Determinants and prevalence of symptomatic dengue fever among adults in the Central Region of Burkina Faso: a hospital-based cross-sectional study.

BACKGROUND: Dengue fever (DF) is a significant public health concern in Burkina Faso, particularly in the Central Region, previously endemic for malaria. However, limited research has focused on dengue prevalence and associated factors among adult febrile patients in this region. This study aimed to estimate the prevalence of symptomatic dengue fever among adults and identify the sociodemographic and clinical determinants of the disease. METHODS: A seroepidemiological cross-sectional study was conducted in the Central Region of Burkina Faso, through a three-stage sampling. Five health facilities, one from each of the region five districts, were purposively selected. Febrile patients aged 16 and older, suspected of having dengue, were included in the study, after consenting. Bivariate analyses and multivariate binary logistic regression were done at a 5% confidence level. RESULTS: A total of 637 patients between the ages of 16 and 90 years were included. Most of the participants were females (58.71%). Most dengue cases resided in Arrondissement 4 (59.62%), or were present in the Arrondissement 4 at daytime during the previous days (51.92%). 52.90% of the participants knew of dengue. Dengue prevalence was estimated at 8.16% (95% CI: 6.16%-10.57%). The most frequent markers for dengue were immunoglobulins M detected in 4.40% (2.94%-6.29%), followed by Antigen NS1 at 4.24% (95% CI: 2.81%-6.11%). The Antigen NS1 marker was associated with myalgia (p = 0.024), vomiting (p < 0.001), hemorrhagic manifestations (p = 0.001), and anorexia (p < 0.001). Staying at Arrondissement 4 (vs staying at Saaba) during daytime (aOR = 2.36 95% CI: 1.03-5.45; p = 0.044) significantly increased the odds of dengue. Dengue cases were about 3 times more likely to have vomited (aOR = 2.99 95% CI: 1.58-5.64; p = 0.001). Participants knowing of dengue (aOR = 0.53 95% CI: 0.29-0.98; p = 0.042) and those coinfected with malaria (aOR = 0.28 95% CI: 0.14-0.57; p < 0.001) instead had reduced odds of dengue. CONCLUSION: The study revealed a relatively high prevalence of symptomatic dengue fever among adults in the Central Region of Burkina Faso in 2022. These findings emphasize the need for continuous surveillance and targeted control measures. The low coinfection of dengue and malaria warrants further investigation.

In Vivo Diuretic Activity and Anti-Hypertensive Potential of Hibiscus sabdariffa Extract by Inhibition of Angiotensin-Converting Enzyme and Hypertension Precursor Enzymes.

Aqueous extracts of calyx from Hibiscus sabdariffa (HS) (roselle) are highly appreciated for their nutritional and therapeutic effects, especially as anti-hypertensive substances. This study aimed to evaluate their anti-hypertensive potential through an in vitro inhibition assay of angiotensin-converting enzyme (ACE) and hypertension precursor enzymes and to assess the in vivo diuretic activity of HS. Results showed that HS extract inhibited enzymes belonging to several classes, such as α-amylase, trypsin, chymotrypsin, xanthine oxidase, lipoxygenase, and angiotensin-converting enzyme. In particular, enzymatic kinetics of ACE indicated a competitive inhibition fashion of HS extract. Furthermore, the extracts showed remarkable diuretic and natriuretic effects at doses of 50 mg/kg/bw, 100 mg/kg/b.w, and 200 mg/kg.b.w. These activities can be explained by the high content of phenolic compounds and essential amino acids. Roselle could be a potential source of nutraceuticals and anti-hypertensive bioactive compounds.

Estimating dengue burden among family contacts through cluster investigation around probable cases in 2022 and 2023 in the Central Region, Burkina Faso.

