Is biological larviciding against malaria a starting point for integrated multi-disease control? Observations from a cluster randomized trial in rural Burkina Faso.

OBJECTIVES: To evaluate the impact of anti-malaria biological larviciding with Bacillus thuringiensis israelensis on non-primary target mosquito species in a rural African setting. METHODS: A total of 127 villages were distributed in three study arms, each with different larviciding options in public spaces: i) no treatment, ii) full or iii) guided intervention. Geographically close villages were grouped in clusters to avoid contamination between treated and untreated villages. Adult mosquitoes were captured in light traps inside and outside houses during the rainy seasons of a baseline and an intervention year. After enumeration, a negative binomial regression was used to determine the reductions achieved in the different mosquito species through larviciding. RESULTS: Malaria larviciding interventions showed only limited or no impact against Culex mosquitoes; by contrast, reductions of up to 34% were achieved against Aedes when all detected breeding sites were treated. Culex mosquitoes were captured in high abundance in semi-urban settings while more Aedes were found in rural villages. CONCLUSIONS: Future malaria larviciding programs should consider expanding onto the breeding habitats of other disease vectors, such as Aedes and Culex and evaluate their potential impact. Since the major cost components of such interventions are labor and transport, other disease vectors could be targeted at little additional cost.

Biological larviciding against malaria vector mosquitoes with Bacillus thuringiensis israelensis (Bti) - Long term observations and assessment of repeatability during an additional intervention year of a large-scale field trial in rural Burkina Faso.

The first line of malaria vector control to date mainly relies on the use of long-lasting insecticidal nets (LLINs) and indoor residual spraying (IRS). For integrated vector management, targeting the vector larvae with biological larvicides such as Bacillus thuringiensis israelensis (Bti) can be an effective additional mainstay. This study presents data from the second intervention year of a large-scale trial on biological larviciding with Bti that was carried out in 127 rural villages and a semi-urban town in Burkina Faso. Here we present the reductions in malaria mosquitoes that were achieved by continuing the initial interventions for an additional year, important to assess sustainability and repeatability of the results from the first intervention year. Larviciding was performed applying two different larviciding choices ((a) treatment of all environmental breeding sites, and (b) selective treatment of those that were most productive for Anopheles larvae indicated by remote sensing based risk maps). Adult Anopheles spp. mosquito abundance was reduced by 77.4% (full treatment) and 63.5% (guided treatment) compared to the baseline year. The results showed that malaria vector abundance can be dramatically reduced using biological larviciding and that this effect can be achieved and maintained over several consecutive transmission seasons.

Frequency and Mortality Risk Factors of Acute Ischemic Stroke in Emergency Department in Burkina Faso.

OBJECTIVE: To determine the prevalence of ischemic stroke deaths and their predictive factors in the Emergency Department at Yalgado Ouedraogo University Teaching Hospital (YOUTH). Methodology. This was a retrospective study with an analytical and descriptive focus over a period of three years from January 1, 2015, to December 31, 2017. RESULTS: During the study period, 302 acute ischemic stroke patients with a mean age of 62.2 ± 14.26 years were included. Atrial hypertension was the most common vascular risk factor in 52.5%. On admission, 34.8% of patients had loss of consciousness. The mean time to perform brain CT was 1.5 days. The average length of stay was 4 days. Electrocardiogram, echocardiography, and cervical Doppler were not performed during hospitalization in ED. The mortality rate was 39%, respectively, 37.6% in male and 41.6% in female. The mean age of patients who died in ED was 63.6 ± 13.52 years. Hypertension was the most common vascular risk factors in 54.2% of death. After logistic regression, the predictors of death were past history of heart disease, consciousness disorders, hyperthermia, hyperglycemia on admission, poststroke pneumonia, and urinary tract infection. CONCLUSIONS: Acute ischemic stroke was frequent in Emergency Department with high mortality rate. The mortality risk factors were the same than those found in literature. This higher mortality can be avoided by early diagnosis and an adequate management.

