeding sites in Luanda, January-March 2015. Total Parameters % del total Pupae were not recorded as they cannot be differentiated from (N= 179) non-of HealthAnopheles in Luanda for the identification only at genus level. Sunlit 136 75,9 Partially sunlit 34 19,1 Each site was categorized as one of the following habitat type: species in the field. Shaded 9 5,0 Any vegetation presence 86 49,1 natural lagoons, cisterns, tanks, swampy areas, puddles, ground No vegetation presence 93 51,9 wells,concrete concrete drains, wells, ground wells drains, covered flooded with yards,tires of flooded used cars houses, and Clear water 72 40,2 sewerage. Semi-polluted water 80 44,7 A total of 512 potential mosquito breeding sites were sampled, Polluted water 27 15,1 Permanent breeding sites 148 82,7 Semi- permanent breeding sites 31 17,3 75 (14,6%) were negative to mosquito