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2.
PLoS One ; 15(5): e0232909, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32379812

RESUMO

BACKGROUND: Geographical variation may likely influence the effectiveness of prevention efforts for malaria across Indonesia, in addition to factors at the individual level, household level, and contextual factors. This study aimed to describe preventive practices at individual and a household levels applied by rural communities in five provinces in eastern Indonesia and its association with the incidence of malaria among adult (≥15 years) populations. METHODS: This study analyzed a subset of data of nationally representative community-based survey 2018 Riset Kesehatan Dasar (Riskesdas). Data for socio-demographic (age, gender, education and occupation) and preventive behaviors (use of mosquito bed nets while slept, insecticide-treated mosquito nets (ITNs), mosquito repellent, mosquito electric rackets, mosquito coil/electric anti-mosquito mats, and mosquito window screen) were collected. Data were analyzed using bivariate and multivariable logistic regression model. RESULTS: Total of 56,159 respondents (n = 23,070 households) living in rural areas in Maluku (n = 8044), North Maluku (n = 7356), East Nusa Tenggara (n = 23,254), West Papua (n = 5759) and Papua (n = 11,746) were included in the study. In the multivariable models, using a bed net while slept likely reduced the odds of self-reported malaria among Maluku participants. Reduced odds ratios of self-reported malaria were identified in those participants who used ITNs (North Maluku, ENT, Papua), repellent (Maluku, West Papua, Papua), anti-mosquito racket (ENT), coil (Maluku, North Maluku, Papua) and window screen (West Papua, Papua). CONCLUSION: Our study concluded that the protective effects of preventive practices were varied among localities, suggesting the need for specific intervention programs.


Assuntos
Malária/prevenção & controle , Controle de Mosquitos/métodos , Adolescente , Adulto , Antimaláricos/farmacologia , Estudos Transversais , Características da Família , Feminino , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Incidência , Indonésia/epidemiologia , Repelentes de Insetos , Mosquiteiros Tratados com Inseticida/estatística & dados numéricos , Malária/epidemiologia , Masculino , Razão de Chances , Prevalência , População Rural/estatística & dados numéricos , Autorrelato , Inquéritos e Questionários/estatística & dados numéricos
3.
Lancet ; 395(10232): 1292-1303, 2020 04 18.
Artigo em Inglês | MEDLINE | ID: mdl-32305094

RESUMO

BACKGROUND: Long-lasting insecticidal nets (LLINs) are the primary malaria prevention tool, but their effectiveness is threatened by pyrethroid resistance. We embedded a pragmatic cluster-randomised trial into Uganda's national LLIN campaign to compare conventional LLINs with those containing piperonyl butoxide (PBO), a synergist that can partially restore pyrethroid susceptibility in mosquito vectors. METHODS: 104 health sub-districts, from 48 districts in Uganda, were randomly assigned to LLINs with PBO (PermaNet 3.0 and Olyset Plus) and conventional LLINs (PermaNet 2.0 and Olyset Net) by proportionate randomisation using an iterative process. At baseline 6, 12, and 18 months after LLIN distribution, cross-sectional surveys were done in 50 randomly selected households per cluster (5200 per survey); a subset of ten households per cluster (1040 per survey) were randomly selected for entomological surveys. The primary outcome was parasite prevalence by microscopy in children aged 2-10 years, assessed in the as-treated population at 6, 12, and 18 months. This trial is registered with ISRCTN, ISRCTN17516395. FINDINGS: LLINs were delivered to households from March 25, 2017, to March 18, 2018, 32 clusters were randomly assigned to PermaNet 3.0, 20 to Olyset Plus, 37 to PermaNet 2.0, and 15 to Olyset Net. In the as-treated analysis, three clusters were excluded because no dominant LLIN was received, and four clusters were reassigned, resulting in 49 PBO LLIN clusters (31 received PermaNet 3.0 and 18 received Olyset Plus) and 52 non-PBO LLIN clusters (39 received PermaNet 2.0 and 13 received Olyset Net). At 6 months, parasite prevalence was 11% (386/3614) in the PBO group compared with 15% (556/3844) in the non-PBO group (prevalence ratio [PR] adjusted for baseline values 0·74, 95% CI 0·62-0·87; p=0·0003). Parasite prevalence was similar at month 12 (11% vs 13%; PR 0·73, 95% CI 0·63-0·85; p=0·0001) and month 18 (12% vs 14%; PR 0·84, 95% CI 0·72-0·98; p=0·029). INTERPRETATION: In Uganda, where pyrethroid resistance is high, PBO LLINs reduced parasite prevalence more effectively than did conventional LLINs for up to 18 months. This study provides evidence needed to support WHO's final recommendation on use of PBO LLINs. FUNDING: The Against Malaria Foundation, UK Department for International Development, Innovative Vector Control Consortium, and Bill and Melinda Gates Foundation.