BACKGROUND: In 2023, Burkina Faso experienced the largest dengue epidemic ever in Africa. This study aimed to estimate the prevalence of symptomatic, subclinical, and asymptomatic dengue and determine the associated factors among adult contacts of dengue in the Central Region, Burkina Faso. METHODS: This cross-sectional study included contacts of dengue probable cases through cluster sampling in 2022-2023. These suspected cases that tested positive were identified from the five health facilities (Pissy CMA, Saaba CM, Kossodo CMA, Samandin CM, and Marcoussis CSPS) that reported the highest number of cases in 2021 per district. All participants underwent dengue and malaria rapid diagnostic tests (RDT). Samples positive for non-structural 1 protein antigen (AgNS1) and/or immunoglobulin M (IgM) were tested for serotype detection by reverse transcription polymerase chain reaction (RT-PCR). Binary logistic regression was done to identify the determinants of asymptomatic, subclinical, and symptomatic dengue among contacts of probable dengue cases. RESULTS: A total of 484 contacts were included, mostly in 2023 (75.2%). Most participants were females (58.6%), residing (24.3%) and passing their daytime (23.1%) in Saaba. The overall prevalence of dengue was estimated at 15.1% [95% confidence interval (CI): 12.0-18.6%], representing cases not seeking care in hospitals. Asymptomatic cases represented 2.9% (95% CI: 1.6-4.8%). Subclinical and symptomatic cases accounted for 6.0% (95% CI: 4.1-8.5%) and 6.2% (95% CI: 4.2-8.7%), respectively. Of the 58 samples tested by RT-PCR, 10 were confirmed for serotype 3 in 2023. Malaria cases were estimated at 5.6% (95% CI: 3.7-8.0%). After adjustment, participants claiming that a virus transmits dengue were likelier to have asymptomatic dengue [adjusted odds ratio (aOR) = 7.1, 95% CI: 2.4-21.0]. From the multivariable analysis, subclinical dengue was statistically associated with being included in the study in 2023 (aOR = 30.2, 95% CI: 2.0-455.5) and spending the daytime at Arrondissement 4 (aOR = 11.5, 95% CI: 1.0-131.0). After adjustment, symptomatic dengue was associated with living less than 50 m away from cultivated land (aOR = 2.8, 95% CI: 1.1-6.9) and living less than 50 m from a stretch of water (aOR = 0.1, 95% CI: 0.0-0.6). CONCLUSIONS: The overall burden of dengue among populations not seeking care in hospitals was quite high, with few asymptomatic cases. Efforts to manage dengue cases should also target non-hospital cases and raise population awareness. The 2023 epidemic could be due to dengue virus (DENV)-3.

[School-age children'S knowledge and perceptions concerning Soil-transmitted Helminthiases and Targeted Preventive Chemotherapy in Ghana's Oti Region]. / Connaissances et perceptions des enfants d'âge scolaire concernant les géo-helminthiases et la Chimiothérapie Préventive Ciblée dans la Région D'oti au Ghana.

Background: The Ghana Neglected Tropical Diseases control program aimed to raise population awareness on soil-transmitted helminth (STH) infections and achieve a 100% coverage of preventive chemotherapy (PCT) by 2020. This study aims at determining the factors associated with the knowledge of school-age children and describing their perceptions at Krachi East Municipal in Ghana. Patients and methods: It was a cross-sectional study. Children and their caregivers were selected from 8 communities following a two-stage stratified sampling. Descriptive statistics and binary logistic regression were performed at a 5% significance level. Results: 352 children and their caregivers were surveyed, mainly from Dambai (66.48%). The median age was 11 (IQR: 9-12) years and the children aged 7-14 years. About half of the children were males (53.13%) and most caregivers were females (66.48%). Most children perceived a benefit associated with PCT (94.89%). The proportion of children perceiving a health risk did not differ significantly from those not perceiving a risk (49.72% vs 50.28%; p=0.8802). In general, children had poor knowledge (91.19% vs 8.81%; p<0.0001). Good knowledge was associated with ethnic group [Guan: aOR=3.96 95%CI 1.11-14.12; p=0.034], child age [(11-12 years: aOR=6.05 95%CI 1.21-30.22; p=0.026); (13-14 years: aOR=8.19 95%CI 1.64-40.89; p=0.010)] and caregivers' sex (Female: aOR=2.97 95%CI 1.02-8.66; p=0.046) in the adjusted model. Conclusion: Younger children and male caregivers seem to have low knowledge of intestinal worms and PCT. Therefore, they must get more attention regarding health education.

Preclinical Evaluation of the Antihypertensive Effect of an Aqueous Extract of Anogeissus leiocarpa (DC) Guill et Perr. Bark of Trunk in L-NAME-Induced Hypertensive Rat.

