Impact of using long-lasting insecticide-treated mosquito nets on malaria parasitaemia in the outskirts of Kisangani

Introduction: Notwithstanding the large-scale use of mosquito nets and peri and intra-residential sanitation measures to control malaria in DR Congo, malaria remains the first of the deadliest diseases. The purpose of this study was to measure the impact of mosquito net use on malaria parasitaemia. Subjects and methods: We carried out an analytical cross-sectional study from 21 September to 17 December 2015. Two hundred and fifty-two subjects aged ? 5 years, living in the villages of Madula and Wanierukula(30 and 58 km from Kisangani), using a mosquito net in good condition every day, or not at all, were included. Pregnant women and subjects who took antimalarial treatment in the last two months before the study were excluded. Results: The mean malaria parasitaemia in subjects who used anet was 439.2 parasites / ?l, less than half of those who did not use a net (895.5 parasites / ?l). On the other hand, in those who slept after 22:00, the use of the net did not influence their malaria parasitaemia. Conclusion: The use of the mosquito net reduces asymptomatic parasitaemia in half in those who use netsin the outskirts of Kisangani. It shows certain limits, among other things, a not insignificant malaria parasitaemia, even in the subjects who use it regularly and a low efficiency in the subjects who used it after 22h00. It deserves to be reinforced by other prevention methods such as the spraying of residual insecticides

A review on the incidence, interaction, and future perspective on Zika Virus

Zika virus(ZIKV) belongs to the family Flaviviridae and genus Flavivirus. It is a single-stranded positive-sense ribonucleic acid(RNA)virus, has its origin traced to Zika forest in Uganda. Its infection leads to ZIKV fever, characterized by arthralgia, myalgia, rash,conjunctivitis, and asthenia. Clinical presentation of the infection is nonspecific and may often be confused with symptoms of other flaviviral diseases (dengue, West Nile [WN], and chikungunya). Recently, ZIKV has been associated with congenital malformations and neurological complications such as microcephaly and Guillain­Barre' syndrome. The viral tropism revealed an infection of the skin fibroblasts, keratinocytes, and immature dendritic cells through enhanced expression of dendritic cell­specific intracellular adhesion molecule 3­grabbing nonintegrin or anexelecto (Greekword: 'uncontrolled') and tyrosine protein kinase receptor 3 systems. Silencing of T-cell immunoglobulin (Ig) and mucin domain 1(TIM-1) and AXL RNAs has shown blockage of viral entry through their anti-TIM-1 and anti-AXL antibodies, hence serving as a potential target for ZIKV drug development. Biotechnological approaches targeted toward ZIKV vector control include the development of transgenic mosquitoes to disrupt the genome pool of wild strains and use of an endosymbiotic bacterium to prevent replication of arboviruses within its vector. Other approaches include the use of gene drive and exploration of the genetic redundancy to disrupt the receptors used by the virus to gain entry into its host. It is also imperative to explore the modality through which neutralizing antibodies block this viral infection as this may prove as a potential target to arrest the viral life cycle

The mosquito dunk (Bacillus thuringensis israelienses) as a control agent against mosquito larvae in Khartoum State, Sudan Abdalmagi

Background: During the mid-1970s, larvicides have become available that are highly effective, yet selective in action, and therefore environmentally safe to non-target organisms, as well as for human exposure(1). Objectives: The small field trial was carried out from 12th of January to 16th of February 2008 in Khartoum State to evaluate the efficacy and persistence mosquito dunk® (Bti) against mosquito larvae and to measure the effect of physic-chemical properties on mosquito dunk. Material & Methods: The efficacy and persistence of Bacillus thuringiensis subspecies israelensis (mosquito dunk®) as a biological control agent against mosquito larvae was conducted in Khartoum State. Twelve ponds were used as natural breeding habitats of mosquitoes; six of them were treated with dunk at a rate of 1 dunk per 100 square feet and six ponds left untreated (control). Results: The study revealed that more than 80% reduction in immature stages density was observed up to 5, 3 and 2 weeks for the 3rd, 2nd and 4th instars of Anopheline spp., respectively. However, the study showed that the mosquito dunk was noteffective (under 80% mortality) against 1st, instar larvae and pupae of Anopheline species as well as Culex developmental stages. Conclusion & Interpretations: The dunk was very effective in controlling 3rd and 4th instars of Anopheles spp; for 2 weeks interval. Therefore we propose a surface application regime of once every 2 weeks for mosquito dunk

