74 research outputs found
Oncogenic viruses associated with vulva cancer in HIV-1 patients in Botswana
BACKGROUND: Oncoviruses such as HPV, KSHV, and EBV have been reported in patients with HIV infection and AIDS. How oncovirus-associated cancers rise in AIDS patients has not been fully established. The purpose of our study was to identify the viral agents in vulvar cancer and to assess their contribution to pathogenesis. METHOD: We retrospectively identified a total of 13 vulva tissue samples from HIV-1 positive and 9 vulvar samples from HIV-1 negative patients from the Botswana National Health Laboratory in Gaborone, Botswana, a Southern African country with a high incidence of HIV. We utilized PCR and IHC to identify HPV, EBV, KSHV, and JC virus in FFPE preserved tissue samples. RESULTS: Using the GP5(+)/GP6(+) primer set we detected several HPV types in tissue samples. EBV was detected in all of the positive cases (100%) and in most of the negative cases (89%). KSHV was detected in 39% of the HIV-1 positive samples and in 11% of the negative samples, and no JC virus was detected in any of the samples. Using IHC we demonstrated that LANA was expressed in 61% of the positive samples and in 44% of the negative samples. The ubiquitous EBV was more consistently expressed in negative cases (100%) than in positive cases (69%). Interestingly, the HPV-16 E6 transcript was detected in 56% of the negative samples compared to 31% of the positive samples. However, the cell cycle protein P21 used as a surrogate marker for HPV was detected in 77% of the positive samples and in 44% of the negative samples, while VEGF signals were similar in both positive (92%) and negative samples (89%). CONCLUSION: Our study, suggests that in Botswana, vulvar squamous cell carcinoma (VSCC) is associated with oncogenic viruses present in the niche but the contribution and progression may be regulated by HPV and other immunosuppressive infections that include HIV-1
Évaluation des clones de manioc à pulpe jaune pour leur teneur en β-carotène, rendements en tubercules frais et teneur en matière sèche à Ngandajika en République Démocratique du Congo
Objectifs: Cette étude avait pour objectif d’identifier les rendements, les taux de matière sèche, les taux d’amidon et les teneurs en caroténoïdes totaux des clones et de les comparer avec ceux des témoins en vue de sélectionner les nouvelles variétés de manioc biofortifiés afin de combattre la carence en vitamine A.Méthodologie et résultats: L’évaluation des 80 clones de manioc à pulpe jaune a été effectuée de 2012 à 2017 au centre de recherche de l’INERA Ngandajika. Le dispositif standard et le dispositif des blocs complètement randomisés avec 4 répétions étaient utilisés respectivement pour le EC et le reste des essais du schéma de sélection. Les résultats ont révélé que GKA12/149, GKA12/141 et GKA12/151 étaient significativement supérieurs pour le rendement en tubercules frais et le TCC, et non significative pour la matière sèche avec Mudiela Manyi. Concernant Kindisa, aucune différence significative sur rendement et MS, sauf en EPR, EAR et EUR1. Pour TCC, GKA12/149 est premier, suivi de GKA12/151, de GKA12/141 et de Kindisa.Conclusion et application des résultats: les clones GKA12/149 et GKA12/151 se sont montrés, d’une manière générale, plus performants que le témoin amélioré Kindisa et peuvent être proposés à la diffusion. Les croisements divers entre ces génotypes, qui ont enrichi le germoplasme de manioc à pulpe jaune, entre eux et avec d’autres variétés devront se poursuivre.Mots clés: Manioc bio-fortifié, variétés, sélectionEnglish Title: Evaluation of yellow fleshed cassava genotypes for β-carotene, fresh root tuber yield and dry matter content in Ngandajika , DRCEnglish AbstractObjectives: The objective of this study was to identify yields, dry matter levels, starch levels, and total carotenoid contents of clones and to compare them with controls to select new bio-fortified cassava varieties to fight vitamin A deficiency.Methodology and results: The evaluation of the 80 yellow pulp cassava clones was carried out from 2012 to 2017 at the INERA Ngandajika research center. The standard device and the device of the completely randomized blocks with 4 repetitions were used respectively for the clonal evaluation trial (CET) and the rest of the tests of the selection scheme. The results revealed that GKA12/149, GKA12/141 and GKA12/151 were significantly higher for fresh tuber yield and Total Carotenoid Content, and not significant for dry matter with Mudiela Manyi. Regarding Kindisa, no significant difference for yield and dry matter content, except in Preliminary Yield Trial (PYT), Advanced Yield Trial (AYT) and Uniform Yield Trial (UYT1). For TCC, GKA12/149 is first, followed by GKA12/151, GKA12/141 and Kindisa.Conclusion and application: clones GKA12/149 and GKA12/151 were generally more efficient than the improved Kindisa control and can be proposed for diffusion. The various crosses between these genotypes, which have enriched the germplasm of yellow-fleshed cassava with each other and with other varieties, will have to be continued.Keywords: Bio-fortified cassava, varieties, selectio