Assuntos
Mosquiteiros Tratados com Inseticida/estatística & dados numéricos , Malária/prevenção & controle , Sinergistas de Praguicidas/farmacologia , Butóxido de Piperonila/farmacologia , Animais , Anopheles/parasitologia , Anopheles/fisiologia , Criança , Pré-Escolar , Estudos Transversais , Feminino , Humanos , Resistência a Inseticidas , Malária/sangue , Masculino , Mosquitos Vetores/parasitologia , Mosquitos Vetores/fisiologia , Uganda
4.
PLoS Negl Trop Dis ; 14(4): e0008097, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32275653

RESUMO

Dengue is one of the most important vector-borne diseases, resulting in an estimated hundreds of millions of infections annually throughout the tropics. Control of dengue is heavily dependent upon control of its primary mosquito vector, Aedes aegypti. Innovative interventions that are effective at targeting the adult stage of the mosquito are needed to increase the options for effective control. The use of insecticide-treated curtains (ITCs) has previously been shown to significantly reduce the abundance of Ae. aegypti in and around homes, but the impact of ITCs on dengue virus (DENV) transmission has not been rigorously quantified. A parallel arm cluster-randomized controlled trial was conducted in Iquitos, Peru to quantify the impact of ITCs on DENV seroconversion as measured through plaque-reduction neutralization tests. Seroconversion data showed that individuals living in the clusters that received ITCs were at greater risk to seroconverting to DENV, with an average seroconversion rate of 50.6 per 100 person-years (PY) (CI: 29.9-71.9), while those in the control arm had an average seroconversion rate of 37.4 per 100 PY (CI: 15.2-51.7). ITCs lost their insecticidal efficacy within 6 months of deployment, necessitating re-treatment with insecticide. Entomological indicators did not show statistically significant differences between ITC and non-ITC clusters. It's unclear how the lack of protective efficacy reported here is attributable to simple failure of the intervention to protect against Ae. aegypti bites, or the presence of a faulty intervention during much of the follow-up period. The higher risk of dengue seroconversion that was detected in the ITC clusters may have arisen due to a false sense of security that inadvertently led to less routine protective behaviors on the part of households that received the ITCs. Our study provides important lessons learned for conducting cluster randomized trials for vector control interventions against Aedes-transmitted virus infections.


Assuntos
Dengue/prevenção & controle , Dengue/transmissão , Transmissão de Doença Infecciosa/prevenção & controle , Mosquiteiros Tratados com Inseticida , Controle de Mosquitos/métodos , Adolescente , Adulto , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Criança , Pré-Escolar , Vírus da Dengue/imunologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Testes de Neutralização , Peru , Soroconversão , Resultado do Tratamento , Adulto Jovem
6.
PLoS Med ; 17(3): e1003055, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32203504

RESUMO

BACKGROUND: Housing is essential to human well-being but neglected in global health. Today, housing in Africa is rapidly improving alongside economic development, creating an urgent need to understand how these changes can benefit health. We hypothesised that improved housing is associated with better health in children living in sub-Saharan Africa (SSA). We conducted a cross-sectional analysis of housing conditions relative to a range of child health outcomes in SSA. METHODS AND FINDINGS: Cross-sectional data were analysed for 824,694 children surveyed in 54 Demographic and Health Surveys, 21 Malaria Indicator Surveys, and two AIDS Indicator Surveys conducted in 33 countries between 2001 and 2017 that measured malaria infection by microscopy or rapid diagnostic test (RDT), diarrhoea, acute respiratory infections (ARIs), stunting, wasting, underweight, or anaemia in children aged 0-5 years. The mean age of children was 2.5 years, and 49.7% were female. Housing was categorised into a binary variable based on a United Nations definition comparing improved housing (with improved drinking water, improved sanitation, sufficient living area, and finished building materials) versus unimproved housing (all other houses). Associations between house type and child health outcomes were determined using conditional logistic regression within surveys, adjusting for prespecified covariables including age, sex, household wealth, insecticide-treated bed net use, and vaccination status. Individual survey odds ratios (ORs) were pooled using random-effects meta-analysis. Across surveys, improved housing was associated with 8%-18% lower odds of all outcomes except ARI (malaria infection by microscopy: adjusted OR [aOR] 0.88, 95% confidence intervals [CIs] 0.80-0.97, p = 0.01; malaria infection by RDT: aOR 0.82, 95% CI 0.77-0.88, p < 0.001; diarrhoea: aOR 0.92, 95% CI 0.88-0.97, p = 0.001; ARI: aOR 0.96, 95% CI 0.87-1.07, p = 0.49; stunting: aOR 0.83, 95% CI 0.77-0.88, p < 0.001; wasting: aOR 0.90, 95% CI 0.83-0.99, p = 0.03; underweight: aOR 0.85, 95% CI 0.80-0.90, p < 0.001; any anaemia: aOR 0.87, 95% CI 0.82-0.92, p < 0.001; severe anaemia: aOR 0.89, 95% CI 0.84-0.95, p < 0.001). In comparison, insecticide-treated net use was associated with 16%-17% lower odds of malaria infection (microscopy: aOR 0.83, 95% CI 0.78-0.88, p < 0.001; RDT: aOR 0.84, 95% CI 0.79-0.88, p < 0.001). Drinking water source and sanitation facility alone were not associated with diarrhoea. The main study limitations are the use of self-reported diarrhoea and ARI, as well as potential residual confounding by socioeconomic position, despite adjustments for household wealth and education. CONCLUSIONS: In this study, we observed that poor housing, which includes inadequate drinking water and sanitation facility, is associated with health outcomes known to increase child mortality in SSA. Improvements to housing may be protective against a number of important childhood infectious diseases as well as poor growth outcomes, with major potential to improve children's health and survival across SSA.