BACKGROUND: The present study investigates the effect of an aqueous extract of Anogeissus leiocarpa (AEAL) on normotensive Wistar rats and its chronic antihypertensive effects in L-NAME-induced hypertensive rats by using a non-invasive tail-cuff model. METHODS: The effects of AEAL (50mg/kg) and NaCl 0.9% on blood pressure were investigated by daily oral administration in normotensive Wistar rats over four weeks. L-NAME-induced hypertensive rats were produced by L-NAME (40mg/kg) daily oral administration for two weeks. For chronic antihypertensive effects, induced hypertensive rats have received L-NAME in combination with AEAL (10 or 50mg/kg/day) for two following weeks. RESULTS: In normotensive rats, daily administration of AEAL (50mg/kg) has no significant effect on their blood pressure, which was similar to that of the control group. L-NAME's daily oral administration induces a progressive increase in systolic blood pressure (SBP) from 115.8 ± 7.9mmHg to 153.5 ± 4.6mmHg after two weeks, which was maintained to the end of the treatment. In L-NAME-induced hypertensive rats, AEAL (50mg/kg/day) significantly decreases the SPB from 160.0 ± 5.8 mmHg to 108.8 ± 2.7mmHg after only four days of administration. However, the lower dose of AEAL (10mg/kg) also normalized the SBP of L-NAME-induced hypertensive rats but only evident after seven days of administration. Moreover, AEAL does not effect on the serum biochemical parameters (ALAT, ASAT, CREAT, etc.) and any macroscopic adverse effect was detected on the sensible organs involved during hypertension. In the aorta rings from treated rats, AEAL (50mg/kg/day) alone or in combination with L-NAME has enhanced the vasodilation effect of acetylcholine. However, the vasodilation effect of AEAL alone or in association with L-NAME has enhanced the sodium nitroprusside effect in treated rat aorta rings after autopsy. CONCLUSION: These findings suggest that AEAL affords significant antihypertensive effects against L-NAME-induced hypertensive rats without modification of serum parameters and deleterious effects.

Pharmacological Evaluation of the Bronchorelaxant Effect of Waltheria indica L. (Malvaceae) Extracts on Rat Trachea.

Waltheria indica L. (Malvaceae) is a plant used in Burkina Faso for the treatment of various ailments including asthma. The aim of the study was to evaluate the pharmacological relaxant effect of the leafy stem extracts of Waltheria indica and thereby verify claim of use in treating asthma. Aqueous decoction and hydroalcoholic extracts obtained from the powdered leafy stems were screened for the presence of some phytoconstituents. The in vitro relaxant effect of the two extracts was evaluated on acetylcholine- (ACh 10-5 M) and potassium chloride- (KCl 6 × 10-2 M) induced contractions on rat-isolated tracheal preparations. To examine whether the potassium (K+) channels are involved in the relaxant effect, glibenclamide, an ATP-sensitive potassium channel inhibitor, was used. Moreover, to assess the safety of the extracts, acute oral toxicity was carried out on mice. The phytochemical screening revealed the presence of alkaloids, flavonoids, saponins, steroids, triterpenoids, tannins, and coumarins in the hydroalcoholic extract. Tannins, steroids, triterpenoids, and coumarins were not detected in the aqueous decoction. With respective EC50 values of 1.517 ± 0.002 mg/mL and 1.433 ± 0.001 mg/mL on ACh-and KCl-provoked contractions, the hydroalcoholic extract was found more potent in relaxing the isolated rat tracheal preparations compared to the aqueous decoction. In the presence of glibenclamide, the relaxant effect of the hydroalcoholic extract (EC50 = 0.191 ± 0.002 mg/mL) increased and was higher than that of the aqueous decoction. At dose of 5000 mg/kg of body weight, the extracts did not produce deaths or any significant changes in the general behavior of mice. The results suggest that different mechanisms including modulation of calcium and potassium channels, particularly the ATP-sensitive K+ channels, could be involved in the relaxation effect. These findings could justify the traditional use of W. indica in the management of asthma.

Toxicity and bacterial anti-motility activities of the hydroethanolic extract of Acacia senegal (L.) Willd (Fabaceae) leaves.