Oral fexinidazole for stage 1 or early stage 2 African Trypanosoma brucei gambiense trypanosomiasis: a prospective, multicentre, open-label, cohort study
BACKGROUND: Staging and treatment of human African trypanosomiasis caused by Trypanosoma brucei gambiense (g-HAT) required lumbar puncture to assess cerebrospinal fluid (CSF) and intravenous drugs that cross the blood-brain barrier for late-stage infection. These procedures are inconvenient in rural health systems of disease-endemic countries. A pivotal study established fexinidazole as the first oral monotherapy to be effective against non-severe stage 2 g-HAT. We aimed to assess the safety and efficacy of fexinidazole in early g-HAT. METHODS: In this prospective, multicentre, open-label, single-arm cohort study, patients with stage 1 or early stage 2 g-HAT were recruited from eight treatment centres in the Democratic Republic of the Congo. Primary inclusion criteria included being older than 15 years, being able to ingest at least one complete meal per day (or at least one sachet of Plumpy'Nut®), a Karnofsky score higher than 50, evidence of trypanosomes in the blood or lymph but no evidence of trypanosomes in the CSF, willingness to be admitted to hospital to receive treatment, having a permanent address, and being able to comply with the follow-up visit schedule. Exclusion criteria included severe malnutrition, inability to take medication orally, pregnant or breastfeeding women, any clinically important medical condition that could jeopardise patient safety or participation in the study, severely deteriorated general status, any contraindication to imidazole drugs, HAT treatment in the past 2 years, previous enrolment in the study or previous intake of fexinidazole, abnormalities on electrocardiogram that did not return to normal in pretreatment repeated assessments or were considered clinically important, QT interval corrected using Fridericia's formula of at least 450 ms, and patients not tested for malaria or not having received appropriate treatment for malaria or for soil-transmitted helminthiasis. Patients were classified into stage 1 or early stage 2 g-HAT groups following evidence of trypanosomes in the blood, lymph, and absence in CSF, and using white-blood-cell count in CSF. Patients received 1800 mg fexinidazole once per day on days 1-4 then 1200 mg fexinidazole on days 5-10. Patients were observed for approximately 19 months in total. Study participants were followed up on day 5 and day 8 during treatment, at end of treatment on day 11, at end of hospitalisation on days 11-18, at week 9 for a subset of patients, and after 6 months, 12 months, and 18 months. The primary endpoint was treatment success at 12 months. Safety was assessed through routine monitoring. Analyses were done in the intention-to-treat population. The acceptable success rate was defined as treatment efficacy in more than 80% of patients. This study is completed and registered with ClinicalTrials.gov (NCT02169557). FINDINGS: Patients were enrolled between April 30, 2014, and April 25, 2017. 238 patients were recruited: 195 (82%) patients with stage 1 g-HAT and 43 (18%) with early stage 2 g-HAT. 189 (97%) of 195 patients with stage 1 g-HAT and 41 (95%) of 43 patients with early stage 2 g-HAT were finally included and completed the 10 day treatment period. Three patients with stage 1 g-HAT died after the 10 day treatment period and before the 12 month primary follow-up visit, considered as treatment failure and were withdrawn from the study. Treatment was effective at 12 months for 227 (99%) of 230 patients (95% CI 96·2-99·7): 186 (98%) of 189 patients (95·4-99·7) with stage 1 and 41 (100%) of 41 patients (91·4-100·0) with early stage 2, indicating that the primary study endpoint was met. No new safety issues were observed. The most frequent adverse events were headache and vomiting. In total, 214 (93%) of 230 patients had treatment-emergent adverse events, mainly common-terminology criteria for adverse events grades 1 to 3. None led to treatment discontinuation. INTERPRETATION: Fexinidazole is a valuable first-line treatment option in the early stages of g-HAT. FUNDING: Through the Drugs for Neglected Diseases initiative: the Bill & Melinda Gates Foundation, the Republic and Canton of Geneva (Switzerland), the Dutch Ministry of Foreign Affairs (also known as DGIS; Netherlands), the Norwegian Agency for Development Cooperation (also known as Norad; Norway), the Federal Ministry of Education and Research (also known as BMBF) through KfW (Germany), the Brian Mercer Charitable Trust (UK), and other private foundations and individuals from the HAT campaign