Assuntos
Anemia/epidemiologia , Saúde da Criança , Transtornos da Nutrição Infantil/epidemiologia , Diarreia/epidemiologia , Habitação , Malária/epidemiologia , Determinantes Sociais da Saúde , África ao Sul do Saara/epidemiologia , Fatores Etários , Anemia/diagnóstico , Anemia/mortalidade , Anemia/prevenção & controle , Transtornos da Nutrição Infantil/diagnóstico , Transtornos da Nutrição Infantil/mortalidade , Transtornos da Nutrição Infantil/prevenção & controle , Pré-Escolar , Estudos Transversais , Diarreia/diagnóstico , Diarreia/mortalidade , Diarreia/prevenção & controle , Água Potável , Feminino , Nível de Saúde , Inquéritos Epidemiológicos , Humanos , Lactente , Recém-Nascido , Mosquiteiros Tratados com Inseticida , Malária/diagnóstico , Malária/mortalidade , Malária/prevenção & controle , Masculino , Estudos Prospectivos , Fatores de Proteção , Medição de Risco , Fatores de Risco , Saneamento
7.
BMC Public Health ; 20(1): 216, 2020 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-32050923

RESUMO

BACKGROUND: Despite rapid upscale of insecticide-treated nets (ITNs) and indoor residual spraying (IRS), malaria remains a major source of morbidity and mortality in Zambia. Uptake and utilization of these and novel interventions are often affected by knowledge, attitudes and practices (KAP) amongst persons living in malaria-endemic areas. The aims of this study were to assess malaria KAP of primary caregivers and explore trends in relation to ITN use, IRS acceptance and mosquito density in two endemic communities in Luangwa and Nyimba districts, Zambia. METHODS: A cohort of 75 primary caregivers were assessed using a cross-sectional, forced-choice malaria KAP survey on ITN use, IRS acceptance and initial perception of a novel spatial repellent (SR) product under investigation. Entomological sampling was performed in participant homes using CDC Miniature Light Traps to relate indoor mosquito density with participant responses. RESULTS: Ninety-nine percent of participants cited bites of infected mosquitoes as the route of malaria transmission although other routes were also reported including drinking dirty water (64%) and eating contaminated food (63%). All caregivers agreed that malaria was a life-threatening disease with the majority of caregivers having received malaria information from health centers (86%) and community health workers (51%). Cumulatively, self-reported mosquito net use was 67%. Respondents reportedly liked the SR prototype product but improvements on color, shape and size were suggested. Overall, 398 mosquitoes were captured from light-trap collections, including 49 anophelines and 349 culicines. Insecticide treated nets use was higher in households from which at least one mosquito was captured. CONCLUSIONS: The current study identified misconceptions in malaria transmission among primary caregivers indicating remaining knowledge gaps in educational campaigns. Participant responses also indicated a misalignment between a low perception of IRS efficacy and high stated acceptance of IRS, which should be further examined to better understand uptake and sustainability of other vector control strategies. While ITNs were found to be used in study households, misperceptions between presence of mosquitoes and bite protection practices did exist. This study highlights the importance of knowledge attitudes and practice surveys, with integration of entomological sampling, to better guide malaria vector control product development, strategy acceptance and compliance within endemic communities.


Assuntos
Cuidadores/psicologia , Conhecimentos, Atitudes e Prática em Saúde , Malária/prevenção & controle , População Rural , Adulto , Cuidadores/estatística & dados numéricos , Estudos de Coortes , Estudos Transversais , Feminino , Habitação , Humanos , Mosquiteiros Tratados com Inseticida/estatística & dados numéricos , Inseticidas/administração & dosagem , Malária/epidemiologia , Controle de Mosquitos/métodos , População Rural/estatística & dados numéricos , Zâmbia/epidemiologia
8.
Am J Trop Med Hyg ; 102(4): 758-767, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32043439

RESUMO

Kala azar occurs among seasonal and migrant agricultural workers in northwest Ethiopia and accounts for almost 60% of the disease burden in the country. We conducted a quantitative study on the level of knowledge and practice of this vulnerable group in relation to kala azar transmission and acceptability of its vector control tools. A total of 403 workers were randomly selected from eight farms using a purposive sampling technique. Knowledge and practice scores were calculated based on 12 and 9 core questions, respectively. Binary logistic regression was used to identify factors associated with knowledge and practice. A large gap in knowledge of the disease and the vector was evident with 61.8%, 24.6%, and 13.6% of the workers having poor, moderate, and good levels of knowledge scores, respectively. Similarly, 95% of the seasonal workers reported poor level of use of protective measures against the bite of the sand fly vector. Good level of knowledge about kala azar and its sand fly vector was statistically associated with formal education (adjusted odds ratio [AOR] = 2.11; 95% CI = 1.17, 3.80; P < 0.05) and previous exposure to health education (AOR = 4.72; 95% CI = 1.99, 11.16; P < 0.001). Despite poor current knowledge and practice, a large proportion of the study participants showed interest in using vector control tools if made available, with 78% of the seasonal and migrant workers expressing some willingness to pay for different measures that can protect against sand fly bites. Therefore, we strongly recommend that comprehensive health education and vector control programs should be provided to these workers.