BACKGROUND: Acacia senegal is a plant traditionally used for its various properties, including the treatment of infectious diseases. Recently, our team has demonstrated the ability of the hydroethanolic extract of the leaves to increase the activity of phenicol antibiotics against multi-resistant bacteria. The aim of this work is to determine the toxicological effects of the extract and its capacity to inhibit the bacterial mobility of Gram-negative bacteria, in order to evaluate the level of safety use of this plant. METHODS: The cytotoxicity test was performed using the neutral red absorption method. Acute and sub-acute oral toxicity were conducted on NMRI mice and Wistar rats. The behaviour and adverse effects were recorded during the 14 days of the acute study. For the subacute test, biochemical parameters, food and water consumption, and morphological parameters were determined. The anti-motility activities were evaluated on Pseudomonas aeruginosa PA01 and Escherichia coli AG100, using specific concentrations of Agar as required by the method. RESULTS: HEASG induced inhibition of keratinocytes cell growth with an IC50 of 1302 ± 60 µg/mL. For the acute toxicity study in mice, the single dose of extract of 2000 mg/kg body weight caused no deaths and no behavioural changes were observed; therefore, the median lethal dose (LD50) of HEASG was calculated to 5000 mg/kg body weight. In Wistar rats, no mortality was observed at 250, 500 and 1000 mg/kg/day during the 28-day subacute oral toxicity study. The weights of both females and males increased globally over time, regardless of the batch. No statistically significant differences were registered for organ weights and biochemical parameters, except for chloride for biochemical parameters. Water and food consumption did not change significantly. Furthermore, no macroscopic changes in organ appearance were observed. Regarding anti-motility activity, the extract has reduced the swarming motility of PA01 and AG100 significantly at the concentration of 32 µg/mL (P < 0.001). The extract has reduced the swimming motility (P < 0.01) of PA01 but not AG100. CONCLUSIONS: The results suggest that hydroethanolic extract of A. senegal leaves has significant activity against bacterial motility and relatively low toxicity.

Ethyl Acetate Fraction of Lannea microcarpa Engl. and K. Krause (Anacardiaceae) Trunk Barks Corrects Angiotensin II-Induced Hypertension and Endothelial Dysfunction in Mice.

Traditional remedies prepared from Lannea microcarpa leaves, barks, roots, and fruits are used to treat many diseases including hypertension. This study investigated whether oral administration of the ethyl acetate fraction of Lannea microcarpa trunk barks (LMAE) corrects angiotensin (Ang) II-induced hypertension in mice. Its effects on vascular function were specifically investigated. Experiments explored hemodynamic and echocardiographic parameters in vivo and vascular reactivity to acetylcholine (ACh) and CaCl2 ex vivo on isolated aortas. Mice received LMAE for 3 weeks (50 mg/kg/day) by oral gavage. In the last two weeks of treatment, mice were implanted with osmotic minipumps delivering NaCl (0.9%) or Ang II (0.5 mg/kg/day). LMAE completely prevented the increase in systolic and diastolic blood pressure induced by Ang II. Echocardiographic and kidney parameters were not affected by the different conditions. LMAE abrogated Ang II-induced impairment of ACh-induced relaxation without affecting that of sodium nitroprusside. LMAE also completely prevented CaCl2-induced contraction in KCl-exposed aorta ex vivo. The extract alone did not modify superoxide (O2 -) and nitric oxide (NO·) production in femoral arteries from control mice but significantly limited Ang II-induced O2 - production. These effects were associated with reduced expression of inducible isoform of cyclooxygenase- (COX-) 2 and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase isoform NOX-2 in aortas. Finally, phytochemical analysis showed that LMAE contains sterols, triterpenes, coumarins, and anthraquinone. These results showed that LMAE prevents Ang II-induced hypertension and vascular dysfunction through a reduction of oxidative stress linked to COX-2 and NOX-2 pathway and inhibition of calcium entry. This study provides pharmacological basis of the empirical use of Lannea microcarpa trunk bark extract against hypertension.

Ethanol Extract of Leaves of Cassia siamea Lam Protects against Diabetes-Induced Insulin Resistance, Hepatic, and Endothelial Dysfunctions in ob/ob Mice.