An Investigation of the Use of Rectangular Insecticide-Treated Nets for Malaria Control in Chipinge District; Zimbabwe: a Descriptive Study

Introduction: In 2007; Zimbabwe government distributed rectangular insecticide treated nets in Chipinge District; covering 100 of population at risk. However; malaria morbidity continued increasing from 492/1000 (49.2) in 2007 to 667/1000 (66.7) in 2008. A study was conducted in Chipinge District in May 2009 to investigate the use of rectangular insecticide treated nets and factors affecting their use in malaria prevention: METHODS: A descriptive cross-sectional study was conducted. Quantitative and qualitative methods were triangulated to assess utilisation of rectangular insecticide treated nets. Five interviewers administered 380 questionnaires to senior matriarchs selected from five wards; with 19;667 sampling frame (19;667/380 = 52). Five focus group discussions were conducted. Quantitative data were analysed using Statistical Package for the Social Sciences; while qualitative data were summarised into thematic areas. RESULTS:Approximately; 95 of respondents knew that malaria was caused by mosquito bites. Perception of nets as malaria preventative measure was high (88). Utilization of rectangular insecticide treated nets was low (33) with 81of those not using them expressed difficulty procedures of mounting them and unavailability of related accessories as main reasons. People preferred conical insecticide treated nets (84) compared to rectangular insecticide treated nets (15). Conclusion: Although the Chipinge people accepted insecticide treated nets for malaria prevention; procedure of mounting rectangular insecticide treated nets and accessing related accessories prevented consistent use.In order for insecticide treated net project to have impact on malaria prevention; priority should be given to conical shape or rectangular shape with adequate accessories like wire nails and strings or twine

Rapid Increase in Ownership and Use of Long-Lasting Insecticidal Nets and Decrease in Prevalence of Malaria in Three Regional States of Ethiopia (2006-2007)

Following recent large scale-up of malaria control interventions in Ethiopia; this study aimed to compare ownership and use of long-lasting insecticidal nets (LLIN); and the change in malaria prevalence using two population-based household surveys in three regions of the country. Each survey used multistage cluster random sampling with 25 households per cluster. Household net ownership tripled from 19.6in 2006 to 68.4in 2007; with mean LLIN per household increasing from 0.3 to 1.2. Net use overall more than doubled from 15.3to 34.5; but in households owning LLIN; use declined from 71.7to 48.3. Parasitemia declined from 4.1to 0.4. Large scale-up of net ownership over a short period of time was possible. However; a large increase in net ownership was not necessarily mirrored directly by increased net use. Better targeting of nets to malaria-risk areas and sustained behavioural change communication are needed to increase and maintain net use

Field Evaluation of Three Commercial Repellents Formulations against Afrotropical Vectors Mosquitoes in Camerooun

Three synthetic commercial insert repellents; Buzz-Off TM (30DEET); Cinq-sur-CinqTM (25IR3535 + essential oils) and prebutix TM(25IR3535) were tested in field conditions for their efficacy and persistence against mosquitoes in the forest area of Cameroon. During 48-days; 7; 569 mosquitoes belonging to four genera were collected: Mansonia spp (67.3); Anopheles spp (27.4); Aedes spp(3.8); and Culex spp (1.5). At the end of the 8-hours exposure period; the DEET-based repellent; Buzz Off TM produced the highest protection against Aedes spp; Culex spp and Mansonia spp. For Anophelines; results were more variable : PrebutixTM showed better protection against An. mouchetti; Cinq-sur-CinqTM was more efficacious against An. Funestus and An.ziemani; whereas Buzz-OffTM appeared more effective against An. Gambiae s.s. and An. nili. Efficacy and persistence parameters were estimated only for An. moucheti and Mansonia spp. The effective dosages (ED50 and ED95) as well as the effective half-life obtained with the DEET-based repellent were highly variable among replicates in the case of An. moucheti. For mansonia spp; the estimated EDO value for the DEET -based repellent was = 0.06mg/cm2. For the two IR3535-based repellents; the ED50 values varied from 0.06 to 0.10 mg/cm2; and 0.15 to 0.20 mg/cm2 for An. moucheti and Mansonia spp; respectively. Globally; the ED95 values values of the three repellents were around 1mg/cm2 except that of Cinq-sur-CinqTM which was ? 0.3mg/cm2 in the case of An. moucheti. The estimated effective half-lifes of the three repellents were approximately between 3 and 5h. Our results highlight the heterogeneity in the response of different mosquito species when exposed to the tested insect repellents; showing the relevance of evaluating efficacy and persistence profiles of different formulations in specific environmental contexts

