Ampleur de la dengue dans la ville de Ouagadougou, Burkina-Faso, 2016: Magnitude of dengue fever in the city of Ouagadougou, Burkina-Faso, 2016

Introduction: En Octobre 2016, le Burkina Faso a connu une flambée de cas de dengue dont l’ampleur est peu connue. Aussi aucune étude n’a été réalisée durant les dix dernières années, donnant lieu à un manque d’information actualisée sur sa prévalence et son incidence. Cette étude avait pour objectif de déterminer l’ampleur de la dengue à Ouagadougou et le type de virus circulant. Méthodes: Nous avons mené une étude transversale sur les cas de dengue enregistrés dans les formations sanitaires (FS) de la ville de Ouagadougou du 1er août au 31 décembre 2016. Un cas de dengue était défini comme toute personne résident dans la ville de Ouagadougou présentant une maladie fébrile aiguë (2-7 jours), avec au moins deux des symptômes suivants : céphalées, douleur rétro-orbitale, myalgie, arthralgie, éruption cutanée, manifestations hémorragiques, syndrome de choc et un test biologique positif à la PCR ou avec TDR-Dengue positif ayant un lien épidémiologique avec un cas confirmé. Nous avons réalisé une recherche active des cas à travers une revue documentaire des registres de laboratoire, consultation et/ou d’hospitalisation des FS, Une fiche de collecte a été utilisée pour recueillir les caractéristiques sociodémographiques, cliniques, biologiques des cas. Résultats: Au total, 5094 cas de dengue ont été enregistrés dans les FS. L’âge médian était de 27 ans avec un intervalle interquartile de 16 à 37 ans. Quinze cas (51,72%) ont été testés positifs à la PCR dont 10 (66,67%) au DENV2 et 5 (33,33%) au DENV3. Parmi les cas, 2569 (50,76%) étaient de sexe féminin et 1494 (28,16%) cas avaient été hospitalisés. Sur les cas recensés, 73% avaient été notifiés par les structures privées et 3174 (88,88%) étaient des éleves/étudiants ou fonctionnaires ou commerçants. Le taux d’attaque global était de 201 cas (5094/2532311) pour 100000 habitants. Le taux de létalité était de 35/5094 (0,69%). Conclusion: Le taux d’attaque global de la dengue en 2016 était de 201 cas pour 100000 habitants. La dengue touchait plus les adultes jeunes surtout les élèves/étudiants et les fonctionnaires et était causée par les types 2 et 3. Les cas étaient plus notifiés par les structures privées. Une surveillance hebdomadaire associée à une surveil-lance sentinelle et la sensibilisation de la population sur la dengue contribueraient à endiguer ce fléau au Burki-na Faso. Background: In October 2016, Burkina Faso experienced an outbreak of dengue fever that the magnitude is little known. Also, no studies have been performed in the past ten years, giving rise to a lack of updated information on its prevalence and incidence. We conducted an investigation to determine the magnitude of dengue fever in Ouagadougou’s city and the type of virus circulating. Methods: We conducted a cross-sectional study on the cases of dengue recorded in health facilities (HF) in Ouagadougou’s city from August 1st to December 31st, 2016. We defined a case of dengue as any person resident in the city of Ouagadougou with acute febrile illness (2-7days), with at least two of the following symptoms (headache, retro-orbital pain, myalgia, arthralgia, rash, hemorrhagic manifestations, shock syndrome) and a positive PCR test or with dengue-RDT positive, having an epidemiological link with a confirmed case. We carried out an active search for cases through a documentary review of laboratory, consultation and/or hospitalization registers of HF, used a file to collect the socio-demographic, clinical and biological characteristics of the cases. Results: A total of 5094 cases of dengue fever were recorded in the HF. The median age was 27 years with an interquartile range of 16 to 37 years old. Fifteen (51.72%) cases tested positive with PCR including 10(66.67%) for DENV2 and 5(33.33%) for DENV3. Among the cases, 2,569(50.76%) were female and 1,494(28.16%) cases were hospitalized. Of the cases listed, 73% were notified by private’s hospitals and 3,174 (88.88%) were pupils/students or civil servants or traders. The overall attack rate was 201 cases (5094/2532311) per 100,000 populations. The case fatality rate was 35/5094 (0.69%). Conclusion: The overall dengue attack rate in 2016 was 201 cases per 100,000 populations. Dengue more affected young adults especially the pupils/students or civil servants and was caused by types 2 and 3. The cases were more notified by the private hospitals. We recommend weekly surveillance, sentinel surveillance and public awareness of dengue fever

Cross-Clade Recognition of HIV-1 CAp24 by CD4+ T Cells in HIV-1-Infected Individuals in Burkina Faso and Germany