Despite long traditional utilization and some reports on the antihyperglycemic and antihyperlipidemic action of Cassia siamea, the mechanisms involved have not been investigated yet. Thus, the objective of the present study was to investigate whether and how oral administration of the ethanolic extract of Cassia siamea Lam leaves (LECS) improves glucose and insulin homoeostasis, liver damage, and endothelial dysfunction in an experimental model of type 2 diabetes, the leptin-deficient ob/ob mice. Oxidative stress and protein expression of insulin-dependent and insulin -independent signaling pathways were studied. Obese ( ob/ob) vs. control (ob/+) mice were treated daily with intragastric administration of either vehicle or LECS (200 mg/kg, per day) for 4 weeks. Fasting blood glucose, body weight, food intake, glucose and insulin tolerance, oxidative stress, and liver damage as well as vascular complications with respect to endothelial dysfunction were examined. Administration of LECS in obese mice significantly reduced blood glucose and insulin levels, improved glucose tolerance and insulin sensitivity, and restored the increase of circulating AST and ALT without modification of body weight and food intake. These effects were associated with increased activity of both insulin and AMPK pathways in the liver and skeletal muscles. Of particular interest, administration of LECS in obese mice completely prevented the endothelial dysfunction resulting from an increased NO· and decreased reactive oxygen species (ROS) production in the aorta. Altogether, oral administration of LECS remarkably attenuates features of type 2 diabetes on glucose, hepatic inflammation, insulin resistance, endothelial function, and vascular oxidative stress, being as most of these effects are related to insulin-dependent and insulin-independent mechanisms. Therefore, this study points for the therapeutic potential of Cassia siamea in correcting both metabolic and vascular alterations linked to type 2 diabetes.

An aqueous extract of the Anogeissus leiocarpus bark (AEAL) induces the endothelium-dependent relaxation of porcine coronary artery rings involving predominantly nitric oxide.

BACKGROUND: Anogeissus leiocarpus is a Sahel tree traditionally used by the residents of Burkina Faso for its antihypertensive properties. In this study, experiments were conducted to evaluate whether an aqueous extract of the Anogeissus leiocarpus (AEAL) trunk bark induces a vasorelaxant effect on porcine coronary artery rings and to investigate the underlying mechanism. METHODS: AEAL-induced relaxations were assessed using porcine coronary artery rings suspended in organ chambers. The phosphorylation levels of Src, Akt and endothelial nitric oxide synthase (eNOS) were assessed in a primary endothelial cell culture by Western blot. The reactive oxygen species (ROS) formation was assessed using dihydroethidine. RESULTS: In porcine coronary artery rings, AEAL at 0.1-300 µg/mL induced endothelium-dependent relaxations, which were inhibited in the presence of inhibitors of nitric oxide (NO) and the endothelium-derived hyperpolarization pathways. Moreover, the AEAL-induced NO-mediated relaxations were significantly reduced by the inhibitors of Src and PI3-kinase as well as by the membrane-permeant ROS scavengers. In cultured porcine coronary artery endothelial cells, treatment with AEAL is associated with an intracellular generation of ROS. Moreover, the AEAL induced the phosphorylations of Akt (Ser473), eNOS (Ser1177) and a transient phosphorylation of Src (Ser17) in a time-dependent manner. CONCLUSIONS: These findings indicate that AEAL is a potent inducer of endothelium-dependent NO-mediated relaxations in porcine coronary arteries through the redox-sensitive Src/PI3-kinase/Akt pathway-dependent activation of eNOS.

Non-muscular myosin light chain kinase triggers intermittent hypoxia-induced interleukin-6 release, endothelial dysfunction and permeability.

Obstructive sleep apnea is characterized by intermittent hypoxia (IH) which alters endothelial function, induces inflammation and accelerates atherosclerosis-induced cardiovascular diseases. The non-muscular myosin light chain kinase (nmMLCK) isoform contributes to endothelial cell-cell junction opening. Deletion of nmMLCK protects mice from death in septic shock models and prevents atherosclerosis in high-fat diet-fed mice. The aim of the study was to analyze the implication of nmMLCK in IH-induced vascular inflammation. Human aortic endothelial cells were exposed to 6 hours of IH in absence or presence of nmMLCK inhibitors, ML-7 (5 µM) or PIK (150 µM). IH increased reactive oxygen species (ROS) and nitric oxide (NO) production, p65-NFκB activation and IL-6 secretion. While nmMLCK inhibition did not prevent IH-induced ROS production and p65-NFκB activation, it decreased NO production and partially prevented IL-6 secretion. IH-induced IL-6 secretion and vesicle-associated membrane protein-associated vesicles re-organization were inhibited in presence of the inhibitor of protein secretion, brefeldin A, or ML-7. IH increased monocytes transendothelial migration that was partially prevented by ML-7. Finally, IH reduced endothelium-dependent relaxation to acetylcholine of aortas from wild-type but not those taken from nmMLCK-deficient mice. These results suggest that nmMLCK participates to IH-induced endothelial dysfunction resulting from cytokines secretion and endothelial permeability.