Clinical Characteristics and Outcomes of Patients Hospitalized for COVID-19 in Africa: Early Insights from the Democratic Republic of the Congo
Little is known about the clinical features and outcomes of SARS-CoV-2 infection in Africa. We conducted a retrospective cohort study of patients hospitalized for COVID-19 between March 10, 2020 and July 31, 2020 at seven hospitals in Kinshasa, Democratic Republic of the Congo (DRC). Outcomes included clinical improvement within 30 days (primary) and in-hospital mortality (secondary). Of 766 confirmed COVID-19 cases, 500 (65.6%) were male, with a median (interquartile range [IQR]) age of 46 (34-58) years. One hundred ninety-one (25%) patients had severe/critical disease requiring admission in the intensive care unit (ICU). Six hundred twenty patients (80.9%) improved and were discharged within 30 days of admission. Overall in-hospital mortality was 13.2% (95% CI: 10.9-15.8), and almost 50% among those in the ICU. Independent risk factors for death were age < 20 years (adjusted hazard ratio [aHR] = 6.62, 95% CI: 1.85-23.64), 40-59 years (aHR = 4.45, 95% CI: 1.83-10.79), and ≥ 60 years (aHR = 13.63, 95% CI: 5.70-32.60) compared with those aged 20-39 years, with obesity (aHR = 2.30, 95% CI: 1.24-4.27), and with chronic kidney disease (aHR = 5.33, 95% CI: 1.85-15.35). In marginal structural model analysis, there was no statistically significant difference in odds of clinical improvement (adjusted odds ratio [aOR] = 1.53, 95% CI: 0.88-2.67, P = 0.132) nor risk of death (aOR = 0.65, 95% CI: 0.35-1.20) when comparing the use of chloroquine/azithromycin versus other treatments. In this DRC study, the high mortality among patients aged < 20 years and with severe/critical disease is of great concern, and requires further research for confirmation and targeted interventions
FACTEURS EXPLICATIFS DE LA PERSISTANCE DU CHOLERA DANS LA VILLE DE GOMA
Le choléra est une toxi-infection intestinale grave, contagieuse, causée par l’enterotoxine de V. cholerae des sérogroupes O1 et O139 associées à des épidémies majeures .C’est une urgence de santé publique. L’objectif général de cette étude était de  déterminer les facteurs explicatifs de la persistance de l’épidémie de choléra dans la ville de Goma.
MATERIEL ET METHODE :Une étude cas-témoins  a été réalisé  dans  2 zones de santé de la ville de Goma (Goma et  Karisimbi). L’échantillon a été tiré de la liste linéaire de l’épidémie de 2017 (124 cas appariés aux 246 témoins), tirés au hasard au tour des ménages des cas. Les variables indépendantes étaient introduites  dans le modèle de régression logistique par le logiciel SPSS 23.0 pour identifier les facteurs significativement associés à la persistance des épidémies de choléra dans la ville de Goma après ajustement des variables indépendantes les unes sur les autres.  Il y a  eu calcul d’ ORA : IC à 95%  , le p au seuil de signification : de 5% de chaque variable indépendante retenue.
RESULTATS :Sur un total de 370 enquêtés (124 cas et 246 témoins),  le choléra a touché toutes les tranches d’âge dans les 2 communes enquêtées de la ville de Goma. L’âge de moins de 5 ans était  plus touché avec  28,8 % des cas, suivi de 5 -14 ans soit 21,6 % et de 15 – 24 ans soit 17,6 % . La moyenne d’âge des cas et des témoins était de 19,06 ans pour les cas et 19,45 ans pour les témoins ,avec un écart-type de 17,77 et 17,95.Le sexe masculin  était plus touché  avec 53,7%  que  le  sexe féminin avec 46,3%.La persistance du choléra dans la ville de Goma est significativement associé au :  non traitement de l’eau de boisson :[OR=10,721, IC à 95% : [8,14337,737] p=0,021] ; à la présence  des mouches dans les toilettes : [OR=7,049 IC à 95% : [2,08216,421] p=0,037 ]; à la source  d’approvisionnement d’eau de boisson non améliorée : [OR : 4,689, IC à 95% : [1,57315,121] ; p : 0,008], à  la présence des matières fécales tout autour du trou des toilettes  [OR=2,864 IC à 95% : [2,2747,182] p=0,011]; à la consommation  des aliments vendus le long de la rue non couvert .[OR=2,233IC à 95% : [1,4015,735] p=0,001].