Assessment of Insecticide Treated Nets Coverage for Malaria Control in Kafta-Humera District; Tigray: Possession versus Use by High-risk Groups

Background: In endemic areas; children under five and pregnant women are vulnerable to malaria and are likely to benefit most from the use of mosquito nets. Use of insecticide treated nets (ITNs) for protection against mosquito bite during sleep is highly effective. Nevertheless; prioritization pertaining to the use of nets does not seem to be optimal inmost endemic setups. Objective: To examine the status of ITNs coverage; use and its determinants for malaria control among children under five and/or pregnant women in Kafta-Humera District in Tigray Regional State. Methods: A comparative cross-sectional quantitative study was conducted in the rural and urban areas of the District. Qualitative data were also collected through focus group discussions (FGDs) to identify views of participants; pertaining to possession and utilization. An early morning survey was also carried out in order to observe the actual behavior of the community towards net use. Result: Net and ITN possession was 84.5and 80.0for rural; but 96.1and 91.1for urban settings; respectively. Net possession was higher among urban (OR 3.33; 95CI 1.39; 7.98) compared to rural areas. Observed net and ITN use during the preceding night by children under five years of age was 68.6and 67.0for rural; and 84.6and 79.5for urban areas; respectively. Likewise; similar practice for net and ITN in 52.1and 64.7of pregnant women was observed in rural and urban areas; respectively. The FGD results of this study suggested that lower net possession in rural areas could be due to insufficiency of mosquito net provision and inequity during distribution. Occupation; family size in rural areas; radio possession in urban areas and relative wealth and number of sleeping places had significant effect in both settings to own a net. Relative wealth; radio possession; malaria education message in rural and occupation in both settings had a positive effect on net use. Conclusion: Not all nets owned by the households were being utilized properly. Yet; maldistribution and shortage of ITN were also observed within rural and urban settings. Effective Information; Education and Communication (IEC) should be promoted and continuous availability of ITNs should be in place to achieve effective control of malaria among the high-risk groups

Assessment of distribution, knowledge and utilization of insecticide treated nets in selected malaria prone areas of Ethiopia

Background: Insecticide Treated Nets (ITNs) reduce malaria related mortality and morbidity significantly. Taking this into account; the Ethiopian Federal Ministry of Health has been distributing ITNs to malaria prone areas of the country through the support of the Global Fund. Objective: To study distributional coverage and assess the knowledge and utilization of insecticide treated nets in Ethiopia. Methods: A cross-sectional study was conducted in 17 malarious districts targeted for the first phase free distribution of long lasting insecticide treats nets (LLITNs) by the Ministry of Health in 9 administrative regions from October 2005 to September 2006. Region specific list of malarious districts where MOH distributed ITNs was used as the sampling frame for stratified random sampling of districts. One kebele (sub district) was selected from each of the selected districts using simple random sampling; and 15of the total households in the selected kebeles were selected using systematic random sampling. Upon obtaining informed consent from the household head or the oldest person in the household the questionnaire was administered and information was recorded. Data were double entered using EpiData version 3 and analyzed using SPSS version 12. Results: A total of 3131 households were visited; and 51.6of the respondents were males. The overall ITN distribution and utilization were 97.6and 81.6; respectively. The majority of households (53.2) owned a single net per family; highest in Dire Dawa (93.7) and lowest in Afar (17.6). Thirty eight percent of the respondents owned two nets per household. Most of the respondents (91.1) cited that ITNs are useful to control malaria either through prevention of mosquito bites (60) or prevention of the disease (39). Conclusion: ITN distribution; utilization; knowledge of users and its acceptability were good considering the recent introduction of the products. However; the person net ratio gap should be narrowed and emphasis needs to be given to vulnerable groups