[Epidemioclinical Profile Of Chronic Hemodialysis Patients At Tengandogo University Hospital, Ouagadougou]. / Profil Epidemio-Clinique Des Patients En Hemodialyse Chronique Au CHU De Tengandogo, Ouagadougou.

Nephrology in Burkina Faso faces many challenges, including insufficient epidemiological data. AIMS: Our study aims to describe the epidemiological and clinical characteristics of patients on chronic hemodialysis in a new hemodialysis center. METHOD: This was a cross-sectional, descriptive, monocentric study conducted in the hemodialysis unit of Tengandogo University Hospital from February 1, 2018 to January 31, 2019. RESULT: We recorded 94 patients undergoing hemodialysis for end-stage kidney disease, including 63 patients with hemodialysis incidents versus 31 patients transferred to us from other centers. The average age was 43.7 years[4-85 years]. The average age of hemodialysis was 42.5 years[4-85 years]. The average duration of hemodialysis was 1.2 years[0-12 years].The sex ratio was 2.48. The main comorbidity was high blood pressure with 63.8%. In 43.6% of cases, the cause of chronic kidney disease could not be determined. Vascular nephropathy of hypertensive origin and chronic glomerulonephritis are found respectively with 27.6% and 12.7%. The mortality rate is 23.4 per 100 people years. In 82% of cases, death occurred within the first month following hemodialysis.Young age, diagnostic difficulties and high mortality rates reveal the inadequacies of our health system and negatively affect socio-economic development. CONCLUSION: These data show the need for a kidney disease prevention program.

La néphrologie au Burkina Faso est confrontée à de nombreux défis dont l'insuffisance de données épidémiologiques. BUT: Notre étude a pour but de décrire les caractéristiques épidémiologiques et cliniques des patients en hémodialyse chronique dans un nouveau centre. MÉTHODE: Il s'est agi d'une étude transversale, descriptive, monocentrique, menée dans l'unité d'hémodialyse du CHU de Tengandogo du 1er février 2018 au 31 janvier 2019. RÉSULTATS: Nous avons enregistré 94 patients pris en charge en hémodialyse pour insuffisance rénale chronique terminale, dont 63 patients incidents en hémodialyse contre 31 patients qui nous ont été transféré à partir d'autres centres. L'âge moyen était de 43,7 ans [4-85 ans]. L'âge moyen de mise en hémodialyse était de 42,5 ans [4-85 ans]. La durée moyenne en dialyse était de 1,2 ans [0-12 ans]. Le sexe ratio était de 2,48. La principale comorbidité était l'hypertension artérielle avec 63.8%. Dans 43,6% des cas, la cause de la maladie rénale chronique n'a pas pu être déterminée. La néphropathie vasculaire d'origine hypertensive et la glomérulonéphrite chroniqueétaient retrouvés respectivement avec 27,6% et 12,7%. Le taux de mortalité étaitde 23,4 pour cent personnes années. Dans 82% des cas, le décès est survenu dans le premier mois suivant la mise en hémodialyse. Le jeune âge, les difficultés de diagnostic, le taux de mortalité élevé, révèlent les insuffisances de notre système sanitaireet affectent négativement le développement socio-économique. CONCLUSION: Ces données montrent la nécessité de la mise en place d'un programme de prévention des maladies rénales.

Reduction of malaria vector mosquitoes in a large-scale intervention trial in rural Burkina Faso using Bti based larval source management.