Assuntos
Agricultura , Leishmaniose Visceral/prevenção & controle , Estações do Ano , Migrantes , Adulto , Animais , Etiópia/epidemiologia , Feminino , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Mordeduras e Picadas de Insetos/prevenção & controle , Repelentes de Insetos/economia , Repelentes de Insetos/farmacologia , Mosquiteiros Tratados com Inseticida , Masculino , Pessoa de Meia-Idade , Roupa de Proteção/economia , Psychodidae , Adulto Jovem
9.
PLoS One ; 15(2): e0224718, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32097407

RESUMO

BACKGROUND: Understanding the interactions between increased insecticide resistance and resting behaviour patterns of malaria mosquitoes is important for planning of adequate vector control. This study was designed to investigate the resting behavior, host preference and rates of Plasmodium falciparum infection in relation to insecticide resistance of malaria vectors in different ecologies of western Kenya. METHODS: Anopheles mosquito collections were carried out during the dry and rainy seasons in Kisian (lowland site) and Bungoma (highland site), both in western Kenya using pyrethrum spray catches (PSC), mechanical aspiration (Prokopack) for indoor collections, clay pots, pit shelter and Prokopack for outdoor collections. WHO tube bioassay was used to determine levels of phenotypic resistance of indoor and outdoor collected mosquitoes to deltamethrin. PCR-based molecular diagnostics were used for mosquito speciation, genotype for knockdown resistance mutations (1014S and 1014F) and to determine specific host blood meal origins. Enzyme-linked Immunosorbent Assay (ELISA) was used to determine mosquito sporozoite infections. RESULTS: Anopheles gambiae s.l. was the most predominant species (75%, n = 2706) followed by An. funestus s.l. (25%, n = 860). An. gambiae s.s hereafter (An. gambiae) accounted for 91% (95% CI: 89-93) and An. arabiensis 8% (95% CI: 6-9) in Bungoma, while in Kisian, An. arabiensis composition was 60% (95% CI: 55-66) and An. gambiae 39% (95% CI: 34-44). The resting densities of An. gambiae s.l and An. funestus were higher indoors than outdoor in both sites (An. gambiae s.l; F1, 655 = 41.928, p < 0.0001, An. funestus; F1, 655 = 36.555, p < 0.0001). The mortality rate for indoor and outdoor resting An. gambiae s.l F1 progeny was 37% (95% CI: 34-39) vs 67% (95% CI: 62-69) respectively in Bungoma. In Kisian, the mortality rate was 67% (95% CI: 61-73) vs 76% (95% CI: 71-80) respectively. The mortality rate for F1 progeny of An. funestus resting indoors in Bungoma was 32% (95% CI: 28-35). The 1014S mutation was only detected in indoor resitng An. arabiensis. Similarly, the 1014F mutation was present only in indoor resting An. gambiae. The sporozoite rates were highest in An. funestus followed by An. gambiae, and An. arabiensis resting indoors at 11% (34/311), 8% (47/618) and 4% (1/27) respectively in Bungoma. Overall, in Bungoma, the sporozoite rate for indoor resting mosquitoes was 9% (82/956) and 4% (8/190) for outdoors. In Kisian, the sporozoite rate was 1% (1/112) for indoor resting An. gambiae. None of the outdoor collected mosquitoes in Kisian tested positive for sporozoite infections (n = 73). CONCLUSION: The study reports high indoor resting densities of An. gambiae and An. funestus, insecticide resistance, and persistence of malaria transmission indoors regardless of the use of long-lasting insecticidal nets (LLINs). These findings underline the difficulties of controlling malaria vectors resting and biting indoors using the current interventions. Supplemental vector control tools and implementation of sustainable insecticide resistance management strategies are needed in western Kenya.


Assuntos
Anopheles/genética , Malária Falciparum/epidemiologia , Malária Falciparum/prevenção & controle , Controle de Mosquitos/métodos , Mosquitos Vetores/fisiologia , Plasmodium falciparum/imunologia , Descanso/fisiologia , Animais , Anopheles/classificação , Anopheles/parasitologia , Ensaio de Imunoadsorção Enzimática , Comportamento Alimentar/efeitos dos fármacos , Feminino , Genótipo , Comportamento de Busca por Hospedeiro/efeitos dos fármacos , Resistência a Inseticidas/genética , Mosquiteiros Tratados com Inseticida , Inseticidas/farmacologia , Quênia/epidemiologia , Malária Falciparum/transmissão , Nitrilos/farmacologia , Reação em Cadeia da Polimerase , Piretrinas/farmacologia , Esporozoítos/imunologia
10.
Parasit Vectors ; 13(1): 17, 2020 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-31924276

RESUMO

BACKGROUND: The efficacy of long-lasting insecticidal nets (LLINs) in preventing malaria in Africa is threatened by insecticide resistance. Bioassays assessing 24-hour mortality post-LLIN exposure have established that resistance to the concentration of pyrethroids used in LLINs is widespread. However, although mosquitoes may no longer be rapidly killed by LLIN exposure, a delayed mortality effect has been shown to reduce the transmission potential of mosquitoes exposed to nets. This has been postulated to partially explain the continued efficacy of LLINs against pyrethroid-resistant populations. Burkina Faso is one of a number of countries with very high malaria burdens and pyrethroid-resistant vectors, where progress in controlling this disease has stagnated. We measured the impact of LLIN exposure on mosquito longevity in an area of the country with intense pyrethroid resistance to establish whether pyrethroid exposure was still shortening mosquito lifespan in this setting. METHODS: We quantified the immediate and delayed mortality effects of LLIN exposure using standard laboratory WHO cone tests, tube bioassays and experimental hut trials on Anopheles gambiae populations originating from the Cascades region of Burkina Faso using survival analysis and a Bayesian state-space model. RESULTS: Following single and multiple exposures to a PermaNet 2.0 LLIN only one of the four mosquito populations tested showed evidence of delayed mortality. No delayed mortality was seen in experimental hut studies using LLINs. A delayed mortality effect was only observed in WHO tube bioassays when deltamethrin concentration was increased above the standard diagnostic dose. CONCLUSIONS: As mosquito pyrethroid-resistance increases in intensity, delayed effects from LLIN exposure are substantially reduced or absent. Given the rapid increase in resistance occurring in malaria vectors across Africa it is important to determine whether the failure of LLINs to shorten mosquito lifespan is now a widespread phenomenon as this will have important implications for the future of this pivotal malaria control tool.