Community Awareness about Malaria; its Treatment and Mosquito Vector in rural Highlands of Central Ethiopia

Background: Despite the rapid expansion of malaria into highland areas of Ethiopia and the movement of malaria inexperienced people to endemic areas; there is no enough information about how highland communities perceive malaria. Objective: To assess communities' awareness of malaria and its mosquito vector in highland rural communities of central Ethiopia. Methods: A community-based cross-sectional survey involved 770 heads of household was conducted during September 2005 to February 2006 in nine peasant associations of five purposely selected districts in highland areas where malaria has been recently introduced; or currently free from the disease. Results: The majority of the study participants knew that malaria is a serious disease that can attack all age groups of a population (81.0). A considerable number of individuals; 357 (47.5) responded that they visited malarious area and about 50of these individuals reported that they or their families had got the disease. A large proportion of participants (81.6) mentioned that mosquito transmits malaria through biting (91.6); while 176 (42.6) individuals are aware that mosquitoes bite during night. Participants from Sheno; Muka Turi and Sululita areas were found to better in associating the cause of malaria with mosquito bites than those participants from Ginchi and Holeta areas (p 0.05). In contrast; participants from Ginchi area were found to better in identifying the common signs/symptoms of malaria and recommending modern antimalarial drug for treatment than participants from other localities (p 0.05). Some of the respondents believed that mosquito bites or landing can be prevented using various methods like mosquito net; eating or keeping garlic in pocket; while more than half (67.1) of the participants had no information about preventive methods of mosquito bites. Conclusion: Communities residing in the highland of the present study areas were aware that malaria is a serious disease. However; they had no clear information about its cause; mode of transmission and preventive methods. Hence; emphasis should be given to increase community awareness through implementation of appropriate health education program for prevention and control of the disease from expanding into highland areas of Ethiopia

Community awareness about malaria; its treatment and mosquito vector in rural highlands of central Ethiopia

Background: Despite the rapid expansion of malaria into highland areas of Ethiopia and the movement of malariainexperienced people to endemic areas; there is no enough information about how highland communities perceive malaria. Objective: To assess communities' awareness of malaria and its mosquito vector in highland rural communities of central Ethiopia. Methods: A community-based cross-sectional survey involved 770 heads of household was conducted during September 2005 to February 2006 in nine peasant associations of five purposely selected districts in highland areas where malaria has been recently introduced; or currently free from the disease. Results: The majority of the study participants knew that malaria is a serious disease that can attack all age groups of a population (81.0). A considerable number of individuals; 357 (47.5) responded that they visited malarious area and about 50of these individuals reported that they or their families had got the disease. A large proportion of participants (81.6) mentioned that mosquito transmits malaria through biting (91.6); while 176 (42.6) individuals are aware that mosquitoes bite during night. Participants from Sheno; Muka Turi and Sululita areas were found to better in associating the cause of malaria with mosquito bites than those participants from Ginchi and Holeta areas (p 0.05). In contrast; participants from Ginchi area were found to better in identifying the common signs/symptoms of malaria and recommending modern antimalarial drug for treatment than participants from other localities (p 0.05). Some of the respondents believed that mosquito bites or landing can be prevented using various methods like mosquito net; eating or keeping garlic in pocket; while more than half (67.1) of the participants had no information about preventive methods of mosquito bites. Conclusion: Communities residing in the highland of the present study areas were aware that malaria is a serious disease. However; they had no clear information about its cause; mode of transmission and preventive methods. Hence; emphasis should be given to increase community awareness through implementation of appropriate health education program for prevention and control of the disease from expanding into highland areas of Ethiopia

Lutte antivectorielle contre le paludisme et resistance des vecteurs aux insecticides en Afrique

La lutte antivectorielle contre le paludisme doit etre adaptee aux vecteurs cibles. Elle repose actuellement sur les moustiquaires impregnees d'insecticide; sur l'aspersion intradomiciliaire d'insecticides et; dans une moindre mesure; sur la lutte contre les gites larvaires. La remanence de l'effet insecticide et l'efficacite de la lutte doivent etre verifiees. La resistance des vecteurs aux insecticides est une des principales limites a leur utilisation