The presence of antigen-specific cellular immune responses may be an indicator of long-term asymptomatic HIV-1-disease. The detection of cellular immune responses to infection with different subtypes of HIV-1 may be hampered by genetic differences of immunodominant antigens such as the capsid protein CAp24. In Nouna, Burkina Faso, HIV-1 circulating recombinant forms CRF02_AG and CRF06_cpx are the 2 major strains detectable in HIV-1-infected individuals, while subtype B strains prevail in Europe and North America. Amino acid sequences of CAp24 were assessed in blood samples from 10 HIV-1-infected patients in Nouna, Burkina Faso. Production of interferon-gamma (IFN-γ) in peripheral blood CD4+ lymphocytes in response to recombinant HIV-1 proteins derived from clade B (including CAp24NL4-3) was measured using a modified flow-cytometry-based whole blood short term activation assay (FASTimmune, BDBiosciences). IFN-γ production following stimulation with a whole length CAp24 protein derived from clade B (CAp24NL4-3) was additionally quantified in comparison to a CAp24 protein derived from CRF02_AG (CAp24BD6-15) in 16 HIV-1-infected patients in Heidelberg, Germany. Amino acid sequence identity of CAp24 obtained from patients in Nouna ranged between 86 and 89% when compared to the clade B CAp24NL4-3 consensus sequence, between 90 and 95% when compared to the circulating recombinant form CRF06_CPX consensus sequence, and between 92 and 96% when compared to the CAp24BD6-15 consensus sequence. Significant numbers of HIV-1-specific CD4+ lymphocytes producing IFN-γ were detected in 4 of 10 HIV-1-infected patients. In 7 of 16 patients in Heidelberg, recombinant CAp24BD6-15 stimulated IFN-γ-production in CD4+ lymphocytes to a similar extent as the clade B-derived CAp24NL4-3. Thus, antigen-specific CD4+ lymphocytes from both West African and European patients infected with different strains of HIV-1 show relevant cross-clade recognition of HIV-1 CAp24 in a flow-cytometry-based whole blood short term activation assay

A non-destructive sugar-feeding assay for parasite detection and estimating the extrinsic incubation period of Plasmodium falciparum in individual mosquito vectors

Despite its epidemiological importance, the time Plasmodium parasites take to achieve development in the vector mosquito (the extrinsic incubation period, EIP) remains poorly characterized. A novel non-destructive assay designed to estimate EIP in single mosquitoes, and more broadly to study Plasmodium–Anopheles vectors interactions, is presented. The assay uses small pieces of cotton wool soaked in sugar solution to collect malaria sporozoites from individual mosquitoes during sugar feeding to monitor infection status over time. This technique has been tested across four natural malaria mosquito species of Africa and Asia, infected with Plasmodium falciparum (six field isolates from gametocyte-infected patients in Burkina Faso and the NF54 strain) and across a range of temperatures relevant to malaria transmission in field conditions. Monitoring individual infectious mosquitoes was feasible. The estimated median EIP of P. falciparum at 27 °C was 11 to 14 days depending on mosquito species and parasite isolate. Long-term individual tracking revealed that sporozoites transfer onto cotton wool can occur at least until day 40 post-infection. Short individual EIP were associated with short mosquito lifespan. Correlations between mosquito/parasite traits often reveal trade-offs and constraints and have important implications for understanding the evolution of parasite transmission strategies

Immune Reconstitution During the First Year of Antiretroviral Therapy of HIV-1-Infected Adults in Rural Burkina Faso

There are no data on the outcome of highly active antiretroviral therapy (HAART) in HIV-infected adults in rural Burkina Faso. We therefore assessed CD4+ T-cell counts and HIV-1 plasma viral load (VL), the proportion of naive T-cells (co-expressing CCR7 and CD45RA) and T-cell activation (expression of CD95 or CD38) in 61 previously untreated adult patients from Nouna, Burkina Faso, at baseline and 2 weeks, 1, 3, 6, 9 and 12 months after starting therapy. Median CD4+ T-cell counts increased from 174 (10th-90th percentile: 33-314) cells/µl at baseline to 300 (114- 505) cells/µl after 3 months and 360 (169-562) cells/µl after 12 months of HAART. Median VL decreased from 5.8 (4.6- 6.6) log10 copies/ml at baseline to 1.6 (1.6-2.3) log10 copies/ml after 12 months. Early CD4+ T-cell recovery was accompanied by a reduction of the expression levels of CD95 and CD38 on T-cells. Out of 42 patients with complete virological follow-up under HAART, 19 (45%) achieved concordant good immunological (gain of ≥100 CD4+ T-cells/µl above baseline) and virological (undetectable VL) responses after 12 months of treatment (intention-to-treat analysis). Neither a decreased expression of the T-cell activation markers CD38 and CD95, nor an increase in the percentage of naive T-cells reliably predicted good virological treatment responses in patients with good CD4+ T-cell reconstitution. Repeated measurement of CD4+ T-cell counts during HAART remains the most important parameter for immunologic monitoring. Substitution of repeated VL testing by determination of T-cell activation levels (e.g., CD38 expression on CD8+ T-cells) should be applied with caution