Assuntos
Anopheles , Inseticidas/farmacologia , Malária/prevenção & controle , Controle de Mosquitos , Animais , Bioensaio , Burkina Faso , Resistência a Inseticidas , Mosquiteiros Tratados com Inseticida/parasitologia , Mortalidade , Mosquitos Vetores/parasitologia , Nitrilos/farmacologia , Piretrinas/farmacologia
11.
Malar J ; 19(1): 3, 2020 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-31900182

RESUMO

BACKGROUND: In Benin, malaria vector control mostly relies on long-lasting, insecticidal-treated bed nets (LLINs) and indoor residual spraying (IRS) operations. From 2011 to 2016, an IRS programme has been implemented in Atacora region. However, in 2017 the programme was withdrawn from two other regions in the northern part of the country, with hopes that gains would be relatively sustained because of the seasonality of malaria transmission. What would be the vulnerability of populations to malaria after the withdrawal of IRS? METHODS: Monthly mosquito collections were performed through human landing captures (HLCs) for 24 months (from January to December 2016 during the last IRS campaign, and from January to December 2018, 2 years after the withdrawal of IRS). Vector mosquitoes biting density was sampled by HLC and was tested for presence of Plasmodium falciparum sporozoites. The carcass of these mosquitoes (abdomens, wing, legs) were subjected to molecular species identification using polymerase chain reaction (PCR) assays. RESULTS: It is noticed a drastic increase (~ 3 times higher) of vector abundance after the withdrawal of IRS. Mosquito biting rates in the 3 survey districts increased significantly after IRS was withdrawn. In 2018, after IRS cessation a significant increase of entomological inoculation rate was recorded, where each inhabitant received an average of 94.9 infected bites/year to 129.21 infected bites/year against an average of 17.15 infected bites/year to 24.82 infected bites/year in 2016. CONCLUSION: It is obvious that the withdrawal of IRS confers a vulnerability of the population with regard to the malaria transmission. Robust monitoring is needed to better understand when and where IRS should be most adequate, or can be safely withdrawn. In case of withdrawal, adapted accompanying measures should be proposed according to the context not only to maintain the gains capitalized with IRS, but also to avoid any rebound of transmission.


Assuntos
Inseticidas/farmacologia , Malária/epidemiologia , Malária/prevenção & controle , Malária/transmissão , África Ocidental , Animais , Benin/epidemiologia , Mordeduras e Picadas de Insetos/epidemiologia , Resistência a Inseticidas , Mosquiteiros Tratados com Inseticida , Controle de Mosquitos/métodos , Mosquitos Vetores , Plasmodium falciparum , Fatores de Tempo
12.
Malar J ; 19(1): 7, 2020 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-31906965

RESUMO

BACKGROUND: Malaria is one of the top-five contributors to under-5 deaths in Myanmar. Use of insecticide-treated nets (ITN) and receiving early appropriate care in case of fever are the core interventions to prevent malaria and its complications and thereby deaths. This study aimed to assess among the under-five children, (a) utilization of ITNs and its associated factors, (b) care-seeking behaviour among their caregivers and its associated factors and uptake of malaria testing among those with fever in the last 2 weeks. METHODS: This was a cross sectional study using secondary analysis of Myanmar Demographic and Health Survey (MDHS) conducted in 2015-2016. Multivariable logistic regression was used to explore the factors associated with non-utilization of ITNs and not seeking care for fever. Effect sizes have been presented using odds ratios with 95% confidence intervals. Data analysis was done using svyset command in STATA to account for the multi-stage sampling design of the survey. RESULTS: Of 4597 alive under-five children, 80.5% did not sleep under an ITN last night. The factors significantly associated with non-utilization of ITNs were residing in malaria elimination regions (aOR = 2.0, 1.3-3.2), urban residence (aOR = 1.8, 1.2-2.9), staying in delta region (aOR = 8.7, 4.7-12.2), hilly region (aOR = 3.0, 2.0-4.6, and having highest wealth quintile (aOR = 1.8, 1.1-3.0). Around 16% had fever in the last 2 weeks, of whom 66.7% sought care for fever and 3% got tested for malaria. Nearly half (50.9%) of the caregivers sought care from a government health facility, followed by private hospital/doctor (27.8%), shop (8.0%), village health worker (4.4%) and pharmacy (3.1%). The factors associated with not seeking care for fever were residing in specific geographical locations (hilly, delta and central plains compared to coastal region) and having lowest wealth quintile (aOR = 2.3, 1.1-5.7). CONCLUSIONS: This study highlighted that ownership and utilization of ITNs was very poor among under-5children. Care-seeking behaviour of the caregivers of under-5 children in case of fever was dismal with two-thirds not seeking care. The programme should seriously consider addressing these barriers if Myanmar is to achieve zero malaria deaths by 2030.