Knowledge and Utilization of Insecticide Treated Mosquito Nets among Freely Supplied Households in Wonago Woreda; Southern Ethiopia

Background: Free distribution of Insecticide Treated Nets (ITNs) for households in malarious areas is currently underway in Ethiopia to prevent malaria. Adequate follow-up of its utilization and status is lacking. Objectives: To assess utilization of ITNs by households and under-five children; and the factors affecting its utilization among freely supplied households. Methods: A community-based cross-sectional study was conducted in Wonago Woreda; Southern Ethiopia; in June and July 2006. Malarious kebeles of the study Town (one of the towns in the Woreda); and 650 households freely supplied with at least one ITN were randomly selected using proportional allocation to size. Results: Of the 944 freely supplied ITNs to 638 households; 649 (68.8) were reported as being used by households. The use of at least one ITN was reported by 482 (75.5) households; and under-five children who slept under ITN in the previous night were 452 (58.0). Availability of separate bedroom significantly increased the use of ITN by households. In addition; possession of two or more ITNs and perception that ITN prevents from mosquito bite were significantly associated with utilization of ITNs by households and under-five children. Conclusion: Not all ITNs supplied to households were used. Its utilization was affected by the unavailability of separate bedroom; less number of ITNs supplied and less perception of ITNs as main preventive measures of malaria. A strong health education program is needed for promoting the proper utilization of this newly adopted malaria control strategy

Mosquito larval habitats and public health implications in Abeokuta, Ogun State, Nigeria

Abstract: The larval habitats of mosquitoes were investigated in Abeokuta, Nigeria in order to determine the breeding sites of the existing mosquito fauna and its possible public health implications on the residents of the City. The habitats were sampled between August 2005 and July 2006 using plastic dippers and a pipette. The habitats were grouped as ground pools/ponds, gutters/open drains, tyres, domestic containers and treeholes/ leaf axils. Ten species of mosquitoes were encountered in the fi ve habitats namely Mansonia africana, M. uniformis, Culex quinquefasciatus, Aedes aegypti, Ae. albopictus, Ae. vittatus, Cx tigripes, Anopheles gambiae s.l., An. funestus and Eretmapodite clnysogaster. Ae. aegypti bred in all the habitats sampled while Cx quinquefasciatus bred in four habitats except tree holes/leaf axils. An. gambiae s.l and Ae. albopictus occurred in three habitats while other species bred only in one or two habitats. Ground pools and domestic containers recorded the highest number of species followed by gutters/open drains. Tree holes/leaf axils was the least preferred habitat with the lowest number of species occurrence. However, statistical analysis revealed non-signifi-cant difference in species occurrence in the fi ve habitats. The availability of the habitats to support the breeding of Aedes, Culex and Anopheles, which are known vectors of urban yellow fever, lymphatic fi lariasis and malaria suggest that the residents of Abeokuta City are at risk of mosquito-borne diseases. It is important that residents of the City are enlighten on the environmental factors that contribute to mosquito breeding and that the Government should institute proper sanitation measures to reduce mosquito breeding sites

Expérience d'utilisation de la moustiquaire imprégnée d'insecticide en zone de haute transmission palustre de Kinshasa