 CONCLUSION: Les facteurs explicatifs de la persistance  de cholera à Goma sont : non traitement de l’eau de boisson, la présence  des mouches dans les toilettes ,  la source  d’approvisionnement d’eau de boisson non améliorée ,  la présence des matières fécales tout autour du trou des toilettes  , la consommation  des aliments vendus le long de la rue non couvert.Le choléra est une toxi-infection intestinale grave, contagieuse, causée par l’enterotoxine de V. cholerae des sérogroupes O1 et O139 associées à des épidémies majeures .C’est une urgence de santé publique. L’objectif général de cette étude était de déterminer les facteurs explicatifs de la persistance de l’épidémie de choléra dans la ville de Goma.
MATERIEL ET METHODE :Une étude cas-témoins a été réalisé dans 2 zones de santé de la ville de Goma (Goma et Karisimbi). L’échantillon a été tiré de la liste linéaire de l’épidémie de 2017 (124 cas appariés aux 246 témoins), tirés au hasard au tour des ménages des cas. Les variables indépendantes étaient introduites dans le modèle de régression logistique par le logiciel SPSS 23.0 pour identifier les facteurs significativement associés à la persistance des épidémies de choléra dans la ville de Goma après ajustement des variables indépendantes les unes sur les autres. Il y a eu calcul d’ ORA : IC à 95% , le p au seuil de signification : de 5% de chaque variable indépendante retenue.
RESULTATS :Sur un total de 370 enquêtés (124 cas et 246 témoins), le choléra a touché toutes les tranches d’âge dans les 2 communes enquêtées de la ville de Goma. L’âge de moins de 5 ans était plus touché avec 28,8 % des cas, suivi de 5 -14 ans soit 21,6 % et de 15 – 24 ans soit 17,6 % . La moyenne d’âge des cas et des témoins était de 19,06 ans pour les cas et 19,45 ans pour les témoins ,avec un écart-type de 17,77 et 17,95.Le sexe masculin était plus touché avec 53,7% que le sexe féminin avec 46,3%.La persistance du choléra dans la ville de Goma est significativement associé au : non traitement de l’eau de boisson :[OR=10,721, IC à 95% : [8,14337,737] p=0,021] ; à la présence des mouches dans les toilettes : [OR=7,049 IC à 95% : [2,08216,421] p=0,037 ]; à la source d’approvisionnement d’eau de boisson non améliorée : [OR : 4,689, IC à 95% : [1,57315,121] ; p : 0,008], à la présence des matières fécales tout autour du trou des toilettes [OR=2,864 IC à 95% : [2,2747,182] p=0,011]; à la consommation des aliments vendus le long de la rue non couvert .[OR=2,233IC à 95% : [1,4015,735] p=0,001].
CONCLUSION: Les facteurs explicatifs de la persistance de cholera à Goma sont : non traitement de l’eau de boisson ,la présence des mouches dans les toilettes , la source d’approvisionnement d’eau de boisson non améliorée , la présence des matières fécales tout autour du trou des toilettes , la consommation des aliments vendus le long de la rue non couvert
Resistance of African tropical forests to an extreme climate anomaly.