Assuntos
Febre , Geografia , Mosquiteiros Tratados com Inseticida/estatística & dados numéricos , Malária/prevenção & controle , Aceitação pelo Paciente de Cuidados de Saúde/estatística & dados numéricos , Cuidadores/estatística & dados numéricos , Pré-Escolar , Estudos Transversais , Demografia , Feminino , Inquéritos Epidemiológicos , Humanos , Lactente , Masculino , Mianmar
13.
Malar J ; 19(1): 11, 2020 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-31910831

RESUMO

BACKGROUND: Indoor attractive toxic sugar bait (ATSB) has potential as a supplementary vector-control and resistance-management tool, offering an alternative mode of insecticide delivery to current core vector-control interventions, with potential to deliver novel insecticides. Given the high long-lasting insecticidal bed net (LLIN) coverage across Africa, it is crucial that the efficacy of indoor ATSB in combination with LLINs is established before it is considered for wider use in public health. METHODS: An experimental hut trial to evaluate the efficacy of indoor ATSB traps treated with 4% boric acid (BA ATSB) or 1% chlorfenapyr (CFP ATSB) in combination with untreated nets or LLINs (holed or intact), took place at the M'bé field station in central Côte d'Ivoire against pyrethroid resistant Anopheles gambiae sensu lato. RESULTS: The addition of ATSB to LLINs increased the mortality rates of wild pyrethroid-resistant An. gambiae from 19% with LLIN alone to 28% with added BA ATSB and to 39% with added CFP ATSB (p < 0.001). Anopheles gambiae mortality with combined ATSB and untreated net was similar to that of combined ATSB and LLIN regardless of which insecticide was used in the ATSB. The presence of holes in the LLIN did not significantly affect ATSB-induced An. gambiae mortality. Comparative tests against pyrethroid resistant and susceptible strains using oral application of ATSB treated with pyrethroid demonstrated 66% higher survival rate among pyrethroid-resistant mosquitoes. CONCLUSION: Indoor ATSB traps in combination with LLINs enhanced the control of pyrethroid-resistant An. gambiae. However, many host-seeking An. gambiae entering experimental huts with indoor ATSB exited into the verandah trap without sugar feeding when restricted from a host by a LLIN. Although ATSB has potential for making effective use of classes of insecticide otherwise unsuited to vector control, it does not exempt potential selection of resistance via this route.


Assuntos
Anopheles/efeitos dos fármacos , Resistência a Inseticidas/efeitos dos fármacos , Inseticidas/farmacologia , Piretrinas/farmacologia , Açúcares/toxicidade , Animais , Ácidos Bóricos , Costa do Marfim , Culex , Feminino , Humanos , Mosquiteiros Tratados com Inseticida , Masculino , Controle de Mosquitos/métodos , Taxa de Sobrevida
15.
Malar J ; 18(1): 412, 2019 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-31823793

RESUMO

BACKGROUND: The long-lasting insecticidal nets (LLIN) are effective against prevention of malaria and its utilization has been proven to save lives. Despite the mass distribution of LLIN, Nigeria remains the country with the highest malaria burden in Africa. The awareness of LLIN in Nigeria is high, but the utilization is low. The aim of this work is to describe factors associated with the utilization of LLIN among women of child-bearing age (WCBA) in Igabi, Kaduna, Nigeria. METHODS: A cross-sectional survey was conducted among 630 WCBA selected using a multi-stage sampling at 63 randomly selected villages in Igabi Local Government Area of Kaduna State. Trained female data collectors administered pre-tested structured questionnaires adapted from the Malaria Indicator Survey. Information collected were demographic profile, knowledge of LLIN as a preventive strategy for malaria, and LLIN ownership and utilization. LLIN utilization was assessed by identifying household members that slept under the hanged LLIN the night before the survey. Questions on the awareness of LLIN, ability to define what it is, use of LLIN, what differentiates LLIN from other bed nets, and duration of use before replacement, were scored and categorized as good, average and poor knowledge of LLIN. RESULTS: A total of 629 WCBA was sampled, their mean age (± SD) was 29.3 (± 6.2) years, 22.0% were pregnant, 40.5% had no formal education, 41.1% were employed, and 47.7% lived in rural communities. Awareness and good knowledge about LLINs for the prevention of malaria was 96.0% and 24.0%, respectively. The proportion of women who slept under a LLIN the night before the survey (utilization) was 70.0% and slightly higher (74.0%) among pregnant WCBA. Women who lived in rural communities were more likely to utilize LLINs compared to their urban counterparts (OR 3.4; 95% CI 2.3-4.9). Younger women (aged < 30 years) were less likely to utilize LLINs compared to the older women (OR 0.7; 95% CI 0.5-0.9). CONCLUSIONS: The knowledge of LLIN among WCBA was poor, but LLIN utilization was moderate. Living in rural communities and older WCBA were significant characteristics associated with LLIN utilization. Strategies that will improve the utilization of LLIN among the young and urban WCBA should be the focus of the Malaria Elimination Programme (MEP).


Assuntos
Conhecimentos, Atitudes e Prática em Saúde , Mosquiteiros Tratados com Inseticida , Malária/prevenção & controle , Controle de Mosquitos/instrumentação , População Rural , Adolescente , Adulto , Estudos Transversais , Feminino , Humanos , Pessoa de Meia-Idade , Nigéria , Gravidez , Inquéritos e Questionários , Adulto Jovem
16.
Malar J ; 18(1): 401, 2019 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-31801579

RESUMO

BACKGROUND: Public sector strategies to promote insecticide-treated net (ITN) access have resulted in increased ITN ownership across sub-Saharan Africa. However, the current status of the private sector distribution channel for nets has not been fully explored. This multi-country study explored the prevalence of net purchases and the characteristics of households that had purchased nets and used such nets in sub-Saharan Africa. METHODS: Data from recent Malaria Indicator Survey (MIS) or Demographic and Health Survey (DHS) in 16 countries were analysed to explore the prevalence of purchased nets. Purchased nets were defined as nets obtained from shops/markets or pharmacies. Additional sub-analysis of factors associated with ownership and use of purchased nets was conducted in seven countries with over 10% of nets reported as purchased. Key outcomes included: prevalence of purchased nets out of all nets, household ownership of a purchased net, and whether a purchased net was used the previous night. Analytical methods included country level tests of association and multivariable logistic regressions. RESULTS: Among all nets, the proportion of purchased nets in the study countries ranged from 0.8 to 32.7% and most (median = 77%) of these purchased nets were ITNs. Although the private nets are presumed to be from the retail, non-public sector, the prevalence of treated purchased nets suggests that some purchased nets may be "leaked" ITNs from public sector distributions, and thus, may be an informal sector rather than part of the formal "private sector". Urban, wealthier households as well as those with educated heads were more likely to own purchased nets. Use of such nets was, however, lower in wealthier households. In addition, net use was higher in households owning insufficient nets for their family size, and when the nets were newer than 24 months. CONCLUSION: The formal and informal private sector have played a role in bolstering net access rates in some settings. Study findings can help relevant malaria control stakeholders gain insight on the contribution of purchased nets on their overall ITN strategy, identify potential target populations for private sector nets as well as inform the design and distribution of private sector insecticide-treated nets that appeal to their target groups.


Assuntos
Mosquiteiros Tratados com Inseticida/estatística & dados numéricos , Controle de Mosquitos/métodos , Propriedade/estatística & dados numéricos , África ao Sul do Saara , Fatores Socioeconômicos
17.
Malar J ; 18(1): 383, 2019 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-31791332

RESUMO

BACKGROUND: Long-lasting insecticidal nets (LLINs) treated with pyrethroids are the foundation of malaria control in sub-Saharan Africa. Rising pyrethroid resistance in vectors, however, has driven the development of alternative net formulations. Here the durability of polyethylene nets with a novel combination of a pyrethroid, permethrin, and the insect juvenile hormone mimic, pyriproxyfen (PPF), compared to a standard permethrin LLIN, was assessed in rural Burkina Faso. METHODS: A compound-randomized controlled trial was completed in two villages. In one village 326 of the PPF-permethrin nets (Olyset Duo) and 327 standard LLINs (Olyset) were distributed to assess bioefficacy. In a second village, 170 PPF-permethrin nets and 376 LLINs were distributed to assess survivorship. Nets were followed at 6-monthly intervals for 3 years. Bioefficacy was assessed by exposing permethrin-susceptible and resistant Anopheles gambiae sensu lato mosquito strains to standard World Health Organization (WHO) cone and tunnel tests with impacts on fertility measured in the resistant strain. Insecticide content was measured using high-performance liquid chromatography. LLIN survivorship was recorded with a questionnaire and assessed by comparing the physical integrity using the proportionate hole index (pHI). RESULTS: The PPF-permethrin net met WHO bioefficacy criteria (≥ 80% mortality or ≥ 95% knockdown) for the first 18 months, compared to 6 months for the standard LLIN. Mean mosquito mortality for PPF-permethrin nets, across all time points, was 8.6% (CI 2.6-14.6%) higher than the standard LLIN. Fertility rates were reduced after PPF-permethrin net exposure at 1-month post distribution, but not later. Permethrin content of both types of nets remained within the target range of 20 g/kg ± 25% for 242/248 nets tested. The pyriproxyfen content of PPF-permethrin nets declined by 54%, from 10.4 g/kg (CI 10.2-10.6) to 4.7 g/kg (CI 3.5-6.0, p < 0.001) over 36 months. Net survivorship was poor, with only 13% of PPF-permethrin nets and 12% of LLINs still present in the original household after 36 months. There was no difference in the fabric integrity or survivorship between the two net types. CONCLUSION: The PPF-permethrin net, Olyset Duo, met or exceeded the performance of the WHO-recommended standard LLIN (Olyset) in the current study but both net types failed the 3-year WHO bioefficacy criteria.


Assuntos
Anopheles , Mosquiteiros Tratados com Inseticida/estatística & dados numéricos , Inseticidas , Controle de Mosquitos , Mosquitos Vetores , Permetrina , Piridinas , Animais , Burkina Faso , Malária/prevenção & controle
18.
Malar J ; 18(1): 417, 2019 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-31831004

RESUMO

BACKGROUND: Mass and continuous distribution channels have significantly increased access to insecticide-treated nets (ITNs) in Ghana since 2000. Despite these gains, a large gap remains between ITN access and use. METHODS: A qualitative research study was carried out to explore the individual and contextual factors influencing ITN use among those with access in three sites in Ghana. Eighteen focus group discussions, and free listing and ranking activities were carried out with 174 participants; seven of those participants were selected for in-depth case study. Focus group discussions and case study interviews were audio-recorded, transcribed verbatim, and analysed thematically. RESULTS: ITN use, as described by study participants, was not binary; it varied throughout the night, across seasons, and over time. Heat was the most commonly cited barrier to consistent ITN use and contributed to low reported ITN use during the dry season. Barriers to ITN use throughout the year included skin irritation; lack of airflow in the sleeping space; and, in some cases, a lack of information on the connection between the use of ITNs and malaria prevention. Falling ill or losing a loved one to malaria was the most powerful motivator for consistent ITN use. Participants also discussed developing a habit of ITN use and the economic benefit of prevention over treatment as facilitating factors. Participants reported gender differences in ITN use, noting that men were more likely than women and children to stay outdoors late at night and more likely to sleep outdoors without an ITN. CONCLUSION: The study results suggest the greatest gains in ITN use among those with access could be made by promoting consistent use throughout the year among occasional and seasonal users. Opportunities for improving communication messages, such as increasing the time ITNs are aired before first use, as well as structural approaches to enhance the usability of ITNs in challenging contexts, such as promoting solutions for outdoor ITN use, were identified from this work. The information from this study can be used to inform social and behaviour change messaging and innovative approaches to closing the ITN use gap in Ghana.