PROBLEMATIQUE. En zone de transmission pérenne du paludisme où la lutte semble s'enliser, la moustiquaire imprégnée d'insecticide (MII) s'impose comme un dispositif efficace de lutte au niveau des ménages. Nos OBJECTIFS DE RECHERCHE consistait à évaluer l'impact sur la morbidité de l'enfant dans une zone de haute transmission du paludisme de Kinshasa, du taux d'utilisation ainsi que l'intégrité de la MII, d'une part, et d'autre part, l'influence de l'âge, des saisons et du standing familial. METHODOLOGIE. Une cohorte de 1.400 enfants d'âge préscolaire habitant dans une zone de haute transmission du paludisme de Kinshasa, a été mise sous MII avec l'accord éclairé des parents, et suivie durant 11 mois. RESULTATS. Le risque fébrile, pour ne prendre que ce paramètre, qui était de 13,5% au début de l'étude, a été divisé pratiquement par trois à la fin de la période d'observation (Rapport de chances = 0,29). Une ou deux nuits passées sans la MII (RC=1,81), de même que la présence d'un seul trou dans la MII (RC=2,2), ont pratiquement doublé ce risque. Ce risque a diminué graduellement avec l'âge. La présence de plus de 10 personnes à charge dans le ménage a augmenté ce risque de près de 20% (RC=1,19). Six décès, dont deux imputés à la rougeole, ont été enregistrés après 4 et 9 mois d'utilisation de la MII. CONCLUSIONS. Pour autant qu'elle soit régulièrement utilisée et que son intégrité soit assurée, la MII réduit significativement le risque morbide imputable au paludisme. L'hypothèse de la perte de la prémunition a été invoquée pour expliquer les décès de cause non définie, probablement due au paludisme, survenus en dépit de l'utilisation régulière supposée de la MII

The Effect of Insectide-Treated Bed Net on Malarial Parasitaemia and Haemoglobin Level of Under-Five Children in a Semi-Urban Community in South-South Nigeria

Background: Imperfect control measures like insecticide-treated bed net that merely reduces transmission; appear unlikely to have any significant effect on malarial morbidity in an area of intense perennial malaria transmission. Also; some field studies have indicated that the efficacy achieved might be due to the high coverage rate achieved during the trial that produced a mass killing of mosquitoes in the communities. Aim : To assess the impact of the use of the insecticide-treated bed net in a programme situation; on malarial parasitaemia; haemoglobin levels and spleen sizes in under-five children; in an area of intense perennial malaria transmission in South-South Nigeria. Methods: The study was carried out over a six-month period in two communities in the Ogba/ Egbema/ Ndoni Local Government Area of Rivers State; South-South Nigeria. A non-randomized control group pre-intervention-post-intervention study design was used. Fifty five children under five years systematically chosen from buyers of the nets sold by a social marketing project were used as the intervention group. Fifty eight children were recruited as controls; from a neighbouring community about ten kilometers away; and matched for age and socio-economic status of their parents with those in the intervention group. Results: The baseline data of the study groups were broadly the same (p 0.1). However; in the post-intervention study; there was a 0.75g/dl (p0.05) difference in the haemoglobin level of the children; with a concomitant difference of 24.05 (p-value 0.05) in the proportion with moderate anaemia (8g/dl). There was also a 2.03cm (p-value 0.001) difference in spleen size; and a 34.42 (p-value 0.05) difference in the prevalence of splenomegaly. The 21.35 difference in the proportion with parasitaemia between the two groups was also found to be significant (p-value 0.05). Conclusion : The study shows that insecticide-treated bed net can be an effective tool for malaria control in an area of intense perennial malaria transmission

Social Marketing of Insecticide-Treated Bed Net for Malaria Control : an Experience in a Semi-urban Community in South-South Nigeria

Background: The effectiveness of the insecticide- treated bed net in reducing the morbidity and mortality associated with malaria has been proved at all levels of malaria transmission. Several models on how to achieve massive coverage have been suggested; but social marketing of the nets is highly favoured for its sustainability.Aim: To report the experience of a small- scale social marketing project for insecticide-treated bed net in a semi-urban community in south-south Nigeria.Methods: The social marketing project was established in 2003 in Egbema; a semi-urban community in Rivers State; with a population of 47;000. A descriptive cross-sectional study design was used for the study; with the sales records of the project and a structured; interviewer-administered questionnaire as study tools. The sales records were analysed to assess the performance of the project; while the questionnaire was used to collect data on the socio-economic characteristics of buyers of the net.Results: In six months; the project achieved an uptake rate of 1.10 ITN per month; per 1000 population; and a 6.5 coverage of the target population. Most; 208 (67); of the paid up sales were achieved at the well-child clinic and the antenatal clinic of the health facilities that serve the community. Buyers in the two lower socio- economic quartiles bought only about one third of the nets. Members of the community were predominantly farmers/fishermen; but only 19 (10) of the buyers of the nets identified themselves as such.Conclusion: The study shows that the use of social marketing for promoting the use of ITN for malaria control is slow in a poor community