The responses of tropical forests to environmental change are critical uncertainties in predicting the future impacts of climate change. The positive phase of the 2015-2016 El Niño Southern Oscillation resulted in unprecedented heat and low precipitation in the tropics with substantial impacts on the global carbon cycle. The role of African tropical forests is uncertain as their responses to short-term drought and temperature anomalies have yet to be determined using on-the-ground measurements. African tropical forests may be particularly sensitive because they exist in relatively dry conditions compared with Amazonian or Asian forests, or they may be more resistant because of an abundance of drought-adapted species. Here, we report responses of structurally intact old-growth lowland tropical forests inventoried within the African Tropical Rainforest Observatory Network (AfriTRON). We use 100 long-term inventory plots from six countries each measured at least twice prior to and once following the 2015-2016 El Niño event. These plots experienced the highest temperatures and driest conditions on record. The record temperature did not significantly reduce carbon gains from tree growth or significantly increase carbon losses from tree mortality, but the record drought did significantly decrease net carbon uptake. Overall, the long-term biomass increase of these forests was reduced due to the El Niño event, but these plots remained a live biomass carbon sink (0.51 ± 0.40 Mg C ha-1 y-1) despite extreme environmental conditions. Our analyses, while limited to African tropical forests, suggest they may be more resistant to climatic extremes than Amazonian and Asian forests
Co-limitation towards lower latitudes shapes global forest diversity gradients
The latitudinal diversity gradient (LDG) is one of the most recognized global patterns of species richness exhibited across a wide range of taxa. Numerous hypotheses have been proposed in the past two centuries to explain LDG, but rigorous tests of the drivers of LDGs have been limited by a lack of high-quality global species richness data. Here we produce a high-resolution (0.025° × 0.025°) map of local tree species richness using a global forest inventory database with individual tree information and local biophysical characteristics from ~1.3 million sample plots. We then quantify drivers of local tree species richness patterns across latitudes. Generally, annual mean temperature was a dominant predictor of tree species richness, which is most consistent with the metabolic theory of biodiversity (MTB). However, MTB underestimated LDG in the tropics, where high species richness was also moderated by topographic, soil and anthropogenic factors operating at local scales. Given that local landscape variables operate synergistically with bioclimatic factors in shaping the global LDG pattern, we suggest that MTB be extended to account for co-limitation by subordinate drivers
High aboveground carbon stock of African tropical montane forests
Tropical forests store 40–50 per cent of terrestrial vegetation carbon1. However, spatial variations in aboveground live tree biomass carbon (AGC) stocks remain poorly understood, in particular in tropical montane forests2. Owing to climatic and soil changes with increasing elevation3, AGC stocks are lower in tropical montane forests compared with lowland forests2. Here we assemble and analyse a dataset of structurally intact old-growth forests (AfriMont) spanning 44 montane sites in 12 African countries. We find that montane sites in the AfriMont plot network have a mean AGC stock of 149.4 megagrams of carbon per hectare (95% confidence interval 137.1–164.2), which is comparable to lowland forests in the African Tropical Rainforest Observation Network4 and about 70 per cent and 32 per cent higher than averages from plot networks in montane2,5,6 and lowland7 forests in the Neotropics, respectively. Notably, our results are two-thirds higher than the Intergovernmental Panel on Climate Change default values for these forests in Africa8. We find that the low stem density and high abundance of large trees of African lowland forests4 is mirrored in the montane forests sampled. This carbon store is endangered: we estimate that 0.8 million hectares of old-growth African montane forest have been lost since 2000. We provide country-specific montane forest AGC stock estimates modelled from our plot network to help to guide forest conservation and reforestation interventions. Our findings highlight the need for conserving these biodiverse9,10 and carbon-rich ecosystems
High aboveground carbon stock of African tropical montane forests
Tropical forests store 40-50 per cent of terrestrial vegetation carbon(1). However, spatial variations in aboveground live tree biomass carbon (AGC) stocks remain poorly understood, in particular in tropical montane forests(2). Owing to climatic and soil changes with increasing elevation(3), AGC stocks are lower in tropical montane forests compared with lowland forests(2). Here we assemble and analyse a dataset of structurally intact old-growth forests (AfriMont) spanning 44 montane sites in 12 African countries. We find that montane sites in the AfriMont plot network have a mean AGC stock of 149.4 megagrams of carbon per hectare (95% confidence interval 137.1-164.2), which is comparable to lowland forests in the African Tropical Rainforest Observation Network(4) and about 70 per cent and 32 per cent higher than averages from plot networks in montane(2,5,6) and lowland(7) forests in the Neotropics, respectively. Notably, our results are two-thirds higher than the Intergovernmental Panel on Climate Change default values for these forests in Africa(8). We find that the low stem density and high abundance of large trees of African lowland forests(4) is mirrored in the montane forests sampled. This carbon store is endangered: we estimate that 0.8 million hectares of old-growth African montane forest have been lost since 2000. We provide country-specific montane forest AGC stock estimates modelled from our plot network to help to guide forest conservation and reforestation interventions. Our findings highlight the need for conserving these biodiverse(9,10) and carbon-rich ecosystems. The aboveground carbon stock of a montane African forest network is comparable to that of a lowland African forest network and two-thirds higher than default values for these montane forests.Peer reviewe
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