Assuntos
Mosquiteiros Tratados com Inseticida/estatística & dados numéricos , Malária/prevenção & controle , Controle de Mosquitos/instrumentação , Adolescente , Adulto , Agentes Comunitários de Saúde , Feminino , Grupos Focais , Gana , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Controle de Mosquitos/métodos , Pesquisa Qualitativa , Inquéritos e Questionários , Adulto Jovem
19.
PLoS One ; 14(12): e0226191, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31869350

RESUMO

BACKGROUND: In view of widespread pyrethroid resistance in malaria vectors in Africa, two long-lasting insecticidal nets (LLINs) incorporated with a synergist, piperonyl butoxide (PBO), DawaPlus 3.0 (deltamethrin + PBO in the roof panel; deltamethrin alone in the side panels) and DawaPlus 4.0 (deltamethrin + PBO in all panels), were evaluated in an experimental hut trial in a rice growing irrigated area in Burkina Faso. Efficacy of nets was tested against free-flying malaria vector, Anopheles gambiae s.l., with high pyrethroid resistance involving L1014F kdr and CYP6P3P450 resistance mechanisms. METHODOLOGY: The efficacy of unwashed and 20-times washed DawaPlus 3.0 (polyethylene roof panel with 120 mg/m2 deltamethrin and 440 mg/m2 PBO; polyester side panels with deltamethrin 100 mg/m2) and DawaPlus 4.0 (same composition as roof of DawaPlus 3.0) was evaluated against DawaPlus 2.0 (80 mg/m2 deltamethrin; positive control). Volunteer sleepers and treatments were rotated in huts using a Latin square design on 63 consecutive nights during August-October 2016. Mortality, human blood-feeding inhibition, deterrence and exit rates of An. gambiae s.l. were monitored. PRINCIPAL FINDINGS: Significantly higher rates of mortality and blood-feeding inhibition were observed with unwashed DawaPlus 4.0 (36%; 47.5%) than unwashed DawaPlus 3.0 (11.8%; 33.3%), DawaPlus 2.0 (4.3%; 6.4%) or untreated net (P < 0.05). Washing reduced personal protective efficacy yet PBO-LLINs were more protective and both met the WHO criteria. CONCLUSIONS: The PBO-containing DawaPlus 4.0 significantly protected against An. gambiae s.l. in the study area. Unwashed DawaPlus 3.0 gave low to moderate protection against the positive control. PBO inhibits oxidase action; hence in areas with active malaria transmission having oxidase mechanisms, PBO nets could confer additional personal protection.


Assuntos
Anopheles/efeitos dos fármacos , Mosquiteiros Tratados com Inseticida , Controle de Mosquitos/métodos , Nitrilos/farmacologia , Butóxido de Piperonila/farmacologia , Piretrinas/farmacologia , Agricultura , Animais , Anopheles/fisiologia , Burkina Faso , Desenho de Equipamento , Voo Animal/efeitos dos fármacos , Gossypium , Humanos , Inseticidas/farmacologia , Malária/prevenção & controle , Mosquitos Vetores/efeitos dos fármacos , Mosquitos Vetores/fisiologia , Oryza
20.
Malar J ; 18(1): 364, 2019 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-31718659

RESUMO

BACKGROUND: Long-lasting insecticidal nets (LLIN), improved diagnosis and artemisinin-based combination therapy (ACT) have reduced malaria prevalence in Papua New Guinea since 2008. Yet, national incidence trends are inconclusive due to confounding effects of the scale-up of rapid diagnostic tests, and inconsistencies in routine reporting. METHODS: Malaria trends and their association with LLIN and ACT roll-out between 2010 and 2014 in seven sentinel health facilities were analysed. The analysis included 35,329 fever patients. Intervention effects were estimated using regression models. RESULTS: Malaria incidence initially ranged from 20 to 115/1000 population; subsequent trends varied by site. Overall, LLIN distributions had a cumulative effect, reducing the number of malaria cases with each round (incidence rate ratio ranging from 0.12 to 0.53 in five sites). No significant reduction was associated with ACT introduction. Plasmodium falciparum remained the dominant parasite in all sentinel health facilities. Resurgence occurred in one site in which a shift to early and outdoor biting of anophelines had previously been documented. CONCLUSIONS: LLINs, but not ACT, were associated with reductions of malaria cases in a range of settings, but sustainability of the gains appear to depend on local factors. Malaria programmes covering diverse transmission settings such as Papua New Guinea must consider local heterogeneity when choosing interventions and ensure continuous monitoring of trends.


Assuntos
Artemisininas/uso terapêutico , Controle de Doenças Transmissíveis/estatística & dados numéricos , Instalações de Saúde/estatística & dados numéricos , Mosquiteiros Tratados com Inseticida/estatística & dados numéricos , Lactonas/uso terapêutico , Malária/prevenção & controle , Controle de Mosquitos , Combinação de Medicamentos , Humanos , Incidência , Malária/epidemiologia , Papua Nova Guiné/epidemiologia , Plasmodium/isolamento & purificação
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