Contrasting effects of the alkaloid ricinine on the capacity of Anopheles gambiae and Anopheles coluzzii to transmit Plasmodium falciparum

Background Besides feeding on blood, females of the malaria vector Anopheles gambiae sensu lato readily feed on natural sources of plant sugars. The impact of toxic secondary phytochemicals contained in plant-derived sugars on mosquito physiology and the development of Plasmodium parasites remains elusive. The focus of this study was to explore the influence of the alkaloid ricinine, found in the nectar of the castor bean Ricinus communis, on the ability of mosquitoes to transmit Plasmodium falciparum. Methods Females of Anopheles gambiae and its sibling species Anopheles coluzzii were exposed to ricinine through sugar feeding assays to assess the effect of this phytochemical on mosquito survival, level of P. falciparum infection and growth rate of the parasite. Results Ricinine induced a significant reduction in the longevity of both Anopheles species. Ricinine caused acceleration in the parasite growth rate with an earlier invasion of the salivary glands in both species. At a concentration of 0.04 g l−1 in An. coluzzii, ricinine had no effect on mosquito infection, while 0.08 g l−1 ricinine-5% glucose solution induced a 14% increase in An. gambiae infection rate. Conclusions Overall, our findings reveal that consumption of certain nectar phytochemicals can have unexpected and contrasting effects on key phenotypic traits that govern the intensity of malaria transmission. Further studies will be required before concluding on the putative role of ricinine as a novel control agent, including the development of ricinine-based toxic and transmission-blocking sugar baits. Testing other secondary phytochemicals in plant nectar will provide a broader understanding of the impact which plants can have on the transmission of vector-borne diseases

Plant-mediated effects on mosquito capacity to transmit human malaria

The ecological context in which mosquitoes and malaria parasites interact has received little attention, compared to the genetic and molecular aspects of malaria transmission. Plant nectar and fruits are important for the nutritional ecology of malaria vectors, but how the natural diversity of plant-derived sugar sources affects mosquito competence for malaria parasites is unclear. To test this, we infected Anopheles coluzzi, an important African malaria vector, with sympatric field isolates of Plasmodium falciparum, using direct membrane feeding assays. Through a series of experiments, we then examined the effects of sugar meals from Thevetia neriifolia and Barleria lupilina cuttings that included flowers, and fruit from Lannea microcarpa and Mangifera indica on parasite and mosquito traits that are key for determining the intensity of malaria transmission. We found that the source of plant sugar meal differentially affected infection prevalence and intensity, the development duration of the parasites, as well as the survival and fecundity of the vector. These effects are likely the result of complex interactions between toxic secondary metabolites and the nutritional quality of the plant sugar source, as well as of host resource availability and parasite growth. Using an epidemiological model, we show that plant sugar source can be a significant driver of malaria transmission dynamics, with some plant species exhibiting either transmission-reducing or -enhancing activities

ARIA digital anamorphosis : Digital transformation of health and care in airway diseases from research to practice

Digital anamorphosis is used to define a distorted image of health and care that may be viewed correctly using digital tools and strategies. MASK digital anamorphosis represents the process used by MASK to develop the digital transformation of health and care in rhinitis. It strengthens the ARIA change management strategy in the prevention and management of airway disease. The MASK strategy is based on validated digital tools. Using the MASK digital tool and the CARAT online enhanced clinical framework, solutions for practical steps of digital enhancement of care are proposed.Peer reviewe

Cabbage and fermented vegetables : From death rate heterogeneity in countries to candidates for mitigation strategies of severe COVID-19

Large differences in COVID-19 death rates exist between countries and between regions of the same country. Some very low death rate countries such as Eastern Asia, Central Europe, or the Balkans have a common feature of eating large quantities of fermented foods. Although biases exist when examining ecological studies, fermented vegetables or cabbage have been associated with low death rates in European countries. SARS-CoV-2 binds to its receptor, the angiotensin-converting enzyme 2 (ACE2). As a result of SARS-CoV-2 binding, ACE2 downregulation enhances the angiotensin II receptor type 1 (AT(1)R) axis associated with oxidative stress. This leads to insulin resistance as well as lung and endothelial damage, two severe outcomes of COVID-19. The nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is the most potent antioxidant in humans and can block in particular the AT(1)R axis. Cabbage contains precursors of sulforaphane, the most active natural activator of Nrf2. Fermented vegetables contain many lactobacilli, which are also potent Nrf2 activators. Three examples are: kimchi in Korea, westernized foods, and the slum paradox. It is proposed that fermented cabbage is a proof-of-concept of dietary manipulations that may enhance Nrf2-associated antioxidant effects, helpful in mitigating COVID-19 severity.Peer reviewe