BACKGROUND: Malaria remains one of the most important causes of morbidity and death in sub-Saharan Africa. Along with early diagnosis and treatment of malaria cases and intermittent preventive treatment in pregnancy (IPTp), vector control is an important tool in the reduction of new cases. Alongside the use of long-lasting insecticidal nets (LLINs) and indoor residual spraying (IRS), targeting the vector larvae with biological larvicides, such as Bacillus thuringiensis israelensis (Bti) is gaining importance as a means of reducing the number of mosquito larvae before they emerge to their adult stage. This study presents data corroborating the entomological impact of such an intervention in a rural African environment. METHODS: The study extended over 2 years and researched the impact of biological larviciding with Bti on malaria mosquitoes that were caught indoors and outdoors of houses using light traps. The achieved reductions in female Anopheles mosquitoes were calculated for two different larviciding choices using a regression model. RESULTS: In villages that received selective treatment of the most productive breeding sites, the number of female Anopheles spp. dropped by 61% (95% CI 54-66%) compared to the pre-intervention period. In villages in which all breeding sites were treated, the number of female Anopheles spp. was reduced by 70% (95% CI 64-74%) compared to the pre-intervention period. CONCLUSION: It was shown that malaria vector abundance can be dramatically reduced through larviciding of breeding habitats and that, in many geographical settings, they are a viable addition to current malaria control measures.

Nightly Biting Cycles of Anopheles Species in Rural Northwestern Burkina Faso.

The biting behavior of anophelines is an important determinant of malaria transmission. Understanding the local vector host-seeking behavior, its outdoor/ indoor biting preference, and nocturnal biting periods is essential for effectively applying and improving vector control methods, such as Long Lasting Insecticidal Nets (LLINs) and personal protective measures. To better understand the biting and host-seeking patterns of Anopheles mosquitoes in Northwestern Burkina Faso, we performed biweekly Human Landing Catches (HLC) in six villages during the period of highest mosquito abundance and malaria transmission. We applied a negative binomial regression framework to statistically analyze the host-seeking activities of Anopheles species and test for differences across hours, months, and villages, as well as for differences between indoor and outdoor capture points. Anopheles gambiae s.l. was identified as the main malaria vector in this region, representing about 90% of the total anopheline population. Biting activity was significantly different across hours and showed a peaked plateau between 2000 and 0200 hours. Differences in the pattern of biting cycles were observed between the early and late rainy season. This study shows that anopheline biting activity in Northwest Burkina Faso is high throughout the night, at indoor and outdoor posts alike. Consequently, bed nets alone may not provide sufficient protection against early biting anophelines and should be complemented with additional strategies such as indoor residual spraying (IRS) and larval source management (LSM) to meet the WHO's ambitious goals that are reflected in the global technical malaria strategy for 2030.

Efficacy of Bacillus thuringiensis var. israelensis against malaria mosquitoes in northwestern Burkina Faso.

BACKGROUND: In Sub Saharan Africa malaria remains one of the major health problems and its control represents an important public health measure. Integrated malaria control comprises the use of impregnated mosquito nets and indoor residual spraying. The use of drugs to treat patients can create additional pressure on the equation of malaria transmission. Vector control may target the adult mosquitoes or their aquatic larval stages. Biological larvicides such as Bacillus thuringiensis israelensis (Bti) represent a promising approach to support malaria control programs by creating additional pressure on the equation of malaria transmission. METHODS: In this study we examined the efficacy of a water-dispersible granule formulation (WDG) of the biological larvicide Bti (VectoBac®) against wild Anopheles spp. larvae. Different concentrations of the larvicide were tested in standardized plastic tubs in the field against untreated controls. In weekly intervals tubs were treated with fixed concentrations of larvicide and the percentage reduction of larvae and pupae was calculated. RESULTS: All used concentrations successfully killed 100 percent of the larvae within 24 hours, while the higher concentrations showed a slightly prolonged residual effect. Natural reconolization of larvae took place after two and three days respectively, late instar larvae were not found before 5 days after treatment. For the higher concentrations, up to three days no new larvae were found, implicating that the residual effect of WDG in tropical conditions is approximately one to two days. The overall pupae reduction in treated tubs was 98.5%. CONCLUSIONS: Biological larviciding with Bti can be a promising, additional tool in the fight against malaria in Africa. Environmental particularities in tropical Africa, first and foremost the rapid development of mosquitoes from oviposition to imago have to be taken into account before implementing such counter measures in national or international vector control programs. Nonetheless biological larviciding seems to be an appropriate measure for selected conditions, offering a significant contribution to the future of